Expecting people to give up air-conditioning is unrealistic, which means we must find ways to ensure that cooling our spaces does not warm the planet further, says NUS’ Khoo Teng Chye. SINGAPORE: Each time a sweltering day comes around, the most common response is to crank up the air-conditioner. But what is perhaps the easiest and most convenient way to beat the heat has increasingly been referred to as a climate felon. For one, air-conditioners are energy guzzlers and emitters of greenhouse