European cities are particularly vulnerable to impacts of climate change. Places that bring people, economies, and innovation together have experienced heatwaves, infectious diseases, wildfires, and other climate-related impacts more frequently in recent years.
The urban heat island effect, high population density, extensive urban infrastructure, and the presence of vulnerable populations all contribute to making cities particularly susceptible to the impacts of climate change.
However, cities are also well positioned to lead climate adaptation and mitigation. Their close engagement with citizens, relatively agile governance structures compared to national governments, and ability to tailor policies to local needs position them as key implementers of climate action. Positively, many European cities are already moving towards better climate change adaptation and mitigation.
Nevertheless, scientists suggest that existing city-level monitoring frameworks and indicators remain scarce and fragmented. They also rarely capture the specific pathways through which climate change affects health in urban contexts.
For the first time, the Lancet Countdown has therefore published a systematic, policy-relevant set of climate change and health indicators for European cities. The report was developed with contributions from 58 researchers from 31 academic institutions and examines 28 indicators across more than 850 cities and five domains.
Domain 1: Climate change exposures, health risks and impacts
The six indicators in this domain reflect the pathways through which climate and environmental change affect urban health. These include heat exposure associated with urban heat islands and impervious surfaces, health impacts from extreme weather events and wildfire smoke, the climatic suitability of non-cholera Vibrio infections, the suitability of conditions for dengue, chikungunya and Zika transmission and exposure to allergenic trees.
Core Insights:The data showed that southern European cities experienced greater heat-related mortality and increased climatic suitability for vector-borne diseases. Northern European cities, meanwhile, experienced higher exposure to allergenic tree pollen and greater climatic suitability for Vibrio infections.
Domain 2: Adaptation, planning and resilience for health
This section includes six indicators assessing the extent to which adaptation measures have been planned or adopted across European cities. These include: city-level climate change risk assessments, heat-health early-warning systems, surface urban heat island adaptation, green leaf area coverage and albedo, exposure to green space, urban tree cover, heat-resilient cycling infrastructure, and city-level climate change adaptation goals and actions.
Core insights: Between 2014 and 2019, average surface urban heat declined by around 0.7°C across European cities. However, as global temperatures continue to rise, further local cooling is urgently needed. Urban trees are among the most effective nature-based solutions for reducing urban heat. Expanding tree cover along cycling routes-particularly in southern Europe and western Asia-could help ensure that active travel remains safe and comfortable as heat-stress days become more frequent.
Domain 3: Mitigation actions and health co-benefits
There are six indicators in this section:sectoral attribution of greenhouse gas emissions,mortality attributable to PM2.5, infrastructure supporting active and public transport, lifecycle emissions from food demand, deaths attributable to dietary risks, city-level climate change mitigation targets and actions.
Core insights: One of the key messages of the Lancet Countdown Cities Report is the importance of harnessing health co-benefits while reducing overall greenhouse gas emissions. These benefits include reduced air pollution, healthier low-carbon diets and increased physical activity.
The suggested actions include promoting travel-related physical activity, increasing urban greening to reduce energy demand for cooling, encouraging public transport and improving energy efficiency in buildings. All of these measures can benefit health and climate mitigation simultaneously.
Between 2000 and 2024, many European cities significantly reduced greenhouse gas emissions, with several northern and western European cities leading the way. The indicators also suggest that larger and higher-income cities could use their innovation, infrastructure and investment capacity to help lower-income and smaller cities reduce emissions.
Domain 4: Economics and finance
The three indicators in this domain were heat-related labour supply, the costs of unhealthy diets, and funding for city-level climate adaptation and mitigation.
Core insights: Rising temperatures reduce labour productivity and increase healthcare expenditure. Working hours decreased by 1.1% between 2020 and 2024 compared with a scenario in which temperatures had remained unchanged. Data from around 85 European cities showed that heat-related mortality associated with the urban heat island effect had a monetised value of €192 per adult resident annually. The report also suggests that unsustainable dietary patterns create significant economic costs for cities. Assessments of city vulnerability also showed that many cities face financial and technical barriers to addressing climate-related health risks.
Domain 5: Public and political engagement
The report measured the following indicators:coverage of health and climate change in scientific articles, studies attributing health impacts to climate change in cities, engagement with health and climate change in urban areas, political engagement with health and climate change in urban areas on social media, corporate-sector engagement with health and climate change in urban areas, coverage of health and climate change in urban areas in online newspaper articles.
Core insights: Studies directly linking health and climate change have declined despite intensifying risks. Climate and health are visible separately across the media, political and corporate spheres. However, the Lancet report suggests that it is important to frame them together to show the interlinked challenges of health, climate change and inequality.
For sustainable action to be taken at the governance level, evidence must be understood correctly. The interlinked nature of climate and health, as well as the unequal burdens of climate change, must be recognised so that policy responses can adequately address these challenges.
Key Take Aways
The Lancet Countdown clearly identifies three key areas that cities should prioritise to implement climate action while maximising health benefits for their residents:
- Heat-health early-warning systems and heat-health adaptation plans.
- Intersectoral urban planning.
- Accelerated reductions in greenhouse gas emissions across sectors, particularly energy, transport and food.
As Europe continues to warm, cities are increasingly vulnerable to heat risks because of their large and densely populated communities, the presence of at-risk groups and the urban heat island effect. The Lancet Countdown Cities Report therefore identifies heat-health early-warning systems and heat-health adaptation plans as priority actions for protecting urban populations.
Intersectoral urban planning should also be prioritised. This includes increasing urban green spaces, particularly tree canopy, using less heat-absorbent building materials, de-sealing impermeable surfaces, and promoting active and public transport.
Accelerating reductions in greenhouse gas emissions across the energy, transport and food sectors can produce immediate health gains through reduced air pollution. It can also reduce the burden of non-communicable diseases through healthier diets and increased physical activity.
What should be considered?
While implementing climate action and exploring synergies between adaptation, mitigation and health, cities must also consider potential trade-offs. For example, increasing green space as part of heat adaptation, if not adequately planned, could contribute to the spread of vector-borne diseases. Compact urban designs that promote walkability and low-carbon transport could also contribute to increased flood risk and urban heat if they result in high levels of impervious surfaces.
City-level strategies should therefore be assessed holistically, considering their potential health benefits alongside equity implications, ecological impacts, and unintended consequences, to identify approaches that maximize overall benefits while minimizing potential harms.
The Lancet Countdown report strongly suggests that the climate action already being led by larger European cities can be amplified to create a healthier and more equitable Europe, with support of evidence, capacity building, financing and the inclusion of smaller cities.
Read the report here:The 2026 Europe Cities Report of the Lancet Countdown on health and climate change: cities at the forefront of climate change action
Contributing researchers from Hei-planet: Hedi K Kriit, Joacim Rocklöv, Peter Fransson, Pratik Singh
