When surveys other than ours have asked simple and direct questions, they have produced results similar to ours. For example, in November, an ABC News/Washington Post survey found that 72 percent of respondents said the earth has been heating up, and a December poll by Ipsos/McClatchy found this proportion to be 70 percent.

Our surveys did reveal a small recent decline in the proportion of people who believe global warming has been happening, from 84 percent in 2007 to 80 percent in 2008 to 74 percent today. Statistical analysis of our data revealed that this decline is attributable to perceptions of recent weather changes by the minority of Americans who have been skeptical about climate scientists.

In terms of average earth temperature, 2008 was the coldest year since 2000. Scientists say that such year-to-year fluctuations are uninformative, and people who trust scientists therefore ignore this information when forming opinions about global warming’s existence. Citizens who do not trust climate scientists, however, base their conclusions on their personal observations of nature. These low-trust individuals were especially aware of the recent decline in average world temperatures; they were the ones in our survey whose doubts about global warming have increased since 2007.

This explanation is especially significant, because it suggests that the small recent decline in the proportion of people who believe in global warming is likely to be temporary. If the earth’s temperature begins to rise again, these individuals may reverse course and rejoin the large majority who still think warming is real.

Growing public skepticism has, in recent months, been attributed to news reports about e-mail messages hacked from the computer system at the University of East Anglia in Britain (characterized as showing climate scientists colluding to silence unconvinced colleagues) and by the discoveries of alleged flaws in reports by the Intergovernmental Panel on Climate Change.

Our new survey discredited this claim in multiple ways. First, we found no decline in Americans’ trust in environmental scientists: 71 percent of respondents said they trust these scientists a moderate amount, a lot or completely, a figure that was 68 percent in 2008 and 70 percent in 2009. Only 9 percent said they knew about the East Anglia e-mail messages and believed they indicated that climate scientists should not be trusted, and only 13 percent of respondents said so about the I.P.C.C. reports’ alleged flaws.

Interestingly, Americans are not alone in having their views portrayed inaccurately. A February BBC News survey asked Britons, “From what you know and have heard, do you think that the earth’s climate is changing and global warming is taking place?” Seventy-five percent of respondents answered affirmatively, down a somewhat improbable eight percentage points from 83 percent in November. A BBC headline blared, “Climate Skepticism on the Rise,” when it should have proclaimed that a huge majority of Britons still share common ground with one another and with Americans on this issue.