Heatwaves are killing people
Adapting to the effects of climate change is helping but is not enough
IN RECENT DAYS heatwaves have turned swathes of America and Europe into furnaces. Despite the accompanying blast of headlines, the implications of such extreme heat are often overlooked or underplayed. Spectacular images of hurricanes or floods grab attention more readily, yet heatwaves can cause more deaths. Heat is one of climate change’s deadliest manifestations. Sometimes its impact is unmistakable—a heatwave in Europe in 2003 is estimated to have claimed 70,000 lives. More often, though, heatwaves are treated like the two in the Netherlands in 2018. In just over three weeks, around 300 more people died than would normally be expected at that time of year. This was dismissed as a “minor rise” by officials. But had those people died in a flood, it would have been frontpage news.
The havoc caused by extreme heat does not get the attention it merits for several reasons. The deaths tend to be more widely dispersed and do not involve the devastation of property as do the ravages of wind and water. Moreover, deaths are not usually directly attributable to heatstroke. Soaring temperatures just turn pre-existing conditions such as heart problems or lung disease lethal.
Heatwaves will inevitably attract more attention as they become more frequent. As greenhouse gases continue to accumulate in the atmosphere, not only will temperatures rise overall but extremes of heat will occur more frequently (see ar
ticle). Britain’s Met Office calculates that by the 2040s European summers as hot as that of 2003 could be commonplace, regardless of how fast emissions are reduced. Urbanisation intensifies the risk to health: cities are hotter places than the surrounding countryside, and more people are moving into them.
The good news is that most fatalities are avoidable, if three sets of measures are put in place. First, people must be made aware that extreme heat can kill and warning systems established. Heatwaves can be predicted with reasonable accuracy, which means warnings can be given in advance advising people to stay indoors, seek cool areas and drink plenty of water. Smart use of social media can help. In 2017 a campaign on Facebook warning of the dangers of a heatwave in Dhaka, Bangladesh’s capital, reached 3.9m people, nearly half the city’s population.
Second, cool shaded areas and fresh water should be made available. In poor places, air-conditioned community centres and schools can be kept open permanently (steamy nights that provide no relief from scorching days can also kill). In Cape Town, spray parks have been installed to help people cool down. Third, new buildings must be designed to be resilient to the threat of extreme heat and existing ones adapted. White walls, roofs or tarpaulins, and extra vegetation in cities, all of which help prevent heat from building up, can be provided fairly cheaply. A programme to install “cool roofs” and insulation in Philadelphia reduced maximum indoor temperatures by 1.3˚C.
It is a cruel irony that, as with other effects of climate change, the places that are hardest hit by heatwaves can least afford to adapt. In poor countries, where climates are often hotter and more humid, public-health systems are weaker and preoccupied with other threats. Often, adaptation to extreme heat is done by charities if it is done at all. Particular attention should be paid to reaching both remote areas and densely populated urban ones, including slums where small dwellings with tin roofs packed together worsen the danger that uncomfortably high temperatures will become lethal.
Adaptation is not an alternative to cutting emissions; both are necessary. But even if net emissions are reduced to zero this century, the persistence of greenhouse gases in the atmosphere means that heatwaves will continue to get worse for decades to come. As the mercury rises, governments in rich and poor countries alike must do more to protect their populations from this very real and quietly deadly aspect of climate change.