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Challenging the Local Warming Effect

Experiment keeps daily weather from shaping climate change opinions


thermometer heat
Can a single warm day affect opinions about climate change?

In addition to making you think about heading for the pool, could a single, notably hot day also alter how you think about global warming? In a recent working paper, IPR political scientist James Druckman discusses how people’s short-term perceptions of daily temperature might do just that, and how these perceptions might be altered to reflect a more long-term view.

Druckman tests the limits of the so-called “local warming effect”—a phenomenon that occurs when people base their beliefs about global warming on the daily temperature. For example, when an individual perceives the day’s temperature to be warmer than usual, he or she is likely to overestimate the number of warm days over the year, which in turn leads to an increased belief and concern in global warming.

The local warming effect could be concerning, Druckman said, because it means that an important policy preference is being based on “fleeting perceptions of daily temperature.”

Building on previous research that ties the local warming effect to perceptions of climate change, he set out to test whether prompting respondents to think beyond daily temperature could ultimately challenge how they formed opinions on global warming.

One group in the experiment was asked to consider not only the daily local temperature but also variations and trends in temperature throughout the year. The other group received no such prompt. All of the participants were then asked to answer a list of questions assessing the day’s temperature, the number of days over the year that seemed to be warmer than usual, as well as their thoughts and concerns about global warming more broadly.

Druckman discovered that those who received the prompt no longer connected their perceptions of daily local temperatures with estimates of the number of warm days in the year, thereby eliminating the local warming effect. 

The results suggest that prompting people to think of global warming in terms of broader changes can eliminate the local warming effect in an experimental setting. But, as Druckman explains, creating this type of prompt in a real-world setting means reframing public discourse on the issue.

“You can’t bombard people with scientific models that won’t resonate with them,” Druckman noted. “Instead, you have to frame global warming as a much broader change in climate beyond daily temperature.”

James Druckman is Payson S. Wild Professor of Political Science and IPR associate director and fellow. “Eliminating the Local Warming Effect” (WP-14-26) can be read here. The article has also been published in Nature Climate Change and can be found here.

Photo credit: Velkr0, Flickr.