Luxury or necessity? Five questions about air conditioning in Switzerland and around the world 

Some two-and-a-half billion air conditioners already exist around the world – like here, on a building in China. Pixabay

Air conditioning helps us cope with increasingly intense and frequent heatwaves. However, the boom in home air conditioners in Switzerland and around the world has an impact on the climate and electricity consumption. 

In winter, when it’s cold, it’s normal to turn on the radiators or put wood in the fireplace. No one disputes the need to adjust the temperature in homes, although heating systems are a major source of CO2 emissionsExternal link. However, when the heat becomes oppressive, ensuring comfort indoors is more of a debate. 

With the increase in heatwaves due to climate change, more people are turning to air conditioning. The demand for air conditioners is growing exponentiallyExternal link in warmer climates in Asia and the Middle East, and also in more temperate regions in Switzerland and Europe. 

Air conditioning has been found to improve the quality of sleep during hot summer nights. It helps maintain concentration in schools and productivity in offices during heatwaves. It can even save lives: in 2019, air conditioners prevented nearly 200,000 premature heat-related deaths worldwide, according to a reportExternal link in the Lancet journal. 

How can summers in the city be made less suffocating? An expert from the ETH Zurich explains:

However, air conditioning is controversial because of its climate impact and high electricity consumption. Its use has increasingly become a political issue. 

Massive reliance on air conditioning is a “bad solution” because it exacerbates the climate crisis, the French government said, reacting to a recent proposal to install air conditioners in all public buildingsExternal link. Air conditioning also agitates the political world in SwitzerlandExternal link, where some cantons limit its use. 

Is air conditioning a superfluous luxury or is it a vital necessity as temperatures rise? Here are answers to five questions about air conditioning. 

Some 20,000 split air-conditioners are installed each year in Switzerland. Keystone / Gaetan Bally

What is the impact of air conditioning on the climate? 

Air conditioners contain refrigerant gases, such as hydrofluorocarbons. When released into the atmosphere, these gases contribute to the greenhouse effect and thus to the climate crisis. 

R-32, a synthetic gas used for years in air conditioning, has about 675 times the warming potential of carbon dioxide (CO2). Refrigerant gases can leak during operation or disposal of air conditioners.

These direct emissions are compounded by indirect emissions related to electricity consumption. 

More than half of the world’s electricity comes from fossil sources (coal and gas), which release large amounts of CO2. Overall, air conditioners are responsible for more than 3% of the world’s greenhouse gas emissionsExternal link. The climate impact is similar to that of aviation. 

“You can use an air conditioner in your home and have a clear conscience”

Stefan Reimann, Empa

International treaties such as the Kigali Amendment to the Montreal Protocol aim to reduce the consumption of hydrofluorocarbons. More sustainable alternatives are gases with less impact on the ozone layer and climate. New generation air conditioners use gases such as butane or propane, which, while flammable, have a smaller effect on global warming. 

“Today, if you use such a refrigerant, you can use an air conditioner in your home and have a clear conscience,” says Stefan Reimann of the Swiss Federal Laboratories for Materials Science and Technology (Empa), cited by the Tages-AnzeigerExternal link newspaper.

However, air conditioners, including new models, still have an effect on the local climate. The heat they release outside contributes to warming the surrounding environment, exacerbating the heat island phenomenon in the city. 

How much electricity does it take to run the world’s air conditioners? 

A household air conditioner uses between 3 and 7 kilowatt hours of electricity per day. That’s five times the consumption of one washing cycle of a modern dishwasher, says Cordin Arpagaus, a researcher at the University of Applied Sciences of Eastern Switzerland. 

Artificially cooling spaces consumes 7% of the world’s electricity (2022 figure), according to the International Energy Agency (IEA). Compared to 2000, the electricity consumption of air-conditioning systems, and to a lesser extent fans, has more than doubled. 

World electricity consumption for air conditioning will triple by 2050, the IEA predictsExternal link. In the future, air conditioners worldwide will use as much electricity as China consumed in all of 2018. 

In places where older buildings do not have air conditioning installed, many people are buying portable air conditioners. However, these consume more electricity to achieve the same cooling effect. 

A large enough boom in air conditioners could overload a power grid. The risk of a blackout is not ruled out, as shown by episodes in early July in Florence, Bergamo and other Italian citiesExternal link. 

But with certain regulations, air conditioners could also contribute to grid stability. 

A pilot projectExternal link tested remote control of air conditioners in a group of private homes in Austin, Texas, in the US. From 2019 to 2023, researchers turned down air conditioners in homes when the grid faced the highest demand. The indoor temperature in homes taking part in the experiment varied by less than one degree Celsius (1.6 degrees Fahrenheit) from that set by homeowners, and the grid remained stable. 

“Air conditioners could play a significant role in increasing flexibility of the grid. And this is without compromising comfort in homes,” says Johanna Mathieu, a professor of electrical engineering and computer science at the University of Michigan who led the experiment. 

Which countries have the most air conditioners? 

More than 2.5 billion air conditioners are in operation worldwide, according to IEA estimates. Most are in the United States, Japan, South Korea, and especially China, where the spread of air conditioning has exploded since 2010. 

About one in three homes in the world (36%) is equipped with an air-conditioning system, according to the IEA. The share is expected to rise to 60% in 2050. 

The increase will be especially pronounced in India, where air conditioning is expected to increase tenfold in the next decade. Mexico, Brazil and the Middle East will also see strong growth, while the trend in Europe will likely be more subdued. 

Demand for air conditioning is expected to increase not only because of climate change, but also because of rising incomes, saysExternal link Hannah Ritchie, data scientist and researcher at the University of Oxford’s Global Development Programme. 

If people living in extremely hot countries like India or Indonesia could afford an air conditioner, they would already have one, she says: “This will happen over the next few decades as incomes grow in many low- and middle-income countries.”

In the US, about 90% of homes have air conditioners. By contrast, the proportion in the European Union was 20% in 2019, with higher percentages in Italy, Greece and Spain (between 50 and 60%), according to the most up-to-date data from the European Environment Agency. 

As for Switzerland, there are no official figures. It is estimated that only 5% of homes are air-conditioned. 

Why are air-conditioned homes in Switzerland rare? 

The most immediate answer is because air conditioners are not essential. In Switzerland, summers are not as scorching and temperatures not as extreme as they are in Mediterranean or Middle Eastern countries. 

But heat waves tend to be more frequent and prolonged. And Switzerland is one of the countries most affected by climate change. The need for cooling homes is growing, and cheap portable air conditioners are selling well: last June, Swiss online store Galaxus sold three times as many units as in June 2024. M

The melting of glaciers is one reason why temperartures in Switzerland are climbing faster than elsewhere:

Sales of stationary air conditioners are also increasing, albeit much more slowly. About 20,000 such units are installed in homes and offices each year. 

Unlike portable models, which can be purchased freely, stationary air conditioners must meet energy and building requirements. Currently, cantonal authorities permit only those with a maximum output of 12 watts per square meter. 

Restrictions can be even stricter. In Zurich, those who want such a system must first adequately insulate the rooms and have a sun-protection device (such as automatic shutters or awnings). In the canton of Fribourg, only those who have solar panels on their roofs can install a split air conditioner. 

For Marco von Wyl, director of the Swiss Association of Manufacturers and Suppliers of Heating, Ventilation and Air Conditioning Systems, the limitation of cooling power is the main obstacle to their installation in Switzerland. Many existing buildings, he says, are cut off. 

What are the alternatives to air conditioning? 

To stay cool without resorting to air conditioning, it is essential to prevent the sun’s rays from penetrating the interior of buildings, especially through windows. Exterior blinds, sunshades and white shutters offer effective protection. 

For Jean-Christophe Hadorn, researcher and energy consultant, the future is in fans. On average they consume 20 times less electricity than air conditioners and still offer some relief. “Soon we will find fans in every home,” he says. 

At the urban level, vegetation, bodies of water and greater permeability of the soil reduce ambient temperatures, and consequently in buildings. Some cities, such as Geneva, use lake water to cool buildings through a network of underground pipes. 

Air conditioning is not a silver bullet. But we have to accept that the demand for cooling will grow, reckons Hannah Ritchie. Air conditioning must be combined with other solutions that make cities and buildings cooler, she says – “especially if we want to protect those who work outdoors and the poorest who can’t afford it.” 

Edited by Gabe Bullard/vm