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close this bookManaging Natural Disasters and the Environment (World Bank, 1991, 232 p.)
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View the documentClimate hazards, climatic change, and development planning
View the documentWhich costs more: prevention or recovery?
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Climate hazards, climatic change, and development planning

William E. Riebsame

The increased risk of climate hazards calls for a new approach to development planning. Development planners must develop a strategy that reflects (1) the sensitivity of resource systems to variations in climate, (2) uncertainty about climate change and how that uncertainty can be incorporated into an expanded repertoire of responses, so decisionmakers are not pressured into premature action or paralyzed by uncertainty, and (3) awareness of development’s effect (good or bad) on the “greenhouse” problem and on social adaptability to climate problems. The development planners’ repertoire should include actions that are easily and cheaply implemented and reversed and adjustments that expand rather than limit future options (such as efforts to conserve crop diversity). Planners should expand on a “tie-in” strategy that links the uncertain threat of climatic change to the certainty that current resource management systems (from power generation to agriculture) contribute to current environmental problems (such as acid rain and erosion). The mitigation of current natural hazards should be linked to concerns about climate warming so that actions taken today have both immediate and long-term benefits, whether the greenhouse effect materializes or not.

Climatic fluctuations pose hazards to agriculture, water, and other resource systems. It can be argued that better management of current fluctuations and extremes would reduce not only some constraints on development but also vulnerability to future climate changes.

Many atmospheric scientists predict that human activity will warm the global climate in the next several decades, but uncertainty about the rate and magnitude of change in specific regions is so great that it is difficult to plan resource development with global warming in mind. Moreover, growing public interest in an international treaty to reduce emissions of greenhouse gases is putting pressure on development planners to mitigate the causes and effects of anthropogenic climatic change. Planners who have assumed that environmental conditions would remain the same and who have sought local sensitivity in development plans must now add global considerations to regional development plans, responding to a threat the outlines of which are still fuzzy. The threat of global warming calls for a new approach to regional development planning, one that includes:

· Analysis of the sensitivity of resource systems to climate fluctuations.

· A gradual stepping up of responsiveness as the threat of global warming becomes more certain.

· Consideration of a wider range of adjustment options.

· New links between multiple development goals (for example, economic and environmental well-being).

The threat of global warming

Many scientists argue that changes in climate attributable to human behavior are likely to emerge from the noise of natural climate variations in the next decade or so - and some analysts believe that record warm temperatures in the 1980s are a signal of global warming (Hansen and others 1988, Hansen and Lebedeff 1988). Average temperatures are likely to increase roughly 3 degrees Celsius in the next century according to several scientific groups (World Meteorological Organization 1985, Carbon Dioxide Assessment Committee 1983, IPCC 1990). Recent debates about the reliability of global warming projections offer no compelling new evidence for or against the threat (Michaels 1989, Lindzen 1990, Schneider 1990), but illustrate the great uncertainty and limited understanding of climate dynamics.

We do know that current extremes of climate regularly disrupt social well-being (National Academy of Sciences 1987, Riebsame and others 1986). Droughts in India or the Sahel, floods in Bangladesh or the Sudan, and frosts in Brazil or Papua New Guinea demonstrate the critical relationship between climate and development (see, for example, Kates 1980). The ability to cope with fluctuations in climate varies among regions: the least developed areas suffer the most from climatic hazards and face the most problems if the climate changes.

Climate is an intellectual construct: the statistical properties of the atmosphere, averaged over time. Fluctuations and extremes of climate are expressions of the tails of the current distribution of temperature, rainfall, storms, and the like. Climatic change is a shift in their distribution over time (figure 1). Both can add stress to regional development projects, but while climatic extremes are certain to affect all regions, there is great uncertainty about whether we face significant climatic change per se.

Despite the uncertainty, development planners should examine the potential implications of climate change. The changes predicted by global warming theorists in the next several decades may seem modest, but recent experience indicates that climatic change of this magnitude would severely disrupt ecological and social systems. A broad review of studies of the effect of climate in the last two decades reveals a common, disturbing pattern (see Kates and others 1985, Riebsame 1988c, Parry and others 1988). Existing research indicates that:

· In some localities and natural resource sectors, relatively small changes in climate can be quite disruptive. Modem systems for managing and using water, energy, agriculture, and forests are generally flexible, but in some (for example, semiarid) regions, climatic changes much smaller than one could expect with the doubling of the greenhouse effect threaten to alter resource flows markedly (see, for example, Parry and others 1988, Bolin and others 1986, Riebsame 1988a).

· There are major disparities in our understanding of the effects of climate. We understand fairly well how climatic change affects agricultural, water, and energy systems, but we know much less about how it affects fisheries, grasslands and livestock systems, human health, transportation, urban development, and the general economy (see, for example, Kates and others 1985). Our understanding of how climate and resources interact is especially fuzzy at environmental and social interfaces - the complex interactions between, for example, crops and soil (affected by soil temperature, erosion, and so forth), fisheries and wetlands (perhaps destabilized by rising sea levels), and different resource management institutions.

· The net consequences of global warming remain ill-defined. Productivity could decline catastrophically in some areas as the result of climatic extremes or rapid climatic change. Forests, for example, could produce less because of wildfires; agriculture could suffer from outbreaks of new pests or diseases; water could be scarce or excessive because of extreme events; changes in habitat could affect the viability of species. On the other hand, mitigating factors could produce unexpected gains. Ambient carbon dioxide could enhance biomass; warmer ocean temperatures or coastal inundation could improve fisheries; societies could adapt to changing conditions (a process poorly understood; see Butzer 1980), possibly through the transfer of new technologies and resources from “winners” to “losers” as part of the international response to the threat itself. At this time, it is difficult to estimate the balance of positive and negative effects, but most analysts expect global warming to produce a net loss, if for no other reason than that it brings change and increases uncertainty.

· Finally, there is a growing sense that the effects of global climatic change will be socially divisive. Developing countries are widely believed to be especially vulnerable because those countries have fewer options and limited resources with which to adjust to or recover from the effects of climatic damage - as experience with natural hazards and recent fluctuations in climate shows (Jodha 1989, Woods Hole Research Center 1989). Thus, the distribution of the benefits and costs of greenhouse gas emissions is unlikely to be equitable.

Figure 1 Schematic relationship between environmental engineering systems and climate variables

a. Normal conditions.

b. Hypothetical new climates with altered frequencies of events approaching or surpassing operating limits.

Source: Riebsame 1990.

Even at the lowest rates projected for the greenhouse effect, it appears that climate change could greatly disrupt activities in certain places and cultures. Thus, despite uncertainty about global warming projections, a consensus is emerging on why and how global warming should be limited (Mintzer 1987 and 1988, Lashof and Tirpak 1989, Jager 1988). The technical feasibility of markedly reducing greenhouse gases has been demonstrated; the potential for needed social change is less clear. A common approach is to stress the logic of taking actions that pay off - for example, increased energy efficiency - even if the dangers of global warming have been exaggerated. This “tie-in,” or no-regret, strategy, links the uncertain threat of climatic change to the certainty that current energy systems waste resources and cause pollution (Schneider 1989).

Proponents of tie-in strategies assume that the threat of global warming sufficiently increases the probability of human damage to the environment to make compelling the need for actions that people have not yet seen fit to take (such as pricing fossil fuels to reflect the full environmental costs of their use). This assumption makes sense, but behavioral studies have identified several factors that limit people’s ability to solve resource management problems such as increases in greenhouse gas: their attitudes toward development; their tendency toward temporal discounting; their limited ability to assess risks; and institutional constraints on individual or collective choice. Nor have such actions been supported with full analysis of the risks and benefits of trying to limit, or simply ignoring the possibility of, global warming.

If strategies to limit global warming fail, and if significant climate change occurs, one option is for social systems to adapt. This possibility has received less attention than others. Indeed, one weakness of studies of the effect of changing climates is that they are static - resource systems are often portrayed as having little potential for change. Can our resource systems adjust to the negative effects of climatic change? We do not know with any certainty, nor do we have robust methods for assessing adaptability. Some researchers expect social systems to adapt readily through technological innovation (Wittwer 1980, Waggoner 1983) and economic adjustment (Easterling and others 1989) but the process of adaptation is rarely described explicitly (Riebsame 1988a). On the other hand, concern about global warming is driven mostly by the intuitive belief that the rate of change will outstrip our ability to adapt. The truth probably lies somewhere between these two positions. There is substantial historical evidence that most agricultural systems, water resources, industrial processes, and settlement infrastructure are quite adaptable, but that the less-managed eco-resource systems - such as grassland and grazing systems, forests, and fisheries - often adapt less well to change. Any policy response must address such differences.

The policy response

Global warming is now a high-priority national and international policy issue. Projections of its impact have led to calls for concrete action to alter energy, agricultural, and forestry practices so as to reduce greenhouse gas emissions. Nations are lining up either for (most of the OECD) or against (United States, USSR) quickly reducing greenhouse gas emissions. The issue was the centerpiece of the Second World Climate Conference in October 1990, and will be high on the agenda for the 1992 Conference on Environment and Development.

The potential for ameliorating climatic change by altering energy and industrial systems has been analyzed extensively. Much less attention has been paid to how well systems for managing climate-sensitive resources can cope with rapid climate change (Rosenberg and others 1989). Yet global warming of 1 to 2 degrees celsius could occur in the next few decades even if greenhouse gases are limited - because of accumulated gases and thermal inertia (Jones and others 1987). If projections of global warming are correct, both preventive and adaptive steps will be needed.

A development planning conundrum. Conventional planning assumes that social factors such as population may change dramatically but that basic environmental elements such as climate are stable. The threat of global warming changes undermines this paradigm. Climatic change would affect the ability of resource management plans to meet future social needs and desires. Moreover, because global warming is caused by human behavior, one must also ask how those plans contribute to the problem.

Some policymakers are responding to pressures for quick action to stem the greenhouse effect without waiting for more scientific understanding of the problem (White 1988). But most resource managers have adopted a wait-and-see attitude and are being criticized for failing to address the issue aggressively (U.S. Senate Agriculture Committee 1989, New York Times 1989). The wait-and-see approach is supported chiefly by three arguments:

· That predictions of climatic change are too uncertain, especially regionally, for specific action (White 1988, Katz 1988).

· That current systems can absorb significant climatic change without failing (Hanchey and others 1988).

· That technological change can offset the negative effects of climatic change (Wittwer 1980).

These arguments have merit. Projections are insufficiently detailed regionally for rational alteration of development plans. It is premature to build new reservoirs or plant different tree species because of the greenhouse threat. But current planning approaches fail even to assess the threat in climate-sensitive resource sectors, or to try dealing better with fluctuations in the current climate. Resource managers are also dissuaded by policy from accounting for potential impacts of their actions on such global commons as the atmosphere and climate (Schelling 1983).

The conundrum, then, is how - faced with uncertainty - to respond to pressure for action. Development planners must develop a strategy that reflects (1) the sensitivity of resource systems to climate fluctuation, (2) uncertainty about climatic changes and how that uncertainty can be incorporated into their repertoire of responses, and (3) awareness of the effect of development (good or bad) on the greenhouse problem and on social adaptability to climatic fluctuations. What is needed is a new paradigm for natural resource planning appropriate to the policy environment being shaped by the threat of global warming (Riebsame 1988c).

A new approach to development planning

The threat of global warming calls for a new approach to development planning, one that builds on (rather than replaces) traditional planning approaches that emphasize empirical analysis, economic efficiency, and environmental protection. The new approach should incorporate at least three elements:

· Sensitivity analysis of resource systems that explicitly recognizes the potential for both variability and fundamental environmental change.

· Gradual adjustment that reflects increasing certainty about the effects of global change.

· A wider range of adjustment options that reflect recognition of links between the causes and effects of climatic change generated by human behavior as well as the value of mitigating current climatic hazards to reduce current and future vulnerability.


The management of most renewable resources - and of some stock resources such as fossil fuels - is sensitive to climatic fluctuation (Kates and others 1985). Factors affecting sensitivity and adaptability include:

· The degree to which factors such as temperature and precipitation affect resource yield or the maintenance of desired management criteria.

· The planning horizons for changes in resource systems.

· How often operational criteria are evaluated and updated.

· Whether potential effects may be incidentally accommodated or exacerbated as planners seek other goals such as more efficient use of energy or water.

Sensitivity to climatic change is especially evident in certain areas: agriculture, forestry, floodplains and coastal zones, water and energy resources, and certain aspects of architecture and urban and regional planning.

Unfortunately, the sensitivity of most natural resource and social systems to climatic change has not been analyzed (Warrick and Riebsame 1981). Planners need to assess how different climatic conditions would affect current resource systems and those systems as they might change over time. Analysis of a range of scenarios will provide a more robust evaluation of sensitivity than use of a single projection (Katz 1988, Lamb 1987, Wigley and others 1986).

While interest is high and before climatic change has had a chance to be disruptive, development planners should assess the sensitivity and adaptability of different resource systems and management practices. Many methods for assessing the effect of climatic change have been developed in the last decade and can be applied to both current variations and broad fundamental changes in climate (for example, Riebsame 1988b). Projections of climatic change are too uncertain to warrant specific action now, but what is needed is a wide range of evaluations of resource systems’ capacity to adapt to both variations and broad changes in climate - and resource managers should create contingency plans for such changes.

Figure 2 An illustration of the tie-in between efforts to achieve sustainable development, reduce losses from material disasters, and limit global climate change


Heightened concern about global warming has elicited demand for immediate mitigating action. The next several years will see a marked improvement in climate forecasting and possibly conclusive detection of climatic change distinctly attributable to human activity. Development planners should differentiate between steps to be taken immediately and those that should await further refinements of climatic projections or more solid evidence of global warming.

Resource managers cannot be expected to adopt costly or disruptive adjustments aimed at reducing the impact of uncertain changes. Nor are they likely to support drastic changes to limit emissions of greenhouse gases. But neither can they ignore the issue. They should focus first on adjustments that can be justified for other environmental or economic reasons, such as more efficient use of water or more flexible systems (Schneider 1989).

At the same time, they should give serious thought to planning for climatic change per se, especially for resource systems that might fail with modest climate change. Slight warming and drying of northeastern Brazil, the Great Plains of the United States, or the Asian steppes, for example, could disrupt social systems there, requiring enormous changes in land use and resource management (Parry and others 1988). A first step might be to assess how current development paths affect adaptability to a changing climate and to identify trends that limit flexibility. Contingency plans should be made for changes in cropping patterns, resource protection, and rural development. They can be put into effect as the change in climate becomes more certain, and may yield benefits even without climate change.


To avoid being pressured into action prematurely or paralyzed by uncertainty, development planners must consider a wider repertoire of planning approaches than they have traditionally used. Their responses should include adjustments that are easily and cheaply implemented and reversed as needed (such as more frequent evaluation of operating rules for reservoirs) and adjustments that expand rather than limit future options (such as efforts to conserve crop genetic diversity, and floodplain or coastal land use that places less fixed investment at risk).

Planners should expand on the tie-in strategy proposed by several analysts (Schneider 1989). They should take immediate steps to reduce greenhouse gas emissions, steps that are also justified because they would help resolve current environmental problems such as acid precipitation. They should also take steps to make resource management systems less sensitive to current climatic variations and more adaptable to future climatic change. These strategies coalesce where (1) the needs for sustainable development are met, (2) sensitivity to current and future fluctuations in climate are reduced, and (3) emissions of greenhouse gases and other global changes are limited (see figure 2).

Efforts to reduce losses from natural hazards, especially those associated with extremes of climate, will make development less sensitive to climate change, should it occur. At the very least, they will help us sharpen analytical tools for assessing the effects of climatic change and informing governments about regional vulnerabilities to variations in climate.

Regional development in the context of global change

The global nature of the greenhouse problem requires new links between local, national, and international decisionmaking and a better understanding of the role of climate in development. Many resource activities - from power generation to the cultivation of rice - are sensitive to climate and produce greenhouse gases. So policy discussions on global warming inevitably embrace links between national resource planning and the global threat. Resource planners at all levels must be prepared to address both how climate change affects their plans and how their activities affect global warming.

How this heightened concern will translate into altered development policy remains uncertain, but the general shape of imminent change can already be discerned. Several principles appear to be emerging from the international dialogue on global warming (World Meteorological Organization 1989, Woods Hole Research Center 1989). First, the greenhouse problem has been caused chiefly by the industrialized nations, which must bear the main burden of its solution. Second, solutions must accommodate Third World needs for economic development. Developing countries cannot be asked to limit greenhouse gas emissions by using less energy, cutting less timber, or cultivating less rice - without equal or better substitutes for the resources those activities yield. Finally, developing countries are most at risk with both current extremes of climate and long-term climate change, so they deserve special attention to help improve their ability to deal with the effects of climate change.

Under these principles, resource planners - even local planners - will be under pressure to change their activities to meet multilateral objectives. Planning principles and global links will be shaped at the highest policy levels, presumably through the international treaty already called for by several political and scientific leaders (World Meteorological Organization 1989: 292-99). Expecting this, development planners at all levels should begin to build a roster of mechanisms that would link planning goals (figure 2) and begin evaluating ways to fit local resource decisions into the emerging global environmental policy framework. Regional forest managers, for example, might begin to account for and alter the carbon balance of their activities in accordance with international agreements (Sedjo 1989) and to measure how reforestation could reduce the impact of climatic change. Links between the use of land and the effects of climate change should be evaluated. National energy ministries could increase research on noncarbon energy systems and on ways to implement them without derailing economic growth. In this way, the threat of global warming adds novel dimensions to traditional planning approaches.


It has been suggested that the best way to prepare the world for climatic change is to achieve full, sustainable development. The fact that developed countries are better able than developing countries to deal with such natural hazards as droughts and floods has not been lost on those arguing for more equitable development. But development makes sense only if it does not increase a region’s vulnerability to climatic impacts. The obvious path for development planning sensitive to the threat of global warming and to losses from natural hazards is first to improve our ability to manage current hazards.

Improved planning for drought and more flexible uses of floodplains and coastal zones would begin to reduce vulnerability to climate. Working climate vulnerability analysis into current development programs requires that planners:

· Analyze selected plans for developing regions (such as the Mekong or Indus basins) for sensitivity to climate, analyzing a range of adjustments to climatic extremes. Methods are now available for such analysis.

· Work with regional planners and resource managers to increase understanding of the effects of climate change and the cause of global change, and to expand the range of adjustments they consider in development projects.

· Link mitigation of current natural hazards to concerns about climate warming so that actions taken today have both immediate and long-term benefits.

· Improve institutional ability to assess the effects of, and possible adaptations to, climate change.

This last recommendation addresses a concern expressed especially by scientists and policy-makers in developing countries: that the issue of the effects of climatic change - whether natural or from human causes - has been defined by research in developed countries. Strengthening institutions would speed the development of climate policies in developing countries, but this will occur only when climate is recognized as a natural concern and when the developing countries can calculate the risks of climate change through their own analysis of the threat.

Which costs more: prevention or recovery?

Mary B. Anderson

The basic argument for integrating disaster awareness into development planning is that it is wasteful not to do so. The value of property lost to disaster (the absolute value of direct costs) is higher in developed than in developing countries, but losses as a percentage of national wealth are 20 percent higher in developing countries. Disasters particularly hurt developing countries because poverty and disasters are mutually reinforcing, undermine incentives for development, and particularly hurt the nonformal sector. Societies do not choose between disaster prevention or recovery - they usually “buy” some of each. The question is, how much of each to buy. By and large, developed nations choose disaster prevention over recovery. In weighing options, methods of cost-benefit analysis that acknowledge and assess the actual outcomes of different courses of action are preferable to those that “handle” them by mathematical manipulation.

“A stitch in time saves nine,” wrote Benjamin Franklin. Policymakers and economists, who consider the opportunity costs, are not so easily persuaded. “What,” they ask, “does the present stitch cost us relative to the later costs (discounted to the present) of the nine stitches? Is it better to take only one stitch now, or two? And how do we know if the rip will occur or when?” The choices about where, when, and how much of a nation’s resources to use to prevent or ameliorate an uncertain event are complicated.

Which is more cost-effective for a developing country: disaster prevention or disaster recovery? What choices do governments of disaster-prone developing countries face as they adopt programs for economic and social development and try, at the same time, to manage losses and suffering from natural disasters? What are the implications for long-term development of prevention versus recovery? What are the costs and benefits of approaches governments - and donors - must consider as they decide when, where, and how much of their resources to allocate for disaster response?

It is important to understand the links between disaster and development. Disasters often undermine development efforts and waste development resources. All societies can now forecast and prepare for disasters, so their failure to allocate resources to disaster prevention is both inefficient and wasteful.

Frederick Krimgold (1974) defined as a crisis an event that outstrips a society’s ability to manage or cope with it, at least for a time. The World Bank identifies a disaster as an extraordinary event of limited duration (such as war or civil disturbance) or a natural disaster (such as an earthquake, flood, or hurricane) that seriously dislocates a country’s economy (World Bank 1989b). For the Bank to consider emergency assistance, the event must be significant enough to “cause the government to modify its economic priorities and programs substantially” - that is, to alter its development strategy, at least for a while (World Bank 1988).

Disasters are different in scope and nature from accidents and everyday emergencies. And disasters are different from catastrophes - in which the effects of disaster are societywide. Not every crisis is a disaster. An earthquake may be severe, but if it occurs in an unpopulated area, or in a populated area where there has been enough preparation so that damage is minimal (as in San Francisco in October 1989), it may not become a disaster. That is, it does not exceed the society’s coping ability and does not qualify for World Bank emergency lending. We use the term “disasters” to refer to events that usually have both a “natural” basis (winds, water, land movement) and a negative impact on human life.

The link between disasters and development

It is important to consider the relative cost-effectiveness of disaster prevention and disaster recovery in terms of their potential impacts on the long-term development of developing countries because there is a basic relationship between development and disaster-proneness. (Oddly, disasters are seldom discussed in development literature but development is discussed in disaster literature.) There are three reasons why the disaster “variable” should be integrated into development planning.

(1) Disasters are linked to poverty. Poverty increases vulnerability to disasters. Most disasters occur in poorer countries, and the people who suffer most from disasters - and from environmental degradation - are almost always a society’s poor people. One study (UNDRO 1976) estimated that 95 percent of deaths from disaster occur among the 66 percent of the world’s population that lives in the poorer countries. In Japan, for example, the average annual death toll from natural disaster is 63; in Peru, with a similar incidence of natural disasters, the annual death toll is 2,900 (Anderson 1985).

Natural events destroy life and property in every country, but the losses, relative to a country’s resources, are more of a burden on the poorer countries. Absolute economic losses may be higher in wealthier countries, because more property of higher value is damaged, but the loss of GNP from disasters is about 20 times greater in developing than in developed countries (Funaro-Curtis 1982). Poverty increases the likelihood that a crisis will become a disaster.

(2) Development can increase disaster-proneness. Under some circumstances, development itself can increase the likelihood of disasters. One might assume that a dollar spent decreasing poverty - that is, on development - is a dollar spent on disaster prevention. This is largely true, but the opposite also occurs. The development of industry, for example, increases the possibility of industrial accidents, some of which - including the accident in Bhopal, India - are disasters. Some development projects are planned without recognizing local natural hazards. Human settlements have been built, for example, with no awareness of heavy seismic activity in the area, using no earthquake-resistant building techniques (Kreimer 1989). Development sometimes increases the probability of disaster indirectly. Improved human and animal health and nutrition, for example, have in some regions contributed to overpopulation, overgrazing, and land depletion - to the point of environmental deterioration and ecological crisis. Elsewhere, populations have moved to urban areas for productive employment but, for lack of planning, have inhabited lands susceptible to flooding and mudslides. The environment is often the point of interface between development programming and disaster vulnerability.

Every development program or project in disaster-prone countries either increases or decreases the likelihood of disasters. When development increases a country’s ability to cope with (predict, manage, ensure, or shore up against) natural hazards, it contributes to disaster prevention. When development is undertaken in ignorance of disaster-proneness, it may add to the possibility or increase the potential damage.

(3) Development resources are often wasted out of failure to consider disaster-proneness. When development projects are undertaken without regard for potential disaster, scarce development resources are often inefficiently allocated. Investment dollars are wasted when a project is wiped out by a (predictable) typhoon, earthquake, or mudslide. Disasters shorten the economic life of development investments yet donor-funded development projects have increased the likelihood of disaster or have been built (and destroyed) in disaster-prone areas. (Community-built centers and newly acquired livestock were wiped out by a typhoon in Asia; export crops, requiring a fairly long cultivation period, succumbed to wind and rain damage from tropical storms in Central America; housing projects built on unstable lands were destroyed by earthquake in the Middle East; and irrigation projects that increase soil salinity threaten subsistence agriculture in Africa.) More often, a disaster interrupts ongoing programs and diverts resources from their originally planned use (Jovel 1989). When disaster-proneness is well-known, failure to factor it into planning represents a serious mismanagement of resources.

Between fiscal 1987 and fiscal 1988, the World Bank reallocated about $2 billion of existing loans to reconstruction and rehabilitation efforts after natural disasters. Specific disasters could not have been predicted, but most Bank postdisaster funding goes to countries known to be disaster-prone. More than 80 percent of the Bank’s reconstruction and rehabilitation loans between 1947 and 1989 were to countries receiving more than one such loan. Of the 57 countries receiving these loans, 18 - more than one third - received loans for more than one type of disaster and three received assistance for three different types of disaster. Certain types of disaster consistently get proportionately more Bank emergency assistance. Discounting war emergencies - which, since 1947, have received the most emergency loans - floods and drought together account for more than half of the emergency assistance since the early 1970s (Kreimer and Zador 1989).

The point is that even without full-scale probability analysis, a lending institution can predict in which countries economic activity is most likely to be disrupted by natural events, and by which types. Disasters affect the returns on investment for any lending venture, so it is rational to factor the likelihood of such events into economic analysis. (One way to include likely disasters in an analysis of returns on investment would be to use a discount rate that ensures that the returns are realized shortly after the investment before any disaster could wipe them out.) Frequent reallocation of loans is inefficient if for no other reason than that reallocation decisions take time and money.

Donor agencies have a mixed record on acknowledging disaster-proneness in deciding about the economic viability of development projects. Seldom is disaster potential included in economic analyses in project design. In some project papers, the potential impact of a disaster is discussed under “social analysis.” One paper, for example, which dealt with the decision to construct a hydroelectric dam in an area of Colombia where seismic activity was common, noted that the project should “pay special attention to the social and environmental effects of a major accident at the hydroelectric site.” No mention was made of the potential economic effects of earthquake damage to the dam from seismic activity nor was the probability of an earthquake considered in the analysis of the project’s profitability.

The basic argument for integrating disaster awareness into development planning is that it is wasteful not to do so.


To identify the relative costs and benefits of disaster prevention and disaster recovery we must first define the two responses. “Disaster prevention” is the activities undertaken before crisis to control or mitigate its impact, so that damage is prevented or reduced to a level with which the society can cope. “Recovery” from a disaster involves only those activities undertaken after a disaster to restore an economy/society to its predisaster condition - or “get things back to normal.” In the real world, activities for prevention and recovery overlap. Most governments maintain permanent disaster recovery institutions to mitigate the negative impacts of disasters through rescue and relief. These operations become active after a disaster, but receive funding and organizational support before and between disasters. In this sense, disaster preparedness is a form of disaster prevention because it focuses on keeping the impact of a crisis within the bounds of society’s ability to cope. Similarly, recovery expenditures are seldom intended only to get things back to normal, because “normal” includes those conditions that gave rise to the disaster in the first place. Usually, rebuilding involves improving the capital stock in a way designed to prevent or mitigate future disasters - for example, replacing earthquake-destroyed housing with earthquake-resistant housing. The World Bank’s recovery and rehabilitation projects almost always support improving stock to lessen the damages from future disasters. The overlapping of disaster prevention and recovery activities complicates the analysis of their relative cost-effectiveness.

Moreover, societies do not choose between all prevention or all recovery. They “buy” some prevention and some recovery; the real decision for governments is how much of each to buy. Economically, the amount of disaster mitigation that is warranted is the amount that can be bought for less than the cost of losses that are averted through mitigation efforts (Milliman 1984). To make this marginal decision, governments must be able to assess the benefits and costs of the options available.

Benefit-cost analysis

Benefit-cost analysis involves three basic steps - first, enumerating all of the expected benefits and costs of an activity; second, assigning monetary values to them all; third, discounting all future benefits and costs to present values. One then chooses the option for which the net present value is both positive and greater than that of all available alternative actions (Kramer and Florey).

When natural hazards are known risks, their probability of occurring is essential to the analysis. This presents a few problems. First, not all benefits or costs associated with disaster responses are quantifiable. It is difficult, for example, to “price” social, political, and psychological costs. You can estimate future income lost from injury or death, but not emotional losses. And when a great deal of economic activity occurs in the nonformal economy, loss of “income” is difficult to estimate. It is equally difficult to price the benefits of disaster responses. What, for example, is the value of the sense of security that comes from living in earthquake-resistant housing? Or what is the political benefit to a government of imposing building codes (or the political cost of not doing so)?

Second, how do you calculate the economic value of geological outcomes (such as acres lost to desert or the extinction of a species)? How do you capture the cost of the loss of nonrenewable resources? Do you price them according to lost production? Over infinity? How do you measure the value of acres, ozone, and lost income?

Third, how do you discount future benefits and costs and incorporate the risk of natural hazards into the analysis? Discount rates are the subject of much debate in the literature and there is an inherent problem in some approaches to handling uncertain future outcomes. Some methods - using a cutoff period or adjusting the discount rate to include a “risk premium,” for example - incorporate risk into benefit-cost analysis through statistical manipulations that effectively minimize the importance of future disasters to present decisions. The effect of these approaches is to obscure the differences in impacts on long-term development of different courses of action. Game theory and sensitivity analysis, which also incorporate risk into benefit-cost analysis, are more useful at highlighting potential differences in outcomes (Kramer and Florey). In disaster response (as in environmental planning), one is concerned with the measurable economic benefits and costs of different courses of action and with a host of other realities that affect human existence. Even if it were “cheaper” to let disasters happen than to prevent them, it is generally agreed that widespread human suffering should be prevented when possible. So in assessing alternative courses of action to respond to disasters, methodologies that acknowledge and assess the actual outcomes of different courses of action are preferable to those that “handle” them by mathematical manipulation.

Models in the developed world

The wealthier countries, which consider marginal costs and returns in their decisions, by and large choose the course of disaster prevention rather than recovery - as statistics on relative death tolls from disasters in the developing and developed world show. London, for example, undertook a disaster prevention project - construction of the Thames Barrier - to prevent flooding of the Thames River. The project cost £730 million but the potential loss of property - if the “demonstrably mathematically certain” flood were not prevented - was an estimated £3.5 billion. The decision was made despite a very long disaster horizon because, although the generations who paid for the prevention were unlikely to suffer from such a flood, the losses in case of such a disaster would be enormous. 1

The San Francisco earthquake of October 1989 did not become a disaster (despite tragic results for some individuals) because major investments in disaster prevention had been undertaken by the region’s construction industry. Following building codes that ensured earthquake resistance added an average 4 percent to building costs, a sizable investment in the years before the earthquake. 2 Society judged those costs justified in preventing loss of life and property.

The calculations on which the Thames and San Francisco decisions were made involved marginal economic analysis - and convincing the public to allocate major resources to disaster prevention. 3 But it would have been politically unthinkable for both governments not to have undertaken actions to mitigate the consequences of natural disasters experts predicted as certain.

In choosing between prevention and recovery, the richer countries calculate that the sum of the economic, political, and social costs of a disaster justify significant investment in prevention and mitigation. Decisions about how much prevention to “buy” are made keeping in mind both economic and noneconomic considerations. One factor to consider is the state of the art in available technologies for prevention and mitigation. The Thames Barrier could not have been built until certain technologies existed - at a cost and level of reliability that made the decision possible. The state of the art for predicting natural crises also affects decisions about prevention or recovery (Holden and others 1989).

Options for funding preventive action - involving who will pay, under what circumstances, and over what period - also affect the decision about whether or not to undertake it. (The costs of earthquake-resistant construction in San Francisco were spread among all builders or buyers of buildings. The Thames project was funded through the sale of bonds - a decision to increase the public debt.) One must face the issue either of distributing the cost of prevention, or of distributing the costs of not preventing a disaster - that is, distributing the costs of recovery. How severe and extensive would the damage from a disaster be? Volcanic damage would remain fairly localized and would have more or less impact depending on what was built at the foot of the volcano. The impact of a major Thames flood would clearly be widespread. The economic and political perceptions of the “right” choice are influenced by the public’s awareness of available technologies (even if expensive) and by people’s expectation that they, or someone they know, might be victimized by a disaster that could be prevented. A major Thames flood in 1953, which caused extensive property destruction and the deaths of 300 people, provided the impetus for the decision to build the elaborate Thames Barrier. Often it takes a catastrophic event to arrive at a decision to invest in disaster prevention rather than recovery (Glantz 1989), even though for a disaster such as an earthquake or volcanic eruption the likelihood of a repeat catastrophe is least immediately after the event. Not all benefits from these investments accrue to future generations. Current generations enjoy the “psychic” security of investments in disaster prevention.

Often people in developed countries conclude that sizable investments in disaster prevention are economically and politically justified even if a disastrous event cannot be predicted with certainty. These countries seem to see such investments as sound, as preferable to recovery. Could the same conclusion be assumed to apply to all countries? Or do different circumstances in the developing countries alter the economics or politics of the calculations?

The higher cost of disaster in developing countries

Disasters are costly in all countries, in both immediate losses and long-term consequences. It is difficult to assemble data across countries, but one report (Zupka 1988) indicates that between 1970 and 1985 disasters of only three types (windstorms, floods, and earthquakes) cost an average US$18.8 million a day and, between 1980 and 1985, affected 216.8 million people or almost 5 percent of the world’s population. Using Red Cross data, another report (UNDRO 1979a) calculates that between 1900 and 1976 an average 60,000 persons were killed and 3 million injured or left homeless by natural disasters each year. Jovel (1989) reports that in Latin America and the Caribbean, more than 6,000 lives and more than $1.5 billion are lost to disasters each year. Disasters affect developing countries disproportionately.

To assess the costs of a disaster one must consider both the immediate impact on physical assets, employment, and output and the impact on future economic prospects. Costs are assessed in three categories: direct, indirect, and secondary. Direct costs, including losses of capital stock and inventories, are usually valued as the cost of replacement. Indirect costs - reflected in lost income, employment, or services - are those resulting from lost productive capacity. Secondary costs - those that result from decreased economic growth - include increased national indebtedness, inflation, and balance of trade deficits. Secondary costs also include effects on income or welfare redistribution because of changes in prices or a particular disaster response. 4

Table 1 Economic losses from natural disasters, Latin America and the Caribbean, 1980-87
(US$ millions, 1987)






Total losses















Secondary effects

Public finances


. . .





. . .



Note: Figures adjusted for inflation through 1987; secondary effects estimated for 1985 through 1987 and projected through 1990. Source: UN-ECLAC (in Jovel 1989).

With development resources limited in developing countries, are disaster costs different than they are in developed countries? Do the impacts of different disaster response strategies on long-term development affect the calculation of their relative cost-effectiveness? The value of property lost to disaster is higher in developed than in developing countries. So the absolute value of direct costs is usually higher in richer countries. But the indirect and secondary costs of disasters are significantly higher in developing countries than in wealthier countries. There are four reasons for this (discussed separately below):

· Losses as a percentage of national wealth are higher in developing countries.
· Disasters and poverty are mutually reinforcing.
· Disasters undermine incentives for development.
· Disasters particularly hurt the nonformal sector.

Losses as a percentage of national wealth are higher in developing countries. Although absolute losses from disaster may be higher in developed countries, losses as a percentage of total assets or national wealth are higher in developing countries. And the marginal utility of a unit of currency is presumably lower in richer countries. So the poorer the country, the greater the impact of direct, indirect, and secondary costs. Sometimes all of an asset of national importance is destroyed (as when a cyclone or earthquake destroys a national university). As a percentage of GNP, disaster losses are an estimated 20 percent higher in developing than in developed countries.

The relative impact of a disaster on national wealth depends on a country’s size and population density, the type of disaster (how local or general), the relationship between the type of disaster and the national economic base, and the level of national assets. Thus a small island nation, dependent on agricultural exports and susceptible to regular, severe tropical storms that sweep across the whole island, would experience worse losses than a country in which a small group of poor, subsistence farmers lives at the base of a volcano that erupts infrequently. The National Academy of Sciences (1988) reports that a one-meter rise in sea level, which is expected by the end of the next century as a result of global warming, will cover broad areas of Bangladesh, Indonesia, and Southeast Asia. These highly populated areas depend heavily on agriculture (Stevens 1989).

Hurricanes, floods, and drought (which affect agriculture) have stronger indirect and secondary effects on an economy than do earthquakes and volcanic eruptions, which are regionally more limited (see table 1). Except for volcanic eruptions, indirect and secondary losses are higher than the direct costs of disasters. Where information is available, secondary costs are more than double the direct losses from disasters.

Disasters and poverty are mutually reinforcing. Poverty is exacerbated by repeated disasters. Some of the worst environmental problems in developing countries are often both a cause and effect of poverty (Schramm and Warford 1989). Poverty increases vulnerability to disasters and disasters help perpetuate poverty (often through effects on and from the environment). If the cycle is never broken by preventing or mitigating the effects of disaster, there is little prospect for sustainable development.

This cycle is perpetuated as much or more through indirect and secondary as through direct losses. The Economic Commission for Latin America estimated, for example, that between 1960 and 1974 the damage caused by natural disasters in the five countries of the Central American Common Market reduced their average annual GDP growth rates about 2.3 percent (UNDRO 1979a). Often the cycle is perpetuated by a disaster’s impact on a country’s debt position - when local products, goods, or infrastructure are destroyed and must be purchased or financed on the international market. As a country’s debt service burden increases, it has fewer resources to break out of poverty. The incomplete and scattered data that exist suggest that disasters have significant, long-lasting effects on growth.

Disasters undermine incentives for development. Development requires an environment stable enough to encourage investment and entrepreneurial activity. Repeated losses from natural disasters discourage investment, creativity, and hard work. Were they to occur in wealthier countries they would create similar disincentives and losses in productive investment - except that limiting the impact of disaster also limits the impact on incentives. Repeated disasters limit developing countries’ ability to attract domestic and foreign investment and to encourage entrepreneurial activity.

A 1985 business report on Fiji, for example, noted that two hurricanes had left much more than $80 million in damage. They made Fiji virtually uninsurable against hurricanes. After 17 hurricanes in nine years, and three in less than two years with more than $130 million in insurance claims, the international reinsurers and the six companies who provided coverage in Fiji decided that the rewards were too small and the risks too great. The insurance sector had concluded that many of the losses incurred through repeated hurricanes could have been prevented through different building techniques and stricter building codes. They refused to continue to insure unsound buildings (Richardson 1985).

World Bank reports on Bangladesh (1989a), the Philippines (1989c), and the Sudan (1987d) also show how disasters affect the overall business climate. The report on Bangladesh describes how the effects of the floods reverberate throughout the economy, altering the outlook for the future and damaging incentives:

The floods have necessitated significant revisions in the Government’s economic goals and targets for the current year. Before the floods, 6 percent overall economic growth was envisaged, with substantial increases in agricultural production (6 percent) and manufacturing (7 percent). A recovery of crop production from the disruptions created by the 1987 floods, an expansionary public expenditure policy which aimed at stimulating economic activity and raising investment levels (supported by a significant new tax effort), and a revival in demand for manufacturing production as a result of these factors were expected to provide the basis for higher growth.

It is now clear that many of these targets will not be realized. Despite the crop recovery and rehabilitation efforts, agricultural production will be substantially less this year. Income losses associated with this setback and reduction in gainful employment opportunities will have a depressing effect on demand (which is unlikely to be offset by public expenditure policy), and on the manufacturing sector, which has also been directly affected by closure of factories during the floods and damage to equipment and inventories. The stagnation and even decline in the key productive sectors will limit the overall growth of the economy to about 1-2 percent in FY89, even though reconstruction and rehabilitation activities in the public and private sectors will help increase activity levels in construction and services sectors.

The dampening effect of disasters on investment and entrepreneurial incentives alone may constrain efforts at development unless disaster prevention strategies can convince investors and entrepreneurs that enough stability exists for productive investment and activity.

Disasters particularly hurt the nonformal sector. The impact of disaster in developing countries is often felt disproportionately by people who live at the margin and subsist in the nonformal economy - activities associated with the production, consumption, and distribution of goods and services not counted in standard systems for quantifying national economic activity. In many countries the nonformal sector represents a significant portion of the economy. Losses in the nonformal sector would include the direct costs of lost equipment, houses (which serve also as business centers), supplies, and the indirect costs of lost employment and income that cannot be made up. These losses are likely to be substantial (UNDRO 1979a).

Hurricane Gilbert affected an estimated 157,000 acres of crops in Jamaica, most of them domestic (Collymore 1988). Even when relief supplies make up the shortfall of crops grown for domestic consumption, this aid may have a sharply negative impact on incentives in the nonformal market. In Bangladesh, imports of relief foods, together with the increases in postflood crops encouraged by government emergency policies, created serious disincentives for small agricultural producers (World Bank 1989a). At the same time, the price increases that result from shortages affect poorer people the most. When these involve inputs, nonformal small enterprises have an especially difficult time.

Nonformal economic activities are invisible to the analyst, so it is difficult to assess the total direct and indirect costs of disasters in countries with a large nonformal market (Peskin 1989). But add the losses in this sector to disaster costs, and costs would rise dramatically both absolutely and as a percentage of national wealth. Preventive actions taken with no regard for their impact on nonformal activities can impose significant costs. The construction of a flood control system, for example, could limit the access of fishing communities to river canals on which they depend for subsistence.

Another secondary cost of disaster, particularly in the nonformal economy, is damage to people’s sense of efficacy. When people in a developing society have a sense of their own ability to affect and manage outcomes, they will produce more with a given set of physical resources than when they do not have it. One of the highest costs of disasters in developing countries is the effective undermining of any sense people have of their ability to control and manage their environments or their lives. 5 When disasters are repeated, the effect is compounded.

The costs and benefits of prevention and recovery

If disasters have more serious repercussions in developing than in wealthier countries, how does this affect the benefit-cost ratio of disaster prevention and disaster recovery strategies in disaster-prone developing societies?


The direct benefits of disaster prevention, in all countries, are equivalent to the savings in losses a disaster would have brought - including lost productive assets in the nonformal and formal sectors. Of special importance in the context of development are such secondary and indirect benefits as maintaining a climate stable enough to promote investment and enterprise and maintaining a sense of efficacy among the people on whom development depends.

In all countries, the costs of disaster prevention include the direct costs of controlling or mitigating the effects of natural crises that could become disasters. These costs may be huge, as in the Thames project, or smaller, as in the construction of fuel-efficient stoves to reduce deforestation and ecological deterioration. The costs of prevention differ significantly with the types of disasters (discussed below) and with available technologies for prevention. Disasters covering large areas that involve heavy environmental degradation are the most difficult - and expensive - to prevent.


Disaster recovery involves spending after a disaster has occurred. The costs of recovery include the direct, indirect, and secondary losses incurred and the costs of supporting rescue and relief operations and recovery management. These costs are significant for developing nations both as a proportion of national wealth and in their long-term effects on development.

Are there any benefits to be gained from disasters that would affect our choice - in particular, any benefits for development? Perhaps two. First, a disaster that gains international attention could attract injections of aid in the form of grants (these could have negative and positive effects). But international aid for disasters seldom exceeds an estimated 4 percent of losses (Zupka 1988), so this benefit is negligible. More important, a disaster may attract significant developmental aid focused on long-term programs to reduce disaster vulnerability and increase productive capacity.

A more important benefit of the recovery option may be the secondary, long-term, economic gain of “starting with a clean slate” (Cuny 1983). The recovery of Europe and Japan after World War II is a dramatic example. Obsolete factories and machinery destroyed by the war were replaced by entirely new installations in the recovery period. Countries that have historically produced a crop susceptible to destruction by cyclones may, when the crop is completely destroyed, decide to plant an alternative (possibly newly developed) crop that is less vulnerable to wind, a crop from which greater profits may be realized. Such recovery benefits are highly specific. They depend on special circumstances: the availability of a modem or invulnerable technology, the means to adopt it, and a pricing situation that makes the replacement of old approaches uneconomical, short of destruction. Benefits such as these could be quantified, but because of the special circumstances do not make much difference in analyzing the costs and benefits of the recovery option.

Measured cost-effectiveness of different types of disaster

The assessment of costs and benefits may vary for different types of disaster. For analysis purposes we discuss three types of disaster: predictable and unpredictable sudden-onset disasters and slow-onset environmental disasters.

Predictable sudden-onset disasters. In many disaster-prone countries, the severity of natural crises varies from year to year, but the crises are seasonal and to that extent predictable. In those circumstances, it is difficult to defend a failure to address disaster prevention when technologies are available for doing so. And often such technologies exist. Technologies exist, for example, for wind-resistant housing that prevents most hurricane and typhoon damage. Flood management and control technologies are more expensive, but they exist and are used in many parts of the world. Winds and floods are often seasonal and therefore predictable. When such crises cause frequent, significant damage, it is unreasonable to carry on with development as if they may not occur.

Unpredictable sudden-onset disasters. It is impossible to predict the time and damage potential of an earthquake but we know which areas are subject to seismic activity and can predict where a severe earthquake will eventually occur. A great deal is known about the design and construction of earthquake-resistant buildings using varied local materials. The damage from earthquakes is potentially extensive and expensive so there is a strong argument for damage prevention. It makes particular sense to factor in potential earthquake damage on development projects (such as dam construction) that could become disasters if any earthquake struck.

Slow-onset, environmentally based disasters. Increasingly, major disasters are the result of slow-onset natural events (such as droughts) combined with environmental degradation (such as deforestation) from human activity. When the causes of disasters are far-reaching - say, when environmental degradation changes patterns of land or water use - communities, even nations, are increasingly unable by themselves to effect the changes needed to avert disaster. Bangladesh, for example - as a recipient of floodwaters and silt from other upstream countries - cannot control floods through domestic programs alone. That requires an international effort using international technologies and financing.

When environmental disaster threatens, the costs and benefits of both disaster prevention and recovery change significantly. To the extent that we can predict them, the costs of not preventing ecological disaster may include the extinction of species - even of the human race. In the worst case, recovery is impossible.

The benefits of preserving life and productive capacity are assumed to be great, but the costs of prevention are equally high. Preventing or mitigating such disasters may involve a series of special, sometimes costly, actions. They involve creating what might be called the nonstructural apparatus of disaster prevention - activities that create the climate and capability for preventive action. Large-scale prevention requires:

· Data and tools for analysis. The more complicated the data, the higher the costs of collecting and analyzing it (Peskin 1989).

· Systems and institutions for coordinated decisionmaking. To the costs of arranging and holding the meetings at which decisions to create systems are made must be added the costs of setting up and maintaining institutions.

· Public education and political lobbying.

The costs of nonstructural apparatus, which apply in some degree to disaster prevention and recovery, are most significant in preventing massive systemic environmental disasters - because prevention is ineffective without broad collaboration. Prevention of environmental disasters is not too costly to be justified - and there may be opportunities for economies of scale. The same data and communication systems developed to address one large-scale disaster, for example, may be used to prevent other types of disasters. We cannot accurately estimate the economic return on investments in the prevention of large-scale environmental disasters. We do know that the physical and social outcomes of prevention are infinitely preferable to the losses such disasters would entail.

Lessons learned

Disasters occur most often in poor countries and cause the most suffering among poor people. These are precisely the societies for whom development is most urgently needed. Yet by ignoring likely disasters, many development efforts do nothing to decrease the likelihood of disasters, and many actually increase vulnerability to them.

Development planners sometimes call disaster prevention efforts “unaffordable extras” as they design development projects and programs. This attitude is unsound. Development spending and disaster spending are not tradeoffs. In a disaster-prone country every decision made about the allocation of resources to development affects the likelihood of damage from future disasters. And every decision about disaster response strategies - by which we mean actions that acknowledge and respond to the likelihood of disasters - has an impact on a country’s potential development.

Anderson and Woodrow (1989) define development as “the process by which a nation’s capacities are increased and its vulnerabilities reduced.” That definition makes explicit the link between development and disasters. Spending on development and disaster prevention are different investments in the same goal of development, linked and at times identical. Capacities and vulnerabilities involve more than physical assets or a disaster-prone environment; equally important are social, organizational, and motivational factors. A materially underendowed society with a strong, effective political system may be “more developed” in the sense of being able to cope with a natural hazard than one with more wealth but great social barriers. People can energetically engage in enterprise or resign themselves to fate, passively accepting whatever comes. When people have a strong sense of their ability to change and manage their society, they are better able to produce national wealth and cope with natural crises.

Development investment should never increase disaster vulnerability and should include measures that improve the nation’s ability to cope with disasters. Physical planning should include an analysis of disaster vulnerability, to avoid increasing the potential for disasters and to reduce environmental and other vulnerabilities. Development planning should also take into account the ways alternative actions may promote, or undermine, society’s attitudes about what is possible in terms of growth. All development efforts should provide for disaster prevention. Not to do so is economically irrational and politically unwise.

Even the most efficiently managed disaster recovery operation leaves a society vulnerable to natural hazards. Prevention not only minimizes damage but promotes a stable environment, incentives for investment and enterprise, and the sense that people can control their own economic destiny. These are crucial for sustainable long-term development.


1. A disastrous flood was a mathematical “certainty” every 2,000 years, according to the mathematician (subsequently knighted) who calculated the benefit-cost ratio for the project. But the environment of the Thames was changing, so by the year 2030 the probability of disastrous flooding would be every 1,000 years.

2. Private conversation with James Polshek (1989), architect and designer of earthquake-resistant buildings.

3. Marginal economic analysis has also been used, of course, as the basis for decisions not to undertake major investments for disaster prevention. See, for example, Holden and others 1989.

4. Jovel 1989, Funaro-Curtis 1982, UNDRO 1979a. Some writers argue that better cost-assessment methods are needed to avoid the double-counting involved in these three categories, which include both “stock” and “flow” concepts. For accounting purposes this is true, but for the purposes of this paper, the distinctions call attention to both the immediate and long-term negative effects of disaster losses (see Milliman 1984).

5. This concept is similar to David McClelland’s “achievement motivation” but we do not limit it to entrepreneurs. In the broader population, it is the opposite of a dependancy syndrome or the malaise of victimization. Lamentably, relief assistance often adds to a sense of victimization on the part of those who have experienced a disaster. Too often relief is completely “managed” by outsiders who wrongly assume that disaster victims are no longer competent.

Case study: Rio Flood Reconstruction and Prevention Project

Mohan Munasinghe, Braz Menezes, and Martha Preece

Until the Rio Flood Reconstruction and Prevention Project, disaster-related projects funded by the World Bank focused primarily on reconstruction - especially immediate, short-term recovery. The Rio project was notable as a targeted effort to reduce disaster vulnerability by promoting long-term multisectoral development strategies. It helped confirm that reconstruction projects must address specific disaster vulnerabilities as well as cross-sectoral needs in improving urban environmental management. The project represents a significant step toward developing a strategy for long-term prevention and mitigation of natural disasters and environmental degradation. It is also a good example of an effort to develop support for long-term environmental policies by strengthening indigenous managerial and planning capabilities - something that was not possible previously through short-term recovery projects.

In February 1988, unusually heavy rains fell in the metropolitan region of Rio de Janeiro, Brazil’s second most important economic pole and second largest city. In some areas, the equivalent of three months’ annual rainfall fell in less than 24 hours. By March 10, the resulting flood and landslides had left about 289 dead, 734 injured, and 18,560 homeless, and had extensively damaged physical infrastructure (roads, bridges, canals, drainage networks, dikes, water and sewerage networks, electric power networks, factories, and commercial establishments). The physical losses severely disrupted Rio’s economic activity, particularly in the northern part of the metropolitan region, and left the predominantly low-income population with limited access to schools, health facilities, and basic sanitation. This had been the heaviest recorded rainfall since 1966, the time of the last flood and landslide disaster in the metropolitan region.

The severity of the disaster can be attributed largely to the region’s vulnerability to natural hazards. Environmental degradation - resulting from the unplanned expansion of human settlements, faulty construction, congested drainage, and inadequate maintenance - contributed heavily to the event’s catastrophic outcome. Poverty was also linked to both the causes and consequences of the disaster. The poor of Rio de Janeiro - who live in such high-risk areas as steeply sloping hillsides, landfills, and floodplains - became both the perpetrators and victims of environmental degradation. Poverty and poor environmental management continue to place the city’s population at risk from natural hazards.

In 1989, the population of the metropolitan region was about 10.2 million; roughly one-sixth of the region’s families live in poverty (on less than three minimum salaries a month). Low-income human settlements have spread rapidly in unsafe, environmentally susceptible areas. Unplanned squatter settlements (favelas) have developed along the narrow coastal strip and across the coastal mountain range. Located on steep hillsides, they often perch precariously above the city and in lowland areas along riverbanks in the flood-prone Baixada Fluminense region north of the city.

Increasing urban poverty has placed heavy demands on national and local institutions and infrastructure, and basic needs for housing and services have not been met. Local institutions for urban environmental planning are mostly weak and do not coordinate their activities. Planning, programming, and budgeting are inadequate and there are no reliable information systems or trained technical staff. Investment decisions are often politically guided, which has led to inefficient resource allocation and poorly targeted spending.

On much of the city’s periphery, especially in favelas, the supply of services has been affected by flawed infrastructure planning, inadequate investment in infrastructure, several years of neglect in management, and poor or nonexistent maintenance of facilities. Drainage networks are severely blocked by silt and uncollected solid wastes, and they overflow, depositing garbage and raw sewage on precariously constructed squatter settlements. Inappropriate disposal of solid wastes and uncollected garbage - about 5,400 tons a day in the metropolitan region - became raw material for the landslides of February 1988, burying homes and sweeping away hillside squatter settlements. To compound the problem, most municipal refuse goes to open dumps, which are often occupied by squatters who have no formal access to land. These landfills are hazardous sites for construction because the soil is unstable, so they are susceptible to runoff and erosion. Uncontrolled wastewater ends up in nearby drains or streets, further degrading already unstable land. Landslides and flooding are common because these environmentally sensitive areas are highly susceptible to rain washout.

Poor environmental and disaster planning

The accelerated process of urban growth has been a burden on the natural environment, accelerating the depletion of natural forests and destroying vegetative cover. Steep slopes have also been stripped of vegetation as the result of illegal mineral extraction by the economy’s informal sector. Inadequate drainage systems and infrastructure have depleted the bare soil’s capacity to absorb water, accelerating runoff and exacerbating landslides.

The degradation of the urban environment - mostly because of institutional inaction and political conflict - coupled with physical damage to health facilities and sanitation networks during the floods, sharply increased the risk of epidemics. Floodwaters contaminated with garbage and human waste led to widespread outbreaks of leptospirosis, hepatitis, typhoid fever, and other gastrointestinal diseases.

Weak policy analysis and program development, inefficient targeting of resources, ineffective implementation, inappropriate and unenforced legislation, and institutional friction have accentuated conflicts among institutions and between government and users. Policy-makers have focused on short-term approaches to resource allocation. Projects are largely unsustainable because they must compete for the scarce resources available for operations and maintenance.

Floods and landslides have cost an estimated US$935 million: $400 million in direct costs (physical damage) and $535 million in indirect costs ($435 million in lost production, $50 million in lost revenues from tourism, and $50 million for the cleanup operation immediately after the disaster).

Rescue and salvage equipment were inadequate at the time of the floods and were located far from the emergency sites. Severe gaps in emergency response and preparedness plans compounded the damage from the floods. The emergency response was not carefully planned so people and materials converged on the area, creating great confusion. The chief problem was poor coordination and sharing of information. A great deal of effort was wasted and many urgent tasks were not addressed.

After the disaster, and with some difficulty, the state and municipal governments implemented short-term disaster relief activities, albeit at a snail’s pace: roads were reopened, emergency services were restored, and the homeless were temporarily housed in schools and other public buildings. At the same time, the government began considering the longer, more arduous, and costly tasks of rehabilitating the affected areas and reestablishing economic activity and physical infrastructure. The disaster stimulated local government (encouraged and assisted by the World Bank) to undertake preventive measures to mitigate the effects of minor periodic floods and to improve the region’s capacity to cope with the major floods that occur every 20 years or so. On March 30, 1988, the state governor created an Executive Group for Reconstruction and Emergency Works to oversee and coordinate short-term disaster relief and medium- and long-term reconstruction and prevention activities. The municipality of Rio also created a special unit to coordinate activities.

The World Bank’s response

The Bank’s strategy in response to the disaster was to strengthen the already considerable flow of technical assistance to improve long-run policy development in urban planning and to initiate a US$393.6 million flood reconstruction project, to which the Bank contributed $175 million. The project was designed to:

· Provide a quick response to immediate needs.
· Restore assets and productivity to preflood levels.
· Increase the metropolitan region’s resilience when floods occur.

The project’s central goal was to strengthen the metropolitan region’s institutional and financial ability to manage urban development and environmental planning. It emphasized the need for fundamental reform, giving high priority to:

· Improving institutional capability for responding to emergencies and natural hazards.

· Rebuilding and rehabilitating basic infrastructure.

· Implementing physical and institutional preventive measures to reduce the damage from future floods.

· Helping the governments of the state and municipality of Rio de Janeiro develop flood prevention and mitigation programs.

· Modifying the management policies of the municipality of Rio and in the Baixada Fluminense region to increase the availability of public funds and the ability to mobilize financial resources for routine maintenance and environmental protection.

What has been done

From the early stages of implementation the project confronted a common difficulty: institutional weakness, exacerbated by the complexity of an emergency situation requiring multisectoral and interagency responses. Responsibilities for execution were distributed among so many agencies that coordination became almost impossible. Efforts by Bank staff to clarify and understand the roles of each institution and level of government were a major problem. Political rivalry between the state and municipal governments, and differences with the federal government, greatly increased project risk. Numerous managerial changes in the Caixa Economica Federal (CEF), Brazil’s financial intermediary and cofinancier of the project in the two years after the disaster, contributed to an 18-month delay in the project.

But now most structural works - mainly infrastructure in the city of Rio - have been substantially completed. Roads and bridges have been repaired, and the massive dredging of rivers and drainage canals choked with debris and silt deposits has begun. Stabilization of steep hillsides and slopes is almost complete. Repairs of sewerage systems will soon permit improved collection of sewage that currently drains into open waterways. Institutional problems have delayed the preparation and implementation of a metropolitan regional program for improving the collection and disposal of solid waste, but progress is under way.

The project’s serviced-sites component provides emergency recovery assistance to families living in high-risk areas. Work has begun on providing families with unrestricted title to the land on 11,000 minimally serviced lots. Housing sites will be provided for about 5,000 families who either lost their homes in the floods and landslides or need to be resettled. Most relocation from housing along the rivers is done under state auspices. Within the city of Rio de Janeiro, about 5,700 refugee families who lost their dwellings have already been moved from high-risk areas in the city.

The state of Rio de Janeiro is being given technical assistance to formulate strategy for disaster mitigation that focuses on developing hazard reduction techniques and reversing environmental degradation. The strategy is to prepare an integrated system that improves the communication technology, land transportation, and equipment needed for a quick and efficient emergency response. The civil defense plan being prepared for the municipality of Rio covers such natural hazards as floods, landslides, and fires in high-rise buildings and such technological hazards as toxic waste spills.

The municipality of Rio de Janeiro is being given technical assistance to provide educational programs in:

· The proper handling and disposal of solid waste.
· Safe self-help techniques for low-cost housing construction.
· Protecting forests.
· Inspection and control of illegal, informal mineral exploration.
· Strengthening the fiscal administration.

Managing natural disasters

In the short and medium term, the project focuses on key problem areas in disaster preparedness, including housing and environmental sanitation services, landslide control measures, environmental planning and management of spatial development, and urban waste collection and disposal. In the long run, the project seeks to develop the foundations for reform in urban environmental policies through:

· Formulation of an in-depth preparedness plan for the greater metropolitan region.
· Preparation of a medium- and long-term reforestation plan for Rio’s metropolitan region.
· A proposal to protect reforested areas.
· An analysis of land-use practices and a proposal for streamlining land tenure issues.
· The preparation and implementation of a program in environmental education.

The Rio Flood Reconstruction and Prevention Project is a remarkable example of an effort to reduce hazard-related losses. Addressing environmental degradation in the city called for integrating environmental policies into the normal activities of public institutions. But the project’s most significant feature may be its focus on preventive measures, based on a comprehensive technical assistance program that emphasizes environmental rehabilitation and increasing the region’s resilience in future catastrophes.

Case study: La Paz Municipal Development Project

Alcira Kreimer and Martha Preece

Located high above sea level, in a deep valley surrounded by steeply sloping mountains, La Paz, Bolivia, is heavily subject to landslides and mudflows. Their incidence and severity are exacerbated by the squatter settlements on precarious land that have proliferated with rapid population growth. Reducing the city’s vulnerability to disaster called for strengthening the city’s institutional capabilities and expanding its investment potential, two goals of the La Paz Municipal Development Project that are unlikely to be achieved until there is a continuous municipal administration. Prevention and mitigation efforts often take longer than a policymaker’s term of office, and projects that address risk prevention do not always produce short-term political or economic gains. They must compete with and often lose out to more visible or politically rewarding projects. Given the difficulty of designing and enforcing land-use plans through “regular” channels, it probably makes more sense in a city such as La Paz to decentralize disaster mitigation and to emphasize community participation - to promote awareness of the need for such activities and to design disincentives that steer settlements away from high-risk areas and incentives for using disaster-resistant construction techniques.

Controlling natural risks is particularly important in urban areas. In developing countries in particular, many poor urban settlers, unable to afford properly serviced homesites, are forced to live in high-risk areas. Squatters are a serious threat to the urban environment, as they tend to dwell on precarious sites highly vulnerable to natural disasters.

The Bank has been involved in recovery from and prevention of disasters in several cities in developing countries. In recent years it has emphasized strengthening municipal ability to deal with environmental degradation. In seeking ways to help institutions integrate preventive measures into urban and municipal development efforts, the Bank - together with partner governments - has emphasized: (1) assessing urban vulnerability to natural hazards, (2) strengthening capabilities for managing disaster, and (3) developing efficient disaster prevention programs.

Bolivia’s vulnerability to disaster

About 44 percent of Bolivia’s population (6.9 million in 1988) lives in urban centers. The country’s recent pattern of urbanization is a function of economic factors and the unusually difficult climatic and geographic conditions of the Altiplano and Valles regions, where nearly 80 percent of Bolivians live. Migration to the once flourishing mining centers has given way to increasing flows of people from rural areas and from such mining towns as Oruro and Potosi to larger cities such as La Paz, Cochabamba, and Santa Cruz.

About 1.2 million people live in La Paz, Bolivia’s capital, which is located between 3,500 and 4,000 meters above sea level in a deep valley surrounded by steeply sloping mountains. The city’s vulnerability stems from its location in a narrow valley of unstable soil, broken relief, and torrential erosion that creates often devastating mudflows and landslides. Plessis-Fraissard (1989) describes La Paz as a city experiencing a continuous earthquake. About half of La Paz is unsuitable for development, and the city lacks administrative capability to enforce any land-use plan that restricts settlement in hazardous areas. La Paz has grown tenfold in the past 50 years, and has roughly doubled in size in the last decade. With no planning, low-income neighborhoods have spread up onto the slopes surrounding the city, further destabilizing the landslide-prone mountainside, where surface materials are generally unstable and rocks are liable to fall. Moreover, urbanization has brought deforestation, which further destabilizes the erodible soil. These problems are compounded by a dearth of basic infrastructure and by the common use of urban rivers for garbage disposal. The result is severe, recurrent floods and landslides. Each rainy season (November to March) is a constant threat to life and economic resources. As unstable terrain becomes saturated, houses are washed away. Development should not be allowed or should be controlled on about half of the valley slopes, but the municipal administration and institutions are too weak to design and enforce sound land-use regulations.

The cost of natural disasters. In the last few decades, rapid urban population growth, caused mainly by rural-to-urban migration, has exacerbated the frequency and severity of natural disasters. The damages produced by catastrophic events represent the equivalent of 1.5 percent of the city’s GNP (Masure 1986). Economic analysis suggests that the La Paz Municipal Development Project’s disaster management component would generate an economic rate of return between 24 percent (for landslide control) to 44 percent (for solid waste management and community education). The cost of disaster control would be about US$2.5 million, or $2.50 per capita, but annual losses from property damage alone are about $8 per capita. In other words, annual losses far exceed the cost of risk reduction.

The Bank’s involvement

When a Bank team began to prepare the Municipal Development Project, disaster mitigation in La Paz seemed a pipe dream. Social, political, and economic constraints - and the extent to which large sections of the La Paz region were at risk - seemed formidable. And the site presented serious physical and managerial problems. The main problems were: (1) deficient infrastructure and services, which have contributed to rapid erosion and chronic landslides, (2) a weak municipal administration, particularly in personnel policy and management, and (3) too little policy attention to education and awareness programs that encourage local involvement in prevention activities.

The Bank’s involvement in the La Paz Municipal Development Project was geared to support the government’s strategy of strengthening municipal management of urban development programs through rational land-use planning, suitable building codes, and the provision of basic services. The Bank’s strategy emphasized management and control of natural risks through planning, information, and community organization, taking into account the limits imposed by the area’s natural risks.

The La Paz Urban Development Plan was of great help in formulating the Bank’s disaster management program. The plan was produced by a team of ecogeologists and urban planners, with technical assistance from the French government. Commissioned by the mayor of La Paz in the late 1970s, the plan aimed to strike a balance between the city’s siting restrictions and its future development needs. Relying on a series of environmental and socioeconomic studies, the technical team produced detailed maps identifying areas where natural risk was high and where construction was suitable. According to their studies, only 19 percent of the urban area was suitable for development, rehabilitating another 35 percent of the region was economically viable, and the rest of the land was unfit for urban settlement. Special conservation and preservation measures were recommended, such as the creation of recreational parks and the promotion of agricultural activities and afforestation. The technical report found the potential for urban expansion in the cuenca of La Paz to be extremely limited. Most of its land is unstable and geotechnically unsuited to building and some of the marginal land would require high-cost development for rehabilitation.

Of particular significance were the criteria and methods used to determine the types of prevention and mitigation measures to be implemented. The Bank team tabulated a ten-year inventory of disaster occurrences and property damage in 10 zones in La Paz. The premise of the analysis was that risk and property damage were foreseeable and quantifiable and so, therefore, were strategies to reduce the probability of disaster. Priority for allocating financial resources and for determining the types of mitigation activities to be implemented was then defined by two criteria: the probability of a hazard’s occurrence (imminent, probable, or possible) and its probable gravity (very severe, severe, or slight). Finally, recommended actions and their priorities were synthesized in a time table that included the construction of civil works, land-use planning, and procedures to prevent uncontrolled “irregular settlements.”

The Project

The La Paz Municipal Development Project was designed to help the municipality strengthen its administrative and fiscal capabilities and redress critical shortcomings in hazard control and the city’s infrastructure. About 35 percent of the project was devoted to natural disaster mitigation, mostly of landslides and floods. Risk management was addressed in a comprehensive way, integrating environmental, institutional, and social considerations. The urban development and infrastructure component addressed disaster management and control by:

· Providing basic services to selected neighborhoods, including water, drainage, and pedestrian walkways.

· Providing flood and erosion control along drainage basins (landslide prevention works and land-use regulations and procedures to prevent irregular settlement).

· Designing and implementing a garbage collection and disposal system and a street cleaning system and developing a laboratory of bromatology and sanitation control.

· Providing community education about urban services, civic duties and responsibilities, and local participation in hazard reduction and emergency recovery activities.

The component to improve local administrative and institutional capabilities focused on:

· Consolidating planning and control.

· Strengthening tax collection, budgeting, and financial and investment planning.

· Increasing revenues from property taxes and improving development planning and the management of urban services.

· Strengthening community relations and promoting local participation.

The urban transport component addressed the low-cost rehabilitation of major access roads, basic improvement of the street network, and the rehabilitation of municipal vehicles and equipment.

The project also aimed to institutionalize disaster management and emergency readiness in La Paz’s municipal agencies. Agencies responsible for different aspects of disaster prevention, mitigation, relief, and recovery were to be coordinated within an efficient organizational framework; contingency plans to facilitate communication after a disaster were to be prepared; and an early warning system, including emergency assistance procedures for disaster victims, was to be established. Municipal employees were to receive training on various disaster-related topics, such as communications, urban planning, flood and landslide control, and infrastructure needs assessment.

Constraints on developing institutional capability

Reducing risk called for strengthening the city’s institutional capabilities and expanding its investment potential. It was estimated that the municipality could invest US$18.0 million per year, or $18 per capita. This would provide the funds needed for maintenance and erosion control works. Little progress has been made so far for several reasons, among them the frequent changes in administration. The project’s long-term objectives of institutional strengthening are unlikely to be achieved without political as well as institutional consensus on long-term goals and priorities. Reorganizing the cadastre to improve public revenues, which is central to project sustainability, has been delayed by protracted technical discussions. A conservative estimate of revenues lost to delays is US$10 million a year.

This is typical of the barriers to achieving realistic disaster mitigation and prevention when an administration lacks continuity. As Persaud (1989) points out, even when cost-benefit analysis indicates the logic of investing in disaster prevention and mitigation activities, politicians and policymakers do not necessarily concur on the priorities. Prevention and mitigation efforts usually have a longer time horizon than the policymakers’ term of office and priorities must survive many competing demands. Projects that address long-term risk prevention do not always produce short-term political or economic gain, so day-to-day planning and more visible or politically rewarding projects often take precedence. The La Paz Municipal Development Project illustrates the financial and administrative difficulties that may be encountered in trying to reduce disaster vulnerability.

The need to create incentives

Despite considerable administrative efforts to control the unplanned expansion of human settlements, population pressures remain and destructive land use continues. Ironically, steps taken to stabilize slopes have encouraged illegal settlements and overpopulation in high-risk zones, undermining efforts at disaster prevention. Aware of the need to control risks, the administration has intensified efforts to encourage sound building practices and to establish the framework needed to promote community participation and to educate citizens about hazard control. Reversing La Paz’s land-use pattern will take political leadership and appropriate policy changes to support community initiatives. To achieve a sustained commitment to disaster prevention and mitigation, the administration should create incentives for local participation and get communities involved meaningfully in construction programs and land-use planning.

As Christian Delvoie (1990) points out, people will not participate in land-use and construction programs they do not perceive to be in their best interests. Local participants in a project must be assured of reaping the benefits of their involvement. La Paz should explore such alternatives to a regulatory approach as providing services, construction materials, and technical assistance to encourage safer building systems. An understanding of social, cultural, and ecological conditions and of people’s perceptions and attitudes must be incorporated in project design. Public education through mass media will help keep future developments from falling victim to natural disasters and must become a priority.

This project achieved four things. First, the civil works, especially the flood and erosion control components, were completed as the result of the municipality’s dynamic entrepreneurial approach. Second, the project paved the way for environmental programs sponsored by the Interamerican Development Bank (IDB), the European Community (EC), and the German Technical Assistance Agency (GTZ), among other aid agencies. Third, the project has helped build up the municipality’s investment capabilities, which were negligible before the project. This has increased the level of funding and resources available to finance new actions. Finally, the Bank’s main contribution to this project has been the promotion of risk management as an integrated process.

This project illustrates the need for a flexible approach to helping governments in hazard prevention and mitigation efforts. Planning and control of land use require incentives and the full participation and support of local communities. Given the administrative and institutional difficulties of designing and enforcing land-use plans through “regular” channels, emphasis should be placed on developing in the people a strong sense of control in coping with natural disasters. Emphasizing the social nature of natural disasters calls for a proactive rather than a reactive stance. Developing disincentives for steering settlement away from high-risk areas and incentives for using disaster-resistant construction techniques is probably the best approach to setting realistic mitigation and prevention goals for a city such as La Paz.

The International Decade for Natural Disaster Reduction

Neelam S. Merani

The International Decade for Natural Disaster Reduction was launched formally on 22 December 1989 by resolution 44/236 of the United Nations General Assembly. Its objective is to prevent or mitigate - in a way the same object - natural disasters and the loss of life, property damage, and social and economic disruption they produce worldwide. Only individual countries themselves can achieve this objective, but the Decade should inspire them to and should help them acquire or reinforce the means to do so. The Decade should be both an umbrella and a sparkplug for international cooperation and activity.

The key is to mobilize strong, coherent, effective national committees that can coordinate the work of different departments, different levels of government, and different parts of the community - including the scientific, professional, business, and industrial communities. If economic and social development efforts are not to be lost to disasters, it is essential that these national committees share experiences and learn from each other how reducing losses from disasters will benefit their national economies. It is important that they create or strengthen regional and global networks to monitor natural phenomena and human behavior, exchange data and assessments, and bring the latest scientific and technological advances to bear on disaster management, including the early, adequate, credible generation of disaster warnings. Achieving the objectives of the Decade will require a concerted international effort involving the most modern and dynamic sectors of society: science, telecommunications, banking, insurance, local authorities, voluntary organizations (in particular, the Red Cross), the media - each and every one of us.

Economic losses and human suffering from natural disasters have increased in the past two decades, endangering social and economic development, particularly in developing countries. Tackling this problem requires a sound evaluation of disaster mitigation policies. Two things must be determined. First, which investments to protect society and reduce its vulnerability to disaster are cost-effective? And second, when we invest billions of dollars each year on infrastructure and long-term capital development, what measures should we take to reduce those investments’ vulnerability to disaster? Our evaluators must remember that disasters are statistically certain to happen, although our scientific knowledge does not yet allow us to predict them with even the certainty with which we predict the afternoon weather.

We must measure the direct costs of restoring or attempting to restore housing, infrastructure, and the economy to predisaster conditions, particularly in the most exposed developing countries. And we must not forget to measure the loss of human lives, the true basis for - and beneficiaries of - development.

To preserve the delicate balance and two-way relationship between the earth and humankind, it is important that we develop a broad-based historical database on disasters. For reliable results, we must combine the knowledge and know-how of the world’s major investment banks (including the World Bank), regional banks, private sources of financing, insurance companies, universities, and economic research centers.

In mobilizing various actors internationally - different international, intergovernment, and nongovernment bodies, scientific and professional communities, and the private sector - the Decade and its secretariat must see itself as catalytic. Its role must be partly to generate resources to support the efforts of others within a framework of commonly supported approaches.

Countries differ in their vulnerability to different natural disasters or combinations of disaster, and in addressing the causes and consequences of disasters must not focus only on those that are easy to address, thus meeting the needs of some countries but not others. We must also attack the causes of the problems, not just the symptoms. In marshalling our knowledge of disasters we must be careful not just to advance the state of knowledge but to find cost-effective, practical solutions.

And we must seek an integrated approach to disaster mitigation. Natural disasters and environmental catastrophes are two sides of the same issue: the two-way relationship between mankind and its environment. Human activities affect the planet earth and our planet affects mankind, sometimes catastrophically. Human beings can adapt only in a limited way to environmental variations, particularly if forces unleashed in the atmosphere or inside the earth’s crust evolve into cataclysms. And mankind’s vulnerability has been increased by development, because human assets - of population, physical infrastructure, and economic resources - are combined in an increasingly complex and valuable system. The effects of natural disasters have been compounded in terms of loss of life, physical damage, and detrimental effects on the economic development of vulnerable countries.

Environmental degradation, by attacking the earth’s resource base, limits the human capacity for long-term development, narrows options, and destroys the heritage of future generations. Environmental degradation has been characterized as a creeping disaster, but hazardous waste is not - nor was Chernobyl. Climate change has been seen as advancing at a slow pace, but our solutions should begin to move beyond a brisk walk. We must see depletion of the ozone layer as an urgent problem. Time is running out.

Natural disasters, on the other hand, are seen as fast-moving events. But activities to prevent or mitigate disasters cannot be conducted in an instant. In many ways they depend in advances in scientific thinking - about plate tectonics and other natural forces that affect our environment, about the interface between biological, geological, and physical forces.

Just as we must integrate our knowledge about the earth, the oceans, and the atmosphere, so we must integrate our approaches to different types of disaster. Although the bell ringers may be different, warnings and preparedness for natural and industrial disasters have much in common. The need to conserve and manage watersheds is the same whether the ultimate concern is flooding or environmental degradation. The UN General Assembly sees drought and desertification as natural disasters in one resolution and as environmental problems in another. What is important is to address them effectively as problems to be resolved.

Nor can a line be drawn in terms of those affected. Environmental degradation, like natural disasters, affects the natural resource base and thus ultimately the human economy. Possibly that is why the last UN General Assembly adopted a resolution, 44/224, on international cooperation in the monitoring, assessment, and anticipation of environmental threats and assistance in environmental emergencies. Resolution 44/224 refers to potential environmental disasters, whether natural, accidental, or caused by human beings - just as the resolution on the Decade recognized the importance of environmental protection for the prevention and mitigation of natural disasters.

It is difficult to foresee putting into place effective measures for preventing climate change; the question may be how much we can moderate it. But sooner than many think, we may need to address the potential for natural disaster that global warming may generate, translate it into regional and country specifics, and prepare for it - hoping to prevent or mitigate its worst consequences. If the consequences will be more tropical storms, for example, we must take appropriate measures in terms of forecasting, warning, and preparedness. Clearly, those in charge of managing natural disasters and those in charge of managing environmental change must work together. The public may not understand if such cooperation fails to materialize. Disaster mitigation policies are essential to the strategy for protecting human survival and life on earth. The International Decade for Natural Disaster Reduction provides us with the framework for an active global approach to protecting that life and earth. Every country must be able to benefit from the scientific and technological knowledge available in some countries that can be used to understand the causes and effects of natural disasters and possible ways to reduce their impact.

Global change and reducing natural disasters

Stephen Rattien

The International Decade for Natural Disaster Reduction (IDNDR) must consciously address two countervailing forces: (1) our ability to mitigate natural disasters through warning, planning, and preparedness and (2) human activity that has contributed to the depletion of stratospheric ozone, the threat of global warming, deforestation, acid rain, the extinction of species, and other negative changes of which we are not yet aware.

Advances in science and technology allow us to mitigate their damage. But the same advances have also made possible the very breakthroughs in medicine, industry, and agriculture that have led to extraordinary population and economic growth - at the price of possibly globe-threatening effects on the environment. To be sure, we have reduced some of the worst environmental effects of early industrialization, but the sheer magnitude of human endeavors has inevitably damaged our planet. Confronting both natural disasters and global change will require a judicious blend of science and technology, public policy and education, help from the industrialized to the developing world, and a partnership between industries, individuals, and governments - within nations and throughout the world.

Certain disaster mitigation activities cost little or nothing; others require changes in practice and investments. Unless governments, industries, and individuals see these activities as being in their self-interest, they will resist them. The same applies to activities to confront global change. Stopping the use of CFCs in aerosol cans is essentially a zero-cost action. But reducing the loss of habitat from the destruction of tropical forests will be far more difficult to accomplish, as it will require assistance that crosses national boundaries.

The challenge of the Decade is to build on already-known science and technology; to replicate successful programs and activities; to find new ways to effectively transfer and implement three decades of disaster research; and, most important, to develop new, flexible, innovative hazard reduction programs that are compatible with, and support, the goals of our communities.

Not surprisingly, confronting the challenge of global change will require a similar approach - on a larger scale and over more time. Cumulatively, individual actions could overwhelm our planet’s assimilative capabilities. It is important to understand what is occurring and to take action. The Cairo Compact, which resulted from the World Conference on Preparing for Climate Change held in Cairo in December 1988, noted: “All nations, and the vulnerable segments of various populations, will be hit by climate change; by rises in sea level that jeopardize coastal areas, by changing weather patterns, by decreased availability of fresh water, by induced heat stress, by increased ultraviolet radiation, and by the spread of pests and disease. All this will devastate food and agricultural production and adversely affect human health, welfare and cultural heritage.”

We generally think of such changes as ozone depletion and the buildup of carbon dioxide as affecting climate - but global change is far more than climate change alone. Ecological diversity is being reduced at an alarming rate, particularly through the destruction of tropical forests; the pollution and overuse of ground-water is reducing its availability for agriculture, while the world’s population is swelling; acid rain is destroying forests and lakes; and even great seas such as the Mediterranean are losing their productivity - indeed, their ability to sustain aquatic life.

Global change is often viewed as the impact of man on his environment and disaster as the impact of nature on man, but man can affect the prevalence and locale of natural hazards, and natural phenomena have historically shaped global change. The effects of many natural hazards are exacerbated by global change. Bangladesh, for example, is essentially a river delta that is flooded when river waters rise or when there is a storm surge. Were the mean sea level to rise through global warming, the frequency and severity of flooding would increase. This is true not only in Bangladesh. New Orleans, much of which is below sea level and protected by dikes, is already vulnerable to hurricanes, as are many low-lying coastal cities around the world. Flooding has been exacerbated by forest-clearing and by certain agricultural practices that promote erosion and reduce the ability of upland soils to retain moisture and of the land to hold back the water.

Similarly, natural hazards can and do affect global change. Historically, global change - rapid, radical global change - was the result of natural forces: meteorites, volcanic eruptions, and firestorms. Relatively recent examples on the paleontological record are the volcanic eruption of Krakatoa and the burning of the North American forests. Now human systems vulnerable to natural hazards can, because of their scale and the materials involved, have a global impact. Oil spills can be the result of a pipeline ruptured by an earthquake or of a tanker or oil platform accident in an ocean storm. Similarly, water pollution is often the result of wastewater systems overwhelmed by stormwater or the runoff during storms of chemical pesticides from farming operations.

Thus, the objectives of mitigating disaster and confronting global change must be intertwined. As Dr. Robert White, President of the U.S. National Academy of Engineering, has stated, “our understanding of the dynamics of the planet and our ability to predict its future state require[s] that all elements of the earth system - the oceans, the atmosphere, the biosphere, and the solid earth - need to be considered as parts of a single interacting and continuously changing earth system. The phenomena of concern [are] interlinked not only by common physical, biological, and chemical forces, but also by common forces of economic and social development.”

Disasters are normally relatively rapid-onset events, but it often takes years, decades - even centuries - to set in place the elements that turn a naturally occurring hazardous event into a disaster. Decisions about where to locate, how to build, and what degree of preparedness is appropriate all have long-term consequences, and we are coming to recognize what we need to know and how we must apply this knowledge to reduce future disasters.

Global change is viewed as a relatively long-term phenomenon but it too is the cumulative effect of many smaller decisions about industrial development, land-use patterns, and environmental protection. Efforts to mitigate the effect of natural disasters will almost invariably reduce the threat of unwanted and unanticipated global change, and efforts to understand and confront human-induced global change will almost surely make the world safer.

Science and technology are the skills needed to address both issues. Gro Harlem Bruntland noted (1989) that as the challenging dynamics of global change gradually become clearer, the role of the men and women of science in shaping our common future becomes more central. The interplay between the scientific process and the making of public policy is not a new phenomenon. Indeed, it has been a characteristic of most of the great turning points in human history. It may be more important now than ever before in history for scientists to keep the doors of their laboratories open to political, economic, social, and ideological currents. The role of the scientist as an isolated explorer of the uncharted world of tomorrow must be reconciled with his role as a committed, responsible citizen of the unsettled world of the present. Bruntland’s comments apply equally to the challenge of disaster reduction. The choice is not between managing global change or mitigating natural disasters. In critical ways, they share common elements - and both require international cooperation in the application of scientific and technological knowledge. Reducing the toll from natural disasters will bode well for our ability to come to terms with the challenge of global change.

Minimizing the greenhouse effect

Erik Arrhenius and Thomas Waltz

The issue of climate change is by its nature potentially divisive, so caution may be in everyone’s long-term interest. International collaboration is essential as no single nation or region is likely to want to bear all costs of mitigation and adjustment. The political obstacles to global collaboration are substantial, however, as different nations and regions have conflicting interests. Creating an effective international system for rationing and curtailing greenhouse gas emissions will take time. In the meantime, other opportunities for collaboration exist. The development community should outline a policy and research program for sustainable economic development that addresses the implications of the greenhouse effect. Clearly the energy sector should get strong attention, but such sectors as agriculture and urban systems are also of importance as emitters of various greenhouse gases - and agriculture could be a sink for carbon.

What we know

We have known since late in the last century that the earth’s climate system could warm because of atmospheric emissions and the radiant properties of industrial and agricultural “greenhouse gases.” The theory of the “greenhouse effect,” conceived more than a century ago by the French mathematician, J-B. Fourier (1827), was given support by Tyndall’s studies (1861) on the absorption of heat by gases. The Swedish physical chemist Svante Arrhenius (1896) first calculated that a global warming of 3.2 to 4.0 degrees Celsius (C.) would result from a doubling of the earth’s atmospheric concentration of carbon dioxide, a level that could be attained sometime in the next century. The theory of the greenhouse effect has passed from conception to hypothesis to the consensus view that it is both real and probably the driving force behind global climate change in our day (Jaeger 1988a).

The greenhouse effect is both normal and essential to life on earth. Without it, the earth would be more than 30 degrees C. (60 degrees Fahrenheit) cooler, and life as we know it would not exist. It is the additional greenhouse effect - the legacy of industrial revolution - that poses a threat to society. The extent and character of future changes will reflect human choices - about the use of fossil fuels, among other things.

The emission of greenhouse gases is expected to increase the global mean temperature more and faster than ever before in mankind’s history. Current models predict a warming of 1.5 degrees to 4.5 degrees C. within the next century. The earth’s temperature rose only 0.5 to 0.7 degrees C. in the last century, and probably has not varied more than 1 to 2 degrees C. in the last 10,000 years, or 6 to 7 degrees C. in the last million years. During the development of human infrastructure in the last 7,000 years, the average global climate has not been 1 degree warmer or colder than today’s climate (Revelle and Waggoner 1983a).

Climate is a statistical description of the mean state of the atmosphere and the variability of the atmosphere, ocean, ice, and land surfaces over time. Climate is conventionally described in terms of historic means, variances, and probabilities (Rosenberg 1987). Climates have been accurately measured instrumentally in some locations for more than a century.

Climatic events that occurred before routine instrumental measurement became established (100 years ago) - and their relation to biogeochemical changes - are by no means unknown. Data from specific climate-related patterns in biological and mineral materials - recovered at time-related positions in sediments and ice cores - have been the main tools for measuring long-term climate change. These data - like “fingerprints” of different climate-influenced ecosystems - provide the basis for reasonably accurate descriptions of prehistoric variations in climate.

The global climate warms largely because certain long-lived industrially and agriculturally generated atmospheric trace gases - mainly carbon dioxide (CO2), chlorofluorocarbons (CFCs), halons, methane (CH4), tropospheric (ground-level) ozone (O3), and nitrous oxide (N2O) - trap some of the radiant heat that the earth emits after receiving solar energy from the sun, in some ways as glass enclosures trap heat (hence the “greenhouse effect”).

We have solid physical evidence of anthropogenic (man-made) emissions of long-lived actively radiating trace gases that contribute to the greenhouse effect. We do not have solid scientific consensus on how these gases will affect the earth’s climate. It is still not possible to say definitively, for example, that the global warming of 0.5 to 0.7 degrees C. that has been observed over land masses in the past century is the result of the greenhouse effect. Air temperature data indicate that five of the warmest years on record occurred in the 1980s, and some scientists have claimed statistical proof of the impact of the greenhouse effect (Hansen 1988), but others question whether we will ever be able to answer the question, Is this the year the greenhouse effect began to bite? Recent events do, however, illustrate what might be expected if the greenhouse effect were now under way.

Industrial greenhouse emissions

Greenhouse gases are accumulating rapidly and changing the chemical composition of the earth’s atmosphere. Human activities are increasing greenhouse gas concentrations worldwide, intensifying the greenhouse effect. The gas that contributes most to the greenhouse effect is carbon dioxide; burning fossil fuels (coal, oil, and natural gas) releases to the atmosphere carbon that had been buried in the earth for 100 million years.

The next most important greenhouse gases are methane, chlorofluorocarbons, and nitrous oxide. Much methane is produced by the anaerobic (in the absence of oxygen) decay of organic matter such as agricultural (rice paddy and livestock) emissions and urban wastes. Methane also leaks during the extraction and transport of fossil fuels, a fact that should be considered when evaluating the relative greenhouse contribution of different fossil fuels (Abrahamson 1989). The level and lifespan of methane in the atmosphere are increased by the emissions of carbon monoxide that result from incomplete combustion of carbon-based fuels in industry, households, and transport - and from the burning of savannahs and forests in land-clearing and slash-and-burn agriculture. Although not a greenhouse gas itself, carbon monoxide interferes with the atmosphere’s self-cleansing capacity by destroying chemical scavengers such as OH radicals, which are present in the atmosphere and would otherwise attack and break down air-borne methane. Thus it extends methane’s atmospheric lifetime and its ultimate greenhouse warming effect. Chlorofluorocarbons - inert gases used as refrigerants, aerosols, foaming agents, and solvents - do not occur naturally but are industrially produced. The sources of nitrous oxide have not been fully characterized, but almost half of the emissions are probably from such natural biosystems as tropical forests and estuaries. Most of the nitrous oxides emitted as a result of human activity are released by soil processes, accentuated by various agricultural practices, land clearing, and tropical deforestation. Other sources of nitrous oxide, such as fuelwood bum-ing, fluidized bed combustion, and the combustion of automobile exhausts, are the result of combustion at low temperatures.

Table 1 Net enhancements of the greenhouse effect


Atmospheric concentration
(parts per million)

Annual increase (1985)

Atmospheric lifespan
(approx. years)

Relative greenhouse efficiency
(CO2= 1)

Cumulative greenhouse contribution (1985)

Present marginal greenhouse contribution (1985)

Carbon dioxide (CO2)

346 a


100 b




Chlorofluorocarbons (CFCs)



100 c

15,000 c


24 c

Methane (CH4)



10 d

32 d


18 d

Tropospheric ozone (O3)







Nitrous oxide (N2O)







a. Preindustrial concentration: 260 parts per million.

b. The estimated lifetime of atmospheric carbon dioxide assumes a dynamic equilibrium between the ocean and atmosphere unlike the lifetimes of other greenhouse gases, which are determined largely by chemical breakdown (Bach 1988). The statistical lifespan (calculated as the average atmospheric lifetime) of a single carbon dioxide molecule as a result of physical removal processes is four years (Laut and Fenger 1989).

c. For chlorofluorocarbons presently in use. These estimates may vary, with compensating shifts in the percentage breakdown in column 6.

d. These estimates may vary, with compensating shifts in the percentage breakdown in column 6.

Source: Columns 1-5, Bach 1988; Laut and others 1989. Column 6, World Bank estimate, highlights the relative priorities for possible mitigation of trace emissions as a function of their greenhouse contributions at the margin of increasing atmospheric loading. Footnotes, World Bank.

Carbon dioxide is the least efficient of the greenhouse gases in its capacity to absorb infrared radiation. The other gases, because of their higher absorptive capacities, contribute substantially more to the greenhouse effect than the same amount of carbon dioxide (see table 1). Column 4 shows that greenhouse gases vary in their efficiency at absorbing infrared radiation.

For example, using CO2 as the baseline unit (equalling one) for absorptive capacity, a molecule of methane has 32 times the greenhouse effect of CO2, and the CFCs average 15,000 times the effect of CO2 Column 5 presents the current cumulative level of past greenhouse contributions, by compound; column 6 shows what each of the greenhouse gases contributes at the margin. What they will contribute to increases in the greenhouse effect will be a function of their relative atmospheric concentrations, rates of annual increase, and radiative absorptive capacities. These figures indicate where the opportunities for reducing greenhouse emissions lie and are useful for evaluating the most cost-effective measures to be taken by the development community.

Breakdowns of carbon dioxide emissions by economic sector are not available for the world but a breakdown for the United States in 1985 is shown in table 2. Here sectors are treated as independent in their greenhouse effects, but they may be interdependent. Some industrial, transport, and residential building users generate all or part of their own electric power, for example, so these percentage distributions are only first-order estimates.

Table 2 U.S. CO2 emissions by sector, 1985

Percent of total

Electric utilities






Residential buildings



Source: Personal communication, G. Marland, Oak Ridge National Laboratory, U.S. Department of Energy.

How much more methane contributes to the net greenhouse effect than carbon dioxide does depends on the period of time - or decision horizon - for which their relative effects are compared. Once methane is released to the atmosphere it is vulnerable to the attack of such chemical scavengers as OH radicals. Thus, although methane’s greenhouse warming effect is initially 32 times as great as that of carbon dioxide on a molecule per molecule basis, its present expected lifetime in the atmosphere is only 10 years - so its net cumulative effect declines from 32 to only four or five over carbon dioxide’s longer lifespan. The contribution of methane and its byproducts to the warming effect will be given more weight for shorter decision horizons and less weight as the decision horizon is longer because methane’s lifespan is shorter than that of carbon dioxide. Moreover, the breakdown of methane may involve a complex array of additional greenhouse gases. Thus, in 10 to 20 years the gross warming effect induced by methane emissions and byproducts could be substantially higher than these figures suggest.

And the various greenhouse gas emissions themselves interact synergistically. Methane is more effective per molecule as a greenhouse gas than carbon dioxide, so even small amounts of carbon monoxide (CO) increase the greenhouse effect significantly by increasing methane’s lifespan. CO is produced by inefficient combustion in automobiles and industrial and household furnaces. It is worth considering ways to reduce CO emissions, such as introducing appropriate energy efficiency and process control technologies. And since CO is a combustible waste, finding more efficient ways to bum it would also provide more energy.

Recent onsite measurements and remote sensing observations confirm that substantial carbon monoxide is being released not only from fossil fuel combustion in industrialized urban areas but also from extensive tropical and savannah burning to clear land for agriculture in South American and African developing countries (Newell and others 1989). So the OH radicals, which give the atmosphere a natural self-cleansing capacity, are much more at risk than had originally been thought.

Although most CFCs are produced and used mainly in the industrialized world (see table 3), developing countries could become important producers and users of CFCs. But, if they had easy access to affordable replacements or substitutes for CFCs, their harmful effects on the environment would be attenuated. Some of the most promising near-term CFC substitutes, such as HCFC-22, break down relatively rapidly within the troposphere, but also have comparatively short atmospheric lifetimes - 15 to 25 years - more like that of methane than of contemporary CFCs, which have lifetimes of 100 years or more. As with methane, however, estimates of the relative greenhouse warming effect of such “new” CFCs will vary with the length of the decision period.

In short, the relative greenhouse effect of different emissions over time is the combined result of their radiative forcings (changes) per molecule, interactions with other gases and sinks, resulting atmospheric lifespans, and the length of the decision period used for the estimate.

Table 3 World production and use of CFCs, 1985

CFC production a

CFC use b

United States



W. Europe, Japan, Canada, Australia, New Zealand, E. Europe, Soviet Union



Developing countries





a. Chemical Manufacturers Association.
b. U.S. Environmental Protection Agency.

Patterns of change in climatic risk

All current long-term projections of climate scenarios are conjectural, not literal. At the present time, scientists generally do not agree on a paradigm for anticipating climate change. Some climate scientists believe that the climate system tends to shift suddenly in equilibrium as boundary conditions change. Others contend that the climate system is linear, more deterministic than probabilistic in nature.

Oceanographer Wallace S. Broecker (1987) is concerned that we may have been “lulled into complacency” by model simulations suggesting a gradual warming over the next century. Broecker argues that the models’ fundamental architecture denies the possibility of critical interactions that we know prevail in the real world. Unfortunately, we are aware of the possibility of so-called “flip-flops” in the climate system, but do not yet know how to incorporate them into our models or predictions.

A system’s stability is a function of both the size of its domain of stability and its resilience, or its ability to maintain its structure and patterns of behavior in a disturbance (Holling 1986). And disturbances may be the result of positive feedback as well as external shocks. In a climate system, we may not be able to pinpoint thresholds along the boundary of the stability domain, but we do know that by pursuing the right approach to mitigating greenhouse emissions, we might be able to avoid climatic change altogether. Policymakers should not lose sight of this fact.

Long-term paleoclimatic records indicate that the earth does not respond to atmospheric forcing (changes in its chemical composition) either smoothly or gradually. Rather, the climate responds in sharp shifts that may involve large-scale transformation of the earth’s climate system. These records also show that changes of 6 degrees C. in air temperature have been typical of the earth’s climatic shifts - and have been positively correlated with changes in the concentration of carbon dioxide in the atmosphere. But none of these events has occurred in recorded human history.

Other feedback effects may be either positive or negative. For example, the feedback effects of a changing global cloud cover depend upon the type of cloud and may tend to be negative (because of enhanced solar reflectivity) or positive (by behaving as an insulating blanket, reflecting infrared radiation back to the earth’s surface). A shift from one type of cloud to another in the process of climate change may thus induce a flip-flop. The ocean also manifests complex feedback interactions within the climate system. Moreover, the ocean is an important sink for CO2 not only through its direct physical and chemical absorption, but also through its capacity to sustain plankton-based biochemical and photosynthetic transformations of inorganic carbon into deep sea sediments. The processes by which clouds and oceans affect climate are not well understood and require increased attention.

Empirical evidence strongly suggests that the probabilities of certain extreme weather events are correlated in a nonlinear way with mean temperatures. Experience has shown that the probability of extreme temperature events critical to the economy (such as consecutive daily temperatures exceeding 95 degrees F) increases as mean temperatures rise. As mean temperatures rise, so does the likelihood of natural disasters - which currently claim more than $40 billion in global resources and at least 250,000 lives annually. Ninety-five percent of these deaths occur in the poorest countries of the world, while 75 percent of economic losses occur in the wealthiest countries (Kates and others 1985).

Some simulations show a nonlinear relationship between precipitation changes and the amount of runoff available to supply irrigation within river drainage basins. In one such study, a 10 percent decrease in precipitation decreased runoff 25 to 40 percent, depending upon the size and mean runoff of the watershed (Nemec 1988). In another study, a 10 percent increase in average annual precipitation, combined with a 2 degree C. rise in average temperature, produced an 18 percent decrease in runoff. To completely counteract the effects of the 2 degree C. warming, a 28 percent increase in precipitation would be necessary (Revelle and Waggoner 1983b).

Some computer simulations with climate models suggest that with global warming the earth’s hydrological cycle and resulting precipitation will not only become more intense, but that many areas presently dependent upon rain-fed agriculture will become hotter and drier. They suggest in particular that midcontinent, midlatitude areas that now produce substantial grain may experience drier summer soil and an increased risk of drought. In some scenarios, grain crops could fail simultaneously in all the earth’s breadbaskets.

Similarly, some areas that have been dry may get more precipitation in a warmer world. And changes that by agricultural convention are viewed as positive may be undesirable for the successful adjustment of some species and ecosystems.

Recent international scientific assessments have led to the conclusion that should the anticipated greenhouse warming take place, global sea levels could rise 20 to 165 centimeters over the next century, mainly because of the thermal expansion of oceans. Such an increase would bring about flooding in many coastal areas, induce saltwater intrusion into aquifers, and submerge wetlands, the vital spawning grounds for commercial fisheries. At least 10 to 15 percent of the arable land, populated areas, and economic productivity of such areas could be lost. These estimates do not include the considerably less probable scenarios of the melting of continental ice sheets in the Antarctic and Greenland, which would substantially increase progressive or sudden rises in sea level.

Another probable result of the anticipated rise in global mean temperatures would be a decrease in the natural thermal gradient on the earth’s surface between the poles and the equator. A likely result will be major shifts in the global patterns of wind and ocean currents.

Why the development community should be concerned

Confronted by serious risks that may be menacing, cumulative, and irreversible, uncertainty argues strongly in favor of action and against complacency. There is a real choice (Waltz 1987). The world can continue with business as usual or it can reassess policies and resource commitments - in light of the risk of climate change, but with a view to endorsing precisely those actions that make economic, social, and environmental sense on their own merits. This approach can help buy time in which to learn more about the climatic and policy responses that might make sense later and can help us prepare for them if necessary. As Louis Pasteur stated, “In science, chance favors the prepared mind.”

Several factors may influence the efforts of individual countries to deal with the greenhouse problem and to reach the international consensus needed:

· Industrialization is indisputably the principal source of trace gas emissions that increase the risk of (and uncertainties about) global climate change.

· The effects of climate change are likely to be widely dispersed.

· Some countries are far more dependent than others on such natural resources and systems as agriculture, forests, fisheries, and monsoon patterns - systems that depend heavily on climate. And these countries often have far fewer resources available for adapting to or mitigating change than other countries do. They are also more vulnerable to such natural disasters as floods, drought, violent storms, and rising sea levels (Gleick 1987).

· Developing countries have a greater need to increase their energy resources, so they also need to focus on policies and measures to mitigate the greenhouse effect.

The stability domain of the present climate system is unknown, so a critical threshold to turbulent change might inadvertently (perhaps avoidably) be crossed. But the climate system, like all systems, also has an inherent resiliency. Doing the right things now may increase our chances of avoiding truly disruptive climate change altogether.

Opportunities in economic development

Delay could mandate more extreme policy measures later, so taking action now seems prudent. Investing in energy efficiency is the best way of “buying” insurance against the hazards of the greenhouse threat, particularly since many options are economically, technically, and politically feasible. Failure to buy this insurance could increase both the risk and the cost of disaster, especially if there is a flip-flop in the climate system. Investing in energy efficiency is not only the quickest and most effective alternative for mitigating the greenhouse problem, it is also the least expensive (Keepin and Kats 1988, Goldemberg and others 1988).

Decisionmakers face the task of determining what specific investments or policies must take the risk of climate change into account (Waltz 1987). If industrial growth and energy demand take off as expected in many countries, without improving energy efficiency or restraining the use of chlorofluorocarbons, the result will be far more greenhouse gas emissions than are technically needed to meet the goals of development.

Agriculture generates less greenhouse gas than industry does. The stock of carbon in existing forests is about equal to the quantity of carbon now in the atmosphere, but the planet’s storehouse of known fossil fuels contains at least 15 times more carbon than either forests or the atmosphere. So deforestation or forestation alone can play only a minor role decreasing carbon dioxide levels in the atmosphere. The extensive burning of rainforests does emit substantial amounts of methane and methane-enhancing carbon monoxide, so reversing policies that encourage such burning should be a high priority. Other opportunities for mitigating the risk of, or adapting to, climate change are discussed below.

Mitigating climatic risks

The climate system is resilient but this resilience is at growing risk of being overwhelmed if steps are not taken to reduce global accumulations of greenhouse gases. One risk is the possibility of abrupt and turbulent transitions, the final outcomes of which are unpredictable and adaptations to which are seriously constrained. The best strategy would be to reduce the risk of turbulent change by more aggressively pursuing mitigation measures.


Industrial policy responses can particularly help reduce emissions of carbon dioxide and chlorofluorocarbons (CFCs). And energy efficiency policies, including those for reducing CO emissions, may significantly reduce the atmosphere’s methane content (Arrhenius 1986). Methane emissions through leakage are prominent in the transport and mining of fossil fuels and the generation and distribution of natural gas (Abrahamson 1989). Fortunately, most leaks can be remedied by adopting improved leakproof natural gas handling systems and technologies.

The anaerobic breakdown of organic material in urban sewage, landfill, and agricultural waste also emits a great deal of methane. The controlled burning of such methane - preferably in association with energy production - would shift the net mix of greenhouse gases away from more absorptive methane toward less absorptive carbon dioxide, while increasing the total supply of energy.

Economic sensitivity analyses and uncertainty studies with global models confirm that end-use energy efficiency is the single most important technological factor determining future carbon dioxide and carbon monoxide emissions (Keepin and Kats 1988, Goldemberg and others 1988). And considerable emissions reductions are possible outside the energy industry. For example, 17 percent of global carbon emissions are associated with energy production to heat, cool, and light buildings. New houses often require as little as 25 percent or less of the energy of earlier designs, and it costs no more to build energy-efficient office buildings than inefficient ones (Rosenfeld and Hafemeister 1988). Recent advances in industrial process control technologies and drive systems, as well as in consumer appliances, offer dramatic opportunities to reduce energy demand and thus emissions of CO and CO2.


The main source of carbon dioxide emissions is the energy sector. Industry (including agriculture) accounts for the largest share of energy use in highly industrialized countries - nearly 43 percent of the energy consumed in the OECD in primary energy equivalent terms in 1985 (Farrell 1987), and nearly 60 percent of total commercial energy production in other countries generally.

The four basic industrial policy response options for reducing CO2 and CO emissions in any economic sector are:

· Energy efficiency and conservation.
· Alternative energy sources.
· Changes in production processes.
· Emission control.

An integrated systems approach to energy policy across all sectors, consistent with sustainable development and the likelihood of climate change, needs to be elaborated. Such an energy strategy must stress increased energy efficiency, synergy among different greenhouse gas emissions (sources and sinks), reduced use of fossil fuels, and the use - where advisable for development - of alternative energy sources such as cogeneration, advanced biomass, and solar, wind, hydroelectric, and possibly nuclear power. Renewable energy technologies such as photovoltaics and hydrogen-based energy, now cost-effective only in limited applications, are rapidly improving in efficiency. Their technical attractiveness in particular applications, such as long-range energy transport and storage, should improve their market potential in industrialized countries, which could stimulate their earlier adaptation by developing countries.

Many developing countries are now beginning a period of rapid expansion in energy- and materials-intensive industries, as they strive to raise their living standards. The industries of many of these countries are far less energy-efficient than those in developed countries. To a certain extent, this energy differential is the result of government subsidies, inappropriate technologies, and poor management skills. Reforms in energy pricing can reduce costs by reducing energy use and can also reduce environmental damage.

A recent study demonstrated that a $10 billion investment in cost-efficient improvements in electricity end use could reduce expected demand for new generating capacity by 22 gigawatts. The capital cost for installing 22 GW of additional capacity would be about $40 billion (Keepin and Kats 1988, Geller 1986, Geller and others 1988, Goldemberg and others 1988).

A related study of energy conservation options in Brazil showed that relatively low electricity tariffs - particularly for industrial customers - were a strong disincentive to investments in conservation. Brazil assembled more efficient air conditioners for export than it produced for sale at home. A 300 percent trade tariff on imported rotary compressors used in the air conditioners effectively inhibited their sale and use within Brazil (Geller and others 1988).

Changes in manufacturing industry process control technologies can measurably reduce CO2 emissions. In the cement industry, for example, where world production has been increasing at an average annual rate of about 6 percent since the 1950s, a variety of cement manufacturing alternatives exist, some of which release more CO2 than others (Goldemberg and others 1988). Carbon dioxide is emitted in the calcining phase of cement-making, when calcium carbonate (CaCO3) is converted to lime (CaO). For every ton of cement produced, 0.14 tons of carbon are emitted as CO2 from this reaction. Generally, even more CO2 is emitted from the fuel used to drive the process.

The energy requirements for cement-making vary from a low of 4 gigajoules per ton in Sweden and Japan to 7 gigajoules per ton in the United States. Energy is used to heat the kiln and grind the raw materials and clinker. Energy requirements vary for dry and wet methods of production. The wet method is more costly as water is added and must be evaporated afterwards, which requires more energy per ton produced. Other technologies - such as suspension preheaters, flash calcining, cold processing, or using less energy-intensive cement than Portland cement - can all reduce the energy costs of cement production 10 to 15 percent (Goldemberg and others 1988).

CO2 emissions are thought to be largely irreversible. The U.S. Electric Power Research Institute (EPRI) estimates that deep ocean burial of CO2 emissions would cost about $426 billion - to eliminate only 30-35 percent of U.S. emissions. So it appears doubtful that, even if proven technically feasible, such technologies would be economical.

Other policy options for reducing carbon dioxide include such emission control interventions as carbon fuel taxes and tightening automobile fuel efficiency standards.

Reducing chlorofluorocarbon emissions

The Montreal Protocol for the Protection of the Ozone Layer, which went into effect on January 1, 1989, calls for staged reductions in consumption, production, and trade in CFCs. Its effectiveness will depend upon the level of participation and compliance. Despite any drop in emissions resulting from implementation of the protocol, the greenhouse effects of CFCs maybe expected to linger because of CFC survival rates of 65 to 110 years in the lower atmosphere (Bach 1988). Compliance standards for developing countries, based on per capita measures, are more lenient than for other countries. Replacement technologies either exist or can be developed for most CFC applications, albeit at some cost - and it will take some time. In the meantime, countries can agree not to export inefficient and obsolete CFC-leaking technologies to other countries.

The issue of chlorofluorocarbon emissions and ozone depletion is closely related to the greenhouse issue, but is different in important ways. Mechanisms to mitigate ozone depletion include producing CFCs with shorter lifespans, thereby preventing them from ever reaching the ozone layer. The greenhouse effect of these more short-lived CFCs is still substantial, however, and in the short term (10-20 years) is almost equal to that of present CFCs. Thus, the introduction of these short-lived CFCs would resolve the ozone depletion issue, while the greenhouse effect of CFCs would remain the same. Thereby, one of the cheapest instruments for reducing the risk from climate change is lost.


The proportionate size of the various compartments of the carbon cycle have important implications for greenhouse warming in the agricultural sector. The amount of carbon in the atmosphere is roughly comparable to the amount in the biosphere, and the amount in soils is half again (1.5 times) as much as either. By contrast, 15 times as much carbon as is found in the atmosphere is stored in the ground as fossilized carbon and peat, and an overwhelming 75 times as much carbon is stored in the oceans.

Reversing the trend toward deforestation could be a cost-effective means of reducing net carbon dioxide emissions in many countries. Policy attention should be given to shifting cultivation, the use of fuelwood, and land use property rights. The destruction of tropical rainforests to develop agriculture and livestock releases large amounts of carbon monoxide, carbon dioxide, and methane - thus amplifying the impact of deforestation by enhancing atmospheric concentrations of methane. But most greenhouse gases are produced by the highly industrialized sectors. The practical potential for modifying the greenhouse effect through deforestation or reforestation is ultimately limited and should be kept in proper perspective.

Reforestation attempts, however, must compete against other demands for land use within the biosphere and must allow for the fact that to remain effective over the long term, the carbon must somehow be sequestered and the process renewed as the trees mature. Efforts to reduce emissions and increase sinks for carbon would be improved if agricultural techniques could be developed to exploit soil’s inherent capacity to store carbon by gradually increasing its organic components. Such opportunities are likely to be greatest in the developing world, where much of the land has already been seriously degraded. They would not compete with the efficient productive use of land.

Methane emissions from ruminating livestock could be reduced by an estimated 25 to 75 percent (Gibbs and Lewis 1989). Methane production from ruminants is probably caused by inappropriate cattle breeding and feeding and by unsuitable environments in stables in intensive animal husbandry. The potential range for converting carbon intake to methane in animal husbandry is large, because output (milk, carcasses, and manure) represents only 10 to 25 percent of the input (feed) in energy content. The livestock industry has not begun reducing methane emissions from animal husbandry (Arrhenius 1986). It is technically feasible, but livestock produce only 15 percent of all methane and contribute only 3 percent of the greenhouse effect.

Adjusting to climatic risk


The risks of climatic change are so imprecisely described that it is neither possible nor desirable to invest now in specific local and regional projects anticipating climatic transformation. But the increasing likelihood of climatic changes suggests the prudence of considering the economic and financial feasibility of building more resilience into the planning and design of industrial and energy infrastructure. The least probable scenario is “no climate change.” It may pay to scale down or delay large or long-lived projects - buying time with smaller, shorter-lived ones - to observe what actually happens climatically in particular regions and countries.


If ocean levels were to rise because of thermal expansion, rising seas would inundate coastal areas and could decimate large areas of coastal wetland. The economic threat to coastal wetlands alone could be hundreds of billions of U.S. dollars.

In the years ahead, the costs of shoreline protection may rise and the relative effectiveness of alternative measures could change. A one-foot rise in sea level would erode most shorelines more than 100 feet, by some estimates. What this means for coastal, especially delta, communities hardly needs elaboration. Proposals for building or expanding ports, coastal cities, housing, or coastal developments or engaging in coastal agricultural activities - any of which could seriously affect economic development because of their multiplier effects on employment and incomes - should be reconsidered. Smaller, more flexibly designed projects with shorter lifetimes are strategically advantageous for planning such projects as dams, irrigation, and ports.

With changes in precipitation, water supplies for irrigation, dams, and sewage systems might all be threatened. With climate change, the recharging of groundwater reserves could obviously be a serious problem that should be kept in mind in defining the scale of infrastructure projects that involve water resources, such as dams, irrigation, and sewage facilities.


In agriculture, the uniformity of plant gene pools and the mechanized synchronization of plant growth and development have made crops more vulnerable to large-scale shifts in weather systems (Rosenberg 1987, Rosenberg and others 1989). Climate change itself may threaten the survival of the natural (wild) gene pool, so we must systematically ensure that an adequate gene pool survives and is sustained. Climatic change also makes crops and livestock vulnerable to extreme weather events such as floods, drought, pests, disease, and soil erosion.

In past long-term temperature changes, forest boundaries have shifted as fast as 1 kilometer a year. Computer-simulated projections of greenhouse-related global increases in surface temperature for the next century suggest faster changes than paleoclimatic records indicate as having occurred before the industrial era. These projections imply that suitable growing areas for forests and agricultural products could shift at an unprecedented pace. This would disrupt mainly forests and unmanaged ecosystems. It is not too early to begin thinking about how such processes might affect investments in agriculture and forestry.


As the risk of hydrological and temperature change increases, so does the potential for worrisome shifts in vector diseases that threaten animal and human populations. Patterns in nutrition, famine, morbidity, mortality, and migration could also change. Investment planning should address such risks.

The key: energy efficiency

The right energy policies in the next few decades could substantially mitigate global warming through greenhouse gas emissions. Energy efficiency, particularly in end uses, appears to be essential for coping with climatic change. And energy conservation makes good economic and environmental sense.

Uncertainties prevent us from knowing how a given level of emissions will affect the rate and magnitude of climate change. And uncertainties about the impact of greenhouse gas buildup are pervasive. But the uncertainties are not about whether the greenhouse effect is real or could raise global temperatures, but about the magnitude and timing of warming regionally and the prospects for cooperatively resolving the results globally.

We can guess about when various levels of warming will occur based on choices we might make now and later. Delaying policy moves toward energy efficiency would substantially increase the global potential for future warming. Fortunately, technical options are available that - if necessary and given sufficient political and economic will - could stabilize greenhouse gas emissions.

Most countries could significantly improve their production efficiency in greenhouse-gas-emitting industries. Such steps would be economically worthwhile even if climatic change were not a risk. But atmospheric emissions could escalate in many countries, so it is crucial for all countries to help stabilize the level of greenhouse gases.

The sooner the international community becomes committed to increasing energy efficiency in all sectors of the global economy - especially end-use energy efficiency - the more time we will have to cushion the inevitable adjustments that may ultimately have to be made by the most vulnerable economic sectors and geographic regions of the world.