Possible Insight

Welcome to the Foreword for my Climate Change Policy blog posts. If you want a quick overview or pointers on which posts might address your specific interests, this is the place.

While I’ve had a strong interest in Global Warming/Climate Change for about 15 years, these posts all stemmed from recent curiosity around the question, “Are the long term climate models, whose results dominate the headlines on future temperature projections, any good?” The project then evolved into examining the policy implications of the answer.

TL;DR:

• The answer to my original question is clearly, “No.”
• This isn’t merely my opinion. A careful meta-analysis of 1154 results from 120 articles in the peer reviewed literature shows that models overestimate the effect of CO2 on temperature by 2-3X.
• This same analysis shows that “high impact” journals are biased toward emphasizing large effect sizes from lower powered studies, explaining why the public’s and even climate scientists’ perceptions are skewed.
• If you run the impact assessment models used by the IPCC and the Obama administration with the central estimate of CO2 effects from the peer-reviewed literature, the conservative (higher) social cost of carbon estimate is $36 per metric ton of CO2 emitted in 2020. This translates into 32 cents per gallon for gasoline, 1.4 cents per kwh for electricity from natural gas, and 2.8 cents per kwh for electricity from coal. Some of the models under some assumptions, actually produce a cost of around $0.
• The standard economic tool for addressing this situation is a tax on carbon emissions. Popular policies like electric car subsidies, rooftop solar subsidies, and renewable mandates are wasteful in comparison.
• Even in absolute terms, those popular policies are mostly not cost justified, even in extreme scenarios.
• The geology and paleontology literature does not support claims that we are anywhere near a “tipping point” or “climate crisis” that threatens human civilization.
• Concept like the “Precautionary Principle” or “Asymmetric Damage Function” do not automatically justify significant additional restrictions on CO2 emissions beyond their expected social cost.

While I wrote Climate Models as Prediction Algorithms first, most people should skip it. It’s simply my analysis of climate model accuracy using a particular technique I hadn’t seen anyone use. In terms of my overall conclusions, it matters very little.

Much more important is Evidence Against Climate Model Accuracy. It reviews what the true professionals have to say. But if you want only the key conclusion, I recommend you read this GrokInFullness blog post. I kind of sped over the climactic point (pun intended) because he did such a great job of explaining it.

Optimal Climate Change Policy discusses what we should do about Climate Change and calculates the social cost of carbon given the best estimates of CO2’s effects on temperature. The first part explains why taxes are better than command an control policies. If you are already comfortable with Pigouvian taxes, skip down to “What a Carbon Tax Looks Like”. Everyone should read “Backup Position: Abatement Costs”. These are the hard numbers on cost effectiveness of various common reduction measures, regardless of policy instrument.

If you think the risk of an extreme outcome trumps these calculations, Climate Change Tail Risk addresses this argument.