Is Global Warming a Myth? How to respond to people who doubt the human impact on the climate
Dear EarthTalk: I keep meeting people who say that human-induced global warming is only theory, that just as many scientists doubt it as believe it. Can you settle the score? -- J. Proctor, London, UK So-called “global warming skeptics” are indeed getting more vocal than ever, and banding together to show their solidarity against the scientific consensus that has concluded that global warming is caused by emissions from human activities. Upwards of 800 skeptics (most of whom are not scientists) took part in the second annual International Conference on Climate Change—sponsored by the Heartland Institute, a conservative think tank—in March 2009. Keynote speaker and Massachusetts Institute of Technology meteorologist Richard Lindzen told the gathering that “there is no substantive basis for predictions of sizeable global warming due to observed increases in minor greenhouse gases such as carbon dioxide, methane and chlorofluorocarbons.” Most skeptics attribute global warming—few if any