On the day the Paris climate pact was signed, nearly a decade ago, it seemed as if world leaders were finally on the same page. They agreed to pursue efforts to limit global warming to 1.5C, in an effort to avoid the most catastrophic impacts of climate change.

Reaching that goal would require rapidly curbing the use of coal, the single most polluting energy source. And in the years that followed, one world leader after another pledged to quit coal entirely.

“We’ve got to accelerate the transition away from old, dirtier energy sources,” US President Barack Obama said in his State of the Union address in 2016, referring to coal. By 2021, UK Prime Minister Boris Johnson declared that the climate summit in Glasgow had “sounded the death knell for coal power”, and had set in motion plans for the UK to close its final coal plant.