Freshman Congresswoman Rep. Alexandria Ocasio-Cortez (D-NY) spoke about her radical Green New Deal resolution on MSNBC recently, claiming the world has 12 years to push back against climate change or hundreds of millions of lives will be in peril, and one lawmaker tweeted to promote her ideology.

“@AOC is right, we have an expiration date when it comes to climate change,” Rep. Barbara Lee (D-CA) tweeted on her campaign Twitter account. “The @UN’s newest report gives us 12 years to turn things around before environmental catastrophe. We need to take climate change seriously. Now”:

.@AOC is right, we have an expiration date when it comes to climate change. The @UN’s newest report gives us 12 years to turn things around before environmental catastrophe. We need to take climate change seriously. Now. pic.twitter.com/M3BM11wA1d — Barbara Lee (@BLeeForCongress) April 5, 2019

The two women and many other climate change believers are referring to a United Nation’s Intergovernmental Panel on Climate Change (IPCC) report released last year, according the Guardian:

The world’s leading climate scientists have warned there is only a dozen years for global warming to be kept to a maximum of 1.5C, beyond which even half a degree will significantly worsen the risks of drought, floods, extreme heat and poverty for hundreds of millions of people. The authors of the landmark report by the U.N. Intergovernmental Panel on Climate Change (IPCC) released on Monday say urgent and unprecedented changes are needed to reach the target, which they say is affordable and feasible although it lies at the most ambitious end of the Paris agreement pledge to keep temperatures between 1.5C and 2C. The half-degree difference could also prevent corals from being completely eradicated and ease pressure on the Arctic, according to the 1.5C study, which was launched after approval at a final plenary of all 195 countries in Incheon in South Korea that saw delegates hugging one another, with some in tears.

“It’s a line in the sand and what it says to our species is that this is the moment and we must act now,” Debra Roberts, a co-chair of the working group on impacts, said in the Guardian report. “This is the largest clarion bell from the science community and I hope it mobilizes people and dents the mood of complacency.”

Not everyone — including many scientists — believe in the climate change expiration date.

In November 2018 more than a dozen prominent scientists met in Germany to cast doubt on the U.N.’s claim about man-made climate change and its consequences.

The scientists spoke at the 12th International Climate and Energy Conference, cosponsored by the free-market think tank, the Heartland Institute:

Among the highlights of the EIKE conference, scientists will discuss the latest science regarding natural climate cycles, sea level, solar variability versus atmospheric carbon dioxide concentrations, shortcomings regarding renewable power, flaws in asserted temperature histories, the benefits of a warmer world, desertification, and ulterior goals of climate activists.

“The scientific evidence and conclusions reported by climate scientists are far different than what the environmental left and their legacy media allies would like the public to believe,” Heartland Institute Senior Fellow James Taylor said.

Ronald Bailey, a science correspondent with Reason magazine who believes in man-made climate change but not the U.N. report, wrote:

There is no denying that man-made global warming could become a significant problem for humanity over the course of this century. In addition, the projections of the climate and econometric models could be way underestimated. Consequently, hedge fund manager Bob Litterman sensibly argues that climate change is an undiversifiable risk that would command a higher risk premium. Litterman likens climate change risk to the systemic risk that investors face in the stock market. It is hard to hedge when unknown unknowns can cause the prices of all assets to decline at once. While Litterman’s analysis strongly suggests that some investments toward mitigating climate risk should be made, it is not unreasonable to question the expensive and rushed decarbonization schemes proposed in the IPCC report.

“In any case, if the worst-case projections of the IPCC report are even approximately correct, Rep. Ocasio-Cortez is wrong—our kids will not be doomed in 12 years, or even in 81, ” Bailey concluded.

Follow Penny Starr on Twitter