Earlier this year, Death Valley hit 54.4C and Siberia hit 38C.
The warming that has already occurred has "increased the odds of extreme events that are unprecedented in our historical experience," Stanford University climate scientist Noah Diffenbaugh said.
For example, historical global warming has increased the odds of record-setting hot extremes at more than 80 per cent of the globe, and has "doubled or even tripled the odds over the region of California and the western US that has experienced record-setting heat in recent weeks," Diffenbaugh added.
The world already has warmed nearly 1.1C since the late 1800s, and the last five years are hotter than the previous five years, the report said.
The speed-up could be temporary, or it might not be. There's both man-made warming and natural warming from a strong El Nino weather pattern in the past five years, said World Meteorological Organisation Secretary-General Petteri Taalas.
"The probability of 1.5C is growing year by year," Taalas told AP. "It's very likely to happen in the next decade if we don't change our behaviour."
That's potentially faster than what a 2018 UN report found: that the world was likely to hit 1.5C sometime between 2030 and 2052.
Breakthrough Institute climate scientist Zeke Hausfather, who wasn't part of the new report, said the document was a good update of what scientists already know. It is "abundantly clear that rapid climate change is continuing and the world is far from on track" toward meeting the Paris climate goals, he said.
Some countries, including the US and many in Europe, are reducing emissions of heat-trapping carbon dioxide, but Taalas said the world is on a path that will be 3C warmer compared with the late 19th century. That would be above the Paris accord's less stringent 2C target.
The latest report was the UN's annual update on "climate disruption" caused by the burning of coal, oil and gas. It highlighted more than just increasing temperatures and rising sea levels.
"Record heat, ice loss, wildfires, floods and droughts continue to worsen, affecting communities, nations and economies around the world," UN Secretary-General Antonio Guterres wrote in a foreword.
Guterres said big polluting countries, like China, the US and India, need to become carbon neutral, adding no heat-trapping gas to the atmosphere, by 2050.
If they don't, "all the effort will not be enough," Guterres said.
The report spotlights unprecedented wildfires in the Amazon, the Arctic and Australia. California is fighting record wildfires as the report was issued.
"Drought and heat waves substantially increased the risk of wildfires," the report said.
"The three largest economic losses on record from wildfires have all occurred in the last four years."
Taalas said the these type of climate disasters will continue at least through the 2060s because of the heat-trapping gases already in the air.
Carbon dioxide emissions will be down 4 per cent to 7 per cent this year because of reduced travel and industrial activities during the coronavirus pandemic, but the heat-trapping gas stays in the air for a century so the levels in the atmosphere continue to go up, Taalas said. And, he said, so will the warming.
So far, this year is the second hottest on record and has a 37 per cent chance of surpassing the global record set in 2016, according to the US National Oceanic and Atmospheric Administration.
- AP
