Michael E. Mann

Opinion contributor

Jordan Harris’ recent commentary in your paper (“The Green New Deal is really the 'Green Scare' over climate change”) subjected readers to falsehoods about the science of climate change and untruthful assertions about me specifically (Sadly, this is not the first time this loyal foot soldier of the Koch Brothers has used the column granted him by this paper to engage in the cherry-picking and misrepresentation of facts in service of an ideological agenda).

In his latest commentary, he favors climate change denier propaganda over well-established science. His denialist screed reads like a game of climate change denial bingo, hitting all of the usual denialist talking points.

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Take for example his dismissive claim that “the contribution by humans cannot be effectively measured.” The truth is that the world’s scientists, including the U.S. National Academy of Sciences (founded in the 19th century by Republican President Abraham Lincoln) have concluded that “most of the recent change is almost certainly due to emissions of greenhouse gases caused by human activities.”

That’s followed by the shopworn myth, often used by denialists to frighten the public, that acting on climate change risks “upending the global economy and dooming billions to poverty.” This is the same scare that has been used by industry front groups and their hired guns for decades. We were told the same thing about acid rain, ozone depletion and now, of course, climate change. The reality, of course, is that the cost of inaction greatly exceeds the cost of taking action (and renewable energy has the potential to create far more jobs than the dwindling, increasingly automated, fossil fuel industry).

And the list goes on. There is no truth to literally any of the claims about climate science made by Harris. He indeed makes false statements about my research in the late 1990s that resulted in the well-known “Hockey Stick” curve that demonstrates recent warming to be unprecedented over the past thousand years, leveling untruthful allegations of “fraud” against me and my co-authors. As I recount in my book, "The Hockey Stick and the Climate Wars," this graph has been ceaselessly attacked by climate deniers like Harris owing to the simple, undeniable message it conveys about the dramatic impact of human activity on our climate.

Harris fails to disclose to readers that our findings have been replicated and extended by dozens of subsequent studies since 1999. The highest scientific body in the U.S., the National Academy of Sciences, confirmed our findings in an exhaustive independent review published in June 2006 (see e.g. "Science Panel Backs Study on Warming Climate," New York Times, June 22, 2006) as did an international team of nearly 80 scientists from around the world in 2013, publishing in the premier journal Nature Geoscience, which extended our original conclusions, demonstrating that recent warmth is likely unprecedented over an even longer time frame of the last 1,300 years.

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Readers interested in the truth behind the science, rather than the falsehoods and smears perpetuated by ideologically-driven science deniers like Mr. Harris should consult scientist-run websites like skepticalscience.com, or books on the topic like my own “Dire Predictions: Understanding Climate Change."

We need to get past the bad faith attacks on whether climate change is real and onto the worthy conversation over what to do about it. But political, antiscience-promoting hacks like Mr. Harris would rather forestall that conversation in the name of short-term fossil fuel industry profits, threatening the future livability of our planet. We must not tolerate this assault on our children and grandchildren’s future.

Michael E. Mann is a professor and director of the Earth System Science Center at Penn State University.