Robert Bryce explains at National Review Online one way in which left-of-center activists have tried to shut down debate about climate change.

The latest WikiLeaks dump contains plenty of insider dirt on John Podesta, the founder of the Center for American Progress and the campaign manager for Hillary Clinton. Perhaps the tawdriest story to be exposed by Podesta’s pilfered e-mails is the bragging by an employee of ThinkProgress, an arm of the Center for American Progress, about how they got Roger Pielke Jr.’s scalp.

A July 2014 e-mail from Judd Legum, an editor at ThinkProgress, to billionaire Democratic climate activist (and former coal-mine investor) Tom Steyer exposes the climate-change McCarthyism that the Left — and its myriad allies in the liberal media — use to discredit or silence anyone who doesn’t adhere to the orthodoxy of the climate catastrophists.

In the e-mail, Legum boasted to Steyer about how ThinkProgress had silenced Pielke by preventing him from publishing at Nate Silver’s then-new website, fivethirtyeight.com, on the issue of climate change. Legum was also asking Steyer, indirectly, for more money. Steyer and Podesta both sit on the board of the Center for American Progress. Between 2008 and 2014, Steyer gave the Center for American Progress some $3.85 million. …

… Pielke, a professor at the University of Colorado since 2001, holds degrees in mathematics, public policy, and political science. He has authored or co-authored seven books. He has won several awards for his academic work. For about two decades, he was a prolific writer and speaker on climate issues. In 2013, he testified before Congress and declared that there is “exceedingly little scientific support for claims found in the media and political debate that hurricanes, tornadoes, floods and drought have increased in frequency or intensity on climate timescales either in the United States or globally.” During that same testimony, he said that global weather-related losses have not increased since 1990 as a proportion of GDP. He went on, saying that there were also no observable increases in floods, tornadoes, or droughts.

Pielke’s work was backed up by data and, in many cases, by the findings of the Intergovernmental Panel on Climate Change. But that didn’t matter to Podesta’s attack dogs at ThinkProgress. Long before his congressional testimony, Pielke had been the subject of a years-long smear campaign led by ThinkProgress’s Joe Romm. In fact, Romm had what can only be described as an obsession with Pielke. In a recent Twitter posting, Pielke wrote: “Propaganda works: I count more than 160 articles at the Center for American Progress trashing me over the years.”