Some environmentalists are thrilled over Tuesday’s announcement of the planned closing of California’s Diablo Canyon nuclear power plant. They might want to reconsider: Fighting climate change requires more nuclear power, not less.

That Diablo Canyon’s two reactors could be allowed to shut down is alarming evidence that too little effort is being made to reduce greenhouse-gas emissions. The electricity that the Diablo Canyon plant generates, which amounts to about 9 percent of California’s power, would be lost.

Yes, a deal reached among the plant’s operator, labor unions and a few environmental groups stipulates that greater energy efficiency and more renewable power – solar, wind and the like – will pick up the slack. But to the extent that these strategies are used to replace clean nuclear power, they make zero progress toward lowering carbon emissions. Diablo Canyon prevents the emission of 6.8 million tons of carbon dioxide annually.

It’s true that Diablo Canyon stands close to a geological fault line. But the plant has operated safely since it opened in the mid-1980s. And it has been built to withstand an earthquake much stronger than anything that fault could be expected to unleash.

Diablo Canyon now joins the list of nuclear plants across the country that are set to close (or already have) because they can’t compete with record-low natural gas prices. Nuclear power is also expensive, because reactors require a relatively large workforce.

The plants should be given full credit for the climate protection they provide – via a carbon tax or through inclusion in state energy portfolio standards – so that they can keep generating clean power for many more decades.

Allowing them simply to close may be satisfying to some environmentalists. But it is a wrong turn in the fight against climate change.