To slow the global growth of emissions, industrial powers may need to put a heavy brake on their own, Bows says. How much? “More than 6 percent per year—beginning immediately,” she says. And that’s to keep warming below 2 degrees Celsius.
She and Anderson also reran their analyses to look at what might occur if industrial countries did limit their reductions to what might be deemed “economically feasible.” This yielded at best a 3 percent drop in annual emissions and eventually, a 4 degree warming of the globe. So in the absence of at least these emissions reductions, she says, “we could be looking at much more than a 4 degree warming.”