I am generally sympathetic to Robert Pollin’s argument. Investing in clean technology is going to be part of any realistic attempt to confront climate change.

However, Pollin makes strong claims for his proposals: he argues that they will reduce emissions and consumption, that they will do so fairly, and that they are “politically realistic.” These three criteria are certainly the right kind by which to judge climate policies. But it is going to be hard to satisfy all three, and Pollin’s attempt to do so depends on a number of contentious assumptions. Of course, his is a short essay and cannot be faulted for failing to provide more extensive documentation. But we do need more evidence on some key points before we accept that his proposal meets his own criteria.

The United States must help other countries to enjoy the benefits of new technologies.

Pollin takes for granted that his recommendations will reduce consumption, dismissing the likelihood of a “rebound effect.” But it is not clear why we should think that energy demand is close to saturation, and he supplies no evidence for this key claim. Why assume “most U.S. energy consumers today will not want to heat, cool, and light buildings, drive long distances, or operate appliances much more than they already do”? Moreover, since Pollin insists that a clean energy program need not require U.S. citizens to make significant sacrifices, we need especially strong assurance that job losses in industries dependent on fossil fuels, and the costs of retraining, will be recouped by the green sector.

But suppose that these and others of Pollin’s empirical assumptions work out. What about fairness? Pollin writes: “To make our minimally fair contribution toward reducing global emissions, we need to cut our own by at least what the IPCC recommends.” This is the first and last time Pollin invokes the idea of fairness, but it is an important part of a defensible energy policy. With any collective goal, it is essential to think about whether it distributes burdens and benefits fairly. But what principle of fairness is at work in Pollin’s essay? Why should we think his proposal is “minimally fair”?

Consider Pollin’s aim of reducing U.S. emissions by 40 percent over twenty years. Although it is hard to tell without more data, it seems that this policy still allows U.S. citizens to produce more per capita emissions than do citizens of many other countries. Is that fair, especially considering that a great majority of U.S. citizens could afford to reduce their energy usage and still lead very fulfilling lives? In addition such a plan takes no account of past emissions. Should a just energy policy ignore the history of U.S. emissions over the last quarter century? If the promise is that the clean energy program is “fair,” these are questions that need answers.

Many of these questions about fairness intersect with questions about foreign policy. Pollin’s essay is focused on a clean energy program for the United States, which he says “bears a special responsibility to deliver dramatic reductions.” But surely such responsibility includes global leadership. The United States must engage in technology transfer to enable other countries to enjoy the benefits of the innovation Pollin calls for. Without technology transfer, the poorest countries won’t be able to develop without contributing to climate change, so it would seem to fall to those with access to clean technology—and especially to countries such as the United States that are wealthy and have a history of high emissions—to guard against dirty development. What, then, is the foreign policy dimension of Pollin’s proposal? Is there a commitment to technology sharing? To the design of appropriate intellectual property rights? If not, why not?

Perhaps Pollin would reply that such commitments are not politically realistic. But that would only serve to remind us where the demand for fairness diverges from what U.S. citizens and political elites are willing to accept.