World likely to blast beyond grim warming milestone in the next 5 years, UN weather agency says

A weather arm of the United Nations on Wednesday warned that within the next five years, the world will likely surpass a critically important warming threshold, reinforcing the urgent need to slash planet-heating greenhouse gas emissions.

In a landmark report timed to coincide with World Environment Day, the World Meteorological Organization said there is now an 80% chance that global average temperatures will exceed 1.5 degrees Celsius, or 2.7 degrees Fahrenheit, above pre-industrial levels for at least one year between 2024 and 2028.

That prediction marks a stark change from 2015 when the WMO considered the prospect of temporarily overshooting 1.5 degrees Celsius close to zero.

The 1.5-degree Celsius limit is the aspirational target of the landmark 2015 Paris Agreement, an international treaty on climate change.

Scientists say that exceeding this temperature threshold over the long term will lead to increasingly frequent and catastrophic extreme weather events.

Even at current levels of global warming, there are already devastating climate change impacts. These include record-breaking heatwaves, extreme rainfall events and droughts, accelerating sea level rise and ocean heating and dramatic reductions in ice sheets and sea ice.

"We are playing Russian roulette with our planet," U.N. Secretary-General António Guterres said in a speech on Wednesday. "We need an exit ramp off the highway to climate hell. And the truth is we have control of the wheel."

Guterres said that the battle to limit long-term temperatures to 1.5 degrees Celsius will be won or lost in the 2020s under the watch of today's world leaders.

Speaking at the American Museum of Natural History in New York City, Guterres called for much more ambitious action to