What green infrastructure offers places
Strengthening green infrastructure is fundamentally about making the most of existing assets and it can transform the quality of places.
A strategic approach to the development and management of GI can have a profound effect – not only on the way a place performs, physically and economically, but also the health of those who live and work there.
You get cleaner air
Plants act as natural filters, trapping dust and harmful chemicals, cleaning the air and helping to make towns and cities healthier and less polluted. Roadside trees can trap up to 90 per cent of traffic-related air-borne dust particles.
Better flood protection
The floods of 2007 caused £10 billion worth of property damage and a great deal of misery. As climate change leads to more torrential rainstorms, green infrastructure can protect communities against flash flooding. Trees intercept rainfall and slow the rate of run-off, while parks and gardens serve as sustainable soakaways. A greener city is a more absorbent city.
Cooler cities which can save lives
Living vegetation helps enormously in countering the urban heat island effect. In summer, the cooler air of a shady street or park is noticeably more comfortable. Average UK temperatures are predicted to rise by as much as 4°C this century but research by the University of Manchester shows that 10 per cent increase in the urban tree canopy cover would cancel out this increase. Across Europe more than 35,000 people died in the 2003 heatwave. For older people and the very young, green infrastructure could be a lifesaver.
More local food
Green infrastructure helps to encourage a healthier, more localised lifestyle. Allotments, domestic gardens and community orchards all play a valuable role, perhaps most importantly through increasing awareness of food issues, although Middlesbrough actually aims to be self-sufficient through its own food growing project. There are already a quarter of a million allotments in the UK, but 100,000 people are on waiting lists.
Sustainable waste management and renewable energy
There is growing interest in the role that green infrastructure can play in waste management. Using natural biological systems for waste, such as mulching with locally produced woodchip and compost, can make the urban environment more self-sustaining.
A number of local authorities are now using biomass as a renewable energy fuel, through harvesting their park and street tree prunings. Public buildings and offices can cut back on the need for air conditioning by using deciduous large canopy trees to shade buildings up to six storeys high.
- Sustainable Places contains advice about green infrastructure for people working in local authorities. The site cuts through the complexities of the climate change debate to provide expert advice, offer clear priorities for action and describe good practice in sustainable urban design and management.
Improved public health
New research using the health records of 350,000 people in the Netherlands found that city dwellers living near parks are healthier and suffer fewer bouts of depression. The effect of green surroundings was greatest for people with low levels of education and income. In urban zones where 90 per cent of the area was green space, the incidence of anxiety was 18 people per 1,000. In areas with only 10 per cent greenery, it was 25 per 1,000.
Critical support for biodiversity
Nationwide wildlife surveys by the RSPB and others confirm that urban green infrastructure is now critical for biodiversity, with species such as hedgehogs, frogs, songbirds and butterflies thriving in the leafier parts of towns and cities. Viewed from above, mature neighbourhoods appear as urban forests, with gardens and other open spaces mimicking woodland glades. Streams, canals and rivers link them together to form a rich mosaic of wildlife habitats and these complex urban ecosystems make a very significant contribution to nature conservation.
A sustainable economy
In Living for the city, a new agenda for green cities, the Policy Exchange highlighted an unexpected strong relationship between three key policy areas: greater participation in community action and local decision making; greener, healthier and safer city environments; and improved economic growth.
A green, healthy environment often goes hand in hand with commercial and economic success. The most prestigious offices, the most expensive hotels and the most profitable industrial headquarters tend to be located in the leafiest part of town, and successful managers often invest generously in planting.
Grey vs Green
- £7.2 billion total local authority spending on highways, 2008/09
- £1.1 billion total local authority spending on parks and open spaces, 2008/09
Well-planned improvements to public spaces in town centres can boost commercial trading by up to 40 per cent. High-quality green spaces increase residential property values by 5–7 per cent over identical properties in the same area.
There are obvious green space job opportunities. These lie in parks and public open spaces and range from allotment officers and green keepers to park rangers and ecologists as well as linked occupations such as sport officers and streetscene managers.
But the employment potential of green infrastructure is even greater. Wetlands for flood defence require skilled bio-engineering. From green roofs to sustainable waste and water management, technological development will require new skills for design, manufacturing and construction. All these emerging job opportunities need to be identified, and the training and resources provided to exploit this potential.
Sustainable Places contains advice about green infrastructure for people working in local authorities. The site cuts through the complexities of the climate change debate to provide expert advice, offer clear priorities for action and describe good practice in sustainable urban design and management.
A beautiful, well designed place
Now is the time to revisit our model of creating world class garden cities. When green infrastructure becomes the driving principle behind urban design, it changes how a place feels to live in. It makes places more beautiful and interesting and distinctive.
Every place has a spirit. And the spirit of a place derives as much from the way a place is thought about or used as it does from its physical aspects. We should learn to understand and feel what gives a place its unique character and identity. Not least
because that allows us to feel a part of the place we are in.
Dan Pearson, landscape architect of the 2009 Stirling Prize winning Maggie's Centre, London, and columnist for The Observer