If you’re reading this while the blinds are drawn against yet another heatwave and wondering whether it’s finally time to buy an air-conditioner, you’re far from alone. At the end of June, as temperatures climbed well above 40 degrees Celsius across Europe, shoppers in France literally forced their way into stores to snatch up portable fans and ACs before they sold out. Such scenes are likely to become more common. As the planet warms, the demand for cooling is rising worldwide.