Study finds urban heat island intensity rising 0.021 degrees Celsius annually

A study in npj Urban Sustainability found surface urban heat island intensity is increasing 0.021 degrees Celsius annually, intensifying faster in low- and lower-middle-income countries. The findings underscore why Indian cities and ESG frameworks must integrate climate-resilience and equity into urban adaptation planning.

A study published in npj Urban Sustainability confirmed that surface urban heat island intensity (SUHII) is increasing at a rate of 0.021 degrees Celsius annually, with intensification occurring more rapidly in low- and lower-middle-income countries. The research, authored by Yuan and colleagues (2025), reveals that developing nations face a disproportionate increase in urban heat, posing significant challenges for climate resilience and equity. Increased heat exposure can exacerbate health issues, strain energy resources, and disproportionately affect marginalized communities, further widening existing inequalities in rapidly urbanizing regions.

The accelerated intensification affects vulnerable urban populations in low- and lower-middle-income countries across the Global South, who already face resource constraints and limited adaptive capacity. The study notes traditional mitigation strategies may be insufficient for the unique challenges of rapidly urbanizing regions. Policymakers, international organizations, and businesses are identified as actors who can respond, with businesses positioned to invest in sustainable urban development projects that promote climate resilience and enhance quality of life for urban residents facing rising heat exposure.

Policymakers in lower-income nations should prioritize urban planning strategies incorporating green infrastructure, reflective surfaces, and energy-efficient building designs to mitigate urban heat island effects. International organizations should provide financial and technical assistance to support these efforts. The research highlights the need to integrate climate resilience and social equity into ESG frameworks, warning that focusing solely on economic growth or domestic emissions reductions may overlook disproportionate impacts on vulnerable Global South populations. Targeted adaptation measures and international support are described as crucial for building resilience.

Key figure — Surface urban heat island intensity increase: 0.021 degrees Celsius annually