How cities can respond to extreme heat

The best thing that has happened in Phoenix, Arizona, since the beginning of July is that the electricity grid has kept functioning. This has meant that during a record-breaking run of daily maximum temperatures above 43°C (110°F), still in progress as went to press, the houses, indoor workplaces and publicly accessible “cooling stations” in the city have been air-conditioned. There have been deaths from heat stroke and there will be more; there has been a lot of suffering; and there will have been real economic losses. But if Arizona’s grid had gone out, according to an academic quoted in “”, a new book, America would have seen “the Hurricane Katrina of extreme heat”.It is not just the United States, where 100m people are under heat-advisory notices, that is suffering. There is currently a spate of such heatwaves around the world. Much of the Mediterranean is in similar straits, with temperatures exceeding 40°C (104°F) from Madrid to Cairo (which is suffering power cuts). In Beijing July 18th saw a 23-year-old record broken by a 27th consecutive day with a maximum temperature above 35°C. By increasing the odds of a wide range of extreme events, also increases the chances that they will come in waves.