Cities and urbanizing spaces combine heat stress from both heat island effect due to the built environment, loss of blue and green spaces as well as global warming. South Korea and India offer contrasting socio-economic and development situations, climate regimes, some similar but many dissimilar urban contexts, but both face the increasing vulnerability from heat stress. Blue and green spaces as nature-based interventions bring the potential to cool cities, support native biodiversity and provide other diverse ecosystem services as co-benefits.

Blue and green spaces (BGS) are potential nature-based solutions in fast urbanising cities for mitigating heat stress through evaporation as well as transpiration besides sequestering carbon and helping in reducing urban risks.  The effectiveness of BGS in mitigating heat stress and other ecosystem services in both countries depends on size, shape, weather, and climate variables, especially humidity, the socio-economic as well as governance context.

We use satellite derived land surface temperature (LST) to quantify and map negative temperature anomalies (cooling) with respect to spatial average across a few cities in India and South Korea in years with different levels of summer temperature, especially due to El Nino.  We analysed the diverse types of blue and green spaces in four metropolitan cities Bangaluru, Nagpur in India while, Seoul and Sejong in South Korea for understanding the impact of BGS.

The geometry landscape and political ecology of existing urban blue and green infrastructure can help inform future planning for blue and green spaces as adaptation and developing resilient cities in the warming urban environment.