The Mauna Loa or Keeling curve. Credit: Robert A. Rhode, Global Warming Art

The extraction, processing and use of energy are major sources of environmental stress at global, regional, and local levels. Atmospheric releases from fossil fuel energy systems comprise 64 per cent of global anthropogenic carbon dioxide emissions from 1850-1990, 89 per cent of global anthropogenic sulfur emissions from 1850 to 1990, and 17 per cent of global anthropogenic methane emissions from 1860-1994.

Fossil energy combustion also releases significant quantities of nitrogen oxide. Power generation using fossil fuels, especially coal, is a principal source of trace heavy metals such as mercury, selenium, and arsenic. These emissions drive a range of global and regional environmental changes, including global climate change, acid deposition, and urban smog.

Upstream energy sectors also have significant local impacts on the environment. Coal mining disturbs vast areas of natural habitat. In the U.S., for every ton of coal mined, 6 additional tons of overburden and waste are generated. The exploration for and extraction of oil and natural gas can have significant impacts, particularly in sensitive ecosystems such as wetlands and tundra, and it releases hazardous and toxic wastes from drilling and field processing operations. While a potentially renewable source of energy, hydropower development can have significant environmental and social costs depending on its location and mode of development. Between 30 and 60 million people—the majority residing in China and India—have been displaced by large dams; about 500,000 square kilometers of land—almost the size of France—are covered by large hydroelectric reservoirs. Much of this is river valley land that supports fertile farmland and diverse forest and wetland ecosystems.

Indoor air pollution from biomass fuels burned in inefficient cook stoves is major health hazard. Credit: UNEP More than half of the world’s population rely on dung, wood, crop waste or coal to meet their most basic energy needs. Cooking and heating with such solid fuels on open fires or stoves without chimneys leads to indoor air pollution. This indoor smoke contains a range of health-damaging pollutants including small soot or dust particles that are able to penetrate deep into the lungs. In poorly ventilated dwellings, indoor smoke can exceed acceptable levels for small particles in outdoor air 100-fold. Exposure is particularly high among women and children, who spend the most time near the domestic hearth. The World Health Organization (WHO) describes indoor air pollution as the 8th most important risk factor and responsible for 2.7% of the global burden of disease . Globally, indoor air pollution from solid fuel use is responsible for 1.6 million deaths due to pneumonia, chronic respiratory disease and lung cancer, with the overall disease burden exceeding the burden from outdoor air pollution five fold.

Sources

• World Health Organization, Health Impacts of indoor air pollution, Accessed 18 March 2008.
• International Energy Agency, Energy and Climate Change, Accessed 18 March 2008.

• Slanina, Sjaak (Lead Author); Howard Hanson (Topic Editor). 2006. Impacts of air pollution on local to global scale.  In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [Published in the Encyclopedia of Earth October 18, 2006; Accessed March 24, 2008].