The US will definitely withdraw from the Paris climate agreement, President Trump has confirmed.
He made the announcement at an energy conference in Pittsburgh on a stage flanked by men in hard hats.
He described the accord as a bad deal and said his pro fossil fuel policies had made the US an energy superpower.
The earliest he can formally start the process of withdrawing the US from the Paris accord is 4 November.
The pull-out will take effect a year later – the day after the 2020 US presidential election – assuming that Mr Trump is re-elected.
The Paris agreement brought together 195 nations in the battle to combat climate change.
It committed the US to cutting greenhouse gases up to 28% by 2025 based on 2005 levels.
President Trump said if he couldn’t improve that deal he’d pull out, but diplomatic sources said there’s been no major effort at renegotiation.
In the meantime, the president’s staff have conducted what critics call a seek-and-destroy mission through US environmental legislation.
Mr Trump promised that he’d turn the US into an energy superpower, and he’s attempting to sweep away a raft of pollution legislation to reduce the cost of producing gas, oil and coal.
He categorised former US President Barack Obama’s environmental clean-up plans as a war on American energy.
The gas and oil industries are indeed thriving, but Mr Trump’s pledge to resurrect the coal industry has proved much more challenging.
Coal can’t compete on price with gas – or, for that matter, with renewables whose costs have plummeted.
Firms are also reluctant to invest billions in coal-fired plants which could have a limited life if the next administration rejoins the rest of the world on climate change.
As coal is the dirtiest fuel, the industry’s woes have held down US emissions, despite the President’s policies.
What’s more, many US states, cities and businesses remain committed to the Paris Agreement, whatever Mr Trump does.
Campaigners say these now represent nearly 70% of US GDP and nearly 65% of the US population. If they were a country, this group would be the world’s second largest economy.
The rebels are led by California, which is locked in a battle with the president over his plans to repeal their powers to impose clean air standards.
So far the biggest negative effect of Mr Trump’s stance has arguably been to relax pressure on countries like Brazil and Saudi Arabia to take action of their own.
Environmentalists say Mr Obama would have acted quickly to press Brazil’s President Jair Bolsonaro to tackle forest fires in the Amazon, for instance.
Mr Obama agreed in Paris that the US should take a lead on climate change because it’s contributed far more than any other nation to the greenhouse gases already in the atmosphere.