Climate change may be more expensive than we think

That is the topic of my latest Bloomberg column, here is the closing bit:

I am struck by the costs of climate change suggested in the UN’s Intergovernmental Panel on Climate Change report, hardly a source of denialism. Its cost estimate — “1 to 5% of GDP for 4°C of warming” — is relatively reassuring. After all, global GDP is right now growing at more than 4 percent a year. If climate change cost “only” 4 percent of GDP on a one-time basis, then the world economy could make up those costs with less than a year’s worth of economic growth. In essence, the world economy would arrive at a given level of wealth about a year later than otherwise would have been the case. That sounds expensive but not tragic.

Unfortunately, that is not the right way to conceptualize the problem. Think of the 4 percent hit to GDP, if indeed that is the right number, as a highly unevenly distributed opening shot. That’s round one, and from that point on we are going to react with our human foibles and emotions, and with our

highly imperfect and sometimes corrupt political institutions. (Libertarians, who are typically most skeptical of political solutions, should be the most worried.)

Considering how the Syrian crisis has fragmented the EU as well as internal German politics, is it so crazy to think that climate change might erode international cooperation all the more? The true potential costs of climate change are just beginning to come into view.