One of President Trump’s first executive orders withdraws the U.S. from the Paris climate agreement. These graphics show why the pact is crucial to curbing the worst effects of global warming

The president on Monday announced his intention to withdraw the country, for the second time, from the global emissions reduction pact.

The Paris agreement is complex and works in a slow bureaucratic manner. It’s a mostly voluntary climate pact originally written in ways that would both try to reduce a worsening climate change problem and withstand the changing political winds in the United States.