Drought in Ethiopia. Photo via Wikipedia

Try Using This Logic on Your Climate-Denying Relatives

People believe their own senses more than they do data


If you can’t stand the heat, you probably believe that climate change is a real thing. That’s the conclusion of a study recently published in the Proceedings of the National Academy of Sciences examining the connection between extremes of local weather and peoples’ belief — or non-belief — in global warming.

The investigators used data from local weather stations, spanning between 30 and 50 years, to map temperature extremes — both of heat and of cold — onto counties across the United States. They then compared county-level temperature extremes with data from a previously conducted survey, specifically answers to the question “do you think that global warming is happening?”

They found that people in counties that had experienced extreme highs in temperature, and experienced them more recently, were much more likely to have answered “yes” to the question, while people in counties that had recently experienced record lows were much more likely to answer “no.”

In other words, people tend to trust their own perceptions over what scientists tell them. Even when a consensus of 97 percent of scientists in the field says otherwise. This is how a United States congressman can bring a snowball onto the senate floor, claim that something he scooped up from the ground as definitive proof against an overwhelming scientific consensus and be met with anything besides open derision.

Of course, open derision might feel good, but it is — shockingly — not exactly a great tool for changing peoples’ minds. And as these results show, neither is simply repeating the scientific consensus ad nauseam.

NASA photo

“Climate scientists, including myself, have to reevaluate the way we communicate climate change to the public,” said Robert Kaufmann, PhD, a professor in the Department of Earth and Environment at Boston University and lead author of the paper. “It’s not enough to say that 97 percent of climate scientists believe that climate change is real, because although it’s real, it doesn’t really sway people.

“As we write in the paper, when a problem is not central to a person’s well-being, they don’t research it and they don’t take expert opinion,” Kaufmann explained. “Statistics matter little to them. Rather, they use experiential learning to decide whether it’s true or not — that is, they use their gut.”

So what can we do?

“We propose in the paper a couple of things,” Kaufmann said. “One thing is, each year, NASA or whoever is reporting the record temperatures should report the number of all-time high temperatures and the number of all-time low temperatures. And then when people see that the number of all-time high temperatures far outweighs the number of all-time low temperatures, that may be a bit more convincing.

“And we also propose the following bet, which we think the current administration will understand, given its previous history in running casinos. And that is, think of climate like a slot machine — a slot machine that pays out in terms of record high and record low temperatures. If climate is not changing, then when you pull that lever back, the odds are 50–50 that, for each record high temperature you get, you should get a record low temperature, right? Because [they say] climate isn’t changing.

“But what happens if your machine is starting to pay out year after year — that it’s starting to generate more record high temperatures than low temperatures? Then you would think that the dice are loaded or that there’s something wrong with the machine.

“And so what we said was, for those people who do not believe in climate change, take the following bet. For every new record high temperature you lose a certain amount of money, and for every new record low temperature, you win a certain amount of money, the same amount. And keep track of how you’re doing, year after year, whether you’re winning or losing money.

“And eventually you’re going to see that, hey, it is warming, because I’m losing year after year,” Kaufmann said. “It’s simple statistical theory. If the world is not getting warmer or colder, then the odds of a record high are equal to the odds of a record low.”

But what about the argument that, sure, climate change may be happening, but it’s natural and has nothing to do with human activity?

“If I can get people that far, then I’ve got them,” Kaufmann said. “If you include factors that cause the planet to warm and that cause the planet to cool, then the evidence is crystal, crystal clear.”


Kaufmann, RK. And CJ Cleveland, 2015, Environmental Science, Trunity Publishing

“The figure shows the relation between global temperature (black line) and radiative forcing (red line),” Kaufmann explained in a followup email. “Radiative forcing is defined as the quantity of heat (Watts) trapped by the Earth’s atmosphere above a square meter of land surface. As such, radiative forcing represents the balance between the heating effects of greenhouse gases and the cooling effects of sulfur emissions.

“Notice that the two lines move together. When radiative forcing is rising (solid lines), so too is temperature. But when radiative forcing is relatively stable (dotted lines) so too is temperature.”

Notice, too, the general tendency of both lines to rise over time. Kaufmann’s bet isn’t one I’d want to take. Of course, maybe it helps that I’m writing this on Christmas Eve in Texas, where it’s about 60 degrees out. Not a snowball in sight.

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