To all the climate-change deniers out there, Penn State meteorology professor Michael Mann has this suggestion:

Stop arguing about whether the globe is warming and whether human pollution from greenhouse gases plays a major role in it. The science on those counts is settled.

Instead, he said, join the debate about what, if anything, the world can — or should — do about it. Is taking action against climate change simply too expensive? Why should we sacrifice given what China and India are doing?

Some critics are asking those questions, he said when interviewed Wednesday in Harrisburg for an event sponsored by PennFuture. And that approach would bring the discussion to “a legitimate level where it’s possible to have a policy debate," he said. In some ways, I welcome that. We can talk about efficacy, fairness” and other issues.

“If that’s where we really were, we’d be in really good shape,” he said.

Alas, we are not, as a flood of commenters on this article will surely demonstrate. Denialists will bring up out-of-context data points and cite the handful of academically-credentialed dissenters who dispute the overwhelming scientific consensus on the subject.

“There are always devil’s advocates and contrarians in science,” said Mann.

“If you want a credentialed physicist who denies the theory of relativity, I promise you you’ll find one. If you want a geophysicist who denies plate tectonics, I promise you’ll find one.” (He might also have added, if you want a credentialed “biologist” who denies the reality of evolution, they are out there, too.)

Critics know how to “cherry pick” data points to mislead people, Mann said. A popular talking point these days is the claim that global temperature hasn’t gone up in the past 15 years. That’s true only if the comparison starts in 1998, which was a record hot year, Mann noted.

The full story, Mann said, is this: “The last decade was the warmest on record.”

The trend in global temperatures is still upward, he said, although the warming is a bit less than expected. He attributed this to higher-than-normal occurrence of the Pacific cooling phenomenon, La Nina, and more volcanic emissions than expected in climate models. Those emissions block incoming radiation from the sun.

The climate-denial industry, abundantly funded by fossil fuel interests and their allies like the billionaire Koch brothers, will surely seize on information like that to continue sowing confusion about the science. They are doing what Big Tobacco did for decades. They are pouring millions of dollars into denying the fundamental scientific reality about their product and attacking those, like Mann, who uncover and speak the truth.

Mann discusses those politically-motivated, and ultimately baseless, attacks in his recent book, The Hockey Stick and The Climate Wars. (The "hockey stick" refers to what the graph of long-term global temperatures looks like – a hockey stick lying on its side, with the "blade" being the recent spike upward.)

Big Tobacco’s disinformation campaign ultimately collapsed under the weight of the honest evidence. The world now knows that using tobacco causes cancer and other deadly diseases in millions of people. And twenty years from now, when the industry-funded fever of climate denialism has run its course, the world will no longer debate whether humans play a big role in the warming of the planet.

“The science has only gotten stronger over the years as the models have gotten better.” Mann said later that night to the PennFuture audience. “Climate change is upon us, and it represents a threat.”

We are conducting “an unprecedented, uncontrolled experiment with the planet,” he said. If we stay on the current course, “We will be leaving our children and grandchildren a fundamentally different planet.”

Matt Zencey is Deputy Opinion Editor of Pennlive and The Patriot-News. Email mzencey@pennlive.com and on Twitter @MattZencey.