Straight: Its fitting that the latest Intergovernmental Panel on Climate Change report was released during Earth Month. After all, the third chapter of its Fifth Assessment focuses on ways to keep our planet healthy and livable by warding off extreme climatic shifts and weather events caused by escalating atmospheric carbon.
Doing so will require substantially reducing greenhouse gas emissions--40 to 70 percent by 2050 and to near-zero by the end of the century. We must also protect carbon sinks such...