It’s been repeated throughout the media that global warming could wipe out one-tenth of the U.S. economy by 2100. Now it’s a top-line finding of a major government climate report, but based on a study funded by groups affiliated with two major Democratic donors.

The oft-repeated claim also stemmed from a global warming projection that’s come under increased scrutiny from experts, including one who called it “outlandish.”

The federal government released the second volume of the National Climate Assessment, or NCA, on Friday. The federal report issued dire warnings, including from “ice sheet disintegration on accelerated sea level rise, leading to widespread effects on coastal development lasting thousands of years.”

The report also claims that “global greenhouse gas emissions is expected to cause substantial net damage to the U.S. economy throughout this century,” including a 10 percent hit to the nation’s gross domestic product in one extreme scenario.

However, NCA’s dire prediction of a 10 percent hit to the GDP comes from a 2017 study supported by the charitable foundations founded by major Democratic donors. The study was also funded by other organizations, including the National Science Foundation, the U.S. Department of Energy, and the Skoll Global Threats Fund.

That 2017 study, published in the journal Science, was funded in part by Bloomberg Philanthropies and Next Generation, which were founded by former New York City Mayor Michael Bloomberg and San Francisco billionaire Tom Steyer, respectively.

University of Colorado professor Roger Pielke Jr. pointed out problems with the study on Twitter Saturday, including the fact it was funded by groups connected with Bloomberg and Steyer.

1/2 By request

Here’s source of the top line conclusion of US National Climate Assessment, 10% damage to US GDP

It’s derived from a study funded by Tom Steyer et al.

The 15 deg F temp increase is 2x most extreme value reported elsewhere in the report (95th percentile of RCP 8.5) pic.twitter.com/KkZjGDVt0D — Roger Pielke Jr. (@RogerPielkeJr) November 24, 2018

Bloomberg and Steyer were the biggest donors to Democratic-aligned political action groups in the 2016 election cycle, according to the Center for Responsive Politics.

Bloomberg, who founded Bloomberg Philanthropies, handed nearly $60 million to liberal super PACs to help put Democratic candidates in office and defeat Republicans in the 2018 election cycle, according to the center.

Steyer, who co-founded Next Generation, gave roughly $58.7 million to liberal super PACs, according to the Center for Responsive Politics. Bloomberg and Steyer back the Paris climate accord and Obama-era policies to phase out fossil fuels.

The Bloomberg-Steyer-funded study found future temperature rise could cost “roughly 1.2% of gross domestic product per [additional one degree Celsius increase] on average.” At the most extreme high-end, that could add up to 10 percent of gross domestic product by 2100.

Pielke called the use of such an extreme scenario “embarrassing” because it’s based on a future that’s 15 degrees Fahrenheit warmer—in other words, twice what the United Nations’ most extreme scenario projects.

But even the United Nations’ worst-case scenario, called RCP8.5, is being called into question by experts. A study published in 2017 found that scenario was “exceptionally unlikely” because it suffered from “systematic errors in fossil production outlooks.”

“Imagine if research funded by Exxon was sole basis for claims. Given weaknesses of the work [it’s] just [foolish] to lean on it so much,” Pielke tweeted.

Major media outlets, however, did no such examination of the NCA’s reliance on such an “outlandish” claim, as Pielke called it.

2/2 Shouldn’t such an outlandish, outlier conclusion been caught in the review process?

Not a good look that sole review editor for this chapter is an alum of the Center for American Progress … which is funded by Tom Steyer.

Even rudimentary attention to COI would avoided this. — Roger Pielke Jr. (@RogerPielkeJr) November 24, 2018