UN WMO report warns last seven years hottest on record

Global sea level rise has also accelerated since 2013 to a new high in 2021, with continued ocean warming and ocean acidification.

The study provides a snapshot of climate indicators such as greenhouse gas concentrations, temperatures, extreme weather, sea level, ocean warming and ocean acidification, glacier retreat and ice melt, as well as socio-economic impacts.

The report combines input from multiple United Nations agencies, national meteorological and hydrological services and scientific experts and highlights impacts on food security and population displacement, harming crucial ecosystems and undermining progress towards the sustainable development goals.

A temporary cooling 'La Niña’ event early in the year means that 2021 is expected to be ‘only’ the fifth to seventh warmest year on record. But experts have warned that this does not negate or reverse the long-term trend of rising temperatures.

Average rises in global temperatures

United Nations Secretary-General António Guterres said: “The provisional WMO state of the global climate 2021 report draws from the latest scientific evidence to show how our planet is changing before our eyes.

“From the ocean depths to mountain tops, from melting glaciers to relentless extreme weather events, ecosystems and communities around the globe are being devastated.

“COP26 must be a turning point for people and planet." He added: “Scientists are clear on the facts. Now leaders need to be just as clear in their actions.

“The door is open; the solutions are there. COP26 must be a turning point. We must act now – with ambition and solidarity – to safeguard our future and save humanity.”

WMO secretary-general professor Petteri Taalas, added: “It rained – rather than snowed - for the first time on record at the peak of the Greenland ice sheet. Canadian glaciers suffered rapid melting.

“A heatwave in Canada and adjacent parts of the USA pushed temperatures to nearly 50°C in a village in British Columbia. Death Valley, California reached 54.4 °C during one of multiple heatwaves in the southwestern USA, whilst many parts of the Mediterranean experienced record temperatures.

“The exceptional heat was often accompanied by devastating fires.”

Temperature rises across the world

He added: “Months’ worth of rainfall fell in the space of hours in China and parts of Europe saw severe flooding, leading to dozens of casualties and billions in economic losses.

“A second successive year of drought in sub-tropical South America reduced the flow of mighty river basins and hit agriculture, transport and energy production.

Professor Taalas warned that “extreme events are the new norm”.

He added: “There is mounting scientific evidence that some of these bear the footprint of human-induced climate change.

“At the current rate of increase in greenhouse gas concentrations, we will see a temperature increase by the end of this century far in excess of the Paris Agreement targets of 1.5 to 2 degrees Celsius above pre-industrial levels.

“COP26 is a make-or-break opportunity to put us back on track.”

Among the findings in the WMO assessment are:

– Temperatures from January to September 2021 were around 1.09C above the 1850-1900 period, with a moderate La Nina reducing temperatures early in the year, but with temperatures rising as the La Nina faded.

The last seven years, 2015-2021 are on track to be the hottest seven years on record.

– Sea level rise has increased from an average of 2.1mm a year between 1993-2000 to 4.4 mm a year between 2013-2021, mostly due to a speed up in the loss of ice from glaciers and ice sheets.

– Arctic sea ice cover was below the average for 1981-2010, while Antarctic sea ice was close to the average.

– Much of the world’s oceans experienced at least one “strong” marine heatwave at some point in 2021.

– On August 14, it rained for several hours at Summit Station, the highest point on the Greenland ice sheet, where no previous rainfall has been recorded.

Air temperatures remained above freezing for nine hours, the third time melting conditions have been seen there in nine years, compared to just once in the 20th century.

– Exceptional heatwaves hit North America in June and July, with previous record temperatures being exceeded by 4C-6C. The town of Lytton, British Columbia, reached 49.6C on June 29, breaking Canada’s previous national record by 4.6C and was devastated by fire the next day.

– The Mediterranean region also saw record hot weather, with Sicily recording 48.8C on August 11, provisionally a record temperature for Europe. There were also national heat records in Spain, Tunisia and Turkey this summer.

There were abnormal cold conditions in Texas in February and in parts of Europe in April.

– Zhengzhou in China had a record 201.9mm (7.9 inches) of rain in one hour on July 20 as extreme rainfall hit the province of Henan over four days, and devastating floods claimed 302 lives.

Western Europe had its most severe flooding on record, with more than 200 deaths in mid-July. There was also significant flooding in northern South America in the first part of the year, and in East Africa, while droughts hit southern Brazil, Paraguay, Uruguay and northern Argentina.

– Conflict, extreme weather and economic shocks, exacerbated by the pandemic, led to increases in people facing food crises, starvation and collapse of livelihoods.

– Events such as the heat wave in the North America and the flooding in western Europe were made more likely by human-induced climate change, rapid attribution studies have shown.

Professor Stephen Belcher, Met Office chief scientist, said the global temperature in 2021 was higher than average, despite the slight, short-term natural cooling cycle associated with La Nina.

“This year’s provisional figure shows that the temperature trend remains upward.

“The fact that the 20-year average has reached more than 1.0C above pre-industrial levels will focus the minds of delegates at COP26 aspiring to keep global temperature rise to within the limits agreed in Paris six years ago,” he said.