2020 deadline to avert climate catastrophe: experts

Humanity must put carbon dioxide emissions on a downward slope by 2020 to have a realistic shot at capping global warming at well under two degrees Celsius, the bedrock goal of the Paris climate accord, experts said Wednesday.With 1.0 degree Celsius (1.8 degrees Fahrenheit) of warming so far, ice sheets that could lift oceans by a dozen metres are melting more quickly, coral reefs are dying from heat stress, and ever more damaging storm surges are hammering coastal communities.The transition to