When Trump announced the U.S. withdrawal from the climate agreement in 2017, the move reverberated around the globe. Nearly 200 nations had committed to reducing greenhouse gas emissions under the pact when it was created in 2015, and they had set ambitious targets to keep global temperature rise well below 2°C, and ideally below 1.5°C.

The United States’ second exit from the Paris Agreement wasn’t unexpected. Even before he was reelected, now-president Donald Trump had promised for months that he would pull the country out of the United Nations pact to limit global warming: the Paris climate “ rip-off ,” as he called it.

Trump's executive order called for an immediate withdrawal from the Paris Agreement. The agreement requires one year notice, but there's room for interpretation.