Like most other climate change observers, I’ve been pretty convinced that “Climategate” – the publication of stolen e-mails from the University of East Anglia that showed climate scientists in an ugly light – has been a big contributor to American doubts about climate change. And those doubts are big: In a post earlier today, my colleague Jim Lindsay (bookmark his new blog on the domestic politics of U.S. foreign policy) flags an October Pew poll that showed only 59% of Americans believing that the earth is warming, and only 34% believing that warming is due to human activity. That’s down from 77% and 47%, respectively, in January 2007.
Here’s what I find surprising: There’s no statistically significant change in the results since the poll was last conducted in October 2009 – a month before Climategate happened. The entire drop occured in the years preceding the debacle. This is true not only at the aggregate level – it’s also true for Republicans, Democrats, and Independents, each considered alone.
The other intruiging thing is how the shifts happened. People don’t appear to have changed their minds from believing that the earth is warming due to human activity to thinking that the causes were natural or unknown. They seem to have decided that it isn’t warming at all. The polls show a steady fraction of people believing that the earth is warming due to natural causes; they also show a steady number who think that it’s warming but don’t know why. But there’s a huge swing from the “yes, it’s warming, and people are causing it” category to the “it’s not happening” one.
There are two possible explanations for this odd pattern. First, there might be much more change than my read of the survey suggests. Perhaps people are slowly sliding down the scale of belief: those who once believed in manmade climate change now think it’s natural, while those who used to think it was natural now think it isn’t happening. My hunch is that’s a bit too cute to be right. (People aren’t, by the way, shifting en masse from “it’s manmade” to “I don’t know” – there simply aren’t enough people in the “unknown causes” category to make that possible.)
The second explanation is more plausible: People who once believed that climate change is manmade haven’t come to doubt their judgment of the causes – they’ve come to think that they were wrong about the entire phenomenon in the first place. That would explain the wholesale shift between categories.
If my guess is right, it suggests that
scientists communicators may need to spend more time simply convincing people that the world is warming, and less trying to make the case that it’s human caused. That goes against my personal intuition, but I long ago gave up on expecting public opinion to follow scientific logic. These patterns suggest that we need to do a better job understanding how peoples’ beliefs about change change evolve if we want to help them better understand what’s really going on.