Climate change beliefs of independent voters shift with the weather

New research from the University of New Hampshire finds that the climate change beliefs of independent voters are dramatically swayed by short-term weather conditions. The research was conducted by Lawrence Hamilton, professor of sociology and senior fellow at the Carsey Institute, and Mary Stampone, assistant professor of geography and the New Hampshire state climatologist.

"We find that over 10 surveys, Republicans and Democrats remain far apart and firm in their beliefs about climate change. Independents fall in between these extremes, but their beliefs appear weakly held -- literally blowing in the wind. Interviewed on unseasonably warm days, independents tend to agree with the scientific consensus on human-caused climate change. On unseasonably cool days, they tend not to," Hamilton and Stampone say.

Hamilton and Stampone used statewide data from about 5,000 random-sample telephone interviews conducted on 99 days over two and a half years (2010 to 2012) by the Granite State Poll. They combined the survey data with temperature and precipitation indicators derived from New Hampshire's U.S. Historical Climatology Network (USHCN) station records. Survey respondents were asked whether they thought climate change is happening now, caused mainly by human activities. Alternatively, respondents could state that climate change is not happening, or that it is happening but mainly for natural reasons.

Unseasonably warm or cool temperatures on the interview day and previous day seemed to shift the odds of respondents believing that humans are changing the climate. However, when researchers broke these responses down by political affiliation (Democrat, Republican or independent), they found that temperature had a substantial effect on climate change views mainly among independent voters.

"Independent voters were less likely to believe that climate change was caused by humans on unseasonably cool days and more likely to believe that climate change was caused by humans on unseasonably warm days. The shift was dramatic. On the coolest days, belief in human-caused climate change dropped below 40 percent among independents. On the hottest days, it increased above 70 percent," Hamilton says.

New Hampshire's self-identified independents generally resemble their counterparts on a nationwide survey that asked the same questions, according to the researchers. Independents comprise 18 percent of the New Hampshire estimation sample, compared with 17 percent nationally. They are similar with respect to education, but slightly older, and more balanced with respect to gender.

In conducting their analysis, the researchers took into account other factors such as education, age, and sex. They also made adjustments for the seasons, and for random variation between surveys that might be caused by nontemperature events.