Birdwatch News Archive
Trees, like this ancient oak in Richmond Park, Surrey/Gtr London, are a lifeline for the wildlife and, it seems, the economy of cities. Cristian Bortes (commons.wikimedia.org).
Trees benefit urban wildlife and economy
Posted on: 03 May 2012
Those worrying about the seemingly ever-decreasing number of trees in our cities being bad for people and wildlife are right to be concerned, new research shows.
Putting green infrastructure such as parks, gardens and trees at the heart of neighbourhoods can bring significant economic benefits, according to a Natural England study. Far from being an expensive luxury in difficult economic times, devoting areas of towns and cities to nature can actually bring important savings for the public purse.
The findings come from a comprehensive review by Natural England of a number of studies into the economic value of green infrastructure. The year-long assessment by Tim Sunderland, an economist at Natural England, confirmed that:
• People are prepared to pay 19 per cent more for homes near a park;
• People with good access to green space are 24 per cent more likely to be physically active;
• A 10 per cent increase in green space in a city like Greater Manchester could prevent a temperature rise of more than 3° C.
The evidence contained in the studies suggests that a range of economic benefits can be gained by planning for the needs of pedestrians, cyclists and wildlife in our urban communities. Firstly, people value green infrastructure and will pay a premium for it. Research in Aberdeen found that people were willing to pay up to 19 per cent more for a property on the edge of a park than one 450 m away. Furthermore, London’s house prices increase with the amount of green space in a ward, roughly equating to a 0.4 per cent increase in price for each 1 per cent increase in the amount of green space.
Secondly, peer-reviewed research shows that people living in areas with more green space tend to be healthier, both physically and mentally, even after accounting for the tendency of wealthier people to live in more attractive areas. One study in Sweden found that use of green space reduced self-reported stress in the long term. In Britain, lack of exercise is estimated to place a huge burden on the economy of around £8.2 billion a year; research suggests that people are 24 per cent more likely to be physically active if they have good access to green space.
Another health benefit of green infrastructure stems from the improvement in air quality. It is estimated that poor air quality leads to an average life expectancy reduction of 7-8 months in Britain. Urban trees and green space help to intercept the particles which cause the pollution. Research in east London found that planting up 5 per cent of an area measuring 100 km² would prevent two deaths a year and two hospital admissions.
Green infrastructure has also proved attractive to city planners because of the ways it can help save money at a city scale. In New York money was invested in protecting the main water catchment area instead of building a traditional filtration plant. Although this cost the city $1.5 billion over ten years, it avoided capital costs of $6 billion for a new filtration plant and annual running costs of $300 million.
Cities can also use green infrastructure to prepare for the challenge of climate change. Concrete and other hard surfaces retain heat much more than trees, plants and grass, which substantially increases heat-wave health risks for urban populations. Modelling at the University of Manchester showed that current maximum temperatures in the city centre of 27.9° C were projected to increase by up to 3.7° C by the 2080s. However, they could be kept close to the current maximum by a 10 per cent increase in the green cover in the area. Conversely, if 10 per cent of the green cover were removed, temperatures in Manchester could be 7-8°C warmer.
With the effects of global warming becoming ever more apparent, drought is now a growing threat to south east Britain, amplified by an increasing population. Green roofs and water butts capturing water for later use will become increasingly valuable. Rain gardens – where plants, soil and gravel are designed to regulate the flow into the water table – and permeable pavements, which avoid run-off by allowing water to soak through, will play an important role in protecting the local water table.
Tim Sunderland, who led the assessment known as MEBIE (Micro-Economic Benefits of Investment in the Environment Review), said: “We believe the evidence is increasingly clear that providing good quality green space in our towns and cities can have significant economic benefits. It can promote investment, improve people’s health and protect our urban communities from the worst effects of climate change – all of which translate into millions of pounds of savings for the public purse.”
The MEBIE Review is now available from the Natural England website.
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