Three out of four Americans believe our planet has been warming as the result of human activity, down from the 84 percent who said so in 2007, according to survey results released today.
"Several national surveys released during the last eight months have been interpreted as showing that fewer and fewer Americans believe that climate change is real, human-caused and threatening to people," said Woods Institute Fellow Jon Krosnick, of Stanford University. "But our new survey shows just the opposite."
With funding from the National Science Foundation, Krosnick conducted the survey from June 1-7, including telephone interviews with 1,000 randomly selected adults.
When asked if the Earth's temperature probably had been heating up over the last 100 years, 74 percent of the respondents said yes. And 75 percent said that human behavior was substantially responsible for any warming that has occurred.
Behind the shifts
As for the decline between 2007 and now, Krosnick said it 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, Krosnick said, adding that these year-to-year fluctuations in temperature aren’t meaningful in the overall picture of Earth’s climate trends.
Even so, "people who do not trust climate scientists base their conclusions on their personal observations of nature," Krosnic said. "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."
The decline in those who support the idea that global warming is occurring is just temporary, Krosnic said, adding that if the temperatures on Earth increase again, so will this group's leaning with the large majority who agree our planet is on a warming trend.
The so-called climategate controversy, in which e-mail messages were hacked from the computer system at the University of East Anglia in England and characterized climate scientists as colluding to silence unconvinced colleagues, made headlines in December 2009 and had many suggesting it would negatively impact the public’s view of the validity of climate-change science.
That didn't bear out in this survey, with only 9 percent of respondents saying they knew about the East Anglia e-mail messages and believing they indicate that climate scientists should not be trusted. Only 13 percent said the same about the controversial Intergovernmental Panel on Climate Change (IPCC) reports. There was some controversy over a few errors in the reports that scientists have said are minor in the grand scope of climate science and do not change the fundamental findings of the report.
"Overall, we found no decline in Americans' trust in environmental scientists," Krosnick said. "Fully 71 percent of respondents said they trust scientists a moderate amount, a lot or completely."
Results also suggest Americans support government action to combat global warming, including:
- 86 percent of respondents said they wanted the federal government to limit the amount of air pollution businesses emit;
- 78 percent opposed taxes on electricity to reduce consumption, and 72 percent opposed taxes on gasoline;
- 84 percent favored the federal government offering tax breaks to encourage utilities to use more alternative energy sources, such as making electricity from water, wind and solar power;
- 4 out of 5 respondents favored the government requiring or offering tax breaks to encourage the production of cars that use less gas (81 percent), appliances that use less electricity (80 percent) and homes and office buildings that require less energy to heat and cool (80 percent);
- And only 14 percent said that the United States should not take action to combat global warming unless other major industrial countries, such as China and India, do so as well.
However, a recent survey by esearchers at Yale and George Mason universities found that while most Americans like the idea of conservation, few practice it in their everyday lives.