Researchers from the Centre for Science and Environment (CSE) found that 76% of Delhi's area has experienced heat stress for at least 10 years [1].
This trend indicates a growing vulnerability to extreme heat events as the city loses its natural ability to dissipate warmth. The findings suggest that rapid urban development is outpacing environmental protections, leaving a vast majority of the population exposed to rising temperatures.
Data covering the period from 2015 to 2024 shows a significant decline in the city's natural cooling infrastructure [1]. Green cover in the National Capital Territory dropped from 25.36% in 2014 to 14.14% in 2024 [2]. This loss of vegetation is coupled with a decrease in water bodies, which fell from 1.25% of the area in 2014 to 0.99% in 2024 [2].
The CSE report identifies these environmental losses as primary drivers of higher surface temperatures. The combination of shrinking forests and dwindling water sources has reduced the city's capacity to mitigate the heat island effect, a phenomenon where urban areas are significantly warmer than surrounding rural areas.
Urban development and rising ambient temperatures have further compounded the crisis [1]. The lack of shade and moisture in the air means that heat is trapped in concrete and asphalt, creating a cycle of persistent stress for residents.
In response to these environmental challenges, the forest department has identified 1,060 sites for a plantation drive. The initiative aims to plant 5 lakh saplings across the city to restore some of the lost canopy [3].
“76% of Delhi’s area has been under heat stress for at least 10 years”
The data highlights a critical failure in urban planning where the removal of 'blue-green' infrastructure—water and vegetation—directly correlates with increased thermal risk. While plantation drives are a step toward mitigation, the scale of the loss suggests that Delhi may require systemic changes in zoning and architecture to prevent heat stress from becoming a permanent public health crisis.
