Ever since climate change entered U.S. public consciousness -- let's date it to James Hansen's 1988 testimony to Congress -- one objection to national climate legislation has remained steady: It will hurt our country without benefiting the climate. If we raise the price of fossil-fuel energy, carbon-intensive industries will simply migrate to other countries, possibly even emitting more carbon there. We'll hobble ourselves economically for no net reduction in carbon. "It's called global warming, not American warming!" (A related argument is sometimes made about investing money in cleantech RD&D: Other countries will enjoy the benefits -- the "spillover" effects -- of our investments without any of the costs.)
This objection was the substance of the famed Byrd-Hagel Resolution, signed by 95 U.S. senators, which said that the U.S. would not ratify the Kyoto Protocol as long as developing countries were exempt from carbon targets. It has been a reliable go-to for those fighting off climate legislation ever since.
For reasons not entirely clear to me, Harvard law professor (and former head of Obama's Office of Information and Regulatory Affairs) Cass Sunstein has rebranded this old chestnut the "sophisticated objection" to climate action. Now that science rejectionism has become the baseline position on climate in the GOP, I guess anything short of outright obscurantism counts as sophisticated.
Sunstein's arguments against it (he believes the U.S. should act unilaterally on climate if necessary) are also fairly familiar: first, that American action is a necessary precursor to international action; second, that regulation spurs cleantech innovation; and third, that many actions we could take unilaterally already pass a cost-benefit analysis based on the widely accepted social cost of carbon.
Over at National Review Online, Reihan Salam has rounded up (and written) some interesting responses to Sunstein. Kudos to Salam, by the way, for being the rare conservative to take climate seriously. I hope he prompts some internal NRO discussions.
The first is from Oren Cass (er, no relation to the other Cass), one of Mitt Romney's top domestic policy advisers in the 2012 campaign. In it, he addresses Sunstein's third argument. He says:
This argument doesn’t answer the Sophisticated Objection, it ignores the Objection altogether. If carbon emissions actually had a quantifiable, linear, ton-by-ton cost then the Sophisticated Objection would make no sense because the value of action at home could be measured independent of what action was or was not taken abroad. If we gain the same benefit every time we reduce emissions by another ton, why would we care what China does? But of course, as Sunstein acknowledges by taking the Objection seriously in the first place, this is not how climate change works.
The entire premise of the Objection is that climate dynamics are extraordinarily non-linear and that the climate change threat is not susceptible to mitigation at the margin. The best science available today attempts to estimate the amount of warming associated with a given level of carbon in the atmosphere, and to determine the thresholds at which such warming is likely to trigger severe and irreversible effects on climate systems. On their current trajectory, global emissions blow through these thresholds; blowing through them by a little bit less does not have much value.
Cass is onto something important here. Many of the damages scientists fear most from climate change are nonlinear -- that is, pressure on an biophysical system builds and builds until it "snaps" suddenly into a new steady state ("suddenly" relative to geological time, that is). Cass is right: If one of those "tipping points" is going to be triggered at, say, 550 parts per million of CO2 in the atmosphere, there's no value at all in a policy that hits 560 instead of 580. If you tip, you tip; irreversible is irreversible.