By JON A. KROSNICK
Published: June 8, 2010
ON Thursday, the Senate will vote on a resolution proposed by Lisa Murkowski, Republican of Alaska, that would scuttle the Environmental Protection Agency’s plans to limit emissions of greenhouse gases by American businesses.
Passing the resolution might seem to be exactly what Americans want. After all, 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.
But a closer look at these polls and a new survey by my Political Psychology Research Group show just the opposite: huge majorities of Americans still believe the earth has been gradually warming as the result of human activity and want the government to institute regulations to stop it.
In our survey, which was financed by a grant to Stanford from the National Science Foundation, 1,000 randomly selected American adults were interviewed by phone between June 1 and Monday. When respondents were asked if they thought that the earth’s temperature probably had been heating up over the last 100 years, 74 percent answered affirmatively. And 75 percent of respondents said that human behavior was substantially responsible for any warming that has occurred.
For many issues, any such consensus about the existence of a problem quickly falls apart when the conversation turns to carrying out specific solutions that will be costly. But not so here.
Fully 86 percent of our respondents said they wanted the federal government to limit the amount of air pollution that businesses emit, and 76 percent favored government limiting business’s emissions of greenhouse gases in particular. Not a majority of 55 or 60 percent — but 76 percent.
Large majorities opposed taxes on electricity (78 percent) and gasoline (72 percent) to reduce consumption. But 84 percent favored the federal government offering tax breaks to encourage utilities to make more electricity from water, wind and solar power.
And huge majorities favored government requiring, or offering tax breaks to encourage, each of the following: manufacturing cars that use less gasoline (81 percent); manufacturing appliances that use less electricity (80 percent); and building homes and office buildings that require less energy to heat and cool (80 percent).
Thus, there is plenty of agreement about what people do and do not want government to do.
Our poll also indicated that some of the principal arguments against remedial efforts have been failing to take hold. Only 18 percent of respondents said they thought that policies to reduce global warming would increase unemployment and only 20 percent said they thought such initiatives would hurt the nation’s economy. Furthermore, just 14 percent said the United States should not take action to combat global warming unless other major industrial countries like China and India do so as well.
Our findings might seem implausible in light of recent polls that purport to show that Americans are increasingly skeptical about the very existence of climate change. But in fact, those polls did not produce conflicting evidence at all.
Consider, for example, the most publicized question from a 2009 Pew Research Center poll: “From what you’ve read and heard, is there solid evidence that the average temperature on earth has been getting warmer over the past few decades, or not?” This question measured perceptions of scientific evidence that the respondent has read or heard about, not the respondents’ personal opinions about whether the earth has been warming. Someone who has had no exposure to scientific evidence or who perceives the evidence to be equivocal may nonetheless be convinced that the earth has been heating up by, say, the early blossoming of plants in his garden.
Or consider a widely publicized Gallup question: “Thinking about what is said in the news, in your view, is the seriousness of global warming generally exaggerated, generally correct or is it generally underestimated?” This question asked about respondents’ perceptions of the news, not the respondents’ perception of warming. A person who believes climate change has been happening might also feel that news media coverage of it has been exaggerated.
Questions in other polls that sought to tap respondents’ personal beliefs about the existence and causes of warming violated two of the cardinal rules of good survey question design: ask about only one thing at a time, and choose language that makes it easy for respondents to understand and answer each question.
Imagine being asked this, from a poll by CNN: “Which of the following statements comes closest to your view of global warming: Global warming is a proven fact and is mostly caused by emissions from cars and industrial facilities like power plants and factories; global warming is a proven fact and is mostly caused by natural changes that have nothing to do with emissions from cars and industrial facilities; or, global warming is a theory that has not yet been proven.”
Notice that the question didn’t even offer the opportunity for respondents to say they believe global warming is definitely not happening — not the sort of question that will provide the most valid measurements.
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.
GLOBAL warming has attracted what political scientists dub an “issue public”: millions of Americans who are passionate about this subject and put pressure on government to follow their wishes. For over a decade, this group has been of typical issue-public size, about 15 percent of American adults.
Although issue publics usually divide about equally on opposing sides — think of abortion or immigration — 88 percent of the climate change issue public in our survey believed that global warming has been happening; 88 percent attributed responsibility for it to human action; 92 percent wanted the federal government to limit the amount of greenhouse gases that businesses can emit. Put simply, the people whose votes are most powerfully shaped by this issue are sending a nearly unanimous signal to their elected representatives.
All this makes global warming a singular issue in American politics. Even as we are told that Americans are about equally divided into red and blue, a huge majority shares a common vision of climate change. This creates a unique opportunity for elected representatives to satisfy a lot of voters.
When senators vote on emissions limits on Thursday, there is one other number they might want to keep in mind: 72 percent of Americans think that most business leaders do not want the federal government to take steps to stop global warming. A vote to eliminate greenhouse gas regulation is likely to be perceived by the nation as a vote for industry, and against the will of the people.
Jon A. Krosnick is a professor of communication, political science and psychology at Stanford.