Right Opinion

Lousy Climate Models Yield Lousy 'Social Cost of Carbon'

Cornwall Alliance · Mar. 14, 2017

By E. Calvin Beisner

Yesterday I reported that Judith Curry has published a paper concluding (my way of putting it) that the computer climate models on which climate change alarmists depend provide no rational basis for predictions of future global temperature and therefore no rational basis for any policy related to such predictions.

One step in climate and energy policy making is establishing the so-called “social cost of carbon” (SCC). That’s a misnomer, of course, for it substitutes “carbon” (an element, a solid, posing a risk of respiratory diseases when it blows around as fine-particle black dust) for “carbon dioxide” (a compound, a gas, odorless, colorless, non-toxic at over twenty times today’s atmospheric concentration but essential to all life, with plants and their fruits increasing as its concentration rises). It’s also consistently calculated with reference only to carbon dioxide’s atmospheric warming effect (and sometimes also its ocean “acidification” effect — another misnomer, since what really happens is only a slight reduction in alkalinity), failing to account for its tremendous benefit in increasing plant growth and therefore food for all things that eat plants or eat things that eat plants, helpful especially to the poor through rising crop yields and consequent falling food prices.

The SCC is used as a rationale for policies to reduce carbon dioxide emissions. It serves as a way to calculate the cost/benefit ratio. The higher the SCC, the higher the costs of CO2 emission reductions that can be justified, and vice versa.

Our ability to calculate SCC, in turn, depends on our ability to predict how much warming comes from added atmospheric CO2, and climate models are our only means of doing that. So if the climate models fail, as Curry argues, then SCC calculation becomes impossible.

Image courtesy of John Christy.

Now add to this Patrick Michaels’s demonstration that the official U.S. government calculation of SCC is based on estimates of CO2-driven warming (called “equilibrium climate sensitivity”) that are too high, even assuming the reliability of the climate models (as shown in the chart above comparing temperature observations, in green, with model simulations, in red). You can read his entire congressional testimony to get the detailed evidence and reasoning, but here’s his conclusion:

The social cost of carbon as determined by the Interagency Working Group in their August 2016 Technical Support Document (updated from IGW reports from February 2010, November 2013, and July 2015) is unsupported by the robust scientific literature, fraught with uncertainty, illogical, and thus completely unsuitable and inappropriate for federal rulemaking. Had the IWG included a better-reasoned and more inclusive review of the current scientific literature, the social cost of carbon estimates would have been considerably reduced with a value likely approaching zero. Such a low social cost of carbon would obviate the arguments behind the push for federal greenhouse gas regulations.

In short, there is no justification for policies to reduce CO2 emissions. None. Nada. Nichts.

Republished from Cornwall Alliance.

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