US move may add 0.3 degrees of warming: UN

The US withdrawal from the Paris climate pact could "in a worst case scenario" add a 0.3 degree Celsius rise in global temperatures over the 21st century, the UN said yesterday.

"We haven't run new models overnight but the indications are that it could be in the worst case scenario in the order of 0.3 degrees Celsius," the head of the World Meteorological Organization's atmospheric research and environment department Deon Terblanche told reporters in Geneva, referring to a possible rise over pre-industrial temperatures.

"That is the worst case scenario and this is probably not what will happen," he added.

Under the Paris deal agreed in 2015, world nations vowed steps to keep the worldwide rise in temperatures "well below" two degrees Celsius (3.6 degrees Fahrenheit) from pre-industrial times.