Roger Pielke Jr. has written many times about the grossly exaggerated emission scenarios used by climate modelers to justify scary global warming studies, especially the dreaded RCP8.5. Despite it and its scurvy companions being clearly unrealistic, climate modelers and authors of so-called “impacts” studies just kept using 8.5, like an addict who can’t quit the drug that once brought pleasure and now just keeps them from collapsing. But over the past year Pielke Jr. wrote several articles expressing a cautious hope that modelers were beginning to detox and get sober, now that scenario analysts have decisively shown the implausibility of RCP8.5 and others like it. Alas he underestimated the grip of the alarmist drug. And so in a new Substack post he discusses a recent report from the IPCC modeling group which rejects scientific advice to quit the high emissions fix and instead declares it’s checking out of rehab and has “chosen – again – to assign the most extreme scenario its highest priority.” And like an addict, climate science is not to be trusted when off the wagon.
Pielke Jr. says that earlier disputes associated with exaggerated emission scenarios arose because of a timing problem. The IPCC process for scenario development, in which it engages anew for each of its Assessment Reports, begins with assessment of plausible future socioeconomic development pathways, showing what the economy might do and what policy might be, then works out plausible emission pathways based on various economic and policy futures, which in turn create plausible GHG concentration projections for the modelers to use. But in each cycle the modelers complain that they need to run their models long before the scenario assessment has been completed if they are to meet IPCC report deadlines.
So last time around the modelers took matters into their own hands and devised an RCP scenario range before the socioeconomic scenarios were done. And alas in doing so they ignored questions of plausibility, instead placing maximum weight on the high end of emission pathways. Eventually the “Shared Socioeconomic Pathways” or SSPs were dreamed up to justify the RCPs and instead confirmed that RCP8.5 was junk. But by then the modelers were junkies and weren’t about to stop.
Now that a whole new scenario-generating exercise is underway, the energy sector analysts issued a call for the modelers to wait until plausible scenarios could be nailed down, and they specifically cautioned against using what had up to now been high-emission scenarios since they were known to be implausible. But in his new essay Pielke Jr. reports that the modelers have said no thank you and are back to using the hard stuff again:
“Surely the climate science community would not again in 2024 repeat the mistake of decoupling plausibility from scenario selection and prioritization? Think again. Last week the climate science community doubled-down on such a decoupling.”
Their rhetorical trick this time is to say that once again science demands they study a whole range of emission scenarios and defer judgments about plausibility until later. But it’s what they also said last time and then, instead of dealing sensibly with the range, even after being shown the implausibility of their favourite scenario they simply ignored this unwelcome information and kept snorting the high lines they and their political masters favour.
Now they’re going into a new round of modeling work pretending they learned nothing about the low likelihood of upper-end emission scenarios and saying such questions can wait until later, a word here meaning never, because they have to start running their models again and need them to run hot.
Pielke Jr. observes:
“The climate modeling community is aware that the plausibility of the highest and lowest scenarios has been questioned... Yet, they have identified the highest priority scenarios to be a very high and a very low emissions scenario – those that have the lowest plausibility.”
As he adds, the insiders know perfectly well the consequences of their decisions. But almost no one else does:
“Few people realize that the next several decades of climate science – and thus peer reviewed research, media coverage, climate advocacy, climate policy – are now being determined by a very small group of researchers, with a very narrow range of disciplinary expertise, without any underlying research on scenario plausibility or utility in decision making.”
At a certain point friends and family of junkies need to stage an intervention. Climate scientists have turned their labs into the scientific equivalent of crack houses. If they can’t stop using grossly exaggerated emission scenarios of their own free will, the rest of us have to save them and their reputations from themselves.
Can't we just declare that climate modelers are in conflict of interest and until they are funded by anyone but the tax collecting folks marketing a crisis to justify unleashing their Jacobin designs for humanity along with their codependent NGOs.