“So, I think it’s obviously a problem.” Among them are America’s Pledge, put together by former California governor Jerry Brown and the former mayor of New York, Michael Bloomberg. They say that states and cities will help cut US emissions by 19% compared to 2025 from what they were in 2005 – that’s not enough to make up for the US promise under Paris but it keeps those targets “within reach”. UK climate change protests Could the US re-join the agreement? For the past three years, US negotiators have attended UN climate talks while the administration has tried to use these events to promote fossil fuels. After a three-year delay, the US has become the first nation in the world to formally withdraw from the Paris climate agreement. The Paris deal was drafted in 2015 to strengthen the global response to the threat of climate change. Related Topics “No matter what you think about global warming, and the nature of it, the pace of it, you have to take these growing economies seriously, and help them and I just didn’t see Paris getting to that end, in any efficient or constructive manner.” Will other countries now leave the agreement? “I don’t think anyone will follow Mr Trump out of Paris,” said Peter Betts, a former lead negotiator for the UK and the EU in the global climate negotiations, and now an associate fellow at Chatham House. “I’m not sure what Paris actually accomplishes,” said Katie Tubb, a senior policy analyst at the Heritage Foundation, a conservative US think tank. President Trump announced the move in June 2017, but UN regulations meant that his decision only takes effect today, the day after the US election. “Under the Paris rules, the US will not be able to participate in that.” The US could re-join it in future, should a president choose to do so. On the business front, there has been growing pressure from shareholders of large fossil fuel-based industries to face up to the climate challenge. So when it becomes the only country to withdraw from a global solution to a global problem it raises questions of trust. By Matt McGrathEnvironment correspondent President Trump made leaving Paris a key part of his election platform in 2016, tying it into his vision of a revitalised US with booming energy production, especially coal and oil. Although this has been a long time coming, there is still a palpable sense of disappointment for many Americans who believe that climate change is the biggest global challenge and the US should be leading the fight against it. Why has this taken so long? media captionTrump: The world won’t laugh any more at US “The EU green deal and carbon neutrality commitments from China, Japan and South Korea point to the inevitability of our collective transition off fossil fuels,” said Laurence Tubiana, one of the architects of the Paris agreement and now chief executive of the European Climate Foundation. Not everyone in the US is upset to leave the Paris agreement? “What Obama did at the end of his second term was fundamentally undemocratic, to sign up to a Paris agreement without going to the Senate and the Congress and instead doing it via executive order,” said former UN climate chief, Yvo De Boer. The Clinton administration was unable to secure Senate backing for the Kyoto Protocol, agreed in 1997.