Critical Overview: Access to Nature and its Link with Mental Health
The coronavirus pandemic has highlighted the importance of green spaces for city dwellers’ mental health and well-being. Ecologists and psychologists are currently investigating the complex effects of nature on human mental health, revealing that access to nature is dwindling in an increasingly urbanized world, with socio-economically deprived people facing the most significant barriers. Building green urban spaces has the potential to boost human well-being, alleviate social inequality and foster biodiversity.
Human beings have only recently become a majority-urban species, with projections indicating that nearly 70% of the population will be urban dwellers by 2050. This relatively late arrival into cities may help to explain our affinity with nature and green spaces. The biologist Edward O. Wilson’s “biophilia” hypothesis argues that the environment in which humans evolved has shaped our brain, priming it to respond positively to cues that would have enhanced our ancestors’ survival, such as trees, savannahs, lakes, and waterways.
Research has shown concrete links between increased exposure to nature and not only improved physical health but also better mental health. Mental health issues account for a significant proportion of all years lived with disability, with depression, anxiety, and mood disorders being some of the most common psychological conditions. Studies show that access to nature can improve sleep and reduce stress, increase happiness and reduce negative emotions, promote positive social interactions and even generate a sense of meaning to life. Being in green environments can boost various aspects of thinking, including attention, memory, and creativity.
However, identifying the optimal nature exposure for an individual prescription is complicated. Nonetheless, some places, such as the UK’s remote Shetland Islands, are now prescribing nature-based activities like birdwatching and beach walks to treat mental health conditions and physical illnesses such as heart disease and diabetes. Other interventions used globally to improve health and well-being include organised gardening programmes and forest bathing.
The reasons behind nature’s positive impact on mental health are still unclear. One possibility is that urban vegetation benefits people’s physical health by absorbing harmful airborne particulates and other pollutants, improving mental health in this way. Exposure to pollutants can damage the central nervous system and is linked to certain mental health conditions like depression. Urban vegetation also helps mitigate noise pollution, which causes stress and sleep disturbance.
Another possibility is that the mental health effect is mediated via physical health, with urban residents living near green spaces more likely to take more exercise, improving their mental health as a result. However, most research suggests that visiting green spaces is less associated with physical exercise than with sedentary social activities, such as picnicking. Socializing can reduce loneliness, anxiety, and depression, and being part of a supportive community is good for mental health. Research shows that attractive public spaces are catalysts for building cohesive neighborhoods.
Recent research in Switzerland found that merely having a view of nature from one’s home can reduce the perception of noise. Attention restoration theory hypothesizes that such effects are entirely psychological. Conclusion: Building green urban spaces could help to alleviate the social inequality arising from dwindling access to nature, while promoting human well-being and biodiversity. Further research is necessary to determine precisely how nature affects human mental health and well-being and identify the optimal nature exposure for a prescription.
he relationship between access to natural space and mental well-being is gaining recognition. Research in the field is becoming increasingly relevant to urban design worldwide. Throughout history, urban planners have looked to nature for inspiration. During the Covid-19 pandemic, city-dwellers across the world found parks and gardens, where they exist, an unexpected source of calm and joy. Psychologists and ecologists studying the effects of nature on mental health and well-being are uncovering complex links that are not yet fully understood. The pandemic highlighted these links, but also exposed the fact that, in an increasingly urbanized world, access to nature is dwindling, particularly for socio-economically deprived people. A focus on greening urban spaces could have a positive impact on human well-being, help reduce social inequality, and support biodiversity.
Our species has existed for at least 300,000 years, but the oldest cities are only around 6,000 years old, and only recently have we become a majority-urban species. Projections suggest that by 2050, almost 70% of people will be urban dwellers. Our late arrival in cities may explain our affinity with nature and green spaces. Biologist Edward O. Wilson proposed the “biophilia” hypothesis in 1984, suggesting that the environment in which humans evolved has shaped our brains to respond positively to cues that would have enhanced survival for our ancestors, such as trees, savannah, lakes, and waterways. Evidence over the past few years has shown concrete links between increased exposure to nature and improved mental and physical health.
Mental health issues are estimated to account for around a third of all years lived with disability, and around 13% of disability-adjusted life-years (DALYs) lost, which is similar to the toll of cardiovascular disease and circulatory disorders. Research has shown positive effects from nature, including improved mental health, better sleep, reduced stress, increased happiness, reduced negative emotions, promoted social interactions, and helped to generate a sense of meaning to life. Being in green environments also improves various aspects of thinking, including attention, memory, and creativity, in people with and without depression.
The effects of nature are hard to distil into an individual prescription, but doctors in the UK’s remote Shetland Islands have been prescribing nature-based activities, such as birdwatching and beach walks, since 2018 to treat mental health conditions and physical conditions such as heart disease and diabetes. Similarly, a review in 2019 identified 28 nature-based interventions used in various countries to improve health and well-being.
Urban vegetation can benefit physical health by absorbing harmful airborne particulates and other pollutants produced by fossil fuel-powered transport and industry, and may improve mental health as well. Exposure to pollutants can damage the central nervous system and is linked with certain mental health conditions, such as depression. Urban vegetation also helps mitigate noise pollution, which causes stress and sleep disturbance. However, the effect of nature on mental health may also be mediated via physical health. For example, urban residents living near green spaces may simply take more exercise, which in turn improves their mental health. But most research suggests that visiting green spaces is less associated with physical exercise and more with sedentary social activities such as picnicking. Socializing can reduce loneliness, anxiety, and depression, and being part of a supportive community is good for mental health. Research shows that attractive public spaces are a catalyst for building cohesive neighbourhoods.
Recent research in Switzerland found that simply having a view of nature from home can reduce the perception of noise, and the closer the green space, the bigger the effect. One hypothesis that attempts to explain such effects is Attention Restoration Theory. Ultimately, we need to understand how nature works to maximize its benefits for the world’s legion of nature-deprived city dwellers.