DOING NOTHING ON CLIMATE CHANGE IS EXPENSIVE.

My new employers sure seem to spend a lot of time publishing columnists who are critical of climate science and then publishing op-eds and arguments that essentially trash the take of the original columns. The latest example comes in response to a frustrating effort by Robert Samuelson that took issue with the uncertainty in the models climate scientists are using. Paul Krugman had a very elegant rejoinder to this over on his blog a few days ago. But today, the op-ed page published a reply from Kristen Sheeran and Mindy Lubber, and they make a point that deserves wider airing:

[Samuelson] assumes that all costs involved in mitigating climate change -- and there will be costs -- represent new costs, without acknowledging the massive error in our market system that equates the price of carbon emissions to zero. This fundamental error skews everything that follows, because if emitting carbon costs nothing on a balance sheet, all steps to reduce pollution count as "new costs."

The real cost of carbon emissions is far from zero. Each new scientific report brings proof of a changing climate that promises to disrupt agricultural patterns, set off a scramble for dwindling resources, raise sea levels, propel population shifts and require massive emergency spending as we try to react to the growing crises. These are the costs of inaction.

Quite so. There's a legitimate space for constructive criticism of the speculative models that are used in the climate debate. Even the best models have problems. And there's no doubt that sharp questions can make them better, and thus improve the information that policy makers use to craft their response. But if your argument is going to be that climate economics needs to be more honest, then your assumptions have to be pretty transparent, too. And that means you need a transparent estimate of the costs of inaction.

This is actually a pretty general problem in Washington. It's easy to show how "doing something" costs money. "Doing something" needs to be written into legislation. It needs to be scored by the Congressional Budget Office. It needs to be explained to the public. But, in general, there's no one who is specifically responsible for explaining how much "doing nothing" would cost. And no one ever has to vote to pass a "do nothing" bill. So they don't pay for the consequences of inaction, even as reformers bear responsibility for the outcome of reform. That makes "doing nothing" a relatively safe play because you never have to argue in favor of nothing. You only have to argue against something.

But if we're going to be honest about the economics here, then you have to assess not only the costs of doing something, but also of doing nothing. And if you're going to argue against reforms, then you have to argue why the consequences of inaction are a preferable outcome, not merely why action might prove expensive or uncertain. Choosing the status quo is, after all, a choice.