It’s possible. Here is Dana Nuccitelli at The Guardian:
This is the rotten state of today’s GOP. They’re happy to sell out the future of humanity for their own short-term political gain. Noam Chomsky was right – the Republican Party may be the most dangerous organization in human history. This move comes at a time when the need to act on global warming has been clear for decades, but the GOP has blocked all American climate policy efforts, and we’re now running out of time to avoid dangerous climate change.
America’s withdrawal from the Paris treaty will take four years, meaning that the 2020 election (and the 2018 midterms) will be a referendum on Trump’s decision today. American voters must send the world a signal in that election. In the meantime, it will be up to the rest of the world – particularly China and the EU – to take up the mantle of leadership on climate change that America has left behind.
Trump, per a source, will follow the 4-yr rule to get out of Paris, meaning the US will leave on Nov 4, 2020.
Election Day 2020: Nov 3.
— Dan Merica (@danmericaCNN) June 1, 2017