(Excerpt from the New York Times)
Dr. Leiserowitz’s unit at Yale, along with researchers at George Mason University, commissioned the survey, conducted by Knowledge Networks. That company surveyed 1,008 American adults by computer in the last half of March, with a margin of sampling error of plus or minus 3 percentage points.
While many online polls are not representative of the broad public, Knowledge Networks is noted for its efforts to overcome this problem, including giving computers to households too poor to have them. The survey reveals public attitudes that are at least roughly consistent with scientific understanding of how the climate is changing.