A New Crisis for Climate Science?

We are just weeks away from the two major climatista jamborees of 2021. The first is the UN COP 26 meeting in Glasgow next month, which the usual people (John Kerry, etc) are calling “the last chance to save the planet,” because all of the previous 25 “last chance” meetings were a false alarm. (You think I exaggerate? Check out the New York Times from June 30: “Democrats Have a Year to Save the Planet.”)

The second is the release of the next comprehensive report of the UN’s Intergovernmental Panel on Climate Change (IPCC), which typically issues a new 5,000-page report every five to seven years that collects and summarizes the latest state of “the science” of climate change. Suffice it to say that not much has changed since the first IPCC report almost 30 years ago. There might be some small, subtle changes in the next report, however.

The latest report was supposed to be done a year ago, but was delayed by you-know-what. But it is also possible that there are enough climate scientists involved in the process who are expressing concern that the climate models the political class is using to generate panic aren’t really working right, and want to dial it back a bit. If this turns out to be the case, these subtle changes in emphasis will likely be buried deep in the full IPCC report, and the 25-page “summary for policy makers” that the IPCC produces for media consumption will still say the end of the world is nigh if we don’t hand over our car keys.

One clue to this inside-baseball drama comes from an unlikely place—Science magazine, which is about as dead center in the scientific establishment as you can get. Last week Science published a remarkable article—remarkable for implicitly ratifying what climate “skeptics” have been saying about climate models for at least a decade, namely, that they are running “too hot.”

The article is entitled, “U.N. climate panel confronts implausibly hot forecasts of future warming,” and it is a real jaw-dropper:

[A]s climate scientists face this alarming reality [of a warming world], the climate models that help them project the future have grown a little too alarmist. Many of the world’s leading models are now projecting warming rates that most scientists, including the modelmakers themselves, believe are implausibly fast. In advance of the U.N. report, scientists have scrambled to understand what went wrong and how to turn the models, which in other respects are more powerful and trustworthy than their predecessors, into useful guidance for policymakers. “It’s become clear over the last year or so that we can’t avoid this,” says Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies.

The story goes on to explain that many of the worst-case warming model predictions—of more than 5 degrees C—are surely wrong, and it appears the next IPCC report may narrow the range of possible warming in the year 2100 to 2.6 to 3.9 degrees C, with this upper bound down from about 4.5 degrees C that has appeared in previous IPCC assessments. You can be assured that the new IPCC report will emphasize that nothing has essentially changed—that even 3.9 degrees will be the end of the everything. But parts of the Science story, even though cautiously written so as not to underline The Narrative, is really devastating for the “certainty” of climate prediction that we’re endlessly told to trust.

Like this:

In the past, most models projected a “climate sensitivity”—the warming expected when atmospheric carbon dioxide (CO2) is doubled over preindustrial times—of between 2°C and 4.5°C. Last year, a landmark paper that largely eschewed models and instead used documented factorsincluding ongoing warming trends calculated a likely climate sensitivity of between 2.6°C and 3.9°C. But many of the new models from leading centers showed warming of more than 5°C—uncomfortably outside these bounds.

The models were also out of step with records of past climate. For example, scientists used the new model from NCAR to simulate the coldest point of the most recent ice age, 20,000 years ago. Extensive paleoclimate records suggest Earth cooled nearly 6°C compared with preindustrial times, but the model, fed with low ice age CO2 levels, had temperatures plummeting by nearly twice that much, suggesting it was far too sensitive to the ups and downs of CO2. “That is clearly outside the range of what the geological data indicate,” says Jessica Tierney, a paleoclimatologist at the University of Arizona and a co-author of the work, which appeared in Geophysical Research Letters. “It’s totally out there.”

In addition to the difficulty climate models have in understanding the complex dynamics of the atmosphere (especially clouds), there is the additional problem of what emissions scenarios you feed into the computer models. Suffice it to say that most of the biggest temperature predictions you hear about are based on future emissions estimates that almost no one believes are remotely realistic (often referred to as the RCP8.5 problem).

Roger Pielke Jr. and Justin Ritchie give a comprehensive takedown of this problem in a recent article in Issues in Science and Technology. A few brief samples:

In our research on the plausibility of IPCC scenarios, we have discovered it is not just RCP8.5 that is implausible, but the entire set of baseline scenarios used by the IPCC. . .

The consequences of pervasive, implausible climate scenarios extend far beyond the IPCC process and the academic literature these scenarios have enabled. A continued focus on implausible emissions scenarios in climate research is a failure of science’s supposed internal quality assurance mechanisms and thus a failure of scientific integrity. The persistent use of implausible scenarios introduces error and bias widely across climate research. They are now woven through the climate science literature in ways that will be very difficult to untangle. . .

Many of these thousands of published papers project future impacts of climate change on people, the economy, and the environment that are considerably more extreme than an actual understanding of emissions and forcing pathways would suggest is likely. . .  And so, with any attempts at scientific nuance lost in technical language, these implausible projections of apocalyptic impacts decades hence are converted by press releases, media coverage, and advocates—as in an extended game of telephone—into assertions that climate change is now catalyzing dramatic increases in extreme events such as hurricanes, droughts, and floods, events that foreshadow imminent global catastrophe.

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