A pivotal study by University College London and the London School of Hygiene & Tropical Medicine, published in PLoS Climate, titled ‘Projections of heat related mortality under combined climate and socioeconomic adaptation scenarios for England and Wales’ predicts a sharp increase in heat-related deaths in England and Wales due to climate change.
From an average of 634 deaths annually (2011–2021), the toll could rise to 3,007–10,317 by the 2050s, 4,004–19,478 by the 2060s, and 4,592–34,027 by the 2070s, depending on warming levels and adaptation measures. The range of deaths predicted is based on the use of a number of temperature and mitigation scenarios known as Representative Concentration Pathways (RCPs).
The lowest temperature scenario is based on a global temperature increase of approximately 0.4–1.6°C by mid-century relative to 1986–2005. This represents a low-emission scenario with strong mitigation policies being implemented.
The middle ground is based on a stabilization scenario with moderate mitigation efforts, leading to a global temperature increase of approximately 1.7–3.2°C by the end of the century.
At the upper end, a high-emission scenario is used with minimal mitigation, leading to a global temperature increase of approximately 3.2–5.4°C by the end of the century, with the study specifically referencing a worst-case scenario of 4.3°C of warming by 2100. At this level heat-related deaths would increase sixteenfold to 10,317 in the 2050s, and would exceed 34,000 by the 2070s.
The number of hot days, i.e., days above the 95th percentile of the regional baseline (1981–2021) temperature series is projected to increase under all of the scenarios. For the lowest scenario this will mean an additional 21–32 hot days each year throughout the 2060s. While for the 4.3°C scenario an additional 64–73 hot days are projected for the same period.
Analyzing 15 climate and socio-economic scenarios, the study considered warming levels, adaptation efforts, aging populations, regional variations, and potential power outages, offering a comprehensive projection of heat impacts. Adaptations such as air conditioning, white-painted walls, rooftop greenery, improved ventilation, urban forests, and support for vulnerable groups could mitigate deaths.
The study observed regional variations in heat-related mortality rates across England and Wales. Northern regions generally exhibit lower rates, likely due to their cooler climates. In contrast, higher rates in London and the East of England are attributed to greater urbanization, which amplifies the urban heat island (UHI) effect, and warmer southern climates. London’s vulnerability is further increased by its lack of improvement in adaptive capacity, unlike other regions where adaptation measures are predicted to progress. The East Midlands shows elevated mortality rates, primarily due to significant population aging, minimal growth in younger age groups, and a notable rise in hot days. The greatest regional disparities occur under the 4.3°C scenario, driven by varying adaptive capacities across regions, a pattern less evident in other scenarios.
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 comments “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”
