Three years ago, world leaders from nearly every country around the world laid out specific plans to fight climate change that included strategies to slash their greenhouse gas emissions. Those commitments generated optimism that the world might finally address global warming and helped seal the deal on the Paris Agreement. Now, the majority of G20 countries aren’t following through on their promises, according to a new report from the United Nation Environment Programme. And, even if countries followed through, the world would fall short of limiting temperature rise to safe levels. The backsliding is largely the result of increased economic...