Sarah Palin speaks during a panel discussion before a preview of the film “Climate Hustle” on Capitol Hill on Thursday, April 14, 2016. (AP Photo/Evan Vucci)

The basic science of climate change is firmly established, and it’s overwhelmingly accepted by experts in the field. And it’s not just theoretical: Real-world evidence of a changing climate assails us constantly. Global temperatures in March were scorchingly hot, a new record for that month, at well over a full degree Celsius (1.8 degrees Fahrenheit) higher than the average March temperature from 1951 to 1980 — and even higher compared with pre-industrial averages.

Nonetheless, there remains a significant coterie of skeptics, doubters and outright deniers, including former Alaska governor Sarah Palin. At the House Rayburn Office Building last Thursday evening, she participated in a discussion panel just before the airing of a new documentary, “Climate Hustle,” featuring Marc Morano, publisher of the skeptical website ClimateDepot.com, who takes viewers on a tour through the arguments that some holdout scientists do still make to undermine mainstream climate concerns.

As nearly the entire Internet noted, Palin claimed, in the session, that Bill Nye the Science Guy, who has stood up for mainstream climate science and debated Morano on live TV, is “as much a scientist as I am.” (Nye, according to the website of the Planetary Society, where he’s the CEO, “earned a degree in mechanical engineering at Cornell University and spent several years working as an engineer.”)

This was the Palin comment most pounced upon by critics and commentators, but her simple description of the issue itself was at least as problematic.

“There is a predetermined agenda, definitely, of those who I think are controlling the narrative right now on changes in the weather, as you mentioned, it used to be called global warming, now it’s called climate change,” said Palin. “There is definitely a political agenda behind all of this.”

Contrary to what Palin said, scientists have repeatedly explained that climate change is not the same thing as changes in the weather. Rather, climate is the statistical average of weather, and in the case of global climate, that means averaged across the entire globe. Distinguishing between climate and weather is foundational in any discussion of climate change.

So with the science so clear, why even engage with claims made by Palin, or those of a similar mind?

The answer is that they still draw significant attention — “Climate Hustle,” according to its producers, is slated to air at a large number of theaters across the U.S. on May 2. And the event was originally supposed to have been introduced by House Science Committee Chairman Lamar Smith (R-Tex.), who was called out but instead left a statement behind saying “it is my hope that films like Climate Hustle can help unmask some of the bias and give the American people the facts.”

So, what are climate skeptics and doubters now arguing? It’s actually the same things they’ve been arguing for many years, albeit with regular touch-ups:

Some scientists disagree with the mainstream. “Climate Hustle” features many scientists who have criticisms of various aspects of the scientific consensus on climate change, and in some cases, it appears, pretty much all of it. You can watch a trailer of some of the things they have to say here.

Unlike some, I don’t doubt that these scientists believe what they say. That they’re genuinely skeptical. Fine. But that doesn’t mean that they win the day on this issue.

One could go point by point through these scientists’ claims — but if you know anything about the climate debate (or human psychology), you know what happens next. You get a flurry of scientific claims and counterclaims, and  both sides always end the encounter unmoved by the other. And so it goes.

The deeper issue, then, is how to think about a situation in which there is a politicized scientific topic, a majority of scientific experts clearly on one side of it, and a minority of researchers still opposed to that perspective. The latter are often aligned with conservative think tanks and political leaders who challenge the science on ideological grounds.

Once you view things in this way, the way to weigh matters is simple. You have to listen to the consensus of experts and to the scientific process that has repeatedly affirmed their point of view — and you have to consider those who would assail this consensus, at minimum, to face a very high burden of proof.

Scientists once thought the globe was cooling. Another skeptic talking point, very much at evidence in “Climate Hustle” and at the Palin event, is the idea that because some scientists once believed the globe was cooling or risked a major cooling event, there is reason to be dubious of current claims of warming.

“If you go back to the 1970s, you had a number of scientists predicting global cooling,” Morano said at the event. “There’s no consensus when you look back on all this stuff. It shifts.”

Let’s go to the data on this one.  Here are the temperatures of the last 130 plus years, via NASA:


(NASA)

Temperatures did not rise much between the middle of the century and around 1980. And this, in combination with concerns about high levels of sulfate aerosol emissions from power plants and other considerations, did prompt some talk of global cooling at the time.

But researchers have documented that there was no scientific consensus on global cooling in the 1970s. When it comes to the idea of such a consensus, “a review of the climate science literature from 1965 to 1979 shows this myth to be false,” found a September 2008 study in the Bulletin of the American Meteorological Society. “The myth’s basis lies in a selective misreading of the texts both by some members of the media at the time and by some observers today.”

The current scientific consensus, in contrast, is well established. And that consensus is particularly hard to ignore when 2014 and 2015 set successive new global temperature records, and 2016 so far has blown away even the temperatures of 2015.

So the idea that some scientists may have cited cooling concerns a long time ago really doesn’t in any way undermine the idea that this is not a seriously held view now, or that the view that is held seriously — we’re warming up — is extremely well supported.

There’s a global conspiracy to advance left-wing economics through scientific subterfuge. Perhaps the most extreme claim embraced by those skeptical of human caused climate change is the idea that scientists and U.N. bureaucrats are coordinating a campaign to mislead basically everybody so as to seize control of the global economy and throttle fossil fuels.

This conspiratorial bent was often present at the Palin event. For instance, the former Alaska governor herself said: “People who are involved in this issue, they are not stupid, they have studied this stuff. They have studied the data that they are erroneously, though, delivering to the public to make us think that we can somehow change the weather. … It’s quite unfortunate, because these people must be purposely doing this … because they are smart enough to know better.”

Conspiracy theories like this one face a very high burden of proof. It is hard to believe that such a coordinated ruse – encompassing the United Nations, universities around the world, large numbers of scientific journals, scientific membership bodies, and more — could be pulled off by global scientists without exposure (or, that scientists would do such a thing).

Making Bill Nye the stand-in for all climate science. And then, well, there’s the latest skeptic tendency, which is to criticize Bill Nye. Nye is a persuasive entertainer who states climate science accurately and stands up for it. But refuting him or his arguments, as Morano and Palin seek to do, really doesn’t mean much. In the end, he’s just the messenger.

Nye is simply articulating the lessons that emerge from a vast body of research, and a  well established scientific understanding of how the planet’s atmosphere works. It begins with the simple greenhouse effect, and the planet’s carbon cycle, and proceeds to show that carbon dioxide is a central atmospheric temperature knob that will warm the planet now, just as it has done in past eras of the Earth’s history.

This mountain of knowledge doesn’t go away even if, somehow, you get people to distrust or dislike Bill Nye. (Though that doesn’t seem to be working very well, either).

The tendency to focus on Nye, though, does reveal a bigger game. It is not to provide a painstaking, step-by-step, scientifically supported critique of everything that researchers have established about how the climate works. Rather, it’s to win in the media and public minds, where Nye does indeed loom large, and where Palin, and documentaries like “Climate Hustle,” might indeed have a persuasive effect.

But even here, the battle is pretty clearly being lost. A recent Gallup survey found a stronger U.S. public consensus on the causes of climate change than ever before — record numbers, 65 percent, now believe humans are the primary cause of climate change.

Read more at Energy & Environment:

Research shows — yet again — that there’s no scientific debate on climate change

This will be the next battle over saving the Amazon

Greenland’s ice sheet just set an ominous new record

For more, you can sign up for our weekly newsletter here, and follow us on Twitter here.

Whether Earth is 6,000 or millions of years old, here are the highlights from Tuesday night's debate between creationist Ken Ham and TV scientist Bill Nye ("The Science Guy"), in less than 5 minutes. (Jason Aldag/The Washington Post)