More Americans now believe in global warming

<i>This post has been corrected, as indicated below.</i>

After several years of finding that fewer and fewer Americans believed in climate change, pollsters are now finding that belief is on the uptick.

The newest study from the National Survey of American Public Opinion on Climate Change, which is a biannual survey taken since fall 2008 and organized by the Brookings Institute, shows that 62% of Americans now believe that climate change is occurring, and 26% do not. The others are unsure.

That is a significant rise in believers since a low in spring 2010, when only about 50% of Americans said they believed in global warming, but still down from when the survey first began, when it was at around 75%. The pollsters talked to 887 people across the country.


What’s caused the sudden rise? Mostly the weather.

“People, for good or for bad, are making connections in what they see in terms of weather and what they believe in terms of climate change,” said Christopher Borick, co-author of the survey. He is an associate professor of Political Science and director of the Muhlenberg College Institute of Public Opinion in Pennsylvania. His co-author is Barry Rabe, a senior fellow at the Brookings Institute and a professor at the University of Michigan.

The years 2009 and 2010 saw cold, nasty winters across the country, and seemed to indicate to a lot of people – rightly or wrongly – that they weren’t feeling any increase of temperatures. That helped drive down belief in climate change. But 2011 was a super-hot year, bad drought, with record-breaking precipitation in the Northeast, lots of weird weather. Public opinion? Must be climate change.

This shows how fickle public opinion can be. For instance, when people who say they believe in climate change were asked if the idea of “drought” affected their decision, their answer depended on their own experience. If they lived in places like Texas, Oklahoma and the South, they were about 15 to 17 points more likely to say drought affected their beliefs than other believers in Pennsylvania or New Jersey.

The danger, of course, is that neither individual weather events nor even an entire season of strange weather are any indication of long-term trends. Those who believe that the planet is warming did say that factors beyond weather, such as polar bear decline, did affect their decisions. In general, however, scientific studies weren’t high on the list of influences among people polled.

“People specifically pointing to scientific studies only make up about 1 in 10 of the population,” said Borick. “That doesn’t meant that science doesn’t weigh in, but it tends to be down the list of factors. And significantly behind things like observations of warmer temperatures in their home areas.”

Weather wasn’t the only reason belief in climate change declined steeply beginning in late 2008. There was also the effect of climate science doubters.


“Our poll, Pew, Gallup, others, saw it drop by about 20 points in about 2 years, which is really odd. You see it with presidential approval levels, you see it with views on transient subjects, but on long-term things, it just doesn’t happen like that. A lot of people mentioned the increased polarization of the subject. Since 2008, there were some really concerted efforts on the part of several groups and interests to discredit climate change. All of these things had a role in chipping away at the levels of belief in the country.”

When participants in the Brookings study said they believed in climate change, they were asked a follow-up question about what they believed to be the cause. Borick noted that about 75 % of participants said they believed that climate change was human-caused, about 20 % thought it was part of a natural cycle, and about 5 % didn’t know.

The overwhelming majority of scientific studies on this subject agree that human activity is causing the rise in mean temperatures around the world.

[For the record, 11:55 a.m., March 9: An earlier version of this post said that 62% of respondents believed that “man-made” global warming was occuring, but actually those who believe that global warming is man-made comprise three-fourths of that total.]


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