SOULAINES-DHUYS, France — Deep in a French forest of oaks, birches and pines, a steady stream of trucks carries a silent reminder of nuclear energy’s often invisible cost: canisters of radioactive waste, heading into storage for the next 300 years.

As negotiators plot out how to fuel the world while also reducing carbon emissions at climate talks in Scotland, nuclear power is a central sticking point. Critics decry its mammoth price tag, the disproportionate damage caused by nuclear accidents, and radioactive leftovers that remain deadly for thousands of years.

But increasingly vocal and powerful proponents — some climate scientists and environmental experts among them — argue that nuclear power is the world’s best hope of keeping climate change under control, noting that it emits so few planet-damaging emissions and is safer on average than nearly any other energy source. Nuclear accidents are scary but exceedingly rare — while pollution from coal and other fossil fuels causes death and illness every day, scientists say.

“The scale of what human civilization is trying to do over the next 30 years (to fight climate change) is staggering,” said Matt Bowen, of Columbia University’s Center for Global Energy Policy. “It will be much more daunting if we exclude new nuclear plants — or even more daunting if we decide to shut down nuclear plants all together.”

Many governments are pushing to enshrine nuclear energy in climate plans being hashed out at the conference in Glasgow, known as COP26. The European Union, meanwhile, is debating whether to label nuclear energy as officially “green” — a decision that will steer billions of euros of investment for years to come. That has implications worldwide, as the EU policy could set a standard that other economies follow.

Reactors worldwide produce thousands of tons of highly radioactive detritus per year, on top of what has already been left by decades of harnessing the atom to electrify homes and factories around the world.

Germany is leading the pack of countries, mainly within the EU, standing firmly against labeling nuclear as “green.” Meanwhile, the Biden administration supports nuclear power, China has a dozen reactors under construction — and even Japan is promoting nuclear energy again, 10 years after the disaster at its Fukushima power plant.