World won't meet temperature goal just by cutting CO2

Oct. 23, 2017
Institutions shunning oil and gas ignore problems of feasibility in the management of global average temperature.

Institutions shunning oil and gas ignore problems of feasibility in the management of global average temperature.

As governments set end dates for sales of new vehicles fueled by gasoline and diesel, BNP Paribas Group announces its withdrawal from investment in hydrocarbons from shale or oil sands.

To meet the international goal of limiting Industrial Age temperature rise to 2°C., says the big French bank, "the world must reduce its dependence on fossil fuels."

In fact, that's not nearly all it must do.

If global emissions of carbon dioxide could be cut by 100%, moderation of temperature rise in 2100 would be, at best, 18% of what's targeted.

And that, according to a calculator created at the libertarian Cato Institute, would be if climate sensitivity were unexpectedly high.

Climate sensitivity is the temperature increase associated with a doubling of CO2 in the atmosphere. Most climate models use sensitivities of 2°-4.5°C.

According to the Cato Institute's Carbon Tax Temperature-Savings Calculator, climate sensitivity of 4.5°C. and CO2 reduction of 100% by industrialized countries avert temperature rise in 2100 by 0.352°C.

Total CO2 reduction with climate sensitivity of 3°C., which the Intergovernmental Panel on Climate Change considers most likely, lowers end-century temperature influence to 0.278°C.

The Cato Institute's web site describes the assumptions and models used by the calculator and points out that temperature outputs go to impossible levels of precision to facilitate comparison.

Lower levels of CO2 reduction and lower assumptions about climate sensitivity yield lower projections for temperature rise averted.

If the calculator is right, meeting the 2°C. target under standard assumptions requires much more than electrifying transportation to cut emissions of CO2.

It also requires curtailing animal agriculture to slash emissions of methane, another greenhouse gas subject to meaningful human influence.

After foreclosing energy and vehicle choices to avert less than half a degree of hypothetical warming, therefore, governments will have to tell people what they cannot eat.

If word gets out, this program's political prospects cannot be good.