Why we need to recognise the climate crisis as a growing health crisis - UKHSA

In this latest blog, Dr. Helen Macintyre from the UK Health Security Agency explores how climate change is not just an environmental challenge, but a pressing health crisis. She highlights the growing risks to public health in the UK—from heatwaves and air quality impacts to emerging infectious diseases—and the inequalities in who is most affected, exploring solutions-focused approaches.

Climate change is already having impacts on public health in the UK and internationally, and these impacts are likely to grow in coming decades. Risks to our health from climate change range from those that are well-established, such as exposure to high temperatures during heat waves, to more emergent issues such as mental health impacts and potential novel pandemics. There is still a lot more to understand, and UKHSA’s latest Health Effects of Climate Change in the UK (2023) report highlights key risks relevant for the UK. 

The impacts on health will not be distributed evenly across our communities. Increased temperatures are going to be particularly dangerous for older people – and the number of people aged over 85 in the UK is projected to more than treble in the next 40 years. People living with existing ill-health are likely to be more susceptible to the health effects of climate change, and people living in areas with higher deprivation may be less able to respond to threats.  

There are geographical differences too, for example some areas of the UK might become suitable for mosquitoes that can carry and transmit diseases not usually spread in the UK, such as dengue and Chikungunya. Research and policy therefore need to tackle climate-related health inequalities and ensure that mitigation and adaptation actions do not exacerbate them, and where possible help to address them. 

Action to mitigate climate change through reducing emissions of greenhouse gases will prevent some of the anticipated adverse health effects of climate change. Some of these actions can also have important health ‘co-benefits’, meaning that besides helping reduce emissions, there are other indirect effects on our health. A well-known example of this is the improvement in air quality through reduced fossil fuel use, for example switching to renewable sources of energy, or shifting short journeys by car to walking and cycling, which has an additional co-benefit of increasing physical activity. It is important to understand and increase awareness of the wider health benefits of climate change action, so that we can identify where opportunities for health can be maximised, and ensure any unintentional ‘dis-benefits’ are identified so that these can be avoided. 

The Centre for Net Positive Health and Climate Solutions takes a solutions-focused approach to ask: How can the UK capitalise on co-benefits (or deal with co-effects) of climate mitigation and adaptation strategies to address environmental, social and health inequalities across the lifecourse? These strategies have the potential to deliver multiple impacts for climate and health, focusing on three core themes of urban environments, green/blue infrastructure, and food systems as critical areas for action and opportunity. 

For example, people are starting to recognise the importance of green spaces for people’s mental and physical health, for biodiversity, and for flood management. Greening of urban landscapes and infrastructure, river or wetland restoration, and improvement of rural landscapes could help reduce the urban heat island effect, support increased biodiversity, and provide opportunities for rest and relaxation, but might also lead to ‘green gentrification’, increased exposure to aeroallergens, or potentially provide a habitat for vectors like mosquitoes and ticks that can carry disease. 

We spend over 90% of our time indoors, so we rely on our buildings to keep us healthy and safe, with our homes being the main setting for our health throughout our lives. In the UK we have some of the oldest building stock in Europe, and as the climate changes in the UK, buildings designed to for past climates might not function well under future conditions. This could affect the health of people who live, work, study, or play in them, so we need to ensure that our buildings are adapted for the future climate. Reducing energy use in buildings is also a key area for efforts to reduce emissions of greenhouse gases driving climate change, through measures like improving home energy efficiency. However, we need to ensure that we are not inadvertently affecting health in negative ways such as through making buildings too air-tight which might affect indoor environmental quality. 

We need better evidence to promote interventions that are equitable and ‘net-positive for health’, maximising benefits and mitigating any unintended consequences. The Net+ Centre’s activities will explore and analyse the complex environment-health-social systems involved, evaluate policies and other interventions, and build climate-health research capacity across communities.  

At UKHSA our scientists study the health effects of climate change, provide early warning and response to extreme weather events, quantify the health impacts of air pollution and monitor the risks posed by changes in the distribution of vector-borne disease. Much of our work is carried out in partnership with others, from local authorities through to national government and academia. Engaging with our key partners and users will be key to the success of the Centre. Activities will be user-led, based on the needs of decision-makers and communities, with co-designed research focused on solutions to deliver net positive solutions for climate and health issues achieved with the support of our policy panel, and taking a community-focused approach in the Centre’s activities. Over time we look forward to broadening and developing further partnerships to include other research institutions, public, private and third sector organisations. 

An important aspect of the Centre is to bring together partners across different sectors. The complexity of the challenge requires integrated approaches – this is why Net+ brings together a team that covers a broad array of expertise across a range of disciplines from data science, public health, classics, economics, climate modelling, epidemiology, humanities and geography. Importantly, it will build and strengthen UKHSA’s collaborations and partnerships with the University of Exeter, Forest Research and the National Trust, working with the Met Office, national environmental and public health agencies and non-governmental organisations (NGOs) to ensure real-world impact and solutions that make a difference to people’s lives.  

Ultimately, our role is to provide the best evidence around the risks to health from climate change, what works in terms of solutions to address these risks, and provide this evidence in a way that is useful so that everyone is able to be safe and healthy in a changing climate.