The third in a series of posts on natural capital and mental health, guest blogger Dr Lindsay Walker explores how urban green space and planning can impact on the mental health of residents.

More than 50% of people currently live in urban areas, with the global urban population projected to be over 75% by 2030. Although there are benefits to living in an urban environment, urbanisation has been linked to increased levels of mental health issues. There is growing evidence that exposure to green spaces can be used as mental health interventions, likely via stress relief (see previous blog entry ). These restorative effects are more complex than just the increased physical activity of residents with nearby parks; in fact  the benefits have been shown to be largely independent of whether people go for walks or not.

Given that 65% of the urban area likely to be required by 2030 has not yet been developed, this presents a major opportunity to create planning regulations that will cultivate healthy living places for now and into the future.

So what evidence might be the foundation for regulations involving green infrastructure in urban developments? What might our future urban green spaces look like?

Urban green space needs to be close to residents

Recent evidence highlights that distance to a green space is an important consideration for incentivising users; people are more likely to visit urban green spaces if they are nearby. Moreover, greater mental health benefits are reported by the most frequent users. Although studies in Australia and America show that low-income neighbourhoods tend to have lower green space availability, where green space is available socioeconomic position does not affect the frequency of use. This suggests that providing more green space in strategic urban locations may help reduce socioeconomic health inequalities. Indeed, individuals in deprived communities with a greater percentage of green space also show physiological signs of being less stressed. Planning regulations involving distance to urban green spaces are imperative to ensure access to this important public health resource. In 2008 Bristol City Council developed accessible green space standards, one of which proposed that residents needed to be within 700m/18 minutes’ walk of natural green space to ensure it is reasonably accessible.

Urban green space needs to be multifunctional

Urban green spaces need to be multifunctional for two key reasons. First, inter-personal differences (such as age, gender, culture) have been shown to impact how people interact with green space. For example, the motivations to visit a green space change as we age; children prefer playing and interacting with the natural environment, whereas older people enjoy green spaces for contemplation. By incorporating multifunctional design features, urban green spaces will be able to serve and attract a wider section of society.

Second, green infrastructure can help mitigate the effects of climate change. Vegetated surfaces have been shown to intercept and store water, thereby reducing the likelihood of flooding. As climate change is likely to induce wetter winters in the UK, green spaces in urban developments could reduce the volume of rainwater run-off. Planning regulations involving urban green space may need to specify recommended flora structure for maximum water retention, for example the planting of trees at strategic locations, as well as being designed for use by visitors. By ensuring that urban green spaces are multifunctional (supporting health benefits and climate change mitigation), there will be maximum population benefit for public expenditure.

Urban green space needs to be (or appear to be) biodiverse

Recently, research has started to focus on understanding the impact of type and quality of natural environments on mental health, and it has been found that higher densities of different greenspace types are associated with a higher prevalence of good health. For biodiversity, it is the perceived species richness of a green space that positively impacts on human wellbeing (although there is suggestive, yet inconclusive, evidence that biodiverse natural environments may promote better health). Moreover, it has been shown that urban green space users are willing to pay for biodiversity enhancement, with people who are willing to pay more than average for species richness also reporting higher wellbeing scores for visiting these green spaces. One method for enhancing both perceived and actual biodiversity is to employ less intensive management practices of urban green spaces such as infrequent or no mowing of grass. Introducing wildflower meadows to urban green spaces provides three-fold benefits: (1) an increase in biodiversity, particularly supporting pollinators, (2) human health and wellbeing improvements, either through perceived or actual higher levels of biodiversity, and (3) substantial savings for the local authorities. For example, Burnley’s “Go to the Park” permaculture project saved nearly £70,000 in the first year of operation due to utilising such lower-maintenance practices. Future urban development regulations may need to consider the inclusion of recommendations for managing green infrastructure so to maximise human health and wellbeing benefits.

Urban green space may need to have multi-source funding 

Local authorities funding has recently come under pressure, with park departments facing 60% or more budget cuts and losing both skilled management and frontline staff. Funding sources may therefore need to diversify to maintain the availability of urban green space. Businesses located close to parks may be one source of alternative funding: by accessing workplace green space, employee stress levels are reduced (directly for males and indirectly for females by increasing positive workplace attitudes). Green spaces also indirectly impact human health and wellbeing through improving air quality and limiting the impact of heatwaves, which can reduce employee sick days and lead to a more productive workforce. There may therefore be potential for local businesses and councils to work in partnership to maintain urban green spaces despite public spending cuts. For example, Darlington Borough Council receives a return on investment of £1.70 of improvements for every £1 spent on a corporate volunteer programme. Future urban green space development may need to publish a framework for guidance for such partnerships.

As the number of people living in an urban environment is projected to increase, it is of paramount importance that urban green spaces are protected, maintained, improved and expanded to ensure maximum exploitation of population health and wellbeing benefits. Future urban development needs to prioritise the inclusion of multi-functional green spaces that maximise proximity to residents.  This may potentially need diverse funding solutions to maintain access to this important public health resource.  Such evidence-based recommendations could be included in a modified National Planning Practice Guidance.