Petroleum

In light of the reserves available and the dismal projections, it is apparent that alternative energy sources will be required to sustain the civilized societies of the world in the future. The options are indeed few, however, when the massive energy requirements of the industrial world come to be appreciated.

Although alternative energy sources, such as geothermal energy, solar energy, and nuclear energy, hold much promise, none has yet proved an economically viable replacement for petroleum products.

Adding to the urgency of finding alternatives to petroleum and other fossil fuels is the problem of global warming. Petroleum combustion releases carbon dioxide, a greenhouse gas, into the atmosphere, and most atmospheric scientists believe that rising levels of greenhouse gases are driving climate change. These changes could cause numerous environmental problems, including disrupted weather patterns and polar ice cap melting. Disrupted weather patterns could lead to extensive drought and desertification. Polar ice cap melting could cause flooding and profound changes in ocean circulation. Many environmental organizations are urging governments and individuals to reduce greenhouse gas emissions by conserving energy with fuel-efficient technologies and by developing alternative, renewable energy sources such as wind and solar power. In the United States most environmental groups have urged the U.S. government to ratify the Kyōto Protocol, a global treaty that sets a specific timetable for reducing greenhouse gas emissions. See also Ocean and Oceanography.

Drilling oil wells also creates environmental problems because the petroleum pumped up from deep reservoir rocks is often accompanied by large volumes of salt water. This brine contains numerous impurities, so it must either be injected back into the reservoir rocks or treated for safe surface disposal. The extraction of unconventional crude oil sources, such as bitumen, poses even greater environmental problems due to the large number of pollutants produced and the use of fossil fuels involved in the extraction.

Petroleum usually must also be transported long distances by tanker or pipeline to reach a refinery. Transport of petroleum occasionally leads to accidental spills. Oil spills, especially in large volumes, can be detrimental to wildlife and habitat.