With 197 signatory nations, of which only 10 have yet to ratify, the Paris Agreement sought to bring the world together in limiting greenhouse emissions. Trump decided to withdraw from the agreement because he believed that the stipulations were unfair to US businesses and taxpayers.

While Trump announced his decision during his first year in office, the process for withdrawal must begin three years after the agreement was adopted, and requires an additional year after notice is given to be official. That places the final official withdrawal date at November 4, 2020.

Trump has long been skeptical of the international consensus on climate change. He has referred to climate change as a “Chinese hoax” and claimed that windmills cause cancer, while rolling back regulations. His administration has rolled back several regulations, including for endangered species, offshore rigs, and coal pollution. Nevertheless, the Department of Defense has asserted that climate change remains a national security issue.

The New York Times – Trump Serves Notice to Quit Paris Climate Agreement
BBC News – Paris climate accords: US notifies UN of intention to withdraw
Foreign Policy – Is the United States Really Leaving the Paris Climate Agreement?
NPR – U.S. Formally Begins To Leave The Paris Climate Agreement
Climate Change News – Which countries have not ratified the Paris climate agreement?
US Department of Defense – DoD Releases Report on Security Implications of Climate Change