The Paris agreement is a mostly voluntary climate pact originally written to both try to reduce warming and withstand the changing political winds in the U.S.

President Donald Trump once again withdrew the United States from the Paris climate deal on Monday, removing the world's biggest historic emitter from global efforts to fight climate change for the second time in a decade.

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.