Can Global Warming Be Real if it’s Cold Outside?

By Jonathan Marshall

The average person doesn’t gauge climate change by reading technical papers or analyzing regional temperature data charts. They just look out the window or walk down the street. As the cliché goes, “seeing is believing.”

That’s why the cold snap across much of the United States last month — which dropped temperatures across the 48 continental states about 2 degrees Fahrenheit below the 20th century average — prompted so many cynical comments about global warming from talk show pundits, Donald Trump, and even a few friends of mine. As one Fox Business commentator said, “We’re looking at global cooling, forget this global warming.”

Scientists did their best to explain that a “polar vortex” contributed to frigid weather over much of the Midwest and Eastern United States, with suggestions that the decline in Arctic sea ice might have amplified the extreme weather. More to the point, as Washington Post blogger Brad Plumer noted, “A single cold snap in the U.S. doesn’t disprove global warming any more than the record heat waves currently hitting Australia prove that it’s happening.”

This striking global temperature map from NASA shows clearly what an anomaly our cold weather has been. A global ocean of yellow, orange and red — representing hotter than historic average temperatures — surrounds our tiny North American sea of blue. (November is the most recent NASA temperature map available, but preliminary December data confirm a similar trend.) That’s why they call it global warming — or in my preferred parlance, global climate disruption.

But most of us still live in a pre-Copernican world that puts us at the center of the universe. Researchers at Columbia University and other institutions have repeatedly shown that people’s belief in and concern about global warming is powerfully affected by their perception of the day’s current temperature — even indoors. (A new paper published just this month in Nature Climate Change confirms the point yet again.) It’s akin to assessing the state of the global economy based on how much money you have in your pocket.

“Global warming is so complex, it appears some people are ready to be persuaded by whether their own day is warmer or cooler than usual, rather than think about whether the entire world is becoming warmer or cooler,” said Ye Li, a postdoctoral researcher at the Columbia Business School’s Center for Decision Sciences. “It is striking that society has spent so much money, time and effort educating people about this issue, yet people are still so easily influenced.”

Speaking of which, temperatures in the Bay Area, where I work, just set record highs. I guess global warming is real after all.

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