As heatwaves become increasingly common, sales of air conditioning units are going up in France and around the world. But while these cooling systems offer relief from high temperatures – in some cases, even saving lives – they are also a source of pollution and extra energy consumption that contributes to worsening climate change overall.
The first week of September brought a new wave of high temperatures across France with the start of the school year.
Large stretches of the country, mainly in the west, have been placed on yellow alert, which encourages residents to be extra attentive to the risks of hot weather. Temperatures up to 34°C were expected Wednesday in cities including Paris, Tours and Bordeaux.
The mercury is expected to climb again on Thursday, reaching up to 37°C in parts of France and potentially breaking records for the highest temperatures ever seen in September.
The warm weather follows an unusually late summer heatwave that swept large parts of the country for eight days in August and record-breaking temperatures in July.
Read moreJuly was hottest month ever recorded says EU climate observatory
For many in France and across the world, the solution to stifling temperatures comes at the click of a button: as global temperatures are rising, so are sales of air conditioning units.
Some 20 percent of homes in Europe are now equipped with air conditioning, according to the European Environment Agency. Globally, the number of installed air conditioning units reached 1.6 billion at the end of 2016 and is expected to triple by 2050, according to the International Energy Agency.
In France, attitudes towards air conditioning are changing. Just 14 percent of homes had air conditioning in 2016. Four years later, a quarter had installed the cooling system, according to the governmental Agency for Ecological Transition.
Despite its rising popularity, the use of air conditioning is still a source of debate. Ecologists argue that air conditioning is detrimental to the environment and contributes to global warming.
But it would be a mistake to underestimate the dangers of hot weather. More than 62,000 people died due to high temperatures in Europe in 2022, according to a study published in health journal “Nature Medicine”. It was the continent’s second-warmest year on record.
France’s public health body attributed 32,658 deaths to high temperatures between 2014 and 2022, with nearly a third of those dying under 75 years old.
For vulnerable people, air conditioning can provide relief. Some 195,000 lives were saved in 2019 globally thanks to air conditioning – a figure which had tripled in the previous 20 years – according to a 2021 report in “The Lancet” medical journal.
“There is a middle ground to be found,” said Dr Kako Naït Ali, a chemical engineer in the energy sector. “Air conditioning is a solution to improve living conditions during periods of intense heat. Some people in France class it as an unneccessary comfort, with the result that others can feel guilty about using it. It’s a shame. We should be able to have a reasonable debate about this tool.”
The ‘snowball effect’
Despite its potential to save lives, the use of air conditioning presents a paradox: AC units contribute directly to the problem they aim to offset – rising temperatures.
“An air conditioning unit works like a fridge. The air inside stays cold, and hot air gets ejected,” said Didier Coulomb, director of the International Institute of Refrigeration, an intergovernmental organisation that provides scientific and technical information on refrigeration.
This can create heat clusters in towns and cities. “It explains that suffocating feeling when you walk down a street with buildings that all contain air conditioning units,” Coulomb said. “Their emissions are adding heat on heat. If the season is already warm, it can create a snowball effect.”
On a larger scale, some experts say that instead of finding sustainable ways to adapt to a changing climate, the use of air conditioners means drawing on the planet’s already-stretched resources.
“Air conditioning consumes energy,” said Coulomb. In France, he said, the electricity required to run AC units is relatively decarbonised, as the vast majority comes from nuclear energy.
“But that is not the case in the rest of the world,” he added. “Using air conditioning puts pressure on electricity infrastructure, which creates the same kind of problems as using heating in winter.”
Another environmental issue with air conditioning units is that most use fluorinated gases, which are potent greenhouse gases. Although used in small quantities in products such as air conditioners, fridges and freezers, they have an even higher warming potential than carbon dioxide and “contribute greatly to climate change”, according to the European Environment Agency.
“There is a lot of progress to be made on energy efficiency when it comes to air conditioners,” said Ali. “There should be international standards for air conditioning models and any units that do not meet those standards should not be sold.”
The European Union has created energy labels for air conditioning units similar to those that appear on refrigerators. It is also in the “advanced stages“ of a process that could lead to a ban on fluorinated gases, the use of which is already strictly limited, Coulomb says.
But questions remain over whether eco-friendly air conditioning is even possible, with current alternatives proving more expensive and less reliable.
“There are units that use hydrocarbons or carbon dioxide that perform well, but they pose dangers,” said Coulomb. “Propane (a hydrocarbon) can be dangerous when used to cool a whole apartment or house, as it’s inflammable. But progress is being made in this sector.”
An alternative solution is to use artificial intelligence to reduce the environmental costs and energy consumption of staying cool. A pilot programme launched in South Korea in 2022 used intelligent devices that automatically adapted interior temperatures based on grid conditions to reduce energy consumption by 24 percent.
Many organisations are also investigating the use of sustainable cooling methods, such as natural ventilation and increasing shade-providing infrastructure.
The French capital, for example, has set up an underground cooling network that transports chilled water from the Seine between different delivery points around the city and stores energy reserves as ice.
“It centralises the cooling system and uses natural resources like water from the River Seine. Paris has been a pioneer in this field,” said Coulomb.
“The best solution is communal air conditioning systems that comply with technical specifications and are well-controlled,” Ali said. “We need to get things in the right place and plan what we need to support our new energy needs in summer. To meet the challenge, we have to plan for the future.”
In the long term, individual air conditioning units are an imperfect and high-polluting fix compared with the potential for more sweeping changes.
But there are ways to use individual units responsibly. The French government has banned companies from using air conditioning to cool interior spaces to temperatures below 26°C, which also means units should not be switched on unless interior temperatures exceed this level.
It suggests that individuals follow the same practice in private spaces.
This article was adapted from the original in French.