Is It Hot in Here or Is It Just Me Telling You It's Hot in Here?

As the mercury drops in the eastern U.S. this week, expect snow, icy driving conditions and ludicrous statements about global warming from Donald Trump and Rush Limbaugh .

These statements are caricatures of debate, and obscure the real and persistent way that weather actually does make climate change confusing.

Many people apparently have weather on the brain when the topic turns to climate change. The ease with which we confuse the two offers a window into how the human mind works: Asked about a complex issue, people often will provide an answer about a related, easier topic. It’s an example of “attribute substitution,” a mental process defined by behavioral economists Daniel Kahneman and Shane Frederick in 2002, the same year Kahneman won the Nobel Prize in economics.

This particular phenomenon, in which people instinctively allow weather to influence their judgments about climate change, has been called the local warming effect .

A new study in a leading peer-reviewed journal, Nature Climate Change , asks why the local warming effect should be so influential. The researchers conducted several experiments to try to overcome participants’ reliance on cues from weather. The work was led by Lisa Zaval of Columbia University’s Center for Research on Environmental Decisions .

They tested to see whether survey questions containing the phrase “global warming” caused people to believe or be concerned about science any more than questions with "climate change" did. They didn't, and the researchers concluded that the local weather effect isn’t driven by buzzwords.

In another test, they gave participants information explaining that local weather and global climate change are different things, adapting NASA material to say, for example, “climate is what you expect, like a hot summer, and weather is what you get, like a hot day with thunderstorms.” Explaining this difference to research subjects didn't kill the local weather effect.

A third approach investigated the effect of "priming," or providing subtle topic cues. Researchers gave subjects hotness or coldness cues before answering questions about climate change. Study participants were asked to make four-word sentences from five-word groups, such as:

potatoes she the roasted it


the shivers man old of

People who were given "hot" priming sentences tended to believe and be concerned about climate change science more than those given "cold" or neutral sentences.

A further test, which involved asking people about yesterday’s temperature, led the researchers to conclude that the previous day’s temperature didn’t have as large an effect as it today's. Recent sensation — “the immediacy of experience with temperature” — influences thoughts about climate change most. Humans evolved big, reasoning brains that still have trouble competing with the five senses.

That weather can guide people’s thinking so strongly, and that this bias is so difficult to overcome, is indicative of a larger problem not limited to climate change. “The local warming effect is an important real-world demonstration of how opinion on important issues can be constructed in response to a direct enquiry, rather than retrieved from memory,” the authors write.

In other words, when asked to say what they think about climate change, many people don't retrieve and open their mental file on climate; they make up a new one, drawing on a seemingly related and easier topic, the temperature outside. After all, as Bob Dylan put it, you don't need a weatherman to know which way the wind blows.

“Priming” studies are common in behavioral research. Scientists still don't know as much about it as one might like. If streets and news media were filled with images of people sweating and thirsty in a desert, it wouldn't lead to a rational federal climate policy. But just why it wouldn't isn't well understood.

As Zaval explained over email: "Unfortunately, we just don’t know how long the effects of temperature cues might last — concern for climate change sometimes seems to be as transient as the weather.”

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