|Diversity, Globalization, and the Ways of Nature (IDRC, 1995, 234 p.)|
|9. Clean energy for planetary survival|
The beginning of the 20th century also witnessed the gradual replacement of solid fossil fuels (coal, peat, and lignite) with liquid fuels (petroleum) and, later, gaseous fuels (natural gas) (see box 7). Until the first oil well was drilled - in 1859 in western Pennsylvania, reaching a depth of 21 metres - petroleum was used only marginally. A few decades later, a hundred wells were active throughout the United States and elsewhere.
The growing availability and use of fluid fuels facilitated the development of more standardized means of transportation. In the early 20th century, the invention of the automobile represented a quantum leap in the use of these fuels, which gradually became the main source of energy in industrial countries. By 1950, daily oil consumption reached 11 million barrels, growing to 46 million in 1970. In the 1970s and 1980s, continuing increases in oil consumption were somewhat curtailed by limited availability and higher prices. In the 1990s, however, daily petroleum consumption is high and still increasing.
The pattern of discovery and development of oil fields reveals that continuing increases in petroleum extraction will not be possible for more than a few decades. Even in the most optimistic scenarios, if growing consumption is not curbed, acute scarcity will be felt between 2030 and 2040.
The effects of petroleum exploitation and use are considerable. First, groundwater injected into geological formations to replace extracted oil depletes usable aquifers, some freshwater reservoirs become brackish, and oil spills contaminate other surface and subsurface geological formations.
Second, emissions from burning oil are often responsible for smog, for increased concentration of pollutant gases and aerosols, and for the increase in CO2 levels in the atmosphere. Lately, more efficient oil-burning technology is reducing the amounts of obnoxious emissions; however, there will always be artificial emissions that contribute to the stress on the atmosphere.
Third, handling oil remains a hazardous enterprise. Currently, most petroleum is obtained offshore and transported by sea in large tankers. Accidents can produce environmental catastrophes in oceans, coastal areas, rivers, and lakes. Some oil spills from out-of-control wells may last for weeks and even months; in Kuwait, after the recent Gulf War, over 70 million tonnes of oil poured into the Persian Gulf. Tankers can break or sink, releasing huge volumes of crude oil. In the last 30 years, there have been more than 10 large oil spills in various coastal areas, several of which involved the release of more than 100 thousand tonnes of oil each into the sea: 300 thousand tonnes spilled as a result of the collision of the Atlantic Empress and the Aegean Captain off Trinidad and Tobago in 1979 (Funk & Wagnalls 1994); more than 200 thousand tonnes from the Amoco Cadiz on the coast of Brittany, France, in 1978; 250 thousand tonnes from the Castillo de Beliver in South Africa in 1983; and enough oil from the Exxon Valdez to contaminate 250 square kilometres of Alaskan coastal waters in 1989. As a result of these and other accidents and leakage, floating hydrocarbons have become a common feature of the worlds oceans, affecting the flora and fauna.
7. Alcohol-powered cars In Brazil
In the 1970s, Brazils energy strategy was based on the use of alcohol from sugarcane to power automobiles instead of gasoline. The experience was only partially successful. About half of the countrys automobile fleet was converted to alcohol, but the early growth based on subsidies and support did not continue at the same rate when subsidies were discontinued. Currently, alcohol-fuel consumption is decreasing in Brazil, and nowhere else has alcohol been used for cars in a significant fashion.
The use of alcohol as fuel is not without problems. Although sugarcane is a renewable resource, its cultivation requires large areas of land, soil fertility is affected, erosion increases, and huge volumes of waste are produced. However, although the Brazilian government is abandoning open support for this alternative fuel, alcohol remains a major fuel for automobiles in Brazil.