On the anniversary of Japan’s Fukushima disaster, NPR’s Christopher Joyce looks at how the country is handling its energy needs. Nukes once provided a third of Japan’s electricity. Now? Almost none. By April, Japan will have shut down its last reactor, most likely for good.

Are these protesters cooking the planet? (YURIKO NAKAO/REUTERS)

Whether this nuclear freeze is a big deal depends on how you look at it. Japan and Germany are two of the world’s six largest emitters, and they’re now expected to spew nearly one billion additional tons of carbon dioxide into the atmosphere between now and 2020. That may be minor in the grand scheme of things — the entire world is likely to emit about 400 billion tons of carbon pollution over that time. But it’s hardly a step in a greener direction. Meanwhile, it’s true that, in Germany’s case, the E.U. has a continent-wide cap-and-trade system for emissions, so that any extra pollution in Germany should be offset by cuts elsewhere. But the 300 million tons of extra pollution out of Germany will also cancel out virtually all of the savings intended by the E.U.’s 2011 Energy Efficiency Directive.

Granted, that’s just Germany and Japan. On a global scale, Fukushima may end up having a fairly minor impact on the nuclear industry. China, India, the United States, the United Kingdom and France are all pushing ahead with plans for new reactors in the years ahead. Italy and Switzerland have said they won’t build any further reactors, but they’re also not planning on mothballing their existing ones.

Even so, as Oliver Morton details in the Economist, nuclear power doesn’t appear poised for a major expansion. Back in 1996, nuclear power provided 18 percent of the world’s electricity. In 2010, that had shrunk to 13 percent. The International Energy Agency predicts that an ambitious drive by countries to build new reactors (and replace those at the end of their natural lifespan) could keep that share constant between now and 2035. But that’s an optimistic scenario, and it would require utilities to pursue aggressive schedules and avoid the delays and cost overruns that have often plagued nuclear projects. In a more pessimistic “low-nuclear” scenario, the IEA expects nuclear’s share of the global electricity market to drop to just 7 percent.

For some environmentalists and climate watchers, that wouldn’t be a fatal outcome. Joe Romm has long argued that nuclear power was always unlikely to play more than a bit role in the world’s efforts to shift away from fossil fuels. Costs for new reactors, after all, keep skyrocketing, even as the price tag for wind and solar power keep tumbling. “That’s why I don’t put [nuclear] in the ‘major climate solution’ category,” Romm writes, “especially in the near term, which is what counts the most.” Plenty of nuclear advocates would disagree, countering that atomic energy is still the most proven and reliable form of carbon-free baseload power around. But whether that’s right or not, nuclear’s role in the energy world seems to be dimming.