1. There is an insidious irony to climate change. When it gets hotter, more and more people are using their air conditioners, which in turn contributes to global warming. Air conditioner sales are surging worldwide, especially in emerging economies such as China, India and Indonesia, where rising incomes make air conditioners more affordable and a warmer, more humid climate makes them a necessity.
2. Keeping buildings cool contributes to global warming in two ways. Air conditioners not only run on electricity, but they can release chemicals with a strong heat-trapping effect as well. Air conditioners account for 16 percent of total electricity used in residential and commercial buildings around the world. This is significantly less than emissions caused by heating buildings - heaters run on natural gas, oil or electricity. Globally, there are over two billion air conditioner units in use today. The units precisely control the temperature and humidity in shops, laboratories or server rooms. They ensure that people feel as comfortable on a transatlantic flight as they do at home. But all that comes at a cost. Unless we switch to fully renewable electricity, the boom in air conditioning will generate more emissions and contribute to global warming, making hot summers even hotter.
3. With every new air conditioner installed, the risk of a leak increases. The technology behind modern air conditioners hasn't changed significantly since 1902 when the air conditioner unit sent air through coils filled with cold water, and cooled the air while removing moisture from the room. All air conditioners use refrigerant, a cold substance that absorbs the heat inside a building. The leakage of so-called fluorinated gases was particularly high by 2014. It accounted for about three percent of all greenhouse gas emissions in Europe, so the European Union adopted a law to cap the amounts of gases sold.