The World Meteorological Organization (WMO) warns global temperatures are likely to surge to record levels in the next five years, with temperatures reaching more than 1.5 degrees Celsius above pre-industrial levels for at least one year.
"We estimate that in the coming five years, we will hit 1.15°C on a temporary basis, but in the coming 15 to 20 years, we estimate that might be the more permanent feature of climate," said Petteri Taalas, WMO secretary-general.
"Actually, there is no return back to the good old days because we already have such a high concentration of carbon dioxide and we also, of course, have increased the methane concentration in the atmosphere."
CO2 and methane and other greenhouse gases that cause global warming are the main drivers of climate change. While many greenhouse gases occur naturally, human activities increase their concentration in the atmosphere.
Talaas said the negative trend was likely to continue until the 2060s and then "the return back to normal level might take even thousands of years because we already have such a high concentration of carbon dioxide" in the atmosphere.
Meteorologists expect the most dramatic changes to happen in the Arctic, where the warming is disproportionately high and temperatures in this region are predicted to be more than three times as large as the global average in the coming five years.
Talaas warns that it will have a major effect on the eco system. "For example, we expect that there will be changes in fisheries and in the melting of permafrost and it also will have big impacts on infrastructures."
He noted that many settlements are built on permafrost—"railroads, roads, gas pipelines and so forth and they are going to be endangered because of this high level of warming."
The WMO report predicts precipitation patterns in the next five years will result in increased rainfall in the Sahel, northern Europe, Alaska and northern Siberia and reduced rainfall over the Amazon and parts of Australia.
Additionally, Talaas said he expected drought in the Amazonian region would adversely affect the global climate because parts of the region have become a source of carbon instead of a carbon sink, which it classically has been.
"This is one of the tipping points that we have to follow because we would again see large amounts of carbon dioxide in the atmosphere from that region," he said.
Leon Hermanson, the United Kingdom's Met Office expert scientist and lead author of the report, said what worries him most is the impact that extreme weather events will have on people.
"Nobody is going to be untouched by these changes that are happening and have happened," he said. "It is leading already to floods across the world, droughts, and big movements of people."
Last year saw stark evidence of that. Countless millions of people have suffered from severe drought and heat in China, Europe, North America, and the Horn of Africa.
Record breaking temperatures in several European countries in 2022 led to the deaths of at least 15,000 people. More than 20 million people have been pushed into acute hunger following three consecutive years of drought in the Horn of Africa. More than 1,700 people were killed and the lives of 33 million others were upended because of climate-related flooding in Pakistan last June.
"We could phase out this negative trend in weather patterns of heat waves, flooding, drought and tropical storm by being ambitious and successful in climate mitigation," said Talaas.
"But there is no turning back to the climate, which persisted during the last century. That is a fact."
Hermanson concurred that it will be a sad day for the world when it passes the 1.5 Celsius mark but added that is not a reason to give up.
"We have to continue working out how we can reduce emissions of greenhouse gases as much as possible, even after that because it will make a difference," he said.
