Make no mistake: All of these drawbacks, combined, should not prevent us from ramping up investment in renewable energy. Wind and solar should be part of the mix, period. But even if we max it out, the numbers don't add up. Bill McKibben says we need to "do the math," which is to take the known fossil fuel reserves that oil and gas companies expect to tap and add that to the carbon already trapped in the atmosphere. The total will end up leading to catastrophic climate change. It's a powerfully frightening equation. But we also need to do the math for the energy equation, which should be equally frightening.
People like Smil and Brook have done the math, and that's why Hansen et al. are hoping nuclear energy will bail us out. But might they, too, be pining for the impossible?
A 2009 report by the Carnegie Endowment for International Peace concluded that nuclear power would not "make a big difference in reducing carbon emissions in the next two decades, when the biggest reductions will have the most impact," because the industry could not build enough reactors during that time. The report cited longstanding problems that have yet to be overcome, such as exorbitant construction costs, and unresolved issues related to uranium waste disposal. The growing sense of climate urgency combined with the slow approval for financing and construction of new nuclear reactors makes for a daunting challenge.
And this was before the 2011 Fukushima Daiichi power plant meltdown in Japan. Since then, safety concerns have prompted some countries to abandon nuclear energy plans; Germany is phasing out nuclear power altogether. (Perversely, this has resulted in more greenhouse-gas-emitting coal being burned.) Not that long ago, the industry was poised for a big rebound, but the future suddenly looks grim. Perhaps that is what led the Economist last year to largely write off nuclear energy as a lost cause—or at least not a viable substitute for fossil fuels.
Another factor stalling the so-called "nuclear renaissance" is cheap natural gas, courtesy of the shale boom. As the New York Times reported last year, the sudden glut and the rapid switch from coal to gas by many utilities "calls into question talk of a nuclear revival in the United States."
At this point, if there is going to be a revival of nuclear energy anywhere, it appears it will happen only with the arrival of new technology (what is referred to as "fourth generation" design) that resolves longstanding concerns and is competitive price-wise with coal and gas. As Hansen himself said last year: "For base-load electric power, I think that we need next-generation nuclear power, which can be much safer and which can burn nuclear waste and solve that major problem with nuclear power." The question is, will that vaunted "next generation" nuclear power arrive soon enough to supplant fossil fuels and save the climate from burning up?
Maybe that's the wrong question to ask. Maybe we shouldn't fixate on only one possible path to a low-carbon future, but rather accelerate progress along all the avenues (from nuclear and clean coal to solar and efficiency) that will get us to the same place—a planet with an atmosphere that remains hospitable. There is no guarantee any of them will get us there fast enough to stave off catastrophic climate change, but we have no other reasonable choice.