“We Cannot Air-Condition Our Way Out of Climate Change,” Cooling Study Finds

Demand for cooling is soaring

The review highlights the rapid growth in cooling demand worldwide. Global electricity consumption for cooling has reached almost 10 per cent of total electricity use, with around 10 new air conditioners sold every second. By 2050, the number of residential air-conditioning units is projected to increase to almost 5.6 billion worldwide.

At the same time, billions of people living in hot climates still lack access to affordable cooling.

Cooling buildings without relying on air conditioning

Passive cooling technologies offer a way to reduce energy demand while making buildings safer and more comfortable, particularly for vulnerable communities.

“The best cooling strategy is to stop unwanted heat entering buildings in the first place. Shading, reflective materials, smarter ventilation and new cooling materials can dramatically reduce indoor temperatures before an air conditioner even needs to switch on,” says Prof. Santamouris.

Rather than replacing air conditioning, Prof. Santamouris and coauthor Dr Konstantina Vasilakopoulou from RMIT argue passive cooling should become the first layer of defence, with mechanical systems providing additional cooling only when required.

The review evaluates emerging innovative technologies, such as super-cool materials, combined radiative/evaporative coatings, sophisticated external shading systems and personalised ventilation, as well as known passive cooling technologies such as reflective cooling materials that release heat directly into the atmosphere and hybrid cooling systems that combine multiple passive approaches.

Integrating passive cooling strategies with efficient building design could reduce cooling demand by as much as 80 per cent in hot climates while lowering peak electricity demand and improving resilience during power outages, according to the review.