Virtually every place that shuts down nuclear plants from San Diego to New York City, Germany to South Korea replaces them with fossil fuels, swapping an abundant source of zero-emissions electricity for the very energy sources roasting the planet.

But with gas prices and emissions on the rise, two governors are rethinking plans to shut down major nuclear power stations.

With just weeks to go before the Palisades Nuclear Generating Station becomes the next U.S. plant to shutter, Michigan Gov. Gretchen Whitmer (D) formally asked the Biden administration on April 20 for federal funding to keep the reactors running.

On Friday, California Gov. Gavin Newsom (D) told the Los Angeles Times he also wanted federal money to keep Diablo Canyon, his states last remaining nuclear plant, open past its 2025 closure date.

The announcements mark a shift in the politics of atomic power. At a time when planet-heating gas pollution is surging and efforts in Congress to cobble together a historic clean-energy spending plan have faced repeated setbacks, nuclear energy is becoming more appealing, even among Democrats whose party has historically championed closing down reactors.

Nuclear energy is by far the most efficient and reliable electricity source humans have ever harnessed. Nuclear reactors produce power 24/7 on vastly less acreage than wind and solar, regardless of weather conditions. Atomic energy is also safer than fossil fuels, which not only cause global warming but lace the air with deadly, disease-causing particles.

But connections to nuclear weapons and rare but catastrophic disasters like the meltdowns in Chernobyl in 1986 and Fukushima in 2011 have long stoked opposition to reactors. Natural gas, made cheap by the U.S. drilling boom, gobbled up nuclear companies share of the electricity market, while state regulators have made increasingly challenging demands of plant operators, making it even harder to compete.