Climate change's devilish detail

In the absence of the US, developing countries stepped forward at COP23, as progress on the “Paris rulebook” inched ahead

For every high-profile climate summit like Paris, Copenhagen or Kyoto, where heads of state gather and treaties are signed, there are usually one or two more prosaic meetings in between. At these, technical issues and rules are decided. COP23 in Bonn this year was one such event. The ground-breaking agreement reached in Paris in 2015 gave nations three years to craft a set of rules governing how nations should work together to reduce greenhouse-gas emissions to net zero by the middle of the century. The summit in Marrakech last year gave negotiators a chance to work out what was needed, and Bonn was tasked with getting ideas down on paper. After two weeks of talks earlier this month under th