
Various news reports and self-serving political pronouncements would have us believe that imposition of a tax on “carbon” — emissions of greenhouse gases (GHG) — now enjoys growing support among Republican policymakers and conservative observers, a political premise advertised at a decibel level vastly higher than actual political reality would support. That reality is straightforward: Any policy to reduce GHG emissions by definition must increase energy costs, and policymakers endorsing such policies would have to describe the benefits that supposedly would redound to the electorate.
And that is a very serious political stumbling block: The most prominent “conservative” proposals for a carbon tax would reduce global temperatures in the year 2100 by about 0.015°C, as estimated by the EPA climate model under a set of assumptions exaggerating the temperature effect of GHG reductions. That effect would not be measurable, as it is an order of magnitude smaller than the standard deviation of the surface-temperature record. A complete elimination of U.S. GHG emissions, envisioned by supporters of the Green New Deal, would yield a temperature reduction of 0.173°C under the same favorable assumptions. (An international policy vastly more aggressive than the Paris agreement, and thus utterly unachievable, would have an effect of about 0.5°C.)
And so the “insurance” argument for a carbon tax — it would ameliorate a future climate crisis — is a nonstarter, as the “insurance” created with any carbon tax even remotely plausible would be effectively nonexistent. (The recent IPCC “1.5 degrees Celsius” report calls for an energy tax equivalent to $29 per gallon of gasoline.)
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