The Paris Climate Agreement represents a crucial step forward in the global fight against climate change, but President Donald Trump’s decision to withdraw the U.S. from the agreement puts the deal’s success in question, according to Alexandra Simon-Lewis of Wired. The agreement was struck with hopes of reducing global warming to less than 2 degrees Celsius. It allowed countries to determine their own national commitment, encouraging nations to stay below the 2 degree goal. 195 countries (including the United States) signed the deal, putting forth plans to reduce emissions and combat climate change.

Mr. Trump cannot actually remove the United States from the deal until 2019 because the U.S. signed a three year commitment, but he can refuse to implement the changes that the Obama Administration had begun. But the rest of the world has reaffirmed its commitment to the deal, hoping to still avoid the 2 degree threshold, even without American involvement.