The Koch network recently made a request to the Trump administration for a red team to attack climate science. In the letter sent to the administration by 140 Koch-affiliated groups and individuals, they claim that models use “climate sensitivities to CO2 concentrations significantly higher than recent research warrants.” (That “recent research” meaning studies that focus on the faux pause.)
Of course, this isn’t true, and the latest results from the new series of models prove it. Carbon Brief ran a great post Thursday on the most recent round of global climate models, called the coupled model intercomparison project, or CMIP. Preliminary results from this new version that will be used for the next IPCC report actually show the climate is probably a little more sensitive to CO2 than we thought, not less.
The last CMIP versions found that a doubling of carbon dioxide in the atmosphere (known as estimated climate sensitivity, or ECS) would ultimately lead to 2.1C to 4.7C of warming. This new round of modeling, which incorporates but doesn’t rely on the “recent research” deniers point to, instead puts that figure a bit higher, at 2.8C to 5.8C.
To put that in context, Carbon Brief provides a helpful timeline showing nearly 20 years of ECS studies. Those findings largely center around 3C, so the most cutting edge research suggests what we’ve come to expect might actually be on the optimistic end of things.
The big question, though, is whether the next IPCC report will properly convey this alarming change, or bury it in uncertainty qualifiers and technical jargon.
Enter a new paper in BioScience that finds the last IPCC report is remarkably conservative in how it describes the climate challenge. The study builds on past research explaining climate scientists’ preference to err on the side of least drama, as well as studies showing how denier propaganda seeps into legitimate climate science.
The team combed through the AR5 report, tallying up all the qualifiers used to express certainty and likelihood of findings. They found 3,191 qualifiers were used in total, with 1,979 qualifiers for certainty and 1,212 describing likelihood.
The researchers then broke it out by whether those qualifiers were expressing very high, high, medium, low or very low confidence, as well as a similar breakdown for the probability ranges. It found that most of the confidence qualifiers were “medium,” and most of the probabilities in the middle 33%-66% range.
In addition to a new set of descriptors that reflect uncertainty a little more clearly for the lay public (switching from high or low confidence to describing the science as divergent, emerging, limited or robust), the paper also recommends the IPCC launch a new working group “focused on climate-change outreach.”
By bringing together communication experts, educators, psychologists and climate scientists, the paper says, the IPCC could formalize the amplification and popularization of the report materials. It would also help reconcile the IPCC’s focus on science over politics, as this outreach arm would be equipped to navigate the political waters in which the IPCC’s science gets put into action.
Taken together, this new study and Carbon Brief’s explanation of the preliminary findings of the new generation of climate models make it clear that the IPCC is hardly alarmist. This information shows that models are, if anything, underestimating how much warming is in store for us.
But even though deniers are attempting to create an official US government panel to “examine” the science, they’re clearly more interested in playing political games.
Don’t take our word for it--just ask them. Back in 2017, remember, internal communications about the red team included the admission that all they need for victory is “to be able to say 'EPA is reconsidering whether CO2 is a pollutant,'” and that the whole effort is “political and not scientific.”
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