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close this bookDisaster and the Environment - 1st edition (Department of Humanitarian Affairs/United Nations Disaster Relief Office - Disaster Management Training Programme - United Nations Development Programme , 1993, 60 p.)
close this folderPART 2. The human dimensions of environmental change
View the document(introduction...)
View the documentThe impact of humanity
View the documentThe effect of hazards on the environment and factors contributing to vulnerability

The impact of humanity

Brazil’s Atlantic forest, which once covered a million square kilometers, is now only 7% of its original size.

Humans began to alter the earth’s environment thousands of years ago, first through the use of simple tools for hunting and gathering, and then later with more complex tools as plants were cultivated. All over the world, evidence exists of human intervention. Almost no remnants of the original vegetation remain around the Mediterranean Sea. In England, 90% of the forest has vanished. Brazil’s Atlantic forest, which once covered a million square kilometers, is now only 7% of its original size.

The major driving forces which influence human interaction with the environment may be roughly grouped as shown below. A great deal remains unknown about the interrelationships of these driving forces and how they combine to effect the environment.

Population growth

The global population doubled between 1950 and 1987, from 2.5 billion to 5 billion. Reaching the first 2.5 billion took the human species from its beginnings up to 1950; the second 2.5 billion took less than 40 years. United Nations’ estimates place the world population at 8.5 billion by 2025 and 10 billion by 2100.

Figure 5 Population growth, 1750-2100.

Source: Thomas Merick, et. al., “World Population in Transition,” Population Bulletin, Vol. 42, No. 2 (1986).

Each person in the world demands from the environment food, water, clothing, and shelter - among other needs. Logically, the more people, the greater the demand will be on the environment. Each person in a developed country uses far more natural resources than a person from a developing country; however, this apparent disparity is somewhat altered by the prediction that 95% of future population growth will occur in developing countries, where resources are already strained.


An estimated 60% of the developing world’s poor live in areas vulnerable to environmental change, such as hillsides and tropical forests

The world’s poor are increasing in number at a more rapid rate than the general population and are the most vulnerable because of the substandard buildings and sites that they inhabit. As do the rest of the world’s inhabitants, the poor depend on the environment and are often forced to degrade it to survive. Due to rapid population growth, the modernization of agriculture and unequal land tenure, increasing numbers of people have little or no access to productive land and are pushed to marginal areas. An estimated 60% of the developing world’s poor live in areas vulnerable to environmental change, such as hillsides and tropical forests (World Resources Institute).


The desperation induced by poverty prevents the consideration of sustainable environmental practices, and the cycle of poverty intensifies as the land loses its productivity and biological resources. The poor also tend to have more children - to increase the family labor force and provide security for old age.

Economic growth

Economic growth historically has affected the state of the environment but, for the first time in human history, human economic activity is so extensive that the global environment is changing. Future environmental outcomes depend on the way societies choose to use resources - such as the types of industries promoted, the amount of land used for agriculture, the amount and types of energy consumed, the way industrial and human wastes are managed. These choices are intricately connected with economic and political structures, social values and norms. Economic growth, however, is clearly necessary to improve standards of living for the poor and give everyone access to education, health care and employment.

Increasing urbanization

A significant percentage of the gross domestic product (GDP) of many countries is generated in urban areas. As conditions become less favorable for agricultural production, and as populations increase, people from rural areas move to cities to find job opportunities and services. The world’s urban population will grow significantly in the future. Today, one quarter of all city dwellers now live below the poverty line; this proportion is also expected to increase.

Cities impose tremendous pressures on environmental resources, particularly air and water. Traffic congestion in Cairo and Mexico City causes serious air pollution. Karachi and Bombay experience chronic water shortages. In developing countries, improvement of the infrastructure cannot keep pace with growth, a situation that limits productivity and results in extensive urban poverty. Cities are expanding rapidly into peripheral areas, claiming agricultural lands but also becoming more densely populated. The density of buildings and people increase the risks associated with disasters.

Figure 6 Population projections for some disaster-prone cities

Technological change

The types of technology that societies use will ultimately determine how the environment will be impacted. In many industrialized countries, technologies that control emissions have significantly improved the air and water in urban areas. As developing countries grow, the types of technologies chosen will influence the amounts of energy consumed and pollution generated.

Political-economic institutions

Markets, governments, and international political economies affect the environment, as do policies and economic structure at the national level. Unequal access to land and other natural resources, to education, financial credit, social services and political rights worsen poverty and create barriers to development.

Conversely, incentives can be provided for environmental protection. The economic choices made by governments can indirectly or directly lead to either environmental preservation or degradation. These include the percentages of national budgets allocated to development needs and the latitude given to economic ventures to earn foreign currency.

Attitudes and beliefs

Beliefs and values, as they relate to material possessions, are frequently the root cause of environmental degradation, often having the greatest effects over generations of human lives. These attitudes and beliefs may have more influence over individual use of resources in some areas than social or economic variables.

Q. What are the major driving forces that influence human interaction with the environment? In terms of your own country, discuss the negative and positive effects of each of these driving forces. Discuss the relationships between economic growth, the urbanization trend and the expected increase in the percentage of urban poor.

A. _____________________________________________________________


Population growth,
poverty, economic
growth, urbanization,
technological change,
institutions, and attitudes
and beliefs