In the 1970s, the environmental movement rallied around cries of “No new nukes” and “Save the whales.”

Now a group of the world’s leading conservation biologists are making a new plea: More new nukes—lots of them—to save whales and other wildlife threatened by global warming.

In a study to be published in the journal Conservation Biology this month, scientists outline the need to ramp up carbon-free nuclear power to avoid catastrophic climate change and the extinction of thousands of species.

Meanwhile, 65 conservation scientists from around the world—including a former U.K. government chief scientist—expressed support for the paper’s findings in a letter to be published in the journal and obtained by The Independent.

It’s all part of a campaign to persuade environmentalists worldwide to rethink their views on nuclear power.

The scientists wrote that in the fight against climate change, trade-offs and compromises are “inevitable and require advocating energy mixes that minimize net environmental damage.”

“Society cannot afford to risk wholesale failure to address energy-related biodiversity impacts because of preconceived notions and ideals,” they added.

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The letter accompanies the new study, which was coauthored by Australian scientists Barry Brook at the University of Tasmania and Corey Bradshaw at the University of Adelaide. The paper calls for more nuclear power plants to be built worldwide, as part of a global strategy to protect habitat and wildlife.

“Our main goal was to show—through careful, objective scientific analysis—that on the basis of cost, safety, emissions reduction, land use, and pollution, nuclear power must be considered in the future energy mix,” Bradshaw told The Independent.

Replacing carbon dioxide–spewing fossil fuel–powered plants with nuclear plants would reduce greenhouse gas emissions, he said. Additionally, the smaller footprint of a nuclear power plant in comparison with that of wind and solar farms would allow for more land to be set aside for wildlife conservation.

The purpose of the letter, Bradshaw said, was to change the views of environmental groups like Greenpeace and other organizations that actively lobby against nuclear power because of “negative stigma.”

That’s easier said than done, given the environmental movement’s decades-long fight against nuclear power and unresolved issues surrounding the disposal of radioactive waste, according to Damon Moglen, a senior strategic adviser at Friends of the Earth.

“Go take a walk around Fukushima City, the Chernobyl fallout zone, or the hundreds of nuclear waste dump sites around the world: It gets clear pretty quickly that nuclear power is not clean, green, or safe,” he said.

Moglen, who has worked with Greenpeace and Friends of the Earth to shut down nuclear plants in California, said replacing fossil fuels with wind and solar energy should be the focus of conservationists—not reviving nuclear power.

Nuclear plants generate about 19 percent of the electricity in the United States. Renewable energy—which includes wind, solar, hydropower, and biomass—generated 14.3 percent of the nation’s electricity in 2014 and is growing fast.

“Putting in a massive amount of wind and solar power plants can be done practically, but getting nuclear power plants built and online during a time when nuclear power is decreasing worldwide is ludicrous,” Moglen said.