Karachi headed for extreme heat: UN report
Karachi has been listed among nine densely built megacities across Asia and the Pacific that are projected to become "substantially hotter" in the coming years, according to a new report released by the UN Economic and Social Commission for Asia and the Pacific (UN-ESCAP).
The report, titled 'The Asia-Pacific Disaster Report 2025: Rising Heat, Rising Risk', released on Wednesday, warns that extreme heat has become the region's fastest-growing climate hazard, intensifying vulnerabilities and reshaping development challenges.
The report notes that urban areas already face heightened temperature exposure due to the urban heat island effect, where concrete, asphalt and dense construction absorb and retain heat, pushing city temperatures far above those of surrounding rural zones.
Rapid and often unplanned urbanisation, combined with the loss of green spaces, is worsening this phenomenon, with projections showing that the heat-island effect alone could raise temperatures by 2°C to 7°C in major cities.
As pressure grows on access to cooling, clean water and healthcare, the report warns that children, the elderly and outdoor workers in congested, low-income neighbourhoods face the greatest risks. Higher-income areas, which typically have more greenery and better infrastructure, remain comparatively cooler, deepening existing inequities.
Alongside Karachi, cities identified as high-risk include Seoul, Tokyo, Beijing, Delhi, Dhaka, Manila, Jakarta and Phnom Penh.
The report also notes that between 2041 and 2060, countries expected to become increasingly arid include Pakistan, Mongolia, Uzbekistan, Iran and Turkmenistan, as rising temperatures evaporate surface water and dry soils, worsening droughts and water shortages.
UN-ESCAP states that the Asia-Pacific region has already experienced a succession of climate-driven disasters in 2024 and 2025, with extreme heat emerging as the most rapidly intensifying hazard. Rising temperatures are now affecting "all, everywhere", stretching risks across food systems, public health, livelihoods, infrastructure and ecosystems.
One of the report's starkest warnings concerns accelerating glacier loss in Asia and the Pacific. It says glaciers worldwide have lost nearly 5% of their volume this century. Of the 58 countries in the region, 17 contain glaciers increasingly prone to melting into unstable lakes that may burst, triggering destructive glacial lake outburst floods.
High Mountain Asia remains the most vulnerable, with 9.3 million people exposed to risks from more than 2,200 glacial lakes. By 2060, countries such as Iran, Mongolia, Myanmar, Turkiye and Uzbekistan could lose more than 70% of their glacier mass, sharply heightening flood risks.
Economic losses linked to climate-related disasters are projected to escalate. By 2100, annual regional losses could rise from $418 billion under current trends to $498 billion under a worst-case scenario.
The report urges governments to adopt long-term, science-based strategies, place extreme heat at the centre of multi-hazard disaster planning and strengthen regional cooperation. It calls for heat-ready early warning systems built on standardised metrics, interoperable alerts and reliable community-level communication.