A few years back, the US public's acceptance of conclusions reached by climate scientists took a dramatic drop. It's only now beginning to recover. Not a lot has changed about the science during that time, raising questions about what's driving the ups and downs in the polls. Studies have found correlations with the weather and a role for political leaders in driving these changes, but a new study suggests some of that is misplaced. Instead, its authors come to a conclusion we've heard before: it's the economy, stupid.
The authors use polling data from a variety of sources, which creates a bit of a challenge. Not all polls ask questions that address the same things. For example, one of the studies we linked above asked about the public's acceptance of a basic fact: has our planet been getting warmer over the past few decades? In contrast, one of the polls used here assessed feelings about climate change by asking its participants whether they felt the media "exaggerate the seriousness of global warming."
Still, there are ways to convert these specific sentiments into a generalized sense about the seriousness of climate change. Plus, the variety of polls provide some distinct advantages. For example, this survey provides a valuable outgroup to the US population, in that a number of surveys cover all the nations of the European Union. In addition, several of the polls (those performed by the Pew) include ZIP code information, allowing the authors to compare polling trends with record high and low temperatures in the nearby area.
As with another recent survey, they do end up seeing a correlation between acceptance of climate change and the weather. However, the correlation with local weather is rather weak. Instead, the authors found a stronger correlation with the global mean temperature. That's somewhat surprising. Most years, the global mean isn't especially well covered by the press, which suggests this correlation might be a bit spurious. (If we accept the economy is an influence, then the correlation will be very difficult to tease apart. Especially considering the coldest global temperature of the last decade happened to correspond to the onset of job losses in the US.)
In any case, the poll numbers indicate there are some things that we probably can't blame them on. For example, acceptance started to drop prior to the Copenhagen climate conference and the release of the e-mails stolen from the University of East Anglia. Both of these may have been big news among people who care passionately about climate change, but they came too late to explain the public's reduced acceptance of the science.
Based on their statistical analysis, the authors conclude the economy is the strongest influence on the public's acceptance of climate science. This held when the authors analyzed things separately in each US state based on its local unemployment rate. The effect showed up in European countries, as well. In Gallup polls, this correlation holds all the way back to 1989, when the current string of unusually warm years began. Overall, the authors found unemployment had an effect that was over three times stronger than either the local weather or skeptical coverage of climate in the media.