Capturing Greenhouse Gases; February 2000; Scientific American Magazine; by Herzog, Eliasson, Kaarstad, sidebars by Martindale and Keith, Parson; 8 Page(s)
The debate over climate change has shifted. Until very recently, scientists still deliberated whether human activity was altering the global climate. Specifically, was the release of greenhouse gases, which trap heat radiating from the earth's surface, to blame? With scientific evidence mounting in favor of the affirmative, the discussion is now turning to what steps society can take to protect our climate.
One solution almost certainly will not succeed: running out of fossil fuels-namely, coal, oil and natural gas. Morris Adelman, professor emeritus at the Massachusetts Institute of Technology and expert on the economics of oil and gas, has consistently made this point for 30 years. In the past century and a half, since the beginning of the industrial age, the concentration of carbon dioxide in the atmosphere has risen by almost one third, from 280 to 370 parts per million (ppm)-primarily as a result of burning fossil fuels. In the 1990s, on average, humans discharged 1.5 ppm of carbon dioxide annually; with each passing year, the rate increased. Even though humans release other greenhouse gases, such as methane and nitrous oxide, experts project that carbon dioxide emissions will account for about two thirds of potential global warming. As apprehension has grown regarding the possible hazards of a changing global climate, environmental groups, governments and certain industries have been trying to reduce the level of greenhouse gases in the atmosphere, often by promoting energy efficiency and alternative energy sources-for instance, wind or solar power.