Nobel Prize Awarded for the Worst Climate Model

Given the persistent headlines about climate change over the years, it’s surprising how long it took the Nobel Committee to award the Physics prize to a climate modeler, which finally occurred earlier this month.

Indeed, Syukuro Manabe has been a pioneer in the development of so-called general circulation climate models (GCMs) and more comprehensive Earth System Models (ESMs). According to the Committee, Manabe was awarded the prize “For the physical modelling of the earth’s climate, quantifying variability, and reliably predicting global warming.”

What Manabe did was to modify early global weather forecasting models, adapting them to long-term increases in human emissions of carbon dioxide that alter the atmosphere’s internal energy balance, resulting in a general warming of surface temperatures, along with a much larger warming of temperatures above the surface over the earth’s vast tropics.

Unlike some climate modelers, like NASA’s James Hansen — who lit the bonfire of the greenhouse vanities in 1988, Manabe is hardly a publicity hound. And while politics clearly influences it (see Al Gore’s 2007 Prize), the Nobel Committee also respects primacy, as Manabe’s model was the first comprehensive GCM. He produced it at the National Oceanic and Atmospheric Administration’s Geophysical Fluid Dynamics Laboratory (GFDL) in Princeton NJ. The seminal papers were published in 1975 and 1980.

And, after many modifications and renditions, it is also the most incorrect of all the world’s GCMs at altitude over the vast tropics of the planet.

Getting the tropical temperatures right is critical. The vast majority of life-giving moisture that falls over the worlds productive midlatitude agrosystems originates as evaporation from the tropical oceans.

The major determinant of how much moisture is wafted into our region is the vertical distribution of tropical temperature. When the contrast is great, with cold temperatures aloft compared to the normally hot surface, that surface air is buoyant and ascends, ultimately transferring moisture to the temperate zones. When the contrast is less, the opposite occurs, and less moisture enters the atmosphere.

Every GCM or ESM predicts that several miles above the tropical surface should be a “hot spot,” where there is much more warming caused by carbon dioxide emissions than at the surface. If this is improperly forecast, then subsequent forecasts of rainfall over the world’s major agricultural regions will be unreliable.

That in turn will affect forecasts of surface temperature. Everyone knows a wet surface heats up (and cools down) slower than a dry one (see: deserts), so getting the moisture input right is critical.

Following Manabe, vast numbers of modelling centers popped up, mushrooms fertilized by public — and only public — money.

Every six years or so, the U.S. Department of Energy collects all of these models, aggregating them into what they call Coupled Model Intercomparison Projects (CMIPs). These serve as the bases for the various “scientific assessments” of climate change produced by the U.N.’s Intergovernmental Panel on Climate Change (IPCC) or the U.S. “National Assessments” of climate.

In 2017, University of Alabama’s John Christy, along with Richard McNider, published a paper that, among other things, examined the 25 applicable families of CMIP-5 models, comparing their performance to what’s been observed in the three-dimensional global tropics. Take a close look at Figure 3 from the paper, in the Asia-Pacific Journal of Atmospheric Sciences, and you’ll see that the model GFDL-CM3 is so bad that it is literally off the scale of the graph.

At its worst, the GFDL model is predicting approximately five times as much warming as has been observed since the upper-atmospheric data became comprehensive in 1979. This is the most evolved version of the model that won Manabe the Nobel.

In the CMIP-5 model suite, there is one, and only one, that works. It is the model INM-CM4 from the Russian Institute for Numerical Modelling, and the lead author is Evgeny Volodin. It seems that Volodin would be much more deserving of the Nobel for, in the words of the committee “reliably predicting global warming.” 

Might this have something to do with the fact that INM-CM4 and its successor models have less predicted warming than all of the other models?

Patrick J. Michaels is a senior fellow working on energy and environment issues at the Competitive Enterprise Institute and author of “Scientocracy: The Tangled Web of Public Science and Public Policy.”