NEW YORK – The evidence was strong 10 years ago, even 20, that the world had a problem with global warming. We knew then that it was going to exacerbate extreme weather and heat waves and raise the sea level. But nearly half of Americans didn’t take it seriously. Now they do, according to polls, and what changed wasn’t the amount of evidence but a shift in political forces and some changes in the way scientists learned to make their case.
A recent report on cumulative damage to the world’s oceans and ice caps, for example, got big attention in the media, though the message wasn’t all that different from earlier reports from the Intergovernmental Panel on Climate Change. A few more specifics are known: The report projects that by 2050, at many coastal locations, the historic once-in-a-century flood will become an annual event, said Princeton University climate researcher Michael Oppenheimer, who was an author of the report.
What’s noticeably changed is the way Americans are reacting to the news — taking these forecasts seriously, and recognizing that this isn’t only about polar bears, but about them. One clue to America’s new attitude comes from tracking polling data over the years, said Yale professor Anthony Leiserowitz, who studies public opinion on climate change. What the data show is a steep 14 percent drop in public acceptance of human-caused global warming between 2008 and 2009.
Lieserowitz said they’ve examined all sorts of possible causes — especially the recession and a spate of snowy winters. But he ultimately concluded that the drop was tied to the rise of the Tea Party. Before 2008, Republican presidential candidate John McCain made the climate a high priority, he said. But with McCain’s loss to Barack Obama in the election, the Tea Party gained new energy and momentum.
Many Americans were persuaded by what Leiserowitz calls “political elite cues” — a fancy way of saying that people follow leaders. If Republican leaders say climate change is exaggerated and the scientists are untrustworthy, people follow. Polling data show that Republicans have consistently considered climate change a low-priority issue, while Democrats put it much higher.
Another tactic of the political right was to create a phony scandal that became known as Climategate, the result of which was to sow doubt about the credibility of scientists and distract from their message. In late 2009, hackers stole thousands of private email messages from climate groups at the University of East Anglia in England and at Penn State University. Nothing obviously incriminating turned up, but by twisting out-of-context words, like harping on someone’s “trick” for graphing, pundits were able to create the impression that the scientists did something wrong and were not to be trusted. Multiple investigations cleared everyone except the hackers, who were never caught.
This non-scandal tied in with a trend toward accusing scientists and science popularizers of being dishonest when they talked about natural disasters. Pundits slammed Al Gore for suggesting in his 2006 film that Hurricane Katrina might have had something to do with global warming. Even The Wall Street Journal bought into this unfair science-bashing, along with the myth that was Climategate.
As a political strategy, discrediting those who talked about natural disasters was effective. Floods, fires and storms make for a powerful way to bring home the dangers of climate change — making it something people can see on their television screens.
There was also a grain of truth to the criticism. It really is impossible to attribute any one hurricane to global warming. The problem was that people were asking the wrong question, said Leiserowitz. They were asking whether global warming caused Hurricane Katrina, for example, when they should have been asking whether global warming was having an effect on the strength and frequency of hurricanes. It is.
It’s a little like asking if smoking caused a particular person’s case of lung cancer, he said. Some people do get lung cancer without smoking, and some people who smoke never get cancer, but overall the statistical evidence is overwhelming that smoking increases a person’s cancer risk. In the same way, human-generated climate change is shifting the background conditions. There’s more energy trapped in the ocean and atmosphere, and that’s leaving a thumbprint on the weather — extreme and otherwise.
It might seem contradictory that people could be gullible enough to fall for Climategate but still sophisticated enough to understand such a statistical argument, but the phenomenon known as motivated reasoning often allows smart people to believe things based on selective evidence.
Public opinion started to change when scientists began to talk about natural disasters again — unabashedly giving statistical evidence. After Hurricane Harvey flooded Houston in 2017, for example, Keven Trenberth (one of the researchers falsely implicated in Climategate) came forward explaining in detail the complex way that warming oceans and changing wind patterns made a disaster like Harvey more likely.
Believing in the problem isn’t enough to spur action, but it’s a vital first step. Many people are now clamoring for action, thanks in part to the popular notion that the next 11 years are critical for minimizing the impacts of global warming. It’s a nice, manageable number — a short enough window to be challenging but long enough to seem doable. There’s a concrete goal of keeping warming below 1.5 degrees Celsius. And there are now proposed solutions, such as the Green New Deal, which, while perhaps not perfectly practical, give people a goal with a name.
A decade ago, scientists would complain that conservatives had bogged everyone down in a false debate over whether human-generated global warming exists, when we should have been debating what to do about it. But even if acceptance had come earlier, it’s hard to get people motivated to care about a problem if they’re simply bludgeoned with guilt and fear.
Nothing like this has ever happened — there’s never been a problem on this scale that calls out for coordinated global action. The ozone hole was a global problem, but it required substitutes for a few industrial chemicals, not a full-scale effort to change the energy sources that support the world economy. But lots of younger people are fired up to do what needs to be done over the next 11 years. There’s nothing quite like the power of a deadline.
Science writer Faye Flam is a Bloomberg Opinion columnist.