Climate Denial Fails Pepsi Challenge
May 20, 2016
Stephen Lewandowsky specializes in conducting research that pulls back the curtain climate denial psychology. He’s done it again.
Researchers have designed an inventive test suggesting that the arguments commonly used by climate change contrarians don’t add up, not only according to climate scientists (we know what they think already) but also in the view of unbiased experts from other fields.
The trick? Disguising the data — and its interpretation — as if it was part of an argument about something else entirely.
First of all, consider that climate doubters (like scientists) often use objective data to back up their claims. They just tend to represent it in ways that scientists have long found objectionable.
Here’s an example: Data indicate that in the long run — over many decades — global temperatures have been rising. But over shorter periods, temperatures might fluctuate up and down quite a bit. Climate contrarians might exploit this fact by pointing to a small block of data from a short-term period when temperatures were on the downswing, or weren’t rising, and use it to suggest that global warming isn’t actually happening. It’s a tactic known as “cherry-picking” — selecting only data that suit one’s purposes, instead of data that reflect the whole story.
It’s hard to talk about these problems, though, without the conversation turning into a figurative shouting match between mainstream climate science and climate doubters, who are generally going to disagree with one another no matter what. So Lewandowsky’s group of researchers decided to take another tack.
They found a way to let an unbiased group of expert scientists judge for themselves how sound climate-doubting arguments are by presenting them with real climate data — but labeling these data as something else. For instance, they presented data on trends in Arctic sea ice extent, but relabeled as data on the profits of a fictitious company. And they re-cast numbers on global sea-level rise as stats on world lithium production.
“So instead of saying, there’s a recovery of Arctic ice, we would say, there’s a recovery of our share prices,” Lewandowsky said.
Just to shake things up a little, the researchers also administered the test to some participants using statements supporting the ideas of mainstream climate science (also disguised, of course). The difference between the responses in each case was striking.
“Across two groups of experts and across six different scenarios, contrarian claims were judged to be misleading, inaccurate, and unsuitable for policy advice,” the researchers wrote in the paper. “Conversely, mainstream scientific interpretations were found to be accurate and suitable for policy advice overall.”
“It’s a huge effect,” Lewandowsky added. “They are about as far apart as anything I’ve seen.”
As an added test, the researchers asked the participants to predict what the masked data should look like in the future — and in general, the experts made predictions in line with what’s been projected by mainstream climate scientists.
“So no one thought the Arctic was going to recover — they thought it was going to continue melting, because that is what the data show,” Lewandowsky said.
Speaking of tastes, everyone knows what a blind taste test is. They’re a staple of the marketing world, and check whether or not you can really taste the difference between diet and regular soda. Which you prefer, is the consume-ate question that will never be decisively answered and will keep bubbling up again and again.
But blind tests can be useful for delivering refreshingly unbiased answers to questions even more contentious than Coke vs Pepsi. For example, is the ice cover of the Arctic growing or shrinking? And are sea levels rising or stable?
These are two questions posed in a new study that uses the tried and true blind test approach to gauge the reliability of denier arguments. Researchers relabeled climate data as population and economic data and served it up to economists and statisticians. That way the subjects were blind to the true meaning of the data, so no one could accuse them of being biased in their responses.
The results were more one sided than any diet soda commercial could possibly hope for. The contrarian interpretations were judged to be misleading, while the mainstream climate claims were deemed “accurate and policy relevant.” According to the lead researcher Stephen Lewandowsky, the results were stark, with the mainstream claims rated as very reliable and the denier’s incredibly misleading, and the two groups rated “about as far apart as anything I’ve seen.” So in this blind test, the denier claims fell flat and were hard to swallow, and the mainstream science went down easy.