InsideClimate: Roughly half of the world's species are currently on the move. As global warming drives ocean and air temperatures higher, they are chasing the habitats they are accustomed toheading further north or to higher elevations or following the trail of their food sources. Those that can't keep up with the pace of change face extinction, and if warming continues at its current pace, one in six species is projected to go extinct. That number falls to one in 20 if the rise is constrained to 2 degrees Celsius,...