Green War on Air Conditioning is Heating Up

Essay by Eric Worrall

“We cannot air condition our way out of climate change” according to UNSW author Professor Mat Santamouris.

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

A new global review argues passive cooling technology must become central to climate adaptation.

Published: July 6, 2026 
Original story from the University of New South Wales, Sydney

As temperatures rise around the world, air conditioning is saving lives. But a growing reliance on it is also placing unprecedented pressure on electricity grids, increasing greenhouse gas emissions and making cities even hotter.

A global review led by UNSW Sydney’s Professor Mat Santamouris AM – an expert in innovative heat mitigation technologies and strategies for cities– argues that keeping buildings cool without relying solely on air conditioning will be critical for adapting to climate change.

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Prof. Santamouris says passive cooling should no longer be viewed as a niche architectural feature, but as essential infrastructure for a warming world.

“Air conditioning saves lives and will remain essential during extreme heat,” he says. “But we cannot air-condition our way out of climate change. If every building depends entirely on mechanical cooling, we create enormous pressure on electricity systems while adding even more heat to our cities.”

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.

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Read more: https://www.technologynetworks.com/tn/news/we-cannot-air-condition-our-way-out-of-climate-change-cooling-study-finds-414335

The abstract of the study;

• Review Article
• Published: 02 July 2026

Passive cooling for the built environment

• Matthaios Santamouris & 
• Konstantina Vasilakopoulou 

Nature Reviews Clean Technology (2026) Cite this article

Abstract

Passive cooling technologies reduce heat and solar gains in buildings and public spaces while dissipating excess heat. This approach could reduce impacts of mechanical air conditioning, which has environmental impacts and consumes electricity, contributing to peak demand and grid stress. In this Review, we discuss advances in passive cooling technologies, focusing on smart solar control, ventilation, and radiative, evaporative and hybrid dissipation systems. These technologies are at different stages of development and deployment, ranging from technologically mature approaches such as ventilative cooling and solar control to emerging materials for passive and radiative cooling. Each technology has benefits and trade-offs. Ventilative, radiative and evaporative cooling have low energy use, but their effectiveness is dependent on climate, timing and air quality. Solar control improves thermal comfort, requires maintenance or has design constraints. Implementation of these technologies can reduce cooling-related energy consumption and provide thermal comfort in communities where access to affordable cooling is limited. However, increasing temperatures and humidity changes could challenge their effectiveness. Policies are needed to encourage uptake of passive cooling approaches in communities that currently rely on mechanical cooling and enable uptake for those that lack cooling access.

Read more: https://www.nature.com/articles/s44359-026-00177-y

I don’t know why Professor Santamouris is so dismissive of existing efforts to adapt buildings to conditions.

Buildings have been designed to enhance comfort ever since there are buildings. Ancient buildings in the Persian Gulf were designed with primitive but surprisingly effective passive air conditioners. My grandpa explained how a building he constructed in the 1940s, he put all the insulation in the living area, so the living area would be slow to warm in the summer heat, but the bedrooms would cool quickly after nightfall.

But if an air conditioner is cheaper than retrofitting some exotic passive environmental technology, why not use the air conditioner?

If power is in short supply, just build a few more coal plants. Or nuclear plants if you are feeling all precious about CO2 emissions. Only nations and states which place impediments in the path of energy providers have to worry about electricity shortages or high prices.