KARACHI, Pakistan–More than 25 people have suffered heat-related deaths in the state of Maharashtra in India since the beginning of an unprecedented heat wave in the subcontinent that has put the lives of over a billion people at risk. 

For the past two months people in India and Pakistan have experienced levels of heat higher than national and global records. In Pakistan, March remained the hottest recorded month since 1961. In northwest and central India the average maximum temperature throughout April was the highest in over a century, according to the Indian Meteorological Department. 

A week ago,  Jacobabad, a city in Pakistan’s Sindh province, which a 2021 Amnesty International report categorized as “unlivable for humans,” reached 120.2 Fahrenheit, a record high for the Northern Hemisphere this year, according to data from the Pakistan meteorological department. 

Although high temperatures in the months of March and April are not uncommon in some parts of the subcontinent, where relief from heat comes after the beginning of the monsoon season in late May, the ongoing heat wave is cause for serious concern. “This is the first time in decades that Pakistan is experiencing what many call a ‘spring-less year,” said Sherry Rehman, Pakistan’s minister for climate change, in a statement. 

Heat waves are prolonged periods of excessive heat with temperatures more than 10 degrees higher than normal. According to the World Health Organization, exposure to high levels of heat can cause exhaustion, heat strokes and hyperthermia. Deaths and hospitalizations are likely to occur either immediately or after several days of exposure, which can also worsen chronic illnesses, including cardiovascular, respiratory and diabetes-related conditions. 

In 2015, an extended heat wave on the subcontinent resulted in more than 2,500 deaths in India and more than 1,200 deaths in Pakistan.

“India and Pakistan are projected to see more severe heat waves, coupled with high humidity, which will really begin to test limits to adaptation,” said Chandni Singh, lead author of the Intergovernmental Panel on Climate Change’s Sixth Assessment Report and senior researcher at the Indian Institute of Human Settlements. 

According to the sixth assessment, warming cities like Karachi in Pakistan and Kolkata in India are likely to experience conditions equivalent to the 2015 heat wave on an annual basis at 1.5 degrees Celsius above preindustrial levels, the goal for limiting warming under the 2015 Paris Agreement. 

Both India and Pakistan are headed towards warming of 3.5ºC by the end of the century, according to projections from Berkeley Earth, a non-profit U.S. organization focused on environmental data. 

Although India and Pakistan are not the only countries experiencing high temperatures, the population density, the scale of economic activity and rapid urbanization in the region all make the subcontinent more vulnerable to extreme weather events. 

The urban heat island effect, a concern in most major cities around the world, is exacerbated in India and Pakistan by the lack of green cover and bodies of water that help cool congested neighborhoods. 

“The heat island effects compounded with really unplanned cities adds to the vulnerabilities of the people in this region,” said Ganesh Gorti, a doctoral candidate  at the University of Colorado Boulder. According to research that Gorti contributed to on patterns of outdoor exposure to heat in South Asian cities, low-income communities that mostly reside in extremely congested neighborhoods with little to no access to greenery, bodies of water or cooling facilities are far more likely to experience heightened impacts of extreme heat. 

“It’s a matter of environmental justice when it comes to the global south and developed countries, and it is also a matter of environmental justice when we compare cities and communities within the region,” said Gorti. 

The impacts of extreme heat are felt most strongly within communities with the least access to cooling resources. Agricultural communities in off-grid, rural areas in India and Pakistan, and low income communities in congested city dwellings are the most vulnerable. 

“Climate change is global but its impacts are local,” said Roxy Koll, lead author of the  Intergovernmental Panel on Climate Change’s Sixth Assessment report and a climate scientist at the Indian Institute of Tropical Meteorology.

He emphasized the importance of local efforts that include creating warning systems, developing heat adaptation plans specific to the geographic conditions of South Asian cities and providing access to cooling resources for low-income communities in the region.

The Intergovernmental Panel on Climate Change report—Climate Change 2022, Impacts, Adaptation and Vulnerability—confirms that climate risks for cities have increased significantly, with informal settlements and localities that lack access to basic resources being the most vulnerable. But cities can also be part of the solution. Reimagining the built environment and choices made in urban planning today are likely to have long-term impacts on the planet’s ability to achieve global emissions reduction goals. 

But, for the subcontinent, where cities grow rapidly and often without much planning, Gorti said, reimaging these already built spaces without displacing vulnerable communities or impacting livelihoods is a challenge, making mitigation all the more important to address the region’s growing vulnerability to extreme weather events. “Reimaging sounds great for cities that are coming up right now but I don’t really know how we can do it in an already built, extremely congested neighborhood,” he said. 

The human body has limited ability to adapt to heat. Wet bulb temperatures—a term that accounts for both heat and humidity—around 95 degrees Fahrenheit are considered the upper limit that humans can survive, above which prolonged exposures can prove fatal.

 “Even a healthy person exposed to these temperatures for more than seven or eight hours can not survive,” said Fahad Saeed, climate scientist at Climate Analytics, a global policy analysis organization with a focus on human induced climate change. 

“This is a doomsday scenario,” he said.

As temperatures continue to rise in India and Pakistan, experts worry that the region will soon strain all limits of adaptability.

“We really need to understand that risk management and adaptation are only part of the solution. The other parts are urgent and deep [greenhouse gas] emission reductions and inclusive development that builds capacities of the most exposed,” said Singh. 

Pakistan, which has contributed less than 1 percent to global greenhouse gas emissions, is one of 10 countries most affected by climate change, according to a 2021 global climate risk index published by Relief Web, an information service of the United Nations Office for the Coordination of Human Affairs (OCHA). 

In 2009, at COP15 in Copenhagen, developed countries agreed on climate finance funding of $100 billion for developing countries by the year 2020. This commitment was agreed upon again at COP21 in Paris in 2015, with the additional commitment that climate funding of $100 billion would be provided each year, due to the needs of developing countries. 

Although final figures for 2020 are not available, it is generally agreed that the promise of $100 billion has not been kept. Experts agree that the subcontinent and the global South are in stages of loss and damage—a term used in climate negotiations by the United Nations in reference to the consequences of climate change that exceed adaptation efforts—in which the least responsible are the most vulnerable.

“We are not resilient like the western countries, we need help in terms of finance,” said Saeed.