As the world frets about climate change and starts rooting around for sources of carbon-free energy, nuclear power is poised for a comeback. Peter Scoblic wrote a fantastic piece in this week's TNR about that renaissance, and how it will increase the danger of nuclear proliferation. It's also worth asking, though, how large a role nuclear power can actually play in a carbon-constrained future. Here's Peter:

John Ritch, the head of the World Nuclear Association, an international trade group, has painted nuclear as the only barrier against apocalypse: "We must place ourselves on a trajectory for a twenty-first-century nuclear industry that achieves the deployment of nothing less than 8,000-10,000 gigawatts of nuclear power"--that is, more than 20 times current capacity. "To plan for anything less would be to invite environmental disaster." This kind of hyperbole infuriates skeptics of the nuclear renaissance, who note that nuclear power cannot grow nearly fast enough to "solve" global warming--the optimistic scenario put forward by the International Atomic Energy Agency (IAEA) predicts the amount of nuclear power will merely double by 2030.

Similarly, Charles Ferguson of the Council on Foreign Relations recently argued that it's difficult to envision nuclear power playing more than a bit part in the carbon-reduction game, at least in the short term. The United States has 103 nuclear reactors currently operating. Even if we extend their lifespans by 20 years, those plants will all need to be decommissioned by mid-century, and replacing them alone would mean building a new reactor every four or five months for 50 years—already a "daunting" pace. (If France can get 80 percent of its electricity from nuclear, why can't we? Well, the United States already gets much more total electricity from nukes than France does. Scaling up isn't so simple.)

Another way to think about tackling global warming with existing technology is to do what Joe Romm did and draw up seven or eight "stabilization wedges," divvying up the roles that conservation, nuclear, renewables, carbon capture, and so forth will play in keeping atmospheric carbon concentrations below 450 parts per million. For nuclear to provide one "wedge," according to an in-depth Keystone Center report, the world needs to build as many as 20 to 40 reactors per year for 50 years—plus ten Yucca Mountains for the waste. Again, far, far beyond the IAEA's optimistic scenarios. The Keystone experts disagreed on the feasibility here. One problem is that the supply of building materials and trained personnel would strain under the pace. Already the industry is seeing bottlenecks in these areas, and while the market might adjust eventually, that could take a long time. And we haven't even delved into whether there's enough reasonably priced uranium to go around, a matter of some contention.

The other thing to ponder here is cost. Nuclear is a proven technology, so it's natural for people to assign it a major role for the future. But will it always be more cost-effective than, say, renewable energy? Some folks even argue that wind and solar are cheaper right now—see last year's Wilson Quarterly debate (pro and con) for a fine intro to this dispute. It's not an easy issue, but it's definitely worth exploring further.

--Bradford Plumer