Almost three in four of Americans accept recent global warming, according to a new poll conducted for the Washington Post and Stanford University — but only three in ten agree that it is mainly due to human activity.
Asked "Do you think that the world's temperature probably has been going up ["slowly" was used with half of the sample] over the past 100 years, or do you think this probably has not been happening?" 73% of respondents said yes, 25% of respondents said no, and 2% indicated that they didn't know or refused to answer.
Asked (with two different wordings) about the cause of the rise in the world's temperature, 30% agreed that it was due mostly to human activity, 22% agreed that it was due mostly by natural causes, 47% agreed that it was due about equally to human activity, and 1% indicated that they didn't know or refused to answer.
Asked "How much do you trust the things that scientists say about global warming?" 6% of respondents responded "completely," 22% "a lot," 33% "a moderate amount," 26% "little," 11% "not at all," and 1% indicated that they didn't know or refused to answer.
For the first two of these questions, about the rise in the world's temperature and its cause, the report of the poll provides comparable data extending back to March 2006; the third question, about trusting scientists about global warming, was new.
According (PDF) to the report of the poll, it "was conducted by telephone June 13 to 21, 2012, among a random national sample of 804 adults, including landline and cell phone-only respondents. The results from the full survey have a margin of sampling error of plus or minus 4.5 percentage points."