Catastrophe Awaits If We Surpass 2 Degrees Celsius. And We're Already Halfway There.

Two degrees Celsius is the“magic number,” the global temperature increase scientists say the world must stay below to avoid the worst effects of climate change. Andhumanity is hurtling rapidly toward this hazardous line, according to a new United Nations report. We’re already more than halfwaythere. Global temperatures last year were more than 1 degree Celsius above the pre-industrial average, theU.N. World Meteorological Organization said in the“Global Climate 2011-2015” report publis...