Burning planet: why are the world’s heatwaves getting more intense? | Extreme weather

When the temperature readings started to come through from Antarctic weather stations in early March, scientists at first thought there might have been some mistake. Temperatures, which should have been cooling rapidly as the south pole’s brief summer faded, were soaring – at the Vostok station, about 800 miles from the geographic south pole, thermometers recorded a massive 15C hotter than the previous all-time record, while at Terra Nova coastal base the water hovered above freezing, unheard of for the time of year.

“Wow. I have never seen anything like this,” ice scientist Ted Scambos, of the University of Colorado, told the Associated Press.

But that was not all. At the north pole, similarly unusual temperatures were also being recorded, astonishing for the time of year when the Arctic should be slowly emerging from its winter deep freeze. The region was more than 3C warmer than its long-term average, researchers said.

To induce a heatwave at one pole may be regarded as a warning; heatwaves at both poles at once start to look a lot like climate catastrophe.

Since then, weather stations around the world have seen their mercury rising like a global Mexican wave.

A heatwave struck India and Pakistan in March, bringing the highest temperatures in that month since records began 122 years ago. Scorching weather has continued across the subcontinent, wreaking disaster for millions. Spring was more like midsummer in the US, with soaring temperatures across the country in May. Spain saw the mercury hit 40C in early June as a heatwave swept across Europe, hitting the UK last week.

Scientists have been able quickly to prove that these record-breaking temperatures are no natural occurrence. A study published last month showed that the south Asian heatwave was made 30 times more likely to happen by human influence on the climate.

Vikki Thompson, climate scientist at the University of Bristol’s Cabot Institute, explained: “Climate change is making heatwaves hotter and last longer around the world. Scientists have shown that many specific heatwaves are more intense because of human-induced climate change. The climate change signal is even detectable in the number of deaths attributed to heatwaves.”

Friederike Otto, senior lecturer in climate science at the Grantham Institute, Imperial College London, said heatwaves in Europe alone had increased in frequency by a factor of 100 or more, caused by human actions in pouring greenhouse gas emissions into the atmosphere. “Climate change is a real game changer when it comes to heatwaves: they have increased in frequency, intensity and duration across the world,” she said.

This type of heat poses a serious threat to human health, directly as it puts stress on our bodies, and indirectly as it damages crops, causes wildfires and even harms our built environment, such as roads and buildings. Poor people suffer most, as they are the ones out in fields or in factories, or on the street without shelter in the midst of the heat, and they lack the luxury of air-conditioning when they get home.

Air-conditioning itself is a further facet of the problem: its growing use and massive energy consumption threatens to accelerate greenhouse gas emissions, just as we need urgently to bring them down. Radhika Khosla, associate professor at the Smith School at the University of Oxford, said: “The global community must commit to sustainable cooling, or risk locking the world into a deadly feedback loop, where demand for cooling energy drives further greenhouse gas emissions and results in even more global warming.”

There are ways to reduce the impacts for individuals, and to adapt our cities. Painting roofs white in hot countries to reflect the sun’s rays, growing ivy on walls in more temperate regions, planting trees for shade, fountains and more green areas in cities can all help. More heavy-duty adaptation measures include changing the materials we use for buildings, transport networks and other vital infrastructure, to stop windows falling out of their frames, roads from melting in the heat and rails from buckling.

But these measures can only ever be a sticking plaster – only drastic cuts in greenhouse gas emissions will prevent climate chaos. The current heatwaves are happening as the earth has warmed by about 1.2C above pre-industrial levels – nations agreed, at the Cop26 UN climate summit last November, to try not to let them rise by more than 1.5C. Beyond that, the changes to the climate will be too great to overcome with shady trees or white roofs, and at 2C an estimated 1 billion people will suffer extreme heat. “We cannot adapt our way out of the climate crisis,” Katharine Hayhoe, chief scientist for the Nature Conservancy, told the Observer. “If we continue with business-as-usual greenhouse gas emissions, there is no adaptation that is possible. You just can’t.”
Fiona Harvey

India

Even the mountains, the traditional escape from the unbearable city heat, now offer little respite

Every summer, when the heat in the plains becomes unbearable, software engineer Akhilesh Gupta does what the British used to do when they ruled India – pack the family into the car and head out of New Delhi for a long drive to enjoy the cool air of the mountains.

This year, the family couldn’t wait to go. Since mid-March, the Indian capital has been in the grip of a relentless heatwave with temperatures hovering about 45C, making living and working insufferable.

In earlier years, such high temperatures used to be a fleeting feature of the summer. This year, they are the new normal. Demand for power has soared as Indians use more air conditioners. Water shortages have hit some areas. Those who work outside – construction labourers, autorickshaw wallahs, security guards – are among the worst affected.

Street vendors selling fruit, vegetables and flowers have been cowering under makeshift awnings for shade while constantly splashing water on to their produce to keep it from shrivelling up.

The Guptas reached their destination in Nainital, more than 2,000m above sea level, to find that the town was having the hottest summer for 30 years. One day it touched an unprecedented 34C.

“I have been coming here every summer since I was a kid and have never needed a ceiling fan. It never used to go beyond 28C. We couldn’t go boating it was so hot. It was better than Delhi but it was a huge shock to us,” said Gupta.

His friends went trekking to even higher altitudes and found that mountains usually covered in snow had only a dusting.

Heatwave conditions have affected most areas of India since March. Data from the Meteorological Department shows that Delhi has recorded a maximum temperature of 42C (and above) on 25 days since the summer began – the highest number of days since 2012. March was the hottest in India since records began 122 years ago.

The kind of crop damage that climate experts have predicted is already happening. Farmers in north India have seen their wheat being burnt by the sun. An estimated 15 to 35% of the wheat crop in states close to Delhi – Punjab, Haryana and Uttar Pradesh, India’s “wheat bowl” – has been damaged.

Climate experts say heatwaves are what lie ahead for Delhi. Their estimates suggest that Delhi has become so built-up that it has lost 50 to 60% of its wetlands and natural ecosystem that could have moderated the temperatures.

In fact, Abinash Mohanty, programme lead at the Council for Energy, Environment and Water, wants the definition of a “heatwave” to be updated. He says heatwaves should not be restricted to days when the temperature crosses a certain officially ordained figure because for most poor Indians living in slums in homes with tin roofs, the temperature is always five to six degrees hotter than outside.

“People in Delhi will experience extreme discomfort in the coming years. Their health and productivity will be impacted, along with their cognitive health, because if you can’t sleep at night, you can’t function the next day,” said Mohanty.

Female construction workers already suffer health issues. “There aren’t any clean public toilets around so I limit my water intake to avoid having to go to the toilet. Last month I ended up in hospital with dehydration,” said Sunita Devi, who is carrying rubble away from a construction site in Friends Colony West.

A 2019 International Labour Organization report, Working on a Warmer Planet, predicted that India is expected “to lose the equivalent of 34 million full-time jobs by 2030 as a result of heat stress”.

Individuals are already feeling the impact. The lives of people such as Virender Sharma, who sells flowers on the street, have become harsher. With the sun shrivelling the flowers, his income has dropped drastically. The daily discomfort is getting to him.