Washington Post: Representatives from more than 150 countries will gather at the United Nations on Friday to officially sign a global accord aimed at slashing greenhouse gas emissions and slowing climate change. But in the four months since that historic pact was negotiated in Paris, a drumbeat of grim scientific findings has underscored that staving off the worst consequences of global warming may take far more aggressive actions.
The first three months of 2016 were the warmest on record in 136 years -- by large...