Hong Kong
CNN
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The world’s major capitals are experiencing more scorching hot days than ever before, a dangerous trend that comes as scorching temperatures across Asia worsen the climate crisis, according to a new study.
The world’s 20 most populous cities, home to more than 300 million people, have seen a 52 percent increase in the number of days with temperatures above 35 degrees Celsius (95 degrees Fahrenheit) over the past three decades, according to an analysis released Friday by the International Institute for Environment and Development (IIED).
From Buenos Aires in Argentina to Paris in France to Cairo in Egypt, major capitals are recording more and more extremely hot days as man-made greenhouse gas emissions rise every decade, threatening people’s health, economies and infrastructure, according to the study.
“Climate change is not just a future threat; it’s already happening and getting worse,” Tucker Landesman, a senior researcher at IIED, said in a press release.
“In just one generation, there has been an alarming increase in the number of extremely hot days hitting some of the world’s major capitals, exacerbated by the urban heat island effect,” which occurs when cities replace natural land with roads and buildings that retain more heat.
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Tourists protect themselves from the sun as they visit the Palace Museum during the Dragon Boat Festival holiday in Beijing, China, on June 9, 2024. The Beijing Meteorological Observatory issued the first yellow heat warning of 2024 after the city’s maximum temperature reached 35 degrees Celsius.
Home to about half of the world’s most populous capital cities, Asian cities are experiencing some of the fastest temperature increases, as evidenced by recent heat waves across the continent, from Southeast Asia to China and India. Asia is particularly vulnerable to climate risks because of its large populations, poverty and high proportions of people living in low-lying areas, making them more susceptible to floods, sea-level rise and other natural hazards.
New Delhi tops the list of hottest cities, recording 4,222 days with temperatures above 35°C over the past three decades – more than any other city surveyed. Between 2014 and 2023, the number of days in the Indian capital where temperatures met this threshold will be just under half (44%), compared to 35% between 1994 and 2003 and 37% between 2004 and 2013.
The capital region is only getting hotter. In late May, parts of Delhi reached 49.9 degrees Celsius (121.8 degrees Fahrenheit), the city’s hottest temperature on record, putting a strain on India’s power grid and electricity supplies. The heat lingered into the night, giving residents little time to rest.
“We have lived in the area for 40 years and have never seen a summer like this,” Kalyani Saha, 60, who lives in Lajpat Nagar in southeast Delhi, told CNN.
“Water comes only once a day and it’s so hot that you can’t bathe in it unless you fill a bucket with it and let it cool for the day before using it again.”
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A woman walks past an air conditioning unit outside a building in Seoul, April 30, 2024.
Rickshaw drivers in Delhi told CNN they are seeing fewer passengers as people opt for air-conditioned taxis over open-air modes of transport.
“My body cannot take it but I have to keep riding,” said Sagar Mandal, 39. “We are used to physical labour so we don’t complain. But this heat is not normal. Something has to change.”
Indonesia’s capital, Jakarta, has recorded the largest increase in the number of days with temperatures above 35 degrees Celsius in the past 30 years, from 28 days between 1994 and 2003 to 167 days between 2014 and 2023.
Seoul, South Korea, and Beijing, China have also seen a significant increase in the number of extremely hot days. Seoul had 21 days with temperatures above 35°C in 2018, more than the previous 10 years combined. Beijing has seen a 309% increase in the number of days with temperatures above 35°C since 1994.
The government’s failure to meet climate targets and sufficiently curb emissions has led to longer hotter days in cities: In October 2023, Jakarta recorded 30 consecutive days with temperatures above 35 degrees Celsius, more than in the entire period from 1994 to 2003.
Extreme heat can be deadly, especially for vulnerable groups who lack access to cooler places. Between June 11 and 19, 192 people among Delhi’s homeless population died from the heatwave, the highest ever recorded for the same period in the past five years, according to a report by the non-governmental organization Indian Centre for Health Development.
During heatwaves, young children, the elderly and pregnant women are at higher risk, and they can also have devastating effects on non-regular and hourly workers, who may face work stoppages or be forced to choose between staying home without pay or working in dangerous conditions.
Heat also has a negative impact on the economy, damaging crops and livestock and reducing labor productivity as workers need more breaks to rest and rehydrate, especially in places without air conditioning.
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People shelter from the summer heat in Gurugram, India on June 18, 2024.
Extreme heat also puts strain on infrastructure like highways, roads, power lines and railways, causing supply chain disruptions, power outages and illnesses.
According to a 2022 Dartmouth College study, heatwaves have cost the global economy trillions of dollars since the early 1990s, with the world’s poorest and lowest-emitting countries bearing the brunt of the impacts.
“Meeting the challenge of extreme heat will require bold action from policymakers, including serious investments to adapt to this new reality,” IIED’s Landesman said.
“For many cities, what is preventing large-scale action to address climate change is not a lack of knowledge, capacity or resources, but rather a lack of political will and governance.”