“The valuable contributions from eftec and the Centre for Ecology and Hydrology (CEH) for their initial urban accounts scoping study and their extended work on the valuation of noise mitigation and urban cooling are also gratefully acknowledged.” ONS
The headline messages from the UK Urban Natural Capital Accounts published today, 12 July 2018 are that:
- On average, almost a third of urban area in Great Britain consists of natural land and green space.
- There are over 62,000 urban green space sites in Great Britain adapted for a specific function e.g. public gardens and parks.
- This urban natural land and green space provides society with many services including protecting urban properties from noise pollution and cooling cities by over half a degree Celsius.
- Proximity to natural land and green space can influence property values as premiums are paid for a nice view or easy access to a local park. The value associated with living near a green space is estimated to be just over £130 billion in the UK.
The account shows the significant value provided by the UK’s urban woodland in terms of improved amenity and health outcomes due to noise mitigation. The benefit is estimated on the basis of reduced road noise, the avoided loss of sleep as a result and associated health benefits. Depending on the method used, the present value of this benefit over 100 years ranges from £780 million to £2.168 billion.
The methods used are innovative and experimental appraoches to modelling noise mitigation for valuing urban natural capital. It is a considerable improvement on ecosystem service assessment approaches to date. However, by necessity it differs from conventional noise modelling approaches which use much more sophisticated models, with an associated time and computational cost. In future, the noise mapping commissioned by central and devolved governments could be adapted to include vegetation effects.
The cooling effect in 11 city regions is shown in aggregate, and broken down by greenspace and bluespace feature. The combined average cooling effect is relatively stable across city regions, between 0.63 and 0.88 degrees Celsius. For all city regions, greenspace provides greater overall cooling than bluespace but, the relative contribution of woodland, parks and grassland, and gardens varies between them. The present value of this benefit in the 11 cities over 100 years is around £11 billion.
The cooling effect is monetised on the basis of cost savings from air conditioning and the avoidance of labour productivity loss due to heat. The cost savings from air conditioning are calculated based on a value found in the literature for London; a corresponding value is then applied to each city region based on the relative proportion of their air conditioned floorspace to London’s. The avoided loss of labour productivity is monetised as the GVA that would have been lost due to additional heat stress in the absence of the cooling effect.
11 city regions included in the analysis are: Cardiff, Edinburgh, Glasgow, Greater Manchester, Liverpool, London, Sheffield and the city regions of North East, West Midlands, West of England and West Yorkshire.