REUTERS, Brussels

Each of the past 12 months ranked as the warmest on record in year-on-year comparisons, the EU’s climate change monitoring service said yesterday, as UN Secretary-General António Guterres called for urgent action to avert “climate hell”.

“We need an exit ramp off the highway to climate hell,” he said, adding: “The battle for 1.5 degrees will be won or lost in the 2020s.”

The average global temperature for the 12-month period to the end of May was 1.63 degrees Celsius (2.9 degrees Fahrenheit) above the pre-industrial average - making it the warmest such period since record-keeping began in 1940, the Copernicus Climate Change Service said.

This 12-month average does not mean that the world has yet surpassed the 1.5 C (2.7 F) global warming threshold, which describes a temperature average over decades, beyond which scientists warn of more extreme and irreversible impacts.

In a separate report, the UN’s World Meteorological Organization (WMO) said there is now an 80 percent chance that at least one of the next five years will mark the first calendar year with an average temperature that temporarily exceeds 1.5C above pre-industrial levels - up from a 66 percent chance last year.