European Heat-Related Deaths Expected to Soar by End of Century
By 2099, heat-related deaths across Europe could reach unprecedented levels, even with significant adaptation measures in place. That is the revelation of a new study published in the journal Nature Medicine. But organisations like Shade the UK are already working to prepare communities well ahead of this, developing strategies to protect the most vulnerable and ensure resilience against rising temperatures. In this analysis, we break down the data and explore what it means for the future of European climate policy.
Extreme temperatures pose a significant threat to human health and well-being, but it’s often the indirect consequences that prove most deadly. Malfunctioning life-saving equipment, exacerbation of underlying health conditions, and increased strain on healthcare systems can turn heatwaves and cold snaps into silent killers. In the UK alone, tens of thousands die annually as temperatures soar in summer and plummet in winter. And while climate-driven migration is often associated with Sub-Saharan regions, even in Europe, worsening conditions may force communities to relocate as once-habitable areas become increasingly unliveable.
For the most part, the number of cold-related deaths each year has greatly outstripped those associated with heat. Particularly in the cooler, more temperate regions of Northern Europe, with relatively elderly populations, when the annual frost kicks in, populations are more vulnerable to health complications. With climate change taking hold across the world, our best projections show that many regions will likely experience hotter summers and milder winters.
Meteorologists have suggested that climate change could, in theory, lead to an overall decline in temperature-related deaths, with rising summer fatalities offset by fewer cold-related deaths in winter. However, the validity of this theory has often been called into question, as little research has directly tested it. Meteorologists are not economists or public health experts, and their models often overlook the broader societal impacts, such as increased strain on healthcare systems, failures of critical infrastructure, and economic instability. The indirect consequences of warmer temperatures, particularly in countries historically adapted to cooler climates, remain severely under-researched, leaving us with an incomplete picture of the true human cost of a warming world.
This question got one step closer to being solved with the publication of a new paper from researchers at the London School of Hygiene and Tropical Medicine (LSHTM). Published in the journal Nature Medicine, the researchers analysed historic weather-related mortality rates across Europe and extrapolated them across various climate change, demographic, and adaptation scenarios to generate an estimate of how the hot-cold balance will shift by the end of the century.
Net Effect of Climate Change
To conduct their analysis, the researchers generated a matrix that considered various future scenarios, incorporating considerations around future levels of climate change, demographic shifts, and potential levels of climate adaptation across society. What they discovered made for troublesome reading - even under some of the more optimistic circumstances, the number of heat-related deaths that we will see by the end of the century will vastly outstrip the number of cold-related deaths we see now.
The researchers described this changing balance as the ‘net effect of climate change’.
Much of their work was based on the concept of Shared Socioeconomic Pathways (SSPs), which are essentially UN-backed predictions of how societies and demographics will shift up to 2100, allowing analysts to assess global emissions changes under various future scenarios. Here, 3 separate SSP scenarios were considered:
SSP1-2.6: A more equitable Europe committed to sustainability and low-consumption lifestyles resulting in substantial action toward both mitigation and adaptation.
SSP2-4.5: A Europe maintaining current inequalities with increased privatisation and slow progresses toward mitigation and adaptation.
SSP3-7.0: A Europe with growing instability, regional conflicts, and inequalities, resulting in little to no effort toward mitigation and adaptation.
Adaptation to climate change was then modelled by attenuating vulnerability to heat (i.e. reducing the number of deaths seen at a given temperature range) by 0% (‘no adaptation’), 10%, 50%, and 90%, to reflect the degree of adaptation that can be seen by the end of the century.
This modelling was applied to a series of datasets generated from 854 European areas with populations exceeding 50,000 people, constituting approximately 40% of all 30 European countries. This data consisted of what is known as an exposure-response function (ERF) which, in this context, describes the number of deaths within the population that can be expected at a given temperature level. Hence, demographic changes, levels of warming, and the degree of climate adaptation are all factors that influence these ERFs.
What is the Role of Heat Adaptation?
Looking into the data, what we find is that in every circumstance where European society is unable to commit to any tangible form of climate adaptation, the net effect of climate change was in the positive, meaning the total number of temperature-related deaths increases by the end of the century. This applied to all SSP scenarios, meaning that, even if we were to rein in carbon emissions now and reduce human consumption, thus putting us on a trajectory of lower total warming, increases in temperature will lead to an increase in mortality.
The most severe projection is that in which we see minimal mitigation and minimal adaptation; under SSP3-7.0, the authors estimate that, considering all 854 urban areas in aggregate, we can expect to see 2.3 million temperature-related deaths by the end of the century across the continent, an increase of 50%.
“This study provides compelling evidence that the steep rise in heat-related deaths will far exceed any drop related to cold,” said Professor Antonio Gasparrini, co-author of the study.
By analysing the level of attenuation, we can start to see that different adaptation scenarios can allow for the impact of climate change on mortality to be minimised.
With regards to a small 10% attenuation, the change is minimal. This is across all SSP scenarios, meaning that, even if emissions can be reduced relatively substantially, a general lack of adaptation would still lead to an increase in temperature-related deaths. A stronger attenuation, that of 50%, would be sufficient to reduce the net effect under the first two SSP scenarios, but not the third; to achieve a net reduction under SSP3-7.0, a near-total level of adaptation would need to be seen (90% attenuation).
What this critical study highlights is that, under the levels of warming and adaptation that we can expect to see by the end of the century, which will likely fall at neither extreme, we will require a combination of both adaptive and mitigative solutions to combat the increase in heat-related deaths due to climate change. Oftentimes, adaptation is forgotten about as a crucial tool in our repertoire to defend ourselves against climate change, but this study very effectively refocuses our attention on its importance.
Spatial Divides: North and South
The data revealed a high degree of heterogeneity in terms of the effect size across subregions in Europe. This makes logical sense, given how certain areas, namely in the more southerly regions of the continent around the Mediterranean, already suffer hotter and more deadly summers than more temperate areas to the north.
For instance, under SSP3-7.0, Southern Europe is projected to see one of the largest net effects, reaching an increase of 124.0 deaths per 100,000 person years by the end of the century, in comparison to respective increases of 47.0 and 36.0 for Eastern and Western Europe.
It is only in Northern Europe where the net effect is negative.
We are able to see that when this data is mapped across Europe, we see a strong north-south gradient of effect, whereby the net effect of climate change and the number of heat-related deaths are more substantial the further south you go.
Figure 1: Map showing the spatial variations in the impacts of climate change on heat-related deaths across 854 European urban areas.
There were also extensive variations in the effects of climate adaptation, in terms of spatial differences. For instance, under the worst-case warming scenario, even a 50% reduction in heat-related mortality still sees a substantial increase in the net effect of climate change across most of the Mediterranean region.
What this shows us is that there is a greater level of complexity in how we as a European community combat climate change and safeguard our residents against the worst of its effects. Specifically, we need to consider that a given level of warming, which will likely be relatively uniform across the region, will impact regions differentially, with the solutions to combatting this depending on the area involved. For instance, for warming under the SSP3-7.0 scenario, a much higher level of adaptation would be necessary in a country in Southern Europe than one further to the North.
The Shade the UK View
The raison d’être of Shade the UK is to help advocate for measures, policy changes, and general awareness for the need to reduce heat-related deaths across the world, with a particular focus on adapting the built infrastructure of the UK to better safeguard its population.
As such, the publication of such an eye-opening study like this one that reveals the extent of the problem well into the future is of great value to our work and getting our message across. With its conclusions in mind, our view is that the following measures would need to be implemented in order to limit the effects of overheating across Europe, in a considered and practical manner:
Europe-Wide Heat Adaptation Strategy: Heat-adaptive measures will be crucial to preventing the mortality risk from overheating soaring over the next century. The impacts of this will be experienced by the majority of European nations, meaning that multilateral, cross-country investment in climate adaptation, particularly in urban areas that are more subject to overheating, will be required.
Weighted Investment in Adaptation: As the effects of overheating are estimated to be unequal across the region, so too must the degree of adaptation. With considerations around resources and financing in mind, adaptation should be concentrated in regions - namely Southern Europe - where the effects of overheating are expected to be most pronounced. However, given that those nations least at risk are also the most socioeconomically advanced, there must be a cross-country centralised body that allows wealthier nations to support those less developed to adapt their infrastructure.
Tailor Adaptation to the Locale: With limited resourcing being committed to climate adaptation in general, a tailored approach will be needed; through identifying the most susceptible groups and vulnerable populations across society and developing adaptive measures that protect them specifically will allow for the greatest benefit to be derived from directed investment.
The data reveals that, for us to make any progress towards safeguarding our populations there is a need to combine the adaptation described above with policies that limit carbon emissions and reduce warming. Therefore, the above recommendations on adaptation must only be considered within the context of a wider strategy that seeks to mitigate climate change in an effective manner. However, as recent years have borne out, a lack of climate leadership in this area is limiting the extent to which we can make progress to create a greener and less-polluting society.
To learn more about Shade the UK and the services we offer, please email us at info@shadetheuk.co.uk.
