The green infrastructure valuation toolkit user guide

Building natural value for sustainable economic development: The green infrastructure valuation toolkit user guide
Adapting cities for climate change: the role
of green infrastructure. Gill, Handley et al,
2007
Evaluating Green Roof Energy
Performance. Jeffrey Sonne, Ashrae
Journal 2006
Carbon stored and sequestered in
woodland and forest (including soils)
Carbon storage and sequestration in soils
Key benefit transfer values
Average heating energy savings per tree
Further research needed
c.10tC/ha for grassland - further research
needed
1.3% (Chicago)
3-9% (UK)
emissions if natural gas was the heating fuel. This study also suggests that the
benefit would be more significant in buildings with curtain walls of which U-value
is much lower than a standard wall and in residential buildings.
Further work is needed to provide useable values for the carbon stored in
different land use types, including soils. This is very complex and context-specific
– there is great variety in soil type and usage, and hydrology, climate and ecology
are important factors. It is unrealistic to expect highly accurate estimates to be
possible for all land-use types, but it should be possible to obtain better ‘ball park’
figures for broad groups.
4 Wong N. et al, 2003. Investigation of thermal benefits of rooftop gardens in the tropical
KNOWLEDGE GAPS
The main area for further work is clarification of the current research - to bring
together a consistent view on the science - and work to link temperature rises on
economic activity, measured by gross value added. Coupled with work cited here
on using green infrastructure to adapt to climate change, this would allow an
estimate to be made of the gross value added impact of urban greening
strategies, influencing green roofs, tree planting and green space
protection/enhancement.
Further work is also desirable to model local impacts of green infrastructure on
local temperature regulation in the UK, to inform tree planting strategies in
relation to species type, location, scale of planting and so on.
UK based evidence on the cooling impact of trees on buildings could help
complete tool 1.5. A number of bespoke academic studies have also been
undertaken in the UK and elsewhere assessing the cooling impact of trees on
particular buildings, however it is difficult to generalise findings:
The Centre for Urban Forestry Research (part of the US Forest Service, a USDA
agency) reports that well placed, mature trees can save consumers up to 30% of
annual cooling costs and save 10-25% of energy used for heating 20 .
Royal Institute of Chartered Surveyors sponsored research 21 finds that based on
the typical UK climate, the savings on energy costs from green roof installation
are negligible, with the energy savings possible with a 10cm deep green roof
capable of being delivered with just 3mm extra insulation.
Another study 22 predicted 4.45% annual heating energy savings for a typical
office building in Scotland, equivalent to a reduction of 400 kg of annual CO2
environment. Building and Environment 38: 267-270.
5
Nowak, McPherson and Rowntree, Chicago’s urban forest ecosystem: results of the
Chicago urban forest climate project, USDA,1994
6
Gill, Handley et al, Adapting cities for climate change: the role of green infrastructure, 2007
7
Rawlings for DETR, Environmental rules of thumb, 1999
8
Gill, Handley et al, Adapting cities for climate change: the role of green infrastructure,
2007
9
Jacobs, Valuing England’s terrestrial ecosystems services, 2008
10
Natural England, Research report NERR026: Carbon management by land and marine
managers, 2008
11
Brainard, Lovett and Bateman, Carbon sequestration benefits of woodland, 2003
12
Nowak, McPherson and Rowntree, Chicago’s urban forest ecosystem: results of the
Chicago urban forest climate project, USDA,1994
13
Defra, Safeguarding our soils, 2009
14
Macha, D., and L. Cihacek.. Carbon storage in plant and soil components of selected
grass monocultures. AnMtgsAbsts2009.53321. ASA, CSSA, SSSA, Madison WI, 2009
15
Chang et al, 2007 "A preliminary study on the local cool-island intensity of Taipei city
parks." Landscape and Urban Planning 80(4): 386-395.
16
Yu and Hien, 2006, Thermal benefits of city parks. Energy and Buildings 38, 105-120.
17
Heisler, Energy savings with trees, 1986 and Jones (2003) cited in Landscape
consultants (2004)
18
Forestry Commission
25