Would a Phaseout of Hydrofluorocarbons Avoid Half a Degree of Global Warming?

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This piece was co-authored by Benjamin Zycher 

In a recent “Daily on Energy” report for the Washington Examiner, Josh Siegel and Abby Smith reported: “This morning, the EPA unveiled a proposal to begin limiting potent greenhouse gas coolants known as hydrofluorocarbons, or HFCs. It’s a significant step to curb climate change, as phasing down HFCs could help avoid roughly 0.5 degrees Celsius of warming.”

The claim that a phaseout of HFCs would reduce future warming by 0.5 C is the conventional wisdom, and like many such assertions accepted among Beltway types, it is based upon dubious foundations and assumptions.

For perspective, note that the entire Paris Agreement, if implemented immediately and enforced strictly, would reduce global temperatures by 0.17 C by 2100, as predicted by the Environmental Protection Agency’s climate model under assumptions that exaggerate the effects of reduced greenhouse gas emissions. The temperature effect of a 50% emissions cut by China would be 0.184 C, but that is a distant fantasy given the number of coal plants that it is building.

In its most recent compendium on climate change in 2013, the United Nations’s Intergovernmental Panel on Climate Change estimated only a 0.13 C effect from HFCs through 2100, under its “business as usual” scenario. So, how did the half-degree number emerge? Warren Cornwall reported in Science that “the figure has its origins in a 2006 dinner held by five scientists in a village in the Swiss alps.” The underlying analysis then appeared in a paper published seven years later. It assumed massive and exclusive adoption of HFC-equipped air conditioning in the developing world by 2050, with that equipment remaining in place through 2100.

In other words, market incentives to produce cheaper, more efficient air conditioning would be ignored. The authors assumed as well that all those demanding air conditioning would have it by 2050, a hugely problematic premise applied to Africa, under the premise that in 30 years, the availability of electricity will be widespread and reliable. In reality, solar and wind are not. In addition, the authors assume that any replacement equipment also will be charged with HFCs.

The 2013 paper reported an estimated warming range mitigated by an HFC ban of 0.35 C to 0.5 C. Cornwall noted that “advocates and negotiators tended to cite the higher, 0.5 C estimate in their public remarks.” That latter figure is almost four times larger than the 0.13 C projected by the IPCC, a figure close to the standard deviation (0.11 C) of global average surface temperatures from year to year. Accordingly, the effect would be virtually undetectable from the background variation in temperatures.

This means that a policy-driven phaseout of HFCs cannot satisfy any plausible cost-benefit test if the costs of the phaseout prove greater than trivial. But the current substitutes for HFCs cost multiple times more, not including costs for equipment, repairs, and the like. If the substitutes were efficient in terms of costs and performance, no legislation would be needed to drive the HFC equivalents out of the market. Producers of hydrofluoroolefins and other substitutes for HFCs, and the complementary equipment and the like, would be free to compete. A preference for a forced phaseout of HFCs in place of competition suggests that the substitutes for HFCs are substantially costlier, a reality supported by the available data.

Siegel and Smith noted that “the EPA estimates that the HFC phasedown in the U.S. would eliminate greenhouse gas emissions equal to 4.7 million metric tons of carbon dioxide by 2050.” Does that sound impressive? Suppose that the entire world were to cut greenhouse gas emissions in half by 2050; emissions that year would be about 27 billion tons. The 4.7-million-ton equivalent reduction would be 17 one-thousandths of 1%, the temperature effect of which would be undetectable.

Read the full article at The Washington Examiner.