(p. A15) . . . , an exemplary French report . . . begins, “But uncertainty about how hot things will get also stems from the inability of scientists to nail down a very simple question: By how much will Earth’s average surface temperature go up if the amount of CO2 in the atmosphere is doubled?”
“That ‘known unknown’ is called equilibrium climate sensitivity (ECS), and for the last 25 years the U.N.’s Intergovernmental Panel on Climate Change (IPCC)–the ultimate authority on climate science–has settled on a range of 1.5 C to 4.5 C.”
The French report describes a new study by climate physicists Peter Cox and Mark Williamson of the University of Exeter and Chris Huntingford of the U.K.’s Center for Ecology and Hydrology. Not only does it narrow the range of expected warming to between 2.2 and 3.4 degrees Celsius, but it rules out the possibility of worrying outcomes higher than 4 degrees.
. . .
. . . , [the IPCC] backpedaled in 2013 to adopt a wider range of uncertainty, and did so entirely in the direction of less warming.
. . .
The IPCC’s new estimate was no more useful or precise than one developed in 1979 by the U.S. National Research Council, when computers and data sets were far more primitive.
This 40-year lack of progress is no less embarrassing for being thoroughly unreported in the mainstream press. The journal Nature, where the new study appears, frankly refers to an “intractable problem.” In an accompanying commentary, a climate scientist says the issue remains “stubbornly uncertain.”
For the full commentary, see:
Holman W. Jenkins, Jr. “BUSINESS WORLD; Good Climate News Isn’t Told; Reporting scientific progress would require admitting uncertainties.” The Wall Street Journal (Wednesday, Feb. 28, 2018): A15.
(Note: ellipses added.)
(Note: the online version of the commentary has the date Feb. 27, 2018.)
The “new study” in Nature, mentioned above, is:
Cox, Peter M., Chris Huntingford, and Mark S. Williamson. “Emergent Constraint on Equilibrium Climate Sensitivity from Global Temperature Variability.” Nature 553, no. 7688 (Jan. 18, 2018): 319-322.