
Karachi is among the nine densely built megacities in Asia and the Pacific which are particularly vulnerable to heat and are projected to become substantially hotter in the years ahead, a report released by the UN Economic and Social Commission for Asia and the Pacific (UN-ESCAP) on Wednesday said. The report, titled Asia-Pacific Disaster Report 2025: Rising Heat, Rising Risk, stated that urban areas are already at high risk for extreme heat due to the urban heat island (UHI) effect. Densely built surfaces trap heat and raise city temperatures above those of surrounding rural areas. It added that this challenge is being exacerbated by rapid and often unplanned urbanisation and insufficient green spaces, further warning that UHI would raise temperatures by 2 to 7°C, on top of global warming. As access to cooling, water and healthcare comes under increased strain, children, the elderly and outdoor workers in densely populated urban areas are disproportionately affected. Higher-income areas usually lie in cooler...