John D. Sutter is a columnist for CNN Opinion who focuses on climate change and social justice. Follow him on Snapchat , Facebook and email . The opinions expressed in this commentary are his.

(CNN) Global warming isn't as divisive in the United States as it used to be.

The percentage of conservative Republicans (not just Republicans but conservative Republicans) who believes climate change is happening has jumped 19 percentage points in the last two years, to 47%.

That's according to a national survey released this week by the Yale Program on Climate Change Communication and George Mason University's Center for Climate Change Communication

Overall, three-fourths of registered voters say global warming is real, with that figure up 7 percentage points since spring 2014. And a majority of Americans -- 56% -- say, correctly, that they think climate change is caused mostly by human activities.

"Republicans are not a monolithic block of global warming policy opponents," the report says. "Rather, liberal (and) moderate Republicans are often part of the mainstream of public opinion on climate change, while conservative Republicans' views are often distinctly different than the rest of the American public."

Even those "distinctly different" views are shifting, this evidence shows.

True, there remains a significant knowledge gap on this subject, and it's one we in the news media must do a better job of closing. Only 16% of American voters understand that more than more than 90% of climate scientists -- it's actually at least 97% -- are convinced global warming is real and we're causing it. And while conservative Republicans are warming to the idea that climate change is happening, only 26% of them acknowledge it's mostly humans who are causing the problem by burning fossil fuels and chopping down rain forests.

Those gaps are persistent and troubling.

But I take this survey as cause for optimism.

Politicians should see it as a mandate to do something about the crisis.

A whopping 84% of registered voters, including 75% of Republicans, support funding research in renewable energy sources such as wind and solar, the data show. Three-quarters of voters, and 61% of Republicans, support regulating carbon dioxide as a pollutant. And 68% of voters support a carbon tax on fossil fuel companies if the money collected from taxing pollution is refunded to the people in the form of tax cuts. ( There's a proposal kind of like this up for a vote in Washington state , by the way, which will be a fascinating test.)

Voters are also more likely to choose a presidential candidate who "strongly supports taking action to reduce global warming," according to the survey of 1,004 registered voters, which was conducted in March.

"Asked if they would be more or less likely to vote for a presidential candidate who strongly supports action to reduce global warming, or if it would make no difference, registered voters are three times as likely to say they would be more rather than less likely to vote for such a candidate," the report says.

What accounts for the shift among conservatives?

Anthony Leiserowitz, director of the Yale Program on Climate Change Communication, which released the report Monday, told me by email that it's not exactly clear.

But here are a few news events he suspects are at play:

Pope Francis' encyclical on climate change , which made a moral argument for action, saying that people who have done nothing to cause warming will suffer its effects.

• The Paris Agreement on climate change , which has drawn international media attention and has restored a sense of hope that the world is united in fighting this problem.

• And a frightening string of temperature records , which also have gotten press.

Furthermore, he told me, the climate rhetoric among prominent Republican politicians appears to be softening somewhat -- or is simply less constant than it used to be.

"In the past several years Republican leaders consistently attacked climate change as not happening, a hoax, or worse," he said. "But with the primaries, the issue has faded away. ... It's possible that this absence of anti-climate discourse has actually made it easier for at least some conservatives to start thinking about the issue outside of the political box. This is speculative, but makes some sense, as we know that many people take their cues on this issue from their own trusted leaders.

"So if conservative Republicans aren't talking about it, that's actually a more positive climate of discourse than when they were actively hostile."

There are certainly counterexamples. The two leading Republican presidential candidates more or less have said climate change isn't real or that we shouldn't do anything about it or that China is to blame, anyway.

"Obama's talking about all of this with the global warming and ... a lot of it's a hoax. It's a hoax . I mean, it's a money-making industry, OK? It's a hoax, a lot of it," Donald Trump said in a December interview, according to the site PolitiFact. Ted Cruz said last year that climate change is a " pseudoscientific theory ."

But something is changing in the minds of conservative voters, and for that I'm thankful.

When I took a trip last year to the most climate-skeptical place in the country, Woodward County, Oklahoma , I realized there's much more agreement on this issue -- and particularly on solutions to climate change -- than we tend to think. The county with the highest rate of climate skepticism, I found, is also home to a booming wind industry, and a world-class wind power jobs training center.

I hope politicians will start taking note of these shifts as well.