China’s proposed coal mine developments risk creating an oversupply and derailing climate goals, according to Global Energy Monitor.

More than 450 sites are in development across China, with nearly 40% under construction or in test operation, according to the California-based researcher, which promotes clean energy use. If they are all built, their combined capacity of 1.35 billion tons a year would surpass that operating in Indonesia and Australia, the biggest exporters of the fuel for power generation and steelmaking.

The scale of China’s coal ambitions threatens to overwhelm its own, and global, climate goals. The country accounts for 60% of all proposed mine capacity worldwide, and its buildout alone would generate 80% of the methane emissions tied to planned projects, GEM said. Methane is more than 80 times more potent than carbon dioxide over a 20-year period.

“Without drastically scaling back plans for new mine capacity, the world could see a massive rise in potent methane emissions that would make it all but impossible to reach the goals of the Paris Agreement,” said Dorothy Mei, project manager of the Global Coal Mine Tracker at GEM.

China’s current buildout risks another round of overcapacity similar to that from 2012 to 2015, which triggered price crashes and stranded assets, according to the report. Nearly half of the proposed capacity remains in early-stage planning and could still be scrapped, but a 2024 directive from Beijing seeking to build 300 million tons of reserve mine capacity by 2030 has prompted local governments including Inner Mongolia to fast-track approvals to meet quotas.

Globally, 105 million tons of coal production capacity was added in 2024, down 46% from a year earlier and the lowest in at least a decade. But more than 850 new mines or expansions are still under development across 30 countries. That includes 329 million tons in India and 165 million tons in Australia.

That trend further jeopardizes global climate targets, with the United Nations saying coal production needs to fall 75% in the decade to 2030 and the International Energy Agency calling for a 39% reduction, GEM said. The current output trends are widening the gap to achieve those goals, meaning annual retirements of coal capacity would need to exceed new additions under both the UN and IEA scenarios, it said.