Why the cost of carbon pollution is both too high and too low

(This post originally appeared on EDF Voices)

Tell someone you are a “climate economist,” and the first thing you hear after the slightly puzzled looks subside is, “How much?” Show me the money: “How much is climate change really costing us?”

Here it is: at least $40.

That, of course, isn’t the total cost, which is in the trillions of dollars. $40 is the cost per ton of carbon dioxide pollution emitted today, and represents the financial impacts of everything climate change wreaks: higher medical bills, lost productivity at work, rising seas, and more. Every American, all 300 million of us, emit around twenty of these $40-tons per year.

The number comes from none other than the U.S. government in an effort to uncover the true cost of carbon pollution. This exercise was first conducted in 2010. It involved a dozen government agencies and departments, several dozen experts, and a fifty-page, densely crafted “technical support document,” replete with some seventy, peer-reviewed references and an even more technical appendix.

Cass Sunstein, the Harvard legal scholar of Nudge fame, who was co-leading the process for the White House at the time, recently declared himself positively surprised how the usual interest-group politics were all-but absent from the discussions throughout that process. This is how science should be done to help guide public policy.

The cost of carbon pollution is too low

The number originally reached in 2010 wasn’t $40. It was a bit more than half as much. What happened? In short, the scientific understanding of the impacts of rising seas had advanced by so much, and the peer-reviewed, economic models had finally caught up to the scientific understanding circa 2007, that a routine update of the cost of carbon number resulted in the rather dramatic increase to near $40 per ton. (There are twenty pages of additional scientific prose, if you want to know the details.)

In other words, we had been seriously underestimating the cost of climate change all along. That’s the exact opposite of what you hear from those who want to ignore the problem, and the $40 itself is still woefully conservative. Some large companies, including the likes of Exxon, are voluntarily using a higher price internally for their capital investment decisions.

And everything we know about the science points to the fact that the $40 figure has nowhere to go but up. The more we know, the higher the costs. And even what we don’t knowpushes the costs higher still.

Howard Shelanski, Sunstein’s successor as the administrator of the Office of Information and Regulatory Affairs (OIRA, pronounced “oh-eye-ruh”), has since presided over a further update of the official number. In fact, this one didn’t incorporate any of the latest science. It was simply a minor technical correction of the prior update, resulting in a $1 revision downward. (The precise number is now $37, though I still say $40 at cocktail parties, to avoid a false sense of precision. Yes, that’s what a climate economist talks about at cocktail parties.)

And once again, it all demonstrated just how science ought to be done: Sometimes it advances because newer and better, peer-reviewed publications become available. Sometimes it advances because someone discovers and fixes a small mathematical error.

Your input is needed

While announcing the correction, Shelanski added another layer of transparency and an opportunity for further refinements of the numbers: a formal call for public comments on the way the cost of carbon figure is calculated, open through January 27 February 26th.

We are taking this opportunity seriously. EDF, together with our partners at the Natural Resource Defense Council, New York University School of Law’s Institute for Policy Integrity, and the Union of Concerned Scientists, is submitting formal, technical comments in support of the administration’s use of the cost of carbon pollution number as well as recommending further revisions to reflect the latest science.

The bottom line, as economists like to put it, is that carbon pollution costs society a lot of money. So as the technical experts trade scientific papers, you can help by reminding our leaders in Washington that we need strong, science-based climate policies.

Update (on January 24^th): The official comment period just was extended for another month, through February 26^th. More time to show your support.