New Delhi: Delhi has lost nearly half of its green cover over the last decade, while heat stress has expanded across almost the entire city, according to a new report by the Centre for Science and Environment (CSE). The findings highlight how rapid urbanisation, shrinking vegetation, and rising temperatures are making the national capital increasingly vulnerable to extreme heat.
The report, Making Delhi Heat Resilient: A Roadmap with the Focus on Vulnerable Groups reveals that Delhi green cover declined from 25.36 percent in 2014 to just 14.14 percent in 2024. During the same period, water bodies also shrank, reducing the city’s natural ability to cool itself.
Researchers found that 98.72 percent of Delhi crossed the heat-stress threshold at least once between 2015 and 2024. More than 75 percent of the city remained persistently heat-stressed throughout the decade, indicating that extreme heat is no longer limited to isolated areas but has become a citywide challenge.
Satellite based temperature analysis showed land surface temperatures reaching as high as 60.77 degrees Celsius in some locations around Indira Gandhi International Airport and other barren or sparsely vegetated areas. Industrial zones such as Bawana, Mayapuri, Mundka, Libaspur and Anand Parbat emerged as major heat hotspots, while several residential neighbourhoods regularly recorded temperatures between 44°C and 50°C.
The report also warns that Delhi losing ability to cool down after sunset declined by 9% resulting warmer nights and prolonged heat exposure for residents. Experts say this trend increases dependence on air conditioners which in turn release waste heat into the environment and further raise temperatures.
According to the study, vegetation can lower ambient temperatures by up to 5.7°C, while water bodies can reduce surrounding temperatures by nearly 5°C. Dense tree cover is even more effective, with some studies showing a reduction of around 10°C in land surface temperatures. However, the steady loss of green spaces has weakened these natural cooling benefits.
The report highlights that vulnerable groups are facing the greatest risks. Nearly 80 percent of Delhi’s workforce is employed in the informal sector, with many workers spending long hours outdoors. More than 92 percent of active construction sites and 84 percent of marketplaces are located in recurring heat stress zones. Additionally, around 1.5 million residents living in informal settlements face heightened exposure due to overcrowding, poor ventilation and limited access to cooling resources.
Despite the alarming findings, researchers say solutions are available. Areas such as Lutyens’ Delhi, Civil Lines and Delhi Cantonment remain relatively cool because of extensive tree cover and green corridors. Simulations conducted in public spaces showed that dense canopy trees, shade structures and reflective paving can reduce surface temperatures by up to 20°C.
The report calls for climate sensitive urban planning, expanded green infrastructure and targeted cooling measures to help Delhi remain livable as temperatures continue to rise.