Nature
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It's undeniable that the world is getting hotter and hotter. As heatwaves grow more oppressive and summer days melt into a sweaty, sweltering mess, air conditioning is saving lives. But a new global review argues the energy-hungry AC units are not a long-term solution to the problem.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.Without getting bogged down in the trenches of the “air conditioning culture wars” between the US and Europe, air conditioning does have its place. According to some estimates, it can prevent about 75 percent of heat-related deaths.
And demand is heating up fast. It’s now estimated that around 10 new air conditioners are sold every second. By 2050, this will culminate in 5.6 billion residential air-conditioning units humming across the world.
What's the problem with air-conditioning?
The problem is that air conditioning churns through an incredible amount of electricity and puts real pressure on energy grids. Air conditioning currently accounts for 7 percent of global greenhouse gas emissions, and that burden is only set to grow. Much of the emissions come from the electricity required to power the units, but AC systems also rely on planet-warming refrigerants, hydrofluorocarbons, or alternative chemicals that carry their own ecological costs.
Given this strain, the review argues that the world will need to look to new innovative methods to cool down going forward.
“Air conditioning saves lives and will remain essential during extreme heat,” Mat Santamouris, Professor of High Performance Architecture at UNSW Sydney, said in a statement.
“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,” he explained.
Alternatives to air-conditioning
The review examines a range of passive cooling technologies that can lower temperatures with little to no energy use, including radiative coatings for buildings and reflective materials that passively dissipate sunlight.
“The best cooling strategy is to stop unwanted heat from entering buildings in the first place. Shading, reflective materials, opens in a new window, smarter ventilation, opens in a new window and new cooling materials can dramatically reduce indoor temperatures before an air conditioner even needs to switch on,” said Professor Santamouris.
Many of these technologies come with higher upfront costs, the paper notes, but ultimately pay off with lower long-term operating costs, without the added climate toll.
It also points to the need for smarter architecture and building design, such as integrating sophisticated external shading systems and better ventilation into new construction from the start.
In a punchline, the planet is changing rapidly; if we're going to keep up, we need to start building for the future, not the world of the past.
“The buildings we construct today will still be standing in 2050 and beyond. They need to be designed for the climate they will experience, not the climate we had in the past,” said Professor Santamouris.
The new study is published in the journal Nature Reviews Clean Technology.
