U.S. President Donald Trump has unapologetically withdrawn from the Paris Agreement on climate change. Consequently, the U.S. joins Syria and Nicaragua as the only other nonsignatories to the treaty.
Syria is in the midst a horrific civil war and sanctions mean it is hard for many government officials to travel. Nicaragua refused to sign because, as a developing country listed as fourth-most affected by extreme weather events, it felt the deal did not go far enough. It took the moral position that it could not be a signatory to an agreement that would not do enough to lower global temperature increases.