Climate change: Extreme weather events 'now the norm' as last seven years hottest on record

The last seven years have been the hottest on record – with sea levels rising to new highs and climate-related destructive weather extremes in 2021, UN experts have said.

In its annual state of the global climate report launched as the UN COP26 climate conference gets under way, the World Meteorological Organisation (WMO) said that 2021 is likely to have been the fifth to seventh hottest year on record.

While it is not quite as hot as some recent years, due to a “La Nina” weather phenomenon in the Pacific – which has a cooling affect on global temperatures, it still averaged 1.09C above pre-industrial levels, the WMO said.

The last seven years since 2015, when countries secured the Paris Agreement to curb temperature rises to 1.5C or well below 2C to avoid the worst impacts of climate change, have been the hottest in records dating back to 1850.

And the UK’s Met Office warned the world’s temperature has reached an average exceeding 1C above pre-industrial levels for the past two decades, the first time a 20-year period has been at that level since the records began.

The average global temperature for 2002-2021 was 1.01C above pre-industrial levels, the scientists said.

UN Secretary General Antonio Guterres called for the COP26 talks, where leaders are under pressure to keep the 1.5C temperature limit within reach with more action on cutting greenhouse gas emissions, to be a “turning point for people and planet”.

Communities and natural systems around the world were being devastated, he warned, as he urged leaders to act.

“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,” he said.

And WMO Secretary General Petteri Taalas said extreme events “are the new normal”, with mounting evidence that some bear the footprint of human-induced climate change.

At the current rate of increase in greenhouse gas concentrations in the atmosphere, temperatures by the end of the century would be far in excess of the Paris goals, he said.

“Cop26 is a make-or-break opportunity to put us back on track.”

Dozens of people were killed in northern Europe as heavy rainfall caused deadly flooding in July

UK Chief Scientist Sir Patrick Vallance added his voice to calls for action, warning: “The commitment of leaders to implement changes to limit warming to 1.5C at COP26 will be essential to protect all of us and the planet."

And he said: “This report hammers home the message that climate change is real and present: the seas are rising, glaciers are melting, and floods and wildfires are more frequent.

“Across the world, these changes are already affecting our transport, healthcare and food systems.”

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.

Torrential rain leaves people and cars stranded as China becomes inundated with floodwater as deep as one metre

• 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 Covid-19 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.