A new analysis has drawn a direct line between climate change and a rising number of deaths during the United Kingdom's recent spells of extreme heat, warning that the human cost of hotter summers is climbing. The findings put hard figures on a season that has already stretched emergency services and left health leaders warning that the country is being caught unprepared by the scale of the heat.
The scale of the loss during the early-summer heat was considerable. According to the analysis, around 550 people died from heat-related causes during the nine-day heatwave in May, a toll that pointed to the danger posed even by a relatively short burst of unusually high temperatures at a time of year when the country is not braced for such conditions.
A second, longer spell of heat proved even deadlier. According to the analysis, a further 2,200 people died in England or Wales during the June heatwave, which lasted eleven days. The combined figures underline how repeated periods of extreme heat over a single summer can add up to a heavy and often under-recognised death toll across the population.
Researchers also sought to measure the fingerprint of a warming planet on those temperatures. According to the analysis, maximum daytime temperatures during the heat were around three to four degrees hotter than they would have been without climate change, a difference that researchers said was enough to turn dangerous conditions into deadly ones for the most vulnerable.
That link was translated into an estimate of how many of the deaths were being driven by global warming. According to the analysis, human-produced climate change, tied to the burning of fossil fuels, is pushing up the number of people dying in these heatwaves by about 30 to 40%, meaning the toll is far higher than it would otherwise be in a cooler climate.
The strain has been felt acutely by the services that respond to emergencies. According to health leaders, the London Ambulance Service reported record numbers of people calling for help during the heat and said it had never known a busier summer, with pressures once associated mainly with winter now bearing down on the health system through the hottest months as well. The dangers ranged from heat exhaustion and heat stroke to added stress on the heart and kidneys and the worsening of chronic respiratory conditions and diabetes.
Those behind the analysis framed the deaths as a warning about the future rather than a one-off. According to the report authors, the country simply does not have the infrastructure in place to cope, having been built to conserve heat through cold winters rather than to keep people cool through increasingly hot summers. They cautioned that the number of people dying during heatwaves will keep climbing as long as the events grow more frequent and intense and as long as fossil fuel emissions continue to drive up global temperatures.