Climate change is making extreme heat the norm in more parts of the world, increasing the need for adaptation. But in the case of AC, some experts are concerned about how to balance that need with the harms the solutions can cause.
Global AC sales more than tripled between 1990 and 2016, according to a 2018 report by the International Energy Agency (IEA). This growth is likely to continue, with worldwide cooling energy use expected to triple again by 2050.
Warm countries such as India and Indonesia account for a large part of the increase in AC adoption. By 2050, about half of the growth in AC cooling capacity will come from just two countries, India and China, according to the IEA. Incomes there are rising, giving people access to AC for the first time, says Enrica De Cian, an environmental economics researcher at Ca’ Foscari University in Venice, Italy.
But AC adoption is also increasing in relatively wealthier and colder countries, including those in Europe, largely because urbanization and climate change are driving up temperatures, De Cian says.
Even so, many Europeans are hesitant to welcome air conditioners with open arms. “Seeing AC as a solution to heat waves and climate change is of course somewhat problematic because of the energy that is used,” says Daniel Osberghaus, a researcher in energy and climate economics at the Center Leibniz of European Economic Research in Germany.
Today, cooling devices such as ACs account for about 10% of global electricity consumption, and since most of the world’s electricity still comes from fossil fuels, this is a significant part of global emissions . Because of their massive energy use, “they have a bad reputation,” says Kevin Lane, an energy analyst at the IEA.
Cooling units, in particular, can challenge the power grid because they all tend to turn on at the same time, during the hottest parts of the day. This problem is evident in places like Texas, where summers are hot and air conditioners are widespread. Texas grid operators often ask residents to reduce air conditioning use during peak afternoon hours to avoid blackouts.
Lane says more efficient alternatives to the window units common in many cities today exist. Split units, or heat pumps, can act as both cooling and heating devices and can be more efficient than other options. The initial costs of heat pumps are still relatively high, although lifetime costs can compete with other options due to energy savings.