AS the world marked Environment Day, Pakistan faced a stark reality: our cities are overheating. This urgency was highlighted at the second Breathe Pakistan Climate Change Conference, where climate change impact and solutions in cities emerged as a central concern. This theme echoed globally at the recently concluded 13th World Urban Forum. What used to be hypothetical and occasionally extreme has become the new normal. From Karachi to Lahore, summer temperatures are increasingly reaching the high 40s — and at times even tipping 50 degrees Celsius. Unplanned urban expansion, disappearing green spaces and heat-trapping concrete are intensifying the crisis. For millions, this is now a daily threat to health, productivity and survival.

Urban heat is one of the most dangerous yet under-recognised impacts of climate change. The ‘urban heat island’ effect can raise city temperatures by several degrees, intensifying already severe heatwaves. In Pakistan, where extremes are becoming more frequent and prolonged, this translates into heat stress, rising mortality and economic losses, especially for outdoor workers and vulnerable communities.

Climate action, therefore, must begin with redesigning our cities around cooling, which is now simultaneously a climate, public health, housing, productivity and energy security issue. Above all, it is an equity issue. In cities like Karachi, the people most exposed to dangerous heat are often those least able to access safe, reliable and efficient cooling. Passive cooling must be the first line of defence. Better building design, shaded streets, reflective roofs, ventilation, trees and green public spaces can lower temperatures before an air conditioner is even switched on. According to Global Cooling Watch 2025, passive cooling measures can reduce indoor temperatures by 0.5°C to as much as 8°C, while urban greening and reflective surfaces can significantly reduce peak heat in public spaces.

Solutions exist. Karachi offers an important lesson. After the devastating 2015 heatwave, the city’s Heat Action Plan demonstrated that coordination saves lives. Early warning systems, public outreach, cooling centres and emergency planning reduced heat-related deaths, proving that effective governance can be as important as expensive infrastructure.

Climate action must begin with redesigning our cities.

Lahore, meanwhile, illustrates the value of nature-based solutions. Through urban forestry and green belt initiatives, the city has expanded its tree cover and protected green spaces. While challenges remain, these efforts demonstrate how parks, green corridors and urban forestry can reduce temperatures, improve air quality and make cities liveable.

Bangladesh offers relevant lessons for dense, climate-vulnerable cities. In Dhaka, pilot programmes using cool roofs and shaded community spaces have reduced indoor heat exposure in low-income settlements through simple, low-cost design changes. The city of Rajshahi, meanwhile, has invested in sustained urban greening and water body preservation, helping moderate temperatures and improve adaptation — a testament to long-term municipal leadership.

These examples point to a clear agenda for Pakistan.

First, urban planning and municipal budgets must treat cooling as essential infrastructure. Building codes should mandate reflective roofs, insulation and ventilation to reduce indoor heat and energy demand on air-conditioning. Second, expanding urban green spaces should be a priority. Trees and parks are among the most cost-effective cooling solutions, yet green cover continues to shrink. Third, water-sensitive urban design, including functioning drainage systems, resto­red waterways and better water management, can help regulate local temperatures while re­­ducing flood and he­­alth risks. Fourth, cit­­ies need heat ma­­p­­ping, early warning systems and targeted protection for vulnerable communities. Karachi’s experience shows preparedness saves lives. Finally, institutional coordination is essential. The federal and provincial leadership should set standards and mobilise domestic and blended finance, while municipalities need the authority and capacity to act, and to work in collaboration with civil society, private sector and neighbourhood organisations.

Pakistan is already part of a growing global response. Karachi, Lahore and Turbat joined the ‘50 cities @ 50°C’ World Environment Day campaign, aimed at raising awareness of extreme urban heat and promoting practical cooling solutions before cities become unliveable.

Climate action must go beyond rhetoric. The cities that will thrive in a warming world are not those that simply install more air conditioners. They are those that design, finance and govern cooling as a public good. The question is no longer whether we can afford to act, but whether we can afford further delay.

The writer is UN resident & humanitarian coordinator in Pakistan.

Published in Dawn, June 6th, 2026