Chief Medical Officer's annual report 2024-2025: Realistic Medicine - Critical Connections

Chapter 3: Our Planet for Our Health

The triple planetary health crisis – climate change, loss of biodiversity and air pollution – remains the greatest threat to human health this century. It is a public health emergency, where healthcare systems around the world contribute substantially to the problem, producing around 5% of carbon emissions globally. For several years, I have highlighted the interconnected nature of the population health challenges we face, and the need for urgent action to address the unfolding planetary crisis to lessen the human health impacts that will follow. We must therefore look for the intersecting approaches that enable us to meet these interconnected challenges.

In searching for this intersection, we must recognise that not only is resource stewardship necessary to reduce the overmedicalisation of care, but we must also identify under-use of high-value care that may ultimately prevent disease or its progression. By doing so, we can also reduce inequalities and create a more sustainable healthcare system too. In Canada, this has been done by creating lists of under-used but high-value procedures and diagnostic tests particularly aimed at the early detection or monitoring of disease. In Scotland, particularly with our need to improve cardiovascular outcomes, maximising the health gain from prevention using statins may be especially important.

Scotland’s natural environment is an invaluable resource which we can harness to improve the health and wellbeing of the people we care for, the communities we serve, and our planet.

Wherever we are in Scotland, we are never far from some of the most beautiful natural surroundings in the world. Even our urban cityscapes benefit from close geographical proximity to nature. However, we are yet to make full use of Scotland’s remarkable natural environment to support the health and wellbeing of the people we care for. In addition to mitigating the risks of the harms posed by the planetary crisis, there is much to gain in terms of benefits to our health from protecting our natural resources.

“The physician treats, but nature heals.” – Hippocrates

The concept of using nature for the benefit of health is not a new idea.

Victorian townplanners understood the value of harnessing nature to extraordinary effect for health and wellbeing. After a cholera outbreak in Glasgow claimed the lives of over 4,000 people in 1848-1849, engineers diverted fresh water across 40 miles from Loch Katrine. Cholera deaths dramatically reduced, and the scheme still provides most of the city’s drinking water today.

Glasgow Green, the oldest of the city’s parks, has been repeatedly protected from industrial development so that people from all walks of life could benefit from a leisure space and point of connection for their communities.

Given that the number of people living in Scottish cities is predicted to continue growing, we must think just as radically as our Victorian predecessors in striving to unlock the benefits of nature for our health and wellbeing. This is especially important given the health challenges urbanisation poses to health in terms of higher exposure to pollution, lack of physical exercise, and resulting increase in non-communicable diseases. Locking in community space to promote connection, outdoor activity and creativity, must become part and parcel of our approach to urban planning.

As well as being beneficial for the health and wellbeing of the people and communities we serve, the health of our planet could also benefit from increasing our engagement with nature. The Scottish Climate Survey tells us that while over three quarters of respondents (77%) said they knew little or nothing about Scotland’s biodiversity crisis, six-in-ten (62%) had spent time in local green or blue spaces at least once a week in the past month. A large majority agreed that spending time in local green or blue spaces had benefits for their mental and physical health (both 86%), while over half (54%) felt it made them feel more connected to their community.

The evidence also shows that the physical proximity to nature in our everyday environment influences the practice of environmentally responsible behaviours, with a study of 24,204 people demonstrating neighbourhood exposure to nature to be positively associated with engagement in recycling, encouraging others to make green choices and the purchase of green products. Early exposure to nature appears to have a positive impact on the development of environmental attitudes and behaviours as an adult. A study of 2,004 urban-dwelling adults found positive associations between exposure to nature prior to the age of 11 and self-reported environmental attitudes and behaviours in adult life. Associations were strongest for activities in “wild nature” such as hiking and camping, though were still significant for “domesticated” exposure such as caring for plants, harvesting vegetables and planting trees.

While most literature relies on the self-reporting of environmental behaviours (potentially allowing bias to occur), a randomised control trial of 542 people in 2024 took a different approach. Participants were each given 10 euros and were allocated to either being exposed to nature through a 15-minute walk, exposed to nature through a video of a walk, an urban walk, or no exposure to nature at all. The group exposed to nature on an actual walk were found to be significantly more likely to donate any of the money and indeed donate more of the money to a nature-based charity.

‘‘We abuse land because we regard it as a commodity belonging to us. When we see land as a community to which we belong, we may begin to use it with love and respect.’’ – Aldo Leopold

There is growing evidence that living close to and spending time in and around green or blue spaces (e.g. parks, gardens, ponds) is associated with fewer mental health problems. Exposure to green or blue space is associated with the greatest reduced risk of common mental health problems, particularly for those who live in deprived communities.

Almost two thirds (62%) of Scottish Climate Survey respondents reported spending time in green or blue spaces at least once a week in the past month. One-in-five (20%) reported they spent time in a local green or blue space every day. Just under a third of respondents (31%) did so less than once a week, including 12% who said they did not spend any time at all in green or blue spaces.

Exposure to nature in our towns and cities could be an important strategy for mitigating both environmental harm and preventing ill health. As active members of the communities we serve, we can influence health behaviours for the benefit of the people we care for and for our planet.

Benefits of nature for our health

What then are the benefits of nature for our health?

Evidence shows that exposure to nature-rich green spaces (prominently featuring vegetation such as grass and trees) and blue spaces (prominently featuring water including lochs, rivers and seas) can make a significant positive contribution to physical and mental health, and that these begin at the very start of the life course.

Children and young people want spaces that are close to home, interesting and varied and include nature. They want to feel that they are safe and welcome in those spaces and that the space is valued and maintained.

A large study of children aged between 4 and 7 years found that those with higher lifetime levels of exposure to green space within 250 metres of their residential post code showed greater degrees of development in terms of physical health, social competence, and general knowledge. Green spaces can impact positively on childhood development in a wide range of ways including better balance and coordination, and fewer behavioural problems, through the facilitation of play and exercise. These benefits appear to be longlasting, with one study of 3,585 adults aged between 18 and 75 from across four European cities suggesting that those with less exposure to outdoor environments during childhood had poorer mental health in later life.

It is not just children themselves who benefit from nature– those in contact with them benefit too, with children with better exposure to green spaces benefiting from stronger neighbourhoods, better social cohesion and going on to develop a greater concern for nature as adults. This should give us pause for thought regarding the potential role of outdoor spaces in schools and nurseries and other opportunities for children to learn through nature.

While the evidence of better health and wellbeing is compelling during childhood, there are also benefits for adults too. A 2016 review of 52 studies from Japan found that exposure to green spaces was associated with significant decreases in cortisol levels – a physiological marker of stress. Mild to moderate exercise in green space was associated with a larger drop in cortisol levels when the activity took place in a green space environment compared to an urban one. Furthermore, exposure to green space has been associated with improved cardiovascular health and evidence of better immune system activity.

Blue spaces also positively impact on our health. A longitudinal study of 137,032 people from Scotland showed that those who lived in closest proximity to the regeneration of the Glasgow branch of the Forth & Clyde Canal from the most deprived tertile of the population over the course of 18 years had a lower risk of cardiovascular disease, diabetes, hypertension, stroke and obesity. The creation of traffic-free towpaths promoting walking and cycling, the enhancement of adjacent green spaces and the redevelopment of surrounding sporting and leisure infrastructure, may well have created benefits experienced by the whole community.

“Everybody needs beauty as well as bread, places to play in and pray in, where nature may heal and give strength to body and soul alike.” – John Muir

Integration of nature into our urban spaces for the health and wellbeing of our communities should not therefore be considered a luxury. It is an essential component of our health and wellbeing for both human and planetary health. We must recognise its value in treating and preventing ill health and ask ourselves, what more we can do to support the people we care for to access nature and experience its health benefits.

Promoting health and preventing illness

The Scottish Burden of Disease study predicts that the burden of disease on our population will grow by 21% by 2043.

While we live in an era in which treatment is possible for many of these pathologies, it would clearly be better to prevent them from occurring in the first place. Much of the burden of disease, and its impact on the people we care for, our communities and our health and care system can be prevented if we act now.

“Prevention is better than cure.” – Desiderius Erasmus

It is well recognised that what we traditionally consider as healthcare is not the only factor which contributes to our health and wellbeing, with some citing its contribution to overall health outcomes as approximately 20%.

This means that as much as 80% is made up by other factors. These include social and economic factors such as education and employment opportunities (40%), our health behaviours such as diet and exercise (30%) as well as our physical environment (10%).

It is therefore exciting to see Scotland embark on the first steps towards a multi–factored preventative approach to health with the development of the Population Health Framework, due to be published in June. Through putting prevention at the core of what we do as both a healthcare community and a wider society, we could make real improvements whilst simultaneously reducing inequalities.

We must be bold, urgent and think more widely about how we positively influence the social determinants of health.

The planet’s effect on our health

Ten percent of our health is determined by our physical environment, yet can we honestly say we are truly harnessing its ability to improve and sustain health and wellbeing?

Last year, I talked about air pollution, and the threat it poses to our health in Scotland. It is a striking example of how our physical environment can contribute to our health and wellbeing. Air pollution is implicated in 1,800 to 2,700 deaths each year, and we know that admission rates to hospitals amongst children rise when levels of air pollution are high. This year, I would like to consider how harnessing nature can help address social determinants of health and help us mitigate the effects of air pollution.

While much of the focus on improving air quality is rightly on reducing emissions, there is evidence of a beneficial effect of vegetation itself on improving air quality. Increased exposure to residential greenspace might improve childhood development by reducing the adverse developmental effects of traffic-related exposures, especially NO2 air pollution and noise pollution.

Given the known risks of air pollution to health, integrating nature into our urban environments by increasing vegetation could mitigate the health risks associated with air pollution in areas where people are most vulnerable.

Our role as a healthcare community

Given that the burden of disease is forecast to grow, it will simply not be enough to focus our efforts on the 20% of health outcomes influenced by traditional healthcare. As healthcare professionals, we must think far more broadly to empower the people we care for to positively influence the remaining 80%.

Social prescribing enables the people we care for to access a range of non-clinical services in their local communities. It can be used alongside traditional healthcare interventions such as medication for the betterment of health in a holistic way. Social prescribing offers us ways of enabling those we care for to benefit from nature.

The Bromley by Bow Centre in London is a GP practice which has led the way in the use of social prescribing in their community. Sir Sam Everington, a GP at Bromley by Bow explains:

“There are many things that affect our health and wellbeing that can’t be fixed by traditional medicine. Social prescribing is a crucial way of addressing this. Understanding what matters to people, and connecting them to people, their community and nature, can have a profound impact on improving their health and wellbeing.” – Sir Sam Everington, Bromley by Bow Centre

If we are to be successful in creating a Scotland which truly unlocks the value of prevention, the people we care for must also be able to access services for themselves to prevent the over-medicalisation of care.

A striking example of this in action is the story of Michelle, who attended the Growchapel Community Allotment in Glasgow at a time when she needed support.

Case Study: Growchapel Community Allotment, Glasgow

When Michelle, 52, lost her dad, she fell into a depression and was signed off work.

Determined to do something positive for her mental health, she looked on social media and found the Walking for Health weekly walk in Drumchapel, a joint venture between Chest Heart & Stroke Scotland (CHSS) and the Health & Social Care Alliance Scotland.

After becoming a regular attender, she began volunteering for CHSS at its fledgling Growchapel community allotment and started to give her free time at a dementia support group in nearby Yoker. Now, almost four years on, Michelle is working full time with people living with dementia and credits the regular walk and gardening for restoring her confidence and changing her mood.

“I was in a downhill spiral after losing my dad. I knew I needed to do something, and I knew it had to be physical. Going on the weekly walk and volunteering at Growchapel changed everything.”

“There’s something about gardening – even if you know nothing about it – that gives you such great satisfaction. When we started, the allotment was just mud, but that just made the challenge more fun. So long as you don’t mind getting dirty!”

“The health walk takes me out of myself for an hour every week. It’s been such a positive experience. No matter the weather, it’s worth it for how good it makes you feel. Now I’m working full-time again and so happy with the job I’m doing.”

Michelle’s story not only illustrates the power of enabling people to access the support they need in their local communities, but also the lasting benefits that connecting with nature can have on our health and wellbeing.

We know that physical activity can have huge benefits for our health and wellbeing. The evidence shows that there is no minimum level required to achieve better health and that the greatest potential benefits to increasing physical activity are for those who are the least active.

“If physical activity were a drug, we would refer to it as a miracle cure, due to the great many illnesses it can prevent and help treat.” — UK Chief Medical Officers, 2018

The evidence also shows that nature can enhance the benefits of physical activity, with studies showing that exercise in green environments has a more beneficial effect on physiological stress than exercise undertaken in urban environments. In addition to supporting our physical and mental health, physical activity can bring people together, creating and enhancing connections between people, but also with nature.

Case Study: Boots and Beards

Boots and Beards enable people to use the natural world to improve their health and wellbeing through the provision of group exercise activities, including guided hill walks.

“Exploring nature has been a passion since childhood — it has always made me happy and played a huge role in my mental wellbeing. As a Muslim woman, it isn’t always easy to feel connected with the outside world. In our culture, women are traditionally expected to focus on home and family, making it harder to step outside of those roles. Hill walking has allowed me to break those barriers, giving me the space to explore, breathe, and enjoy the beauty of nature in a way that feels truly liberating. It’s not just exercise — it’s an act of self-care and independence.”

Case Study: Boots and Beards – continued

“Walking and hiking have also had a huge impact on managing my ADHD. Being outside helps me focus, calms my thoughts, and gives me an outlet for my energy in a way that nothing else does. It allows me to process my thoughts more clearly and brings a sense of balance to my day. I’ve noticed that after a good walk, I feel more present, less overwhelmed, and better able to manage daily tasks.” — Boots and Beards participant

Nature in Healthcare Settings

Every healthcare professional in Scotland has a role to play in empowering the people we care for to connect with nature for the good of their health.

The NHS Scotland estate covers a total of 1,582 hectares, which is roughly the size of the city of Stirling. While much of the focus of using the estate is on the provision of healthcare — the grey infrastructure, such as buildings and facilities — we must also consider the potential of NHS green space holds for keeping us well. Recent mapping work undertaken by Public Health Scotland shows that 52% of that land (852 hectares) is green space.

Much of our NHS green space is underused, currently supplying a fraction of its potential to sustain the health and wellbeing of our people, our communities and our planet. We want to realise the full potential of the greenspace resource across the NHS Scotland estate. Our aim is that NHS greenspace is embedded as a core component of Scotland’s health and social care services and managed to improve provision, access, quality and use.

Case Study: Ninewells Community Garden

Since 2012, a team of volunteers, trustees and staff at the Ninewells Community Garden have created an environment which promotes physical activity and healthy living through gardening where community engagement, health and wellbeing and environmental sustainability is at its core.

The garden includes wheelchair accessible paths, herbaceous borders, vegetable beds, a sensory garden, small orchard with wildflowers, picnic area, wildlife habitat, garden room, polytunnel and children’s play area.

“Getting outdoors, in the fresh air, meeting other people. It’s helping me to lose weight for the first time in years.” — Volunteer, Ninewells Community Garden

Volunteers share seeds, plant cuttings, equipment and knowledge with other gardens, connecting with 29 other groups across Dundee to create a network of community growing spaces. As one volunteer put it, “It isn’t really about gardening, it’s about connecting with nature and each other”.

The impact of this network of gardens is undoubtedly making an important difference to the health and wellbeing of those involved now, but I am struck by the potential impact this is having on the future health of everyone involved across this growing network of communities.

Our future direction

When it comes to our future health one thing is clear: providing care the way we always have is not an option.

Just as we as individuals do not exist in isolation, human and planetary health are intertwined. We are part of an interconnected ecosystem and whether it be new approaches to sustainable agriculture, materials or healthcare, this innovation is well established across Scotland.

There is more we can do in areas such as sustainable diets to prevent ill health, reduce pressure on our health services and reduce our impact on the natural world. Shifting towards sustainable, healthy diets and cutting food waste are key opportunities for reducing emissions and pressure on nature, in Scotland and overseas. This can go hand in hand with improving our health and easing pressure on our NHS.

Restoring the connection between ourselves and the planet need not be seen as a challenge, but an opportunity to develop fresh approaches for the health, employment and economic prosperity for the communities in which we live. Addressing the social determinants of health, refocusing our efforts on prevention and empowering people to prevent ill health is our duty and will benefit everyone in society. By nurturing nature we can improve the health of the people we care for, our communities and our planet.

Restoring and strengthening that connection between ourselves and the planet need not be seen as a problem.

When it comes to the future health of both, it is part of the solution.