Earlier this week, we noted the carbon tax being proposed in the legislature would cost the average household about $175 in 2019, increasing to about $530 per houshold in 2029. Since the justification is to fight climate change, the question is, "what do we get for that cost?" We asked Benjamin Zycher of the American Enterprise Institute what climate models say about how much temperature would be reduced if the carbon tax meets its emissions reduction goals. Here is his response.

Governor Inslee proposes that by 2050 Washington state greenhouse gas emissions (GHG) be reduced by half below 1990 levels.  Any such policy can be attempted only by making energy more expensive, whether explicitly or implicitly, and those increased costs would be very substantial.  (No amount of rhetoric can change the central reality that if wind and solar power were competitive, they would not require massive subsidies and guaranteed market shares, and the intermittent and unconcentrated energy content of wind flows and sunlight, together with their high transmission costs, are likely to prevent an improvement in that competitiveness over the foreseeable future.)

But that is a question for another day. Whatever the costs of Inslee's proposal, the central question is: What would the environmental effect be in terms of reduced future temperatures?  That issue can be addressed by using the same climate model that federal policymakers use to estimate the effects of changes in GHG emissions engendered by various regulations and international agreements; the model was developed with funding from the Environmental Protection Agency. Under a set of assumptions that exaggerate the effects of reductions in GHG emissions, Inslee's proposal would yield a temperature reduction by 2100 of one one-thousandth of a degree.  Given the natural year-to-year variability in global temperatures, that effect would not be measurable.  

Different assumptions would yield slightly different answers, but at a qualitative level the differences would not matter: Inslee's proposal would have effects on global temperatures effectively equal to zero. There is no dispute about this; even the Obama administration never claimed that the temperature effects of its climate policies would be substantial. Instead, the argument was that America had to lead the world, a stance not very different from Inslee's argument that the state of Washington should "mark the way."  In the face of reduced investment, employment, consumer wellbeing, and all of the other adverse effects of energy more- rather than less expensive: How much is such virtue-signaling worth?