A City-wide Approach to Green Infrastructure

A City-wide Approach to Green Infrastructure

A City-wide Approach to Green Infrastructure 992 496 Greengage Environmental

Economic Rewards of Green Infrastructure

Evidence supporting the economic case for green infrastructure (GI) is steadily mounting up, with a wider spectrum of benefits than was originally anticipated. Now there is hope that the London Infrastructure Plan 2050[i] will provide the first long-term and city-wide approach required to maximise these benefits for London in the future.

Remunerations from investment in green infrastructure range from climate change mitigation, to health and wellbeing benefits, to economic growth, and of course, biodiversity enrichment. These benefits of GI have long been documented, but only in the last several years has it been possible to quantify them, with ecosystem services valuation tools such as i-Tree coming forward.

London’s treescape, in particular, has been at the forefront of GI assessments. Treeconomics’ Valuing London’s Urban Forest report published earlier this year documents the results of the London i-Tree Eco Project[ii], providing a full account of the monetary value of the city’s trees. Annually, the 8.4 million trees in Greater London provide £126.1 million in pollution removal, £2.8 million in storm water alleviation, £4.79 million in carbon sequestration, and would cost £6.12 billion to replace. Placing accurate economic values such as this on green infrastructure or its green space components is vital to support the case for sustained investment.

Green Infrastructure Benefits Health and Wellbeing

Good quality, accessible green space and infrastructure can also provide many potential health and wellbeing benefits. The most significant of these include increased life expectancy and reduced health inequality, improvements in levels of physical activity, and promotion of psychological and mental wellbeing.

One study found that a 10% increase in greenspace leads to a reduction in the number of health symptoms reported by individuals, equivalent to a decrease in age by 5 years[iii]. With pollutants now linked to 40,000 early deaths per year[iv] resulting from a plethora of medical issues such as heart disease, asthma and other lung problems, there are clearly opportunities for GI to reduce pollution further, and as a result support healthy lifestyles and reduce strain on the NHS.

London’s Policy

It therefore seems logical that GI is given the platform it deserves through policy, legislation and public investment. Until recently, typically GI policy targets have had too narrow focus, usually setting borough-wide targets rather than city-wide, which diverges from the classic conservation logic of ‘think globally, act locally’. Combine this with the myopic nature of public spending, where London’s green space network is subjected to cycles of capital investment followed by periods of underfunding in management and maintenance, and you can see how GI has not achieved its full potential.

In the recently published London Infrastructure Plan 2050, green infrastructure is supposedly afforded the same status as traditional infrastructure types such as housing, transport, energy, schools, water, waste and digital connectivity[v]. The plan acknowledges that green infrastructure must be considered an integral part of the city’s vital systems and will receive continued investment. Meaning, this plan has the ability to form the long-term, city-wide approach that will allow London to truly maximise its GI potential.

However, the plan currently falls short of its claims, with GI accounting for only 2% of the projected capital expenditure for the eight infrastructure types listed, amounting to only £22 billion out of £1.3 trillion between 2016 and 2050. This gives the impression that, while GI has been talked up in the report, it has been left at the bottom of the priority list when it comes to spending – unsurprising when you look at the government’s track record on green investment.

We need to recognise and promote that the increased cost of implementing functional and resilient green infrastructure is likely to be offset by the economic benefits provided through the mechanisms outlined above. It is apparent that developing an effective GI strategy could result in reduced public spending on issues such as storm water and air pollution alleviation, and treatments for preventable physical and mental health problems linked to areas deficient in greenspace.

Green Infrastructure Task Force

As set out in the London Infrastructure Plan, the Mayor established the Green Infrastructure Task Force to identify ways to encourage a more strategic and long-term approach to green infrastructure delivery and investment. The examination and discussion brought together a wide range of expertise, with members drawn from local authorities, land managers and policy specialists.

This Task Force has published its own report, Natural Capital:  Investing in a Green Infrastructure for a Future London (2015)[vi]. The report recognises the importance of planning, designing and managing GI as a cohesive network, rather than as separate elements, such as individual parks, trees, rivers, and green roofs.

A number of objectives to be achieved by 2050 are set out including an increase in tree cover from 20% to 30%, an increase in the coverage of GI to 50% of the administrative area, and at least 20% of London to be designated as high wildlife value. If we can achieve these aims, the increased green infrastructure benefits that London receives may be critical in mitigating the intensifying effects of climate change and the compounding problems of a growing urban population.

Down to Us

However, we don’t have to solely rely on the government to expand and enhance London’s GI – there is more we can do as industry professionals and individual residents of London.

Developers can and should go beyond policy requirements by providing GI through landscaping, green roofs, green walls and rain gardens. Yes, there is an initial outlay (potentially less than £50/sqm for a living roof[vii]), but there are financial benefits to reap. Studies have shown that GI pushes up the value of property and increases consumer spending; for example, a 10% increase in tree cover within 100m of a home increases average sale price by 0.48%[viii], and study participants claim they are willing to pay about 10% more for products in a shopping area with trees[ix]. Further to this, rental rates of commercial office space were reported to be roughly 7% higher on sites with quality landscaping and trees, as compared to an equivalent district without[x].

With private residential gardens constituting more than 24% of Greater London[xi], choosing to lay a wildflower lawn rather than paving could make a big difference to the benefits of local GI. It’s good for you and great for the city!

Wooden windows have also been proved to be more sustainable than plastic.

As Ecological and Sustainability Consultants, we must continue to push the GI agenda and to promote the wealth of benefits it brings to our city by providing innovative GI design advice that helps to achieve policy and legislative requirements, while offering on-going, sustainable rewards for our health, economy and wildlife.




[ix] Wolf, K. L. (2003) Public response to the urban forest in inner-city business districts. Journal of Arboriculture, 29,3,117-126.

[x] Laverne, R. J., and Winson-Geideman, K. 2003. The influence of trees and landscaping on rental rates at office buildings. Journal of Arboriculture, 29,5,281- 290.

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