The world is still headed for catastrophic levels of global warming, even after a slew of new national climate pledges, according to a United Nations report . If countries don’t quickly set stronger emissions-reduction targets, the world will warm 2.7°C by 2100, according to the study released Monday before a Glasgow climate summit . The increase will far exceed the goal of keeping warming below 2°C and preferably 1.5°C that was laid out in the 2015 Paris Agreement signed by all countries. Global warming of 2.7°C compared with pre-industrial levels — about 5° Fahrenheit — would represent a disastrous reshaping of the planet. At just 2°C, an extreme heatwave expected only twice a century would […]