President Donald Trump has announced that the US is withdrawing from the 2015 Paris climate agreement.
He said moves to negotiate a new “fair” deal that would not disadvantage US businesses and workers would begin.
Mr Trump said during last year’s presidential election campaign that he would take the step to help his country’s oil and coal industries.
Opponents say withdrawing from the accord is an abdication of US leadership on a key global challenge.
The Paris agreement commits the US and 187 other countries to keeping global temperatures rises “well below” 2C (3.6F) and “endeavour to limit” them even more, to 1.5C. Only Syria and Nicaragua failed to sign up to the deal.
Speaking in the White House Rose Garden, Mr Trump characterised the Paris agreement as a deal that aimed to hobble, disadvantage and impoverish the US.
He claimed the agreement would cost the US $ 3tn in lost GDP and 6.5 million jobs – while rival economies like China and India were treated more favourably.
“In order to fulfil my solemn duty to protect America and its citizens, the United States will withdraw from the Paris climate accord… but begin negotiations to re-enter either the Paris accord or a really entirely new transaction on terms that are fair to the United States, its businesses, its workers, its people, its taxpayers,” he said.
“So we’re getting out but we will start to negotiate and we will see if we can make a deal that’s fair.”
Trump ‘rejects the future’
Former US President Barack Obama, who agreed to the Paris deal, immediately criticised the move.
“Even in the absence of American leadership, even as this administration joins a small handful of nations that reject the future, I’m confident that our states, cities and businesses will step up and do even more to lead the way, and help protect for future generations the one planet we’ve got,” he said in a statement.
Tech entrepreneur Elon Musk confirmed that he was leaving his role as an adviser to the Trump administration in protest.
“Am departing presidential councils. Climate change is real. Leaving Paris is not good for America or the world,” he tweeted.
UN Secretary General Antonio Guterres had earlier appealed to Mr Trump not to break the commitment – but said the battle against climate change would continue regardless of the US stance.
Mr Guterres told the BBC: “It is obviously a very important decision as the United States is the biggest economy in the world. But independently of the decision of the American government, it’s important that all other governments stay the course.”
Meanwhile, Chinese and EU leaders are set to agree a joint statement backing the Paris agreement, saying it is “an imperative more important than ever”.
The statement – a draft of which has been seen by the BBC – says rising temperatures affect national security and increase “social and political fragility”, while the transition to clean energy creates jobs and economic growth.
What will US withdrawal do? Analysis by BBC environment correspondent Matt McGrath
There’s no doubt that a US pullout will make it more difficult for the world to reach the goals that it set for itself in the Paris agreement. The US contributes about 15% of global emissions of carbon, but it is also a significant source of finance and technology for developing countries in their efforts to fight rising temperatures.
There’s also a question of moral leadership, which the US will be giving up, which may have consequences for other diplomatic efforts.
Michael Brune, from US environmentalist organisation the Sierra Club, said the withdrawal was a “historic mistake which our grandchildren will look back on with stunned dismay at how a world leader could be so divorced from reality and morality”.
What was agreed in Paris?
Climate change, or global warming, refers to the damaging effect of gases, or emissions, released from industry and agriculture on the atmosphere.
The Paris accord is meant to limit the global rise in temperature attributed to emissions.
Countries agreed to:
- Keep global temperatures “well below” the level of 2C (3.6F) above pre-industrial times and “endeavour to limit” them even more, to 1.5C
- Limit the amount of greenhouse gases emitted by human activity to the same levels that trees, soil and oceans can absorb naturally, beginning at some point between 2050 and 2100
- Review each country’s contribution to cutting emissions every five years so they scale up to the challenge
- Enable rich countries to help poorer nations by providing “climate finance” to adapt to climate change and switch to renewable energy