Reuters: Hundreds of top scientists warned on Tuesday against Republican presidential nominee Donald Trump's vow to pull the United States out of the Paris climate-warming accord if elected in November. The 375 members of the U.S. National Academy of Sciences, including 30 Nobel Prize winners, said in an open letter that a U.S. abandonment of the agreement would make it far harder to develop global strategies to lessen the impact of global warming. "Thus it is of great concern that the Republican nominee...