This aerial photo shows two reactors at the Sendai Nuclear Power Station in Satsumasendai, Kagoshima prefecture, southern Japan, last week. (Associated Press)

THE MELTDOWN in 2011 at the Fukushima Daiichi nuclear reactor terrified people in the densely packed nation of Japan, persuaded the government to close all reactors and turned public opinion there and in many other places decidedly against the technology.

Yet last week Japan restarted a reactor at the Sendai nuclear power plant. More Japanese nuclear units could begin producing electricity again soon. This should not concern the world. It should be a relief.

If you care about climate change or air pollution, you cannot casually write off nuclear power, which produces virtually no carbon dioxide emissions while generating a tremendous amount of reliable power. Yes, solar and wind are alternatives. But renewables are intermittent, making them harder to integrate into the power grid at large scale, and they can be expensive. Even if those obstacles weren’t present, it would still take a lot of time to generate the astonishing amount of energy that modern countries need with mostly alternative technologies. Shutting down nuclear plants in the meantime guarantees that countries will burn more coal, oil and natural gas and therefore produce more pollution.

That’s just what happened in Japan. After the nuclear shutdown, the country’s trade deficit ballooned as it imported more coal and gas to run the world’s third-largest economy. Energy efficiency campaigns couldn’t reduce electricity demand enough to eliminate the need for fossil fuels. The country’s aversion to nuclear power, moreover, blew a hole in its plan to cut carbon dioxide emissions, which cause climate change. Japan had planned to ramp up emissions-free nuclear power to generate half of its electricity by 2030. The plan now is to get about a fifth from nuclear by then.

Even that may be wishful thinking. The government would have to do quite a bit to meet its new nuclear target, according to Jane Nakano at the Center for Strategic and International Studies, even as the Japanese public remains worried about reactors. At the moment, it’s planning to reopen additional plants after they’ve passed a new, more rigorous regulatory process. Reaching Japan’s new goal, which is key to reaching its carbon-emissions targets, will require older plants to be relicensed to operate beyond their original 40-year lifespans. Another option is to build new plants, some of which are already under construction, but that would be perhaps even more difficult for the public to accept.

It may be that nuclear power won’t play a leading role in energy production decades from now. But no one concerned about climate change should be willing to take it off the table. At the very least, countries should avoid closing existing plants without good reason. The right response to Fukushima is to make sure reactors meet high safety standards, not to make the fight against global warming much harder.