Cities around the world are adopting passive cooling strategies as alternatives to energy-intensive air conditioning, helping to combat rising urban temperatures and reduce greenhouse gas emissions.
Key Details:
- The UNEP Global Cooling Watch Report 2023 warns that global cooling equipment capacity will triple by 2050, more than doubling electricity consumption, with nearly 1,000 cities facing average summer highs of 35°C.
- Burkina Faso – The Schorge Secondary School in Koudougou uses traditional techniques like laterite bricks (which absorb heat by day and release it at night) and eucalyptus wood shading to keep classrooms cool.
- India – Ahmedabad painted 7,000 low-income rooftops white to reflect sunlight, reducing indoor temperatures and saving an estimated 1,100 lives per year; 30 other Indian cities have followed suit.
- Maldives – A new meteorological building in Addu City uses shading, insulation, and strategic orientation to minimise cooling energy demand.
- Cambodia – UNEP and UN ESCAP are testing passive cooling measures with property developers, aiming to embed the best strategies into national building regulations.
- Republic of Korea – Seoul’s revitalised Cheonggyecheon Stream reduced local temperatures by 3.3°C to 5.9°C compared to nearby roads, demonstrating the power of nature-based urban cooling.
Why It Matters: Passive cooling solutions offer a critical path to reducing the climate “double burden” of air conditioning — cutting both electricity demand and refrigerant emissions — while protecting vulnerable urban populations from increasingly extreme heat.
Air conditioning significantly contributes to climate change. As global cooling demand triples by 2050, cities are exploring sustainable alternatives. Traditional methods like shading, natural ventilation, and white roofs (reducing temperatures by 5°C) offer relief. Revitalizing urban waterways creates natural cooling corridors, mitigating the urban heat island effect. Examples include Burkina Faso’s naturally cooled schools, India’s white roof initiatives saving lives, and Seoul’s revitalized stream significantly lowering temperatures. These passive cooling strategies reduce energy consumption and harmful refrigerant emissions, vital for a cooler, more sustainable future.
The Global Cooling Watch Report 2023: Keeping it chill, released on 5 December 2023, highlights the importance of passive cooling alternatives to energy-hungry air conditioners.
The report, produced by the United Nations Environment Programme (UNEP), points out that between now and 2050 the global installed capacity of cooling equipment will triple, resulting in a more than doubling of electricity consumption.
Cooling is a double burden on the climate: air conditioners and refrigerators have both indirect emissions from electricity consumption and direct emissions from the release of refrigerant gases, the majority of which are much more potent at warming the planet than carbon.
By 2050, unless humanity dramatically lowers its emissions of climate-altering greenhouse gases, close to 1,000 cities will experience average summer highs of 35°C, nearly triple the current number. The urban population exposed to these high temperatures could increase by 800 per cent, reaching 1.6 billion by mid-century.
