The world’s biggest capitals are heating up – and Asia tops the charts

The world’s biggest capitals are seeing more extremely hot days than ever before, according to a new study, which says the dangerous trend is being driven by scorching temperatures across Asia as the climate crisis worsens.

The world’s 20 most populous cities – home to more than 300 million people together – have seen a 52% jump in the number of days exceeding 35 degrees Celsius (95 degrees Fahrenheit) over the past three decades, according to an analysis by International Institute. for Environment and Development (IIED) published on Friday.

From Buenos Aires, Argentina, to the French capital, Paris, and Cairo, Egypt, the study concluded that, with each passing decade, as man-made greenhouse gas emissions increase, the main capitals are experiencing more and more extremely hot days – posing threats to human health and economies. and infrastructure.

“Climate change is not just a future threat – it is already happening and getting worse,” IIED senior researcher Tucker Landesman said in a press release.

“In just one generation, there has been an alarming increase in the number of days of extreme heat affecting some of the world’s largest capital cities – compounded by the urban heat island effect,” which occurs when cities replace natural land with roads and buildings that retain more heat.

Asian cities, which make up around half of the world’s most populous capital cities, have seen some of the biggest temperature rises – a trend that is evident in recent heatwaves across the continent since Southeast Asia for China It is India. Asia is particularly vulnerable to climate risks due to its high population, poverty and the proportion of people living in low-lying areas prone to flooding, rising sea levels and other natural disasters.

New Delhi topped the list of hottest cities, recording 4,222 days above 35 degrees Celsius in the last three decades – more than any other city analyzed. Between 2014 and 2023, just under half (44%) of days in the Indian capital reached this threshold, compared to 35% from 1994 to 2003 and 37% from 2004 to 2013.

The capital region is increasingly hot. In late May, a part of Delhi reached 49.9 degrees Celsius (121.8 degrees Fahrenheit) – the highest temperature ever recorded in the city, straining India’s power grid and power supply. The heat also persisted throughout the night, leaving little rest for residents.

“We have lived in this neighborhood for 40 years, but we have never seen a summer like this,” Kalyani Saha, a 60-year-old resident of Lajpat Nagar in southeast Delhi, told CNN.

“We only get water once a day, and it’s scalding hot, so unless you fill a bucket and let it cool all day before using it, you can’t bathe in this water.”

A Delhi rickshaw driver told CNN he was getting fewer passengers as people opted for air-conditioned taxis rather than open-air transportation.

“My body can’t take it, but I have to keep cycling,” said Sagar Mandal, 39. “We are used to physical work, we are not complaining about it. But this heat is not normal, something has to change.”

Indonesia’s capital Jakarta has seen one of the biggest jumps in the number of days above 35 degrees Celsius in the last 30 years, from 28 days between 1994 to 2003 to 167 days from 2014 to 2023.

Seoul, South Korea and Beijing, China, also recorded significant increases on extremely hot days. In 2018, Seoul had 21 days above 35 degrees Celsius – more than in the previous 10 years combined. The number of days above 35 degrees in Beijing has increased by 309% since 1994.

Cities are also seeing longer periods of high temperatures as governments fail to meet climate targets and sufficiently reduce emissions. In October 2023, Jakarta recorded 30 consecutive days above 35 degrees Celsius – more days than during the entire period between 1994 and 2003.

Extreme heat can be deadly, especially for vulnerable groups who may not have access to cool spaces. Between June 11 and 19, Delhi saw 192 deaths related to heat waves among its homeless population, a record compared to the same period in the last five years, according to a report by the NGO Center for Health Development in India.

Young children, the elderly and pregnant women are most at risk during heatwaves, which can also have a devastating impact on informal and hourly workers, who may face work interruptions or have to choose between staying home without pay or work in dangerous conditions.

Heat also harms economies, harming crops and livestock and reducing labor productivity, especially in places without air conditioning, as workers require more breaks to rest and rehydrate.

And extreme heat strains infrastructure, including highways, roads, power lines and railways, causing supply chain disruptions, blackouts and illness.

According to a 2022 Dartmouth College study, extreme heat has cost the global economy billions of dollars since the early 1990s, with poorer countries and those with lower emissions bearing the brunt of the impact.

“Responding to the challenge of extreme heat will require bold actions by policymakers, including serious investments to adapt to this new reality,” said IIED’s Landesman.

“For many cities, it is not a lack of knowledge, capacity or resources that prevents large-scale action to address climate change, but rather a lack of political will and governance instruments.”

CNN’s Esha Mitra and Kathleen Magramo contributed reporting.

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