I wrote the other day about how it’s insane to write about the costs of carbon pricing without considering the benefits—which is to say without considering the costs of allowing out-of-control climate change. And one should be clear that these costs are likely very high and quite possibly apocalyptic. For example, the most recent probabalistic forecasts out of MIT conclude that there’s an approximately nine percent chance that we’ll see more than seven degree centegrade (i.e., 12.6 degree farenheit) worth of warming by 2100:
The probably won’t happen. But the odds of it happening aren’t all that narrow. If you do a naive projection, that would mean an average July high temperature of over 117 degrees in Phoenix. The city would be uninhabitable. And that’s likely an underestimate, since the extremes would probably grow hotter faster than the average. More to the point, it would set off a lot of irreversible feedback loops. Melting of the permafrost and consequent leakage of gas, removal of high-albedo snow cover, vast regions of permanent desertification, etc.
These things are losses we can’t recoup. Against that backdrop, the prospect of somewhat-slower-growth is not, in my view, especially threatening especially because there are other, offsetting things one could do to increase the rate of growth. Of course precisely which policies would maximize growth is controversial, but I think everyone agree that the policy status quo does not maximize growth. But if Australia ceases to support human life, there isn’t really a good fallback alternative.