Climate change made ‘relentless' Nordic heatwave in July hotter and more likely

Independent

7 days ago

Climate change made the recent 'relentless' heatwave in Norway Sweden and Finland about 2C hotter and at least 10 times more likely, scientists have said.
Researchers from the World Weather Attribution (WWA) network, which assesses the role of climate change in extreme weather, said the two weeks of unusually hot weather from mid-July, with temperatures above 30C, would be 'extremely rare' without human-caused global warming.
The extreme weather for the region, which came at the peak Nordic holiday season, led to heat-related deaths, overcrowded hospitals, an increase in drownings, wildfires, algal blooms on coastlines and sightings of reindeer straying into towns seeking shade and water.
The latest results show how burning fossil fuels such as coal, oil and gas, which release heat-trapping gases that drive global warming, are causing more extreme heatwaves.
They come as southern Europe is hit by record scorching temperatures, soaring past 40C and causing widespread wildfires.
And in the UK, parts of the country are under an 'amber heat health alert' in the fourth heatwave of the summer as temperatures climb into the 30s this week.
Researchers looking at the Nordic heatwave, which in Finland led to a record-breaking 22 consecutive days above 30C, found that in a world without climate change, a similar two-week period of extreme heat would be extremely rare.
But today, with 1.3C of warming caused by humans burning fossil fuels, such a heatwave is at least 10 times more likely and would now be expected about every 50 years.
Climate change also made the event about 2C hotter, the rapid attribution study found.
As the climate warms, Norway, Sweden and Finland will face more dangerous heatwaves, and if warming reaches 2.6C above pre-industrial levels by 2100 as projected, without more rapid action to halt fossil fuel use, they will become five times more likely and another 1.4C hotter than today.
The scientists also said that the 0.2C in global warming since a similar two-week heatwave in the region in 2018 has made such an event twice as likely – showing how small increases in warming expose people to more frequent dangerous heat events.
Dr Clair Barnes, researcher at the Centre for Environmental Policy Imperial College London, and one of the WWA team, said: 'This heatwave was relentless.
'Two weeks of temperatures above 30C in this region is unusual and of course, highly concerning.
'Climate change is fundamentally reshaping the world we live in.
'Cold-climate countries like Norway, Sweden and Finland are now experiencing unfamiliar levels of heat, as recently seen in strained health systems and sightings of reindeer seeking shade in urban areas.
'We found that the likelihood of a prolonged period of heat like this has almost doubled since 2018, when the region last experienced such an intense heatwave – and this trend is going to continue if we don't stop filling the atmosphere with planet-heating gasses.
'A rapid transition from fossil fuels to renewable energy is the only way to slow and, hopefully, ultimately stop this warming.'
Prof Friederike Otto, professor in climate science at the Centre for Environmental Policy Imperial College London, said: 'Even comparably cold Scandinavian countries are facing dangerous heatwaves today with 1.3C of warming.
'This event should be taken as another reminder that no country is safe from climate change.'
She pointed to sweltering temperatures that have hit the US, Japan and South Korea in recent weeks, and triggered huge wildfires in France and Turkey, saying 'burning oil, gas and coal is killing people today'.
In the UK, experts also warn that homes, hospitals, workplaces and schools are not prepared for the impact of increasingly dangerous heat.