Humanity has less than three years to halt the rise of planet-warming carbon pollution, UN climate experts warned Monday, with any delay to peak greenhouse gas emissions likely to result in smashing through warming targets.  

The UN's Intergovernmental Panel on Climate Change said emissions have to peak before 2025 and drop sharply to keep even the more conservative Paris Agreement warming goal of 2 degrees Celsius in play.    

"We are at a crossroads," said IPCC chief Hoesung Lee. "The decisions we make now can secure a liveable future. We have the tools and know-how required to limit warming."