The federal judge overseeing two climate liability lawsuits in California hosted a tutorial on climate science in his courtroom Wednesday, granting climate activists something they’ve long desired – “a trial on climate science.” The activists had hoped for an epic showdown between climate-denying “planet wreckers” and climate scientists, so they were caught off guard when the oil and natural gas companies reaffirmed what they have been saying for years: climate change is real.

But they shouldn’t have been surprised, because the industry has accepted the consensus view on climate change for over a decade, and even telegraphed their arguments ahead of the hearing. But the activists’ view of the energy industry is so detached from reality that when they found themselves in agreement with their adversary, they struggled to figure out how to respond. They finally regrouped and attacked the industry for relying on a climate science report the activists had previously heaped with praise.

Climate science, it would seem, has a very short shelf life.

The industry was represented at the tutorial by a lawyer for Chevron, who presented on the assessment reports issued by the United Nations’ Intergovernmental Panel on Climate Change (IPCC) every few years. The most recent report was published in 2014 and represents “the most comprehensive and authoritative synthesis of knowledge about global climate-change impacts, adaptation, and vulnerability ever generated,” according to a statement by President Obama’s science advisor when the report was published less than four years ago.

Dr. Steve Rintoul, a Coordinating Lead Author of Chapter 3 of the latest report, has called the assessments “an extraordinary exercise,” adding, “I don’t know of any other area of science where scientists attempt to assess what we know, and how well we know it, in such a comprehensive way.”

Anti-fossil fuel activists have praised the report as the definitive collection of the available climate science. The Union of Concerned Scientists’ Peter Frumhoff said “the authoritative and cautiously-written climate science synthesis provokes us to confront profoundly important questions.” InsideClimate News reports that the IPCC’s 2014 assessment represents “the mainstream view of the world scientific community.” Greenpeace called the IPCC’s 2014 report “gamechanging” and #ExxonKnew activist Bill McKibben wrote that it “falls just short of announcing that climate change will produce a zombie apocalypse plus random beheadings plus Ebola.”

But as soon as Chevron started quoting from the IPCC report, the climate activists turned on it, dismissing the report they had once praised and suggesting it was outdated. And yet they also managed to criticize Chevron for not discussing research from the 19th and 20th centuries, which is by all accounts more outdated than the 2014 IPCC report. Brian Kahn, a writer for Earther who followed the tutorial, exemplified the position the activists managed to contort themselves into:

“When it came time to talk about climate history and best available science, the oil company lawyers strangely didn’t delve into Exxon’s decades of research they hid from the public. Nor did they talk about the long history of research connecting carbon dioxide and climate dating back to the 1800s.

“Instead, they talked about the Intergovernmental Panel on Climate Change. You know, the thing Al Gore won the Nobel Prize for. The group has put out authoritative reports every five years on climate change since 1990, with the most recent one published in 2013 and 2014.

“Constraining the discussion to that period basically ignores a ton of major and dire findings. Four years might not sound like a lot, but the thing is it’s actually more than four years because of the time it takes to do research, run and build models, and write a monstrous tome of knowledge.”

Yet the very same article quoted climate scientist Katharine Hayhoe calling the IPCC report “the gold standard of climate science assessment.” It would appear the report is the gold standard except when Chevron decides to use it. University of Colorado Boulder professor Roger Pielke Jr. highlighted the absurdity of their argument in a tweet:

One of the activists following the tutorial even managed to find a way to criticize Chevron’s lawyer for citing a 2017 study by one of the scientists presenting for the cities.

Hunter Cutting is a Director of Strategic Communications for Climate Nexus, which is a project of the Rockefeller Philanthropy Advisors. Recall that the Rockefellers have funded every step of the #ExxonKnew campaign and Climate Nexus has been the go-to firm for activists on this issue. According to Cutting, it was OK for the Griggs to cite a 2014 study in his report last year, but not OK for Chevron to do the same this year.

But while the activists were scrambling to develop new attacks against the oil and gas industry, Judge Alsup was scolding the presenters representing the cities that are suing the energy companies for presenting misleading information.

The tweet refers to Myles Allen, a central figure in the #ExxonKnew campaign. He is well known for advocating for climate lawsuits against energy companies, including a profile in New Scientist profile titled, “I want to show the courts who’s to blame for climate change.” Further, Allen has close ties to activist groups including Union of Concerned Scientists and the Climate Accountability Institute and his work is funded by several wealth anti-fossil fuel foundations.  He attended the now infamous 2012 La Jolla Conference where activists plotted various ways to take down the fossil fuel industry. He also co-authored an op-ed in The Guardian with Peter Frumhoff of the Union of Concerned Scientists – the piece was titled, “Big Oil must pay for climate change. Now we can calculate how much.”

At the conclusion of the five-hour tutorial, Judge Alsup dismissed the activist allegation that fossil fuel companies conspired to suppress climate science. The comment from the Clinton-appointee is a stunning blow to the activists, plaintiffs’ lawyers, and public officials who have spent several years conspiring to accuse energy companies of misleading the public on climate change and undercut the central premise of the lawsuits.