More than 30,000 people a year in England and Wales could die from heat-related causes by the 2070s, scientists have warned.
A new study calculates that heat mortality could rise more than fiftyfold in 50 years because of climate heating. Researchers at UCL and the London School of Hygiene & Tropical Medicine compared different potential scenarios, looking at levels of warming, measures to mitigate and adapt to the climate crisis, regional climatic differences and potential power outages. They also modelled the ageing population.
Between 1981 and 2021, there were on average 634 heat-related deaths in England and Wales a year. The research, published in PLoS Climate, found that – in the worst-case scenario of 4.3C of warming by the end of the century and assuming minimal adaptation to mitigate the effects – heat-related deaths would increase sixteenfold to 10,317 in the 2050s, and would exceed 34,000 by the 2070s.
Even if temperature rises are limited to 1.6C of warming over preindustrial levels and high levels of adaptation are put in place, annual heat-related deaths will still increase up to sixfold by the 2070s.
The record-setting hot summer of 2022 – when temperatures reached 40.3C in Coningsby, Lincolnshire – had 2,985 excess heat deaths, indicating a potential “new normal” by as early as the 2050s, the research concluded.
The findings come as the UK Health Security Agency issued a yellow heat health alert for all regions from Thursday 10 July until Tuesday 15 July. Temperatures were expected to reach 27-29C in large parts of England and Wales on Thursday, with hotter weather of up to 31-33C forecast for the weekend.
Dr Clare Heaviside, a senior author at UCL Bartlett School Environment, Energy & Resources, said the findings painted “a sobering picture of the consequences of climate change”.
“Over the next 50 years,” she said, “the health impacts of a warming climate are going to be significant. We can mitigate their severity by reducing greenhouse gas emissions and with carefully planned adaptations, but we have to start now.”
The research also found that previous research underestimated heat mortality by not assessing the impact of older societies. Over the next 50 years, the population of England and Wales is predicted to age significantly, with the greatest increase in population size for those age 65 and over by the 2060s. Older people are more vulnerable in hot weather, with an extra 250 million people worldwide age 69 or above who will be exposed to dangerous levels of heat by 2050.
Dr Rebecca Cole, of the department of public health, environments and society at the London School of Hygiene & Tropical Medicine and lead author of the study, said the findings showed the need for careful thought and planning in how to reduce the impact of global heating.
“Increases in heat-related deaths are not just a consequence of rising temperatures – they’re also driven by how we build our cities, care for vulnerable populations and address social inequality. Concerted adaptation strategies are required, well in excess of those over the last 30 years.”
Responding to the findings, Matthew Bazeley-Bell, the deputy chief executive of the Royal Society for Public Health, said: “Our health is strongly influenced by the environment and the climate crisis is also a public health crisis. These alarming projections show a devastating impact.
“We need to take action that curbs emissions and also prepare people to deal with the effects of climate change on our health – particularly for vulnerable populations.”
Dr Akshay Deoras, a research scientist at the University of Reading, said: “If floods and storms are the loud alarms of climate change, extreme heat is its silent killer. It is disproportionately lethal, often going unnoticed until it’s too late. With another heatwave bearing down on the UK, this warning feels more urgent than ever.
“Heat is not only claiming more lives, but power outages and an ageing population could make things far worse if adaptation doesn’t keep pace.
“As the UK experiences fewer cold extremes and more frequent and deadly heatwaves, protecting older adults must be at the heart of climate and public health planning – before this silent threat becomes an undeniable crisis.”
Dr Raquel Nunes, an assistant professor in health and environment at the University of Warwick, said the increasing frequency, intensity and duration of heatwaves underscored the urgent need to take protective action.
“Heat-related deaths and illnesses are both preventable and avoidable,” she said, adding that they “expose systemic failures” that require “socially inclusive and institutionally embedded adaptation across governance, infrastructure, and health and care services to prevent increasing vulnerabilities and inequalities”.
Prof Lea Berrang Ford, the head of the UK Health Security Agency’s Centre for Climate and Health Security, said: “The relationship between periods of hot weather and increased mortality is well-established and temperatures are likely to increase until at least mid-century, irrespective of the amount by which we decarbonise in the decades to come.
“The health decisions we make today will determine the severity and extent of climate inherited by future generations, and so it’s vital we take action.
“UKHSA continues to develop its guidance and evidence, working with partners to protect the most vulnerable in our society who are most likely to feel the impacts of hot weather.’’
