Urbanisation Alone Has Led To 60% Enhancement In Warming Of Indian Cities: IIT Bhubaneswar Study

Bhubaneswar: An innovative study by researchers from the Indian Institute of Technology (IIT) Bhubaneswar reveals that urbanisation alone has caused up to 60% additional warming in Indian cities, with significant variability among different cities. This research provides a science-based quantitative ranking of urbanisation for Indian cities. The study titled ‘Urbanization and Regional Climate Change-linked Warming of Indian Cities’ published in the journal ‘Nature Cities’ is first-of-its-kind and provides insight by carefully separating regional climate change and urbanisation in multiple cities.

In the context of rising temperatures, the study investigated the contributions of local-scale urbanisation and regional climate change to the observed surface warming in 141 major Indian cities over the past two decades. By leveraging 18 years of high-resolution land surface temperature data from the MODIS sensor on NASA’s Aqua satellite for the period 2003-2020, the research team carefully compared urban and rural warming trends. Applying strict quality control measures, they subtracted the regional climate change effects observed in rural areas from urban warming to isolate the urbanisation effect.

Notably, Tier II cities in Eastern India showed stronger urbanisation-driven warming compared to larger metro cities like New Delhi and Mumbai. This disparity underscores the importance of targeted urban planning and efforts to mitigate heat impacts, which could also address other urban issues like extreme rainfall, floods, and air pollution. Targeting smaller cities with a systematic heat action plan is expected to be far cheaper with positive outcomes than for large urban agglomerations or megacities. The study emphasises the urgent need for detailed urban climate studies and data generation as Indian cities rapidly expand.

Dr V. Vinoj, Associate Professor, School of Earth, Ocean & Climate Sciences and Soumya Satyakanta Sethi led the research. Commenting on the study, Dr Vinoj said: “A lot more aspects related to urbanisation are still unexplored in the Indian context. However, this study provides an early glimpse of science-backed information that may be useful for national or state-level policymaking to view each city differently and allocate limited resources systematically to reduce the warming of our cities. Such an approach will help in implementing policies that may make our growing smart cities, smarter.”