But have we learned anything? These questions are difficult to answer and the trade-offs nearly impossible to calculate. Even harder, however, will be implementing policy recommendations in a world of vested interests tied to old technologies. Over the past 100 years or so, the world's "energy portfolio" did not diversify very much -- as electric and gas-fueled engines powered industrial development. Renewable energy technologies like wind, solar, and biofuels hold great potential, but require much more rapid development to substitute for fossil fuels and nuclear power in the near term. So it appears now that there are few good choices: Either warm the planet's atmosphere and oceans, with dire consequences for human societies as the climate rapidly changes, or place communities in jeopardy from nuclear plant accidents and releases of deadly radioactive materials.
However, in January 2012, when the Bulletin deliberates about moving the hand of the Doomsday Clock, the most important question will be: What have governments, firms, and citizens learned from the Fukushima disaster about managing Earth-altering technologies? And will they act on what they have learned in time to avert future disaster?