Will heatwaves wake us up to the impact of the climate crisis?

Heat extremes have increased in frequency, intensity and duration, writes Harry Cockburn

People cool off during the heatwave in Madrid, Spain, on 11 June 2022 (Reuters)

It’s getting very hot again. Yes, it’s summer, but what can anomalous temperatures tell us about the state of the climate crisis?

Just as climate crisis-denying politicians can’t use freak cold winter weather as evidence that environmental breakdown isn’t occurring, those concerned about the state of the natural world must not use hot summer days in isolation to back up climate emergency claims.

Variation in the weather is to be expected – industrial revolution or not. Hot summer temperatures can only be seen in a climate context when they become part of a broader pattern of rising temperatures.

But the warming trends are definitively gathering steam.

Dr Fredi Otto, a senior lecturer at Imperial College’s Grantham Institute, which specialises in climate and environmental science, told The Independent the climate crisis is “a real game-changer when it comes to heatwaves”.

"They have increased in frequency, intensity and duration across the world because of our burning of fossil fuels,” she said.

“Trends in heat extremes are particularly strong in Europe, where many studies have shown that they have increased in frequency by a factor of 100 or more due to human-caused climate change.”

After a dry spring, this week parts of Spain are facing a deadly heatwave – the earliest such occurence in 40 years, with red alert warnings of temperatures reaching 50C.

In the UK, so far things are not that severe. The current spike in temperatures is not forecast to be an official heatwave – for this, temperature thresholds (which differ from county to county) must be exceeded on three consecutive days.

But Dr Mark McCarthy, head of the Met Office’s National Climate Information Centre, said: “Reaching 34C during June is a rare, but not unprecedented, event in the historical climate records for the UK. But if it should happen this week it would be notable that it would have occurred on three days during the last six Junes.”

The rising temperatures mean scientists are now desperately concerned about global inaction on tackling the climate crisis – and the lack of planning for extreme weather events.

In Spain, concern has spilled out of the research institutions and onto the streets. In April, thousands of scientists demonstrated, asking to be heard and launching actions of non-violent civil disobedience.

Bob Ward, policy and communications director at the Grantham Institute at the London School of Economics, told The Independent that worsening heatwaves are causing deaths across the UK “every summer”.

He said: “We know that heatwaves are increasing in frequency and intensity across the world, including in the UK. Heatwave conditions cause hundreds of deaths across the UK every summer.” Official statistics show that there were 1,634 extra deaths in England during heatwave conditions in summer 2021, and 2,556 extra deaths in summer 2020.

Heatwaves exacerbate air pollution and can hit those with underlying health conditions hard – particularly respiratory illnesses – resulting in extra deaths.

The government introduced the Heatwave Plan for England after the country experienced what was, at the time in 2003, the hottest summer on record in Europe since at least 1540. In the UK around 2,000 people are estimated to have died, and a new temperature record of 38.5C (101.3F) was recorded at Faversham in Kent on 10 August. This remained the highest recorded temperature in the UK until July 2019.

Mr Ward said that the government has made no meaningful updates to this heatwave plan for almost 20 years. The plan – and updates listed by the government – is published here.

Mr Ward also said in a 2020 review by the London School of Tropical Medicine that there is little evidence that the plan has reduced deaths.

“The government should urgently introduce a National Heat Risk Management Strategy, which should include a better alert system and measures to ensure that new and existing homes do not overheat,” he said.