Ups and Downs of Open Space

Lakeland open space - view from my land

It is easy to think that green space, open space, even the wide blue sea, is good for one’s health. In some respects, this may be the case. The media is full of it. Parks, woodlands, commons, and open countryside are increasingly positioned as solutions to urban stress, climate change, biodiversity loss, and population ill-health.

Yet I well remember sitting at the back of an auditorium some years ago, listening to a lecturer drone on. I can recall little of the content of his lecture, but I do remember his statement that he felt happy when, from his window, he could see only red bricks. He did not like vegetation. How strange, I recall thinking. I imagined everyone would conclude that open space was wonderful, but that was clearly not the case. However, it was my introduction to a type of human who was unable to tolerate the countryside.

Several years later, as a morale-raising exercise, I rented a coach and took 30 members of staff and their children from deepest central London to the hills of North Wales. Imagine my astonishment when a 12-year-old boy pointed at a sheep grazing in a field, somewhere near Reading, and asked his mother, “Mum - what is that?”

Sheep - even this animal may be new to some people

All he knew was his urban life and, to him, nothing else existed. He had seen his first sheep. Yet in the countryside where I spend much of my life, sheep surround me much of the time.

It was clear to me then, as it is now, that open space may be talked up repeatedly, but may not always be wonderful. There are even words for the problem. For example, topophobia, which is the fear of specific, often rural, landscapes or places. Or kenophobia, the fear of vast, open spaces. In extreme cases, there is also agoraphobia, the fear of being outside safe spaces. 

It thus made sense to have a closer look. What are the relative benefits and disadvantages of open space? Clearly, it is not all good.

I wonder...

The Upside

Green space is infrastructure

Green and open spaces encompass a spectrum of environments, from urban parks and street trees to woodlands, wetlands, riversides, agricultural commons, and upland fells. I have plenty of upland fell in the United Kingdom’s Lake District, as I look down on the town of Ambleside. Historically, such spaces have been integral to settlement patterns, subsistence, and culture. In the twenty-first century, rapid urbanisation, biodiversity loss, and climate change have renewed attention on their role in sustaining human well-being. Approximately 85% of the UK’s population is urban, a percentage that is rising.

Open space is a form of infrastructure - here we have The Alps

The modern description of green space as so-called infrastructure reflects a growing consensus that nature supports population health in ways comparable with sanitation, housing, and transport. International bodies, including the World Health Organization, have highlighted the contribution of urban green space to health promotion and disease prevention, particularly in ageing and increasingly sedentary societies. There has been a significant impact on the sedentary nature of society since the expansion of the digital era. Traditional pastimes such as outdoor sports, gardening, and physical play have been replaced by sedentary alternatives, such as video games, streaming services, and social media.^[i]

Reducing chronic disease

Access to green space is consistently associated with higher levels of physical activity. Parks, greenways, and open countryside provide low-cost, accessible settings for walking, cycling, and informal recreation. A greenway is usually a shared-use path along a strip of undeveloped land, set aside for recreational use or environmental protection. It can also be a linear park, and can serve as a wildlife corridor. Large cohort studies have shown that individuals living in greener neighbourhoods are more likely to meet recommended activity levels and have a lower prevalence of obesity, type 2 diabetes, and cardiovascular disease.^[ii],[iii]

A study of over 300,000 adults in England found that proximity to green space was associated with a reduced all-cause mortality, even after adjustment for socioeconomic status.^[iv] Mechanistically, green environments encourage sustained moderate activity, which improves cardiorespiratory fitness, insulin sensitivity, and lipid profiles.

Cardiovascular and metabolic effects

Beyond activity alone, exposure to green environments appears to exert direct physiological effects. Experimental studies demonstrate reductions in blood pressure, heart rate, and sympathetic nervous system activity after time spent in natural settings, compared with urban environments.^[v] These findings align with Japanese research on forest bathing (shinrin-yoku), which found that short woodland visits were associated with improved autonomic balance and immune markers.^[vi]

Healthy ageing

For older adults, accessible green space supports mobility, balance, and independence. Observational studies suggest that elderly populations with access to safe, attractive outdoor spaces experience slower functional decline and lower rates of frailty.^[vii] Importantly, such benefits are not limited to vigorous exercise. Even gentle walking, or sitting outdoors, contributes to musculoskeletal and cardiovascular health.

It is said that open space is good for your heart (Photo by Jamie Street on Unsplash)

 Stress reduction

One of the most robust findings in environmental psychology is the stress-reducing effect of natural environments. The Attention Restoration Theory proposes that nature engages involuntary attention, allowing directed attention capacities to recover.^[viii] I know that when I am on my own land, I find it hard to think about anything other than what I am doing there and then. My problems melt away. Empirical studies confirm reductions in cortisol levels and self-reported stress after exposure to green space, whether through direct contact, or even views from windows.^[ix]

Large population studies have linked greener residential environments with a lower prevalence of anxiety and depression.^[x] These associations persist across age groups and cultures, and suggest a fundamental human response to natural stimuli.

Mental illness

Evidence is accumulating that regular access to green space may reduce the incidence and severity of common mental disorders. A Danish cohort study that followed nearly one million individuals from childhood to adulthood found that a lower exposure to green space during early life was associated with a higher risk of psychiatric disorders later in life.^[xi] While it was hard to be entirely certain, the proposed pathways included buffering against stress and reduced exposure to environmental pollutants.

Cognitive function

Green and open spaces also support cognitive performance. Studies in children show improved attention, working memory, and academic outcomes associated with greener school environments.^[xii] In adults, brief walks in natural settings have been shown to improve executive function compared with urban walks.^[xiii] Such findings have implications for education, the workplace, and rehabilitation.

Social trust

Public green spaces function as shared social arenas, fostering interaction across age, ethnicity, and socioeconomic groups. Sociological studies indicate that neighbourhoods with well-maintained parks and communal green areas exhibit higher levels of social trust and informal social control.^[xiv] These attributes are linked to lower crime rates and greater perceived safety.

Reducing loneliness

Loneliness is increasingly recognised as a major public health issue. Research shows that 7% of adults in England's urban areas report frequent or persistent feelings of loneliness. This figure is slightly less (5%) for those living in rural areas.^[xv]

Open space is said also to reduce loneliness (Photo by Matthew Henry on Unsplash)

 Green and open spaces provide opportunities for casual social contact, volunteering, and community events. For older adults in particular, parks and gardens can mitigate social isolation, with measurable benefits for mental health and longevity.^[xvi]

Sense of place

Landscapes shape cultural narratives and personal identity. From urban commons to rural uplands such as my own, green spaces carry historical, spiritual, and aesthetic meanings. Qualitative research shows that access to familiar landscapes contributes to a sense of belonging and continuity, especially during social change or personal stress.^[xvii] I know I have benefited greatly from my land and spend a lot of time thinking about it. It is on my mind even when I am in far-flung countries. With the news headlines as they are right now, there is every reason to feel personal stress. Social change is underway, sometimes for no good reason.

Childhood development

Exposure to green environments in early childhood is associated with improved motor development, emotional regulation, and resilience. Natural play spaces encourage imaginative play and risk assessment, which are important for cognitive and social development.^[xviii] Children who regularly engage with outdoor environments also demonstrate greater environmental awareness and stewardship later in life.

Adolescence

For adolescents, access to green and open spaces is linked to reduced engagement in risk behaviours such as substance misuse and antisocial activity.^[xix] The presence of safe outdoor spaces offers alternatives to sedentary or harmful pursuits and supports positive peer interactions.

Unequal access

The benefits of green space are not distributed evenly. Deprived communities and marginalised groups often have less access to high-quality green environments, thereby exacerbating health inequalities.^[xx] Studies in multiple countries show that investment in urban greening yields disproportionate benefits for lower-income populations, narrowing gaps in physical and mental health outcomes.

Accessibility

To maximise benefits, green spaces must be accessible to people with disabilities, older adults, and children. Safe pathways, seating, wheeled access, and toilets are critical features. Please do not even think about making an area more accessible without considering the toilets. They are critical. Evidence also suggests that safety and maintenance are as important as proximity when determining use.^[xxi]

Wheelchair and open space (Photo by A.M. Dodo)

 Climate resilience

Green and open spaces moderate urban microclimates by providing shade, evapotranspiration, and airflow. Urban parks and tree canopies can reduce local temperatures by several degrees during heatwaves, directly lowering heat-related morbidity and mortality.^[xxii] As climate change increases the frequency of extreme heat events, such cooling services become vital public health interventions.

Strategically planted trees and urban green spaces can reduce air temperatures by 2 to 8°C. Localised cooling in the direct shade of trees can be even more significant, lowering perceived human temperatures by 7 to 15°C. This cooling effect is achieved through shade and evapotranspiration, where trees release water vapour into the air. 

Air quality and noise

Vegetation can improve air quality by filtering particulate matter and absorbing gaseous pollutants. Although the magnitude of this effect varies, epidemiological studies link greener neighbourhoods with lower exposure to air pollution and associated respiratory disease.^[xxiii] Vegetation purifies the air by absorbing pollutants, but its effectiveness varies greatly depending on the setting. While outdoor plants can reduce fine particulate matter (PM2.5) by up to 63%, indoor potted plants have a negligible impact on air quality. Research suggests a very large number of plants would be needed per square metre to match the cleaning power of a building's ventilation system.^[xxiv]

Vegetation can also significantly reduce noise, typically providing a 5 to 10 decibel (dB) reduction for every 30 metres of depth, which can make sounds seem up to 50% quieter to the human ear. A dense, wide, and varied belt of trees, shrubs, and soft ground works best for absorption and deflection.^[xxv] This noise attenuation contributes to improved sleep and a reduction in stress.

Flood regulation

Wetlands, floodplains, and permeable green spaces reduce flood risk by absorbing and slowing runoff. A mature oak tree can consume up to 150 gallons of water daily. Through interception by leaves and soil moisture uptake, oak woodland can reduce peak flood flows by a good 65%.^[xxvi] The leaf litter and soil under oaks are also highly effective, with woodlands allowing water infiltration 60 times faster than grassland. The human benefits include reduced property damage, displacement, and psychological trauma following extreme weather events.^[xxvii] Such ecosystem services underscore the integration of green space into climate adaptation strategies.

Healthcare savings

By reducing the incidence of chronic disease and mental illness, green and open spaces generate substantial healthcare savings. Economic modelling studies estimate that increased urban green space could save national health systems millions annually through reduced treatment costs and productivity losses.^[xxviii]Overall, parks and green spaces in the UK generate health and well-being benefits valued at over £34 billion annually. That is more than half of the current UK defence budget.

Workplace outcomes

Access to green views and outdoor spaces in and around workplaces has been associated with improved job satisfaction, reduced absenteeism, and enhanced cognitive performance.^[xxix] These findings support the inclusion of green infrastructure in commercial and institutional developments.

Property values

Proximity to well-designed green space is associated with higher property values and increased local economic activity. While this can risk displacement through gentrification, careful planning and community engagement can ensure that economic benefits support, rather than undermine, social equity.^[xxx]

Open space can increase property values (Photo by Emre Can Acer)

Biodiversity

Emerging research suggests that exposure to biodiverse environments may support human immune regulation through contact with a wider range of microorganisms.^[xxxi] Reduced biodiversity in urban settings has been linked to a higher prevalence of allergic and autoimmune conditions, although this field remains under active investigation.

Psychological benefits

Not all green spaces confer equal benefits. Studies indicate that people report greater well-being in environments perceived as natural and biodiverse compared with highly manicured or monocultural spaces.^[xxxii] This has implications for land management and favours ecological richness over purely aesthetic greening.

Public health

It seems clear that there is sufficient evidence to support the integration of green and open spaces into public health policy. Green prescribing, where clinicians recommend nature-based activities, is gaining traction and shows promise for managing mild to moderate mental health conditions.^[xxxiii] However, such initiatives require adequate provision and maintenance of accessible green environments.

Urban planning and long-term protection

Planning frameworks that prioritise the protection of green space and connectivity are essential. Fragmented or tokenistic greening fails to deliver full benefits. Long-term stewardship, community involvement, and cross-sector collaboration are critical to sustaining benefits across generations.^[xxxiv]

And so?

The upside is thus promising, and I can see why the media makes a fuss. Green and open spaces confer wide-ranging benefits to humankind, and span physical health, mental well-being, social cohesion, environmental resilience, and economic value. The evidence supports a shift from viewing such spaces as optional amenities to recognising them as an essential infrastructure. As societies confront the intertwined challenges of climate change, urbanisation, and health inequality, investment in green and open spaces constitutes a cost-effective, equitable, and sustainable strategy, with huge benefits to so many sectors of society.

The Downside

Sadly, it is not all roses. Let us have a look.

Respiratory health

Vegetation is a major source of aeroallergens. Tree, grass, and weed pollen contribute significantly to allergic rhinitis, asthma exacerbations, and reduced quality of life. The rising prevalence of pollen-related diseases has been documented across Europe and North America, with climate change extending pollen seasons and increasing allergenicity.^{[xxxv],[xxxvi]}

Vegetation can sometimes harm your lungs (Photo by cottonbro studio)

Approximately a third of the UK’s population is allergic to something, a prevalence that is increasing rapidly. I know I start scratching when the vegetation begins to grow, but by mid-summer I am fine. The itching starts again in the autumn. Urban greening initiatives that favour high-pollen-producing species can unintentionally worsen respiratory health, particularly in children and those with pre-existing conditions. For example, large-scale planting of male trees, historically favoured for reduced fruit litter, has been associated with increased airborne pollen loads.^[xxxvii]

Zoonotic disease

Green and open spaces provide a habitat for the vectors of human disease. A zoonotic disease (zoonosis) is an infectious disease caused by bacteria, viruses, parasites, or fungi. Examples might include COVID-19, Ebola, rabies, Salmonella, Lyme disease, influenza A (bird/swine ‘flu), plague, and anthrax. Zoonoses account for roughly 60% of existing and 75% of new human infections. These diseases are transmitted through direct contact with animals, contaminated food and/or water, or vectors such as mosquitoes. 

Ticks, mosquitoes, rodents, and other wildlife reservoirs thrive in unmanaged or semi-natural environments. Tick-borne diseases, including Lyme borreliosis, have expanded geographically in Europe and North America, partly linked to changes in land use and increased human interaction with woodland and edge habitats.^{[xxxviii],[xxxix]} I have plenty of ticks on my land. I invariably notice them in the early hours of the morning in those softer areas that other beers cannot reach. Do keep an eye out for ticks if you go anywhere near green space, especially bracken.

Urban green spaces have their problems, too and can support mosquito populations capable of transmitting West Nile virus and other arboviruses.^[xl] While such risks are often low at the individual level, they are genuine public health concerns on a population scale.

Mental health

Although green spaces are often associated with psychological restoration, they can also provoke anxiety and fear. Poorly lit, poorly maintained, or isolated green spaces may be perceived as unsafe, particularly by women, older adults, and marginalised groups.^[xli] Fear of crime can deter use, reduce physical activity, and exacerbate stress rather than relieve it.

Physical injury

Natural and semi-natural environments carry inherent physical risks. Uneven ground, water bodies, steep terrain, and exposure to weather increase the likelihood of falls, drowning, hypothermia, and traumatic injury. Epidemiological data show that outdoor recreational activities contribute substantially to emergency department attendances and mountain rescue callouts.^[xlii] Children are particularly vulnerable to drowning in open water, while older adults face increased fall risk on uneven paths. While risk is not inherently negative, it becomes a disadvantage when exposure is involuntary or poorly managed.

Mountain Rescue helicopter (courtesy Kevin Schmid on Unsplash)

 To put a number on the risk, take the Alps, for example. There are approximately 1600 rescue call-outs there every year. Take heart from the statistics that the risk of dying while hiking is low and is estimated at approximately four deaths per 100,000 hikers annually (0.0064%). Mind you, of those who fall and require rescue, roughly 6% of cases are fatal.

Occupational hazards

Green and open spaces are workplaces for many, including agricultural workers, foresters, conservation staff, and volunteers. Occupational injury rates in agriculture and forestry remain among the highest of all sectors in many countries.^[xliii] There is a fatality rate over 20 times higher than the all-industry average. Exposure to machinery, animals, chemicals, and environmental extremes presents ongoing risks to humankind that are often under-acknowledged in idealised narratives of green space.

Pests

Green spaces can harbour pests that negatively affect human health, comfort, and livelihoods. Rodents, wasps, and other nuisance species are common in urban parks and peri-urban green areas. Invasive non-native species can proliferate in disturbed or unmanaged green spaces, damaging infrastructure, agriculture, and native ecosystems.^[xliv]

Plants such as Japanese knotweed can be found in green spaces and have significant economic impacts, reducing property values and imposing high management costs.^[xlv] Estimates suggest that Japanese knotweed costs up to £246 million to the UK economy each year. That is a lot of money.

Emissions

While vegetation can improve air quality, it can also contribute to the formation of ground-level ozone through the emission of biogenic volatile organic compounds (BVOCs), particularly in hot conditions.^[xlvi] In certain urban contexts, dense tree cover may reduce air circulation, trapping pollutants at street level.^[xlvii] These effects complicate simplistic assumptions that more greenery always equates to better air quality.

Unequal access

Green and open spaces are not equally accessible to all. Socioeconomic deprivation, disability, age, and cultural background shape who can safely and comfortably use such spaces. Studies consistently show that deprived communities often have less access to high-quality green environments.^[xlviii]

When green spaces exist but feel unsafe, unwelcoming, or culturally alien, they may exacerbate rather than alleviate inequality. The mere presence of green space does not guarantee benefit.

Green gentrification

Investment in urban greening can increase property values and attract wealthier residents, a process often termed green gentrification. This can displace lower-income populations and undermine social cohesion.^[xlix],[l] In such cases, the provision of green space may paradoxically harm the very communities it is intended to support.

Financial costs

Green and open spaces require ongoing investment. Maintenance, safety management, pest control, and infrastructure repair impose significant costs on local authorities and landowners. In times of austerity, these costs may divert resources from other essential services, including healthcare and social care.^[li] Poorly funded green spaces can deteriorate, increasing safety risks and reducing usability, thereby amplifying disadvantages. If green space is to be fashioned from nothing, costings suggest that 20% of the total is for the creation but 80% is for maintenance. While construction costs may seem high upfront, the cumulative labour and resources needed to maintain a space over decades far exceed the initial investment. The older the space, the higher the maintenance costs, with construction costs soon disappearing and being overtaken by maintenance. This is so often forgotten.

Liability

Landowners and public bodies face legal liabilities associated with injuries, disease exposure, and environmental harm occurring on green spaces. Fear of litigation can lead to risk-averse management, restricted access, or outright site closures, reducing public benefit while preserving costs.^[lii]

Open space can cause legal liability

Conservation conflicts

Conservation-driven management of green and open spaces may conflict with traditional land uses, including farming, grazing, forestry, and foraging. Restrictions imposed for biodiversity protection may reduce livelihoods, cultural practices, and food security for local populations.^[liii] A good example can be seen on my land. Although I have plenty of trees, there are very few saplings as the sheep and deer from neighbouring land find their way onto my territory and gobble most things on sight, including saplings. The only way a new tree will grow is by epicormic growth once a broadleaf has fallen. The epicormic growth is beyond the reach of sheep or deer.

Such conflicts can generate resentment and undermine public support for conservation, ultimately harming both people and ecosystems.

Loss of agency

When green spaces are managed in ways that prioritise ecological outcomes without community involvement, local people may feel excluded or alienated. This loss of agency can have negative psychological and social consequences, particularly in rural and Indigenous contexts.^[liv] I focus heavily on volunteers, as they spread a positive message.

Extreme weather

Green and open spaces expose users to weather extremes, including heat, cold, storms, and flooding. Climate change is intensifying these hazards. Heat-related illness during outdoor recreation, flash flooding in river corridors, and storm-related injuries in wooded areas are increasingly documented.^[lv],[lvi] While built environments carry their own risks, green spaces are not inherently safer and may, in some contexts, increase risk.

Solastalgia

I love this word - solastalgia. It describes the psychological distress created by the degradation of green and open spaces, and the pain associated with environmental change near home.^[lvii] Green spaces can become sources of grief rather than sources of restoration.

Conflict over values

Green and open spaces are culturally contested. What one group values as wilderness, another may see as neglect or exclusion. Conflicting expectations around access, recreation, conservation, and aesthetics can generate social tension and reduce collective well-being.^[lviii]

What does this mean?

Green and open spaces are not unalloyed goods. They can expose humans to health risks, injury, inequality, economic burden, and psychological distress. Such disadvantages are not arguments against green space provision, but against uncritical, poorly planned, or inequitable approaches. I have seen, for example, multistemmed trees felled to make space for a garage in a house that already had an integral garage. The planners agreed to that, which I find quite astonishing. A mature relationship between humankind and green and open spaces requires acknowledging costs as well as benefits and designing landscapes that minimise harm while maximising shared value.

***

Keywords

green space; health risks; environmental disservices; social inequality; public health; mental wellbeing; urban planning; ecosystem services

Hashtags

#GreenSpaces #EnvironmentalHealth #CriticalEcology #PublicHealth #MentalWellbeing #UrbanNature #ClimateResilience

References

^[i] Sengkey SB, Sengkey MM, Tiwa TM, Padillah R. Sedentary society: the impact of the digital era on physical activity levels. Journal of Public Health. 2024 Mar;46(1):e185-6.

^[ii] Maas J, Verheij RA, Groenewegen PP, de Vries S, Spreeuwenberg P. Green space, urbanity, and health: how strong is the relation? J Epidemiol Community Health. 2006 Jul;60(7):587-92. doi: 10.1136/jech.2005.043125. 

^[iii] Lachowycz K, Jones AP. Greenspace and obesity: a systematic review of the evidence. Obesity Reviews. 2011 May;12(5):e183-9.

^[iv] Mitchell R, Popham F. Effect of exposure to natural environment on health inequalities: an observational population study.The Lancet. 2008;372(9650):1655–60.

^[v] Ulrich RS, Simons RF, Losito BD, Fiorito E, Miles MA, Zelson M. Stress recovery during exposure to natural and urban environments. J Environ Psychol. 1991;11(3):201–30

^[vi] Li Q. Effect of forest bathing trips on human immune function. Environ Health Prev Med. 2010;15(1):9–17.

^[vii] Takano T, Nakamura K, Watanabe M. Urban residential environments and senior citizens’ longevity in megacity areas: the importance of walkable green spaces. Journal of Epidemiology & Community Health. 2002 Dec 1;56(12):913-8.

^[viii] Kaplan R, Kaplan S. The experience of nature: A psychological perspective. Cambridge University Press; 1989 Jul 28.

^[ix] Thompson CW, Roe J, Aspinall P, Mitchell R, Clow A, Miller D. More green space is linked to less stress in deprived communities: Evidence from salivary cortisol patterns. Landscape and Urban Planning. 2012 Apr 15;105(3):221-9.

^[x] Beyer KM, Kaltenbach A, Szabo A, Bogar S, Nieto FJ, Malecki KM. Exposure to neighborhood green space and mental health: evidence from the survey of the health of Wisconsin. International Journal of Environmental Research and Public Health. 2014 Mar;11(3):3453-72.

^[xi] Engemann K, Pedersen CB, Arge L, Tsirogiannis C, Mortensen PB, Svenning JC. Residential green space in childhood is associated with lower risk of psychiatric disorders from adolescence into adulthood. Proceedings of the National Academy of Sciences. 2019 Mar 12;116(11):5188-93.

^[xii] Dadvand P, Nieuwenhuijsen MJ, Esnaola M, Forns J, Basagaña X, Alvarez-Pedrerol M, Rivas I, López-Vicente M, De Castro Pascual M, Su J, Jerrett M. Green spaces and cognitive development in primary schoolchildren. Proceedings of the National Academy of Sciences. 2015 Jun 30;112(26):7937-42.

^[xiii] Berman MG, Jonides J, Kaplan S. The cognitive benefits of interacting with nature. Psychological Science. 2008 Dec;19(12):1207-12.

^[xiv] Kuo FE, Sullivan WC. Environment and crime in the inner city: Does vegetation reduce crime?. Environment and Behavior. 2001 May;33(3):343-67.

^[xv] Department for Culture, Media and Sport. Community Life Survey 2024/25: Loneliness and support networks. See https://www.gov.uk/government/statistics/community-life-survey-202425-annual-publication/community-life-survey-202425-loneliness-and-support-networks#:~:text=9%25%20of%20adults%20reported%20high,24%20(Base:%20All%20adults). Accessed 7 February 2026.

^[xvi] Sugiyama T, Thompson CW. Outdoor environments, activity and the well-being of older people: conceptualising environmental support. Environment and Planning A. 2007 Aug;39(8):1943-60.

^[xvii] Relph E. Place and Placelessness. London: Pion; 1976.

^[xviii] Gill T. No fear: growing up in a risk averse society. London: Calouste Gulbenkian Foundation; 2007.

^[xix] Taylor AF, Kuo FE, Sullivan WC. Coping with ADD: The surprising connection to green play settings. Environment and Behavior. 2001 Jan;33(1):54-77.

^[xx] Jennings V, Johnson Gaither C. Approaching environmental health disparities and green spaces: an ecosystem services perspective. Int J Environ Res Public Health. 2015;12(2):1952–68.

^[xxi] Giles-Corti B, Broomhall MH, Knuiman M, Collins C, Douglas K, Ng K, Lange A, Donovan RJ. Increasing walking: how important is distance to, attractiveness, and size of public open space? Am J Prev Med. 2005;28(2):169–76.

^[xxii] Bowler DE, Buyung-Ali L, Knight TM, Pullin AS. Urban greening to cool towns and cities: A systematic review of the empirical evidence. Landsc Urban Plan. 2010;97(3):147–55.

^[xxiii] Nowak DJ, Crane DE, Stevens JC. Air pollution removal by urban trees and shrubs in the United States. Urban For Urban Green. 2006;4(3-4):115–23.

^[xxiv] Pfrang C. Houseplants purify air, but not as much as you’d think. See https://research.birmingham.ac.uk/en/clippings/houseplants-purify-air-but-not-as-much-as-youd-think/. Accessed 7 February 2026.

^[xxv] Cook DI, Van Haverbeke DF. Trees and shrubs can curb noise, but with quite a few loud 'ifs'. See https://agris.fao.org/search/en/providers/123819/records/647357f553aa8c8963072a11. Accessed 7 February 2026.

^[xxvi] Woodland Trust. Can woods and trees reduce flooding? See https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/flooding/#:~:text=Tree%20roots,tree%20shelterbelts%20than%20adjoining%20farmland. Accessed 7 February 2026.

^[xxvii] Cook BR, Spray CJ. Ecosystem services and integrated water resource management: different paths to the same end? J Environ Manage. 2012 Oct 30;109:93-100. doi: 10.1016/j.jenvman.2012.05.016. Epub 2012 Jun 12.

^[xxviii] Wolf KL, Robbins AS. Metro nature, environmental health, and economic value. Environmental Health Perspectives. 2015 Jan 27;123(5):390.

^[xxix] Bringslimark T, Hartig T, Patil GG. The psychological benefits of indoor plants: A critical review of the experimental literature. J Environ Psychol. 2009;29(4):422–33.

^[xxx] Crompton JL. The impact of parks on property values. Parks Recreat. 2001;36(10):20–8.

^[xxxi] Rook GA. Regulation of the immune system by biodiversity from the natural environment: an ecosystem service essential to health. Proceedings of the National Academy of Sciences. 2013 Nov 12;110(46):18360-7.

^[xxxii] Fuller RA, Irvine KN, Devine-Wright P, Warren PH, Gaston KJ. Psychological benefits of greenspace increase with biodiversity. Biol Lett. 2007;3(4):390–4.

^[xxxiii] Bragg R, Leck C. Good practice in social prescribing for mental health: The role of nature-based interventions. Natural England; 2017.

^[xxxiv] Benedict MA, McMahon ET. Green infrastructure: linking landscapes and communities. Island Press; 2012 Sep 26.

^[xxxv] D’Amato G, Cecchi L. Effects of climate change on environmental factors in respiratory allergic diseases. Clin Exp Allergy. 2008;38(8):1264–74.

^[xxxvi] Ziska LH, Beggs PJ. Anthropogenic climate change and allergen exposure: the role of plant biology. Journal of Allergy and Clinical Immunology. 2012 Jan 1;129(1):27-32.

^[xxxvii] Ogren TL. Allergy-free gardening. Berkeley: Ten Speed Press; 2000.

^[xxxviii] Lindgren E, Jaenson TG. Lyme borreliosis in Europe: influences of climate and climate change. Epidemiol Infect. 2006;134(3):449–58.

^[xxxix] Medlock JM, Hansford KM, Bormane A, Derdakova M, Estrada-Peña A, George JC, Golovljova I, Jaenson TG, Jensen JK, Jensen PM, Kazimirova M. Driving forces for changes in geographical distribution of Ixodes ricinus ticks in Europe. Parasites & vectors. 2013 Jan 2;6(1):1.

^[xl] LaDeau SL, Kilpatrick AM, Marra PP. West Nile virus emergence and large-scale declines of North American bird populations. Nature. 2007;447(7145):710–3.

^[xli] Jorgensen A, Hitchmough J, Calvert T. Woodland spaces and edges: their impact on perception of safety and preference. Landscape and Urban Planning. 2002 Aug 15;60(3):135-50.

^[xlii] Heggie TW, Heggie TM. Search and rescue trends associated with recreational travel in US national parks. J Travel Med. 2009;16(1):23–7.

^[xliii] Jadhav R, Achutan C, Haynatzki G, Rajaram S, Rautiainen R. Risk factors for agricultural injury: a systematic review and meta-analysis. Journal of agromedicine. 2015 Oct 2;20(4):434-49.

^[xliv] Vilà M, Hulme PE (eds). Impact of biological invasions on ecosystem services. Publ. Springer 2017.

^[xlv] Japanese Knotweed Agency. Japanese Knotweed and its impact on property values. Seehttps://japaneseknotweedagency.co.uk/japanese-knotweed-and-its-impact-on-property-values/. Accessed 6 February 2026.

^[xlvi] Chameides WL, Lindsay RW, Richardson J, Kiang CS. The role of biogenic hydrocarbons in urban photochemical smog: Atlanta as a case study. Science. 1988 Sep 16;241(4872):1473-5.

^[xlvii] Vos PE, Maiheu B, Vankerkom J, Janssen S. Improving local air quality in cities: to tree or not to tree? Environmental pollution. 2013 Dec 1;183:113-22.

^[xlviii] Mitchell R, Popham F. Effect of exposure to natural environment on health inequalities: an observational population study. The Lancet. 2008 Nov 8;372(9650):1655-60.

^[xlix] Wolch JR, Byrne J, Newell JP. Urban green space, public health, and environmental justice: The challenge of making cities ‘just green enough’. Landscape and Urban Planning. 2014 May 1;125:234-44.

^[l] Anguelovski I, Connolly JJ, Masip L, Pearsall H. Assessing green gentrification in historically disenfranchised neighborhoods: a longitudinal and spatial analysis of Barcelona. Urban Geography. 2018 Mar 16;39(3):458-91.

^[li] Crompton JL. Measuring the economic impact of park and recreation services. Research Series. 2010. See https://www.nrpa.org/globalassets/research/crompton-research-paper.pdf. Accessed 6 February 2026.

^[lii] Dickinson J, Bennett E, Marson J. Challenges facing green space: is statute the answer? Journal of Place Management and Development. 2019 Mar 4;12(1):121-38.

^[liii] Adams WM. Hutton J. People, parks and poverty: political ecology and biodiversity conservation Conservation and Society. 2007;5(2):147-83.

^[liv] West P, Igoe J, Brockington D. Parks and peoples: the social impact of protected areas. Annu Rev Anthropol 2006 Oct 21;35(1):251-77.

^[lv] Kovats RS, Hajat S. Heat stress and public health: a critical review. Annu Rev Public Health. 2008;29:41–55.

^[lvi] Jonkman SN, Vrijling JK. Loss of life due to floods. J Flood Risk Manag. 2008;1(1):43–56.

^[lvii] Albrecht G, Sartore GM, Connor L, Higginbotham N, Freeman S, Kelly B, Stain H, Tonna A, Pollard G. Solastalgia: the distress caused by environmental change. Australasian Psychiatry. 2007 Jan 1;15(sup1):S95-8.

^[lviii] Gobster PH. Managing urban parks for a racially and ethnically diverse clientele. Leis Sci. 2002;24(2):143–59.