Climate-proofing cities using urban greenspace
Submitting InstitutionUniversity of Manchester
Unit of AssessmentBiological Sciences
Summary Impact TypeEnvironmental
Research Subject Area(s)
Earth Sciences: Atmospheric Sciences, Physical Geography and Environmental Geoscience
Engineering: Geomatic Engineering
Summary of the impact
Urban greenspace cools cities and reduces rainfall runoff but these
effects have been difficult to
quantify. Ennos's research is the first to give realistic figures for the
contribution of greenspace and
assess its potential to climate-proof cities. Key research findings have
furthered the concept of
green infrastructure, influenced local and national planning policy [text
removed for publication].
Novel mapping tools developed by Ennos have had international impact,
including use in the city
master plan for Addis Ababa, Ethiopia. Community forests have altered
their planting practises as
a result of Ennos's research findings.
The impact is based on research that took place at the University of
Manchester from 1999 to
2013. The key researchers are:
Dr Roland Ennos (Reader, 1999-2013)
Professor John Handley (1999-2010)
Dr Sarah Lindley (Lecturer, 2003 to date)
Dr Stefan Pauleit (Lecturer, 2003-2006)
Ms Victoria Whitford (MSc Student, 1999-2000)
PhD students: Dr Susannah Gill (2003-2007), Dr David Armson (2008-2012),
Mr Asrafur Rahman
(2009 to date)
The overall aim of the research was to quantify the physical benefits of
urban greenspace. The first
stage (1999-2007) was to customise theoretical models of the surface
temperature and hydrology
of urban areas , and the data were then used to investigate the effect
of environmental change
in Merseyside . Handley and Ennos led the project and supervised or
postgraduate students listed above. Collaborators were Oxford Brookes
investigated the effects of cooling on human comfort and Southampton
University who specifically
Ennos selected and customised models for use in the UK, including:
Surface temperature model to predict mean maximum and minimum
from meteorological and land cover data
Hydrology model that estimates runoff coefficients based on the
built environment, soil type
Diversity model based on the total area of greenspace and
Geographic Information Systems (GIS) and aerial photograph interpretation
was used to map
greenspace across Greater Manchester. The information was input into the
models to map surface
temperature and runoff across the city, both for current climate and for
future climates  as
predicted by the UK Climate Impacts Program. The research also
investigated the likely effect of
changes to greenspace .
Key datasets were developed including Urban Morphology Typology (UMT)
units that characterise
the urban environment . The UMT units combine biophysical
characteristics with other features
that are relevant to planning to provide a robust geographical outline of
neighborhoods that can be
used for analysis, assessment and planning.
The key advances were:
- Mapping the extent of greenspace over a complete city . This is the
first time that a whole city
has been mapped and provides a unique opportunity to quantify the
of greenspace in reducing the urban heat islands and preventing surface
- Specific recommendations, based on modelling data were;
- A 10% increase in Manchester city centre greenspace would reduce
by 4°C, climate proofing the city until 2080. It would also reduce
rainfall runoff by 7%,
helping to prevent urban flooding .
- Adding green roofs to buildings can have a dramatic effect in reducing
- Greenspace is most effective at reducing surface runoff on sandy
Research from 2008 to 2013 was experimental and aimed at investigating
the actual local
environmental effects of trees and other greenspace.
The key findings were:
- In hot weather, trees can reduce the Physiological Effective
temperature (and so cool people)
by 7°C  and cool surfaces by up to 20°C .
- To maximise growth rate and cooling properties, trees should be
planted in urban soils rather
than in grass verges .
- Trees reduce surface runoff by 60% in rain storms.
References to the research
The research has been published in leading journals in the field, with
most papers in the leading
planning journal Landscape and Urban Planning. Paper 3 won the
DCLG Planning Research
Network Prize Paper Competition in 2007.
1. Whitford, V.L., Ennos, A.R, Handley, J.W. (2001) "City form
and natural process" — Indicators
for the ecological performance of urban areas and their application to
Landscape and Urban Planning. 57. p. 91-103. DOI:
2. Pauleit, S., Golding, Y.C., Ennos, A.R. (2005)
Modeling the environmental impacts of urban
land use and land cover change — a study in Merseyside, UK. Landscape
and Urban Planning.
71. p. 295-310. DOI: 10.1016/j.landurbplan.2004.03.009
3. Gill, S., Handley, J.F., Ennos, A.R., Pauleit, S. (2007).
Adapting cities for climate change: the
role of the green infrastructure. Built Environment. 33. p.
97-115. DOI: 10.2148/benv.33.1.115
4. Gill, S., Handley, J.F., Ennos, A.R., Lindley, S., Theuray,
N., Pauleit, S. (2008).
Characterising the urban environment of UK cities and towns: a template
planning. Landscape and Urban Planning. 87. p. 210-222. DOI:
5. Rahman, M.A., Smith, J.G., Stringer, P., Ennos, A.R.
(2011). Effect of rooting conditions on the
growth and cooling ability of Pyrus calleryana. Urban Forestry
and Urban Greening. 10. p. 185-192.
6. Armson, D., Stringer, P., Ennos, A.R. (2012). The effect of
tree shade and grass on surface
and globe temperatures in an urban area. Urban Forestry & Urban
Greening. 11. p. 245-255.
Details of the impact
Lack of urban greenspace can lead to problems such as urban heat islands
and flooding. Before
this research, most climate prediction models answered very specific
questions and required high
level input. This research enabled the development of accessible and
easy-to-use tools that
planners can use to design urban greenspace intelligently and has informed
policies on a local,
national and international scale.
The work is at the boundary between scientific research, policy making
and adaptation practice,
bringing together the organisations and people responsible for addressing
the challenges that
climate change will bring.
Pathways to impact
- Customised models have been made publically and freely available
online as STAR tools:
Surface Temperature And Runoff tools for assessing the potential of
green infrastructure in
adapting urban areas to climate change. The site had 610 unique visitors
from 351 different
organisations in the period 1st Feb - 22nd Oct
2012 [text removed for publication] with other
international visitors from Singapore, Germany, Japan and Brazil.
- Meeting with stakeholders, seminars and talks across the UK and Europe
by the research team
led to the widespread dissemination of the research.
Reach and significance of the impact
Influencing international planning:
- The UMT approach has been adopted in five African cities including
Saint Louis (Senegal),
Addis Ababa (Ethiopia), Dar Es Salaam (Tanzania), Douala (Cameroon) and
(Burkina Faso). In Addis Ababa in particular, the UMT dataset has
already helped the effective
engagement of local stakeholders and is to form the foundation of the
city's new Master Plan
(May 2013). [text removed for publication] [A].
- In terms of the importance of urban vegetation for aesthetics and
biodiversity, Whitford et al 
was cited in the proceedings of the Ecocity World Summit 2008 [B]. This
is a cross-disciplinary
World Summit on Sustainable Cities, supported by the non-profit
organisation, Ecocity Builders,
who aim to reshape cities for the long-term health of human and natural
Builders are a global network that works in partnership with the United
Nations to develop and
implement policies on a global scale.
Informing national policy:
- The Forest Research report to the Department for Environment, Food and
(DEFRA) and the Department for Communities and Local Government (DCLG),
of green infrastructure' [C] cites data from Whitford et al 
and Gill et al . This report
examined how the policy objectives of DEFRA and DCLG could be supported
evaluation of scientific literature. Whitford et al  is cited under
`hydrological benefits' of
greenspace and Gill et al  is cited under `heat amelioration' and
`sustainable urban drainage'
as `environmental benefits' of green infrastructure.
- Following on from the Forest Research report to DEFRA and the DCLG
[C], the DCLG
produced a National Planning Policy Framework [D].
- The 2012 guidance document produced by CIRIA (Construction Industry
Information Association), `The benefits of large species trees in
urban landscapes' [E], was
influenced by the findings of Gill et al  in terms of `costing,
design and management'. Users of
the guidance document include developers, local authorities, planners,
landscape architects and arboricultural managers.
Informing the planting practices of community forests:
- In collaboration with partners, Community Forests North West, research
planting conditions for street trees is being widely disseminated to the
and architecture community. [text removed for publication] [F].
Influencing policy and securing funding for tree planting in
- [text removed for publication] [G] [H].
Informing the Manchester Climate Change Action Plan:
- Ennos's research has influenced the strategy of local governments in
the North West. The 2009
Manchester Climate Change Action Plan [I], published by Manchester City
models to show the maximum surface temperature in Greater Manchester
from 1970-2080, with
reference to Gill's PhD thesis.
- Research findings were incorporated into the Greater Manchester
Climate Strategy for 2011-2020
[J] under the action `Green and Blue Infrastructure'.
Sources to corroborate the impact
A. Letter from Greenspace Planning Expert, Addis Ababa City Planning
corroborating use of data in the Addis Ababa city master plan.
B. Ecocity World Summit 2008 Proceedings. Ecological Engineering, Green
Roofs and the
Greening of Vertical Walls of Buildings in Urban Areas.
C. Forest Research (2010). Benefits of green infrastructure.
Report to DEFRA and DCLG:
D. Department for Communities and Local Government (DCLG) National
Framework, March 2012: http://www.communities.gov.uk/publications/planningandbuilding/nppf
E. CIRIA (2012). The benefits of large species trees in urban landscapes:
a costing, design and
F. Letter from Forest Director of Red Rose Forest, corroborating uses
of research data.
G. Statement from Transport for London Press Office, verifying the
tree planting strategy for
H. Email from Route Manager for Arboriculture and Landscape at Transport
corroborating that data led to increased tree planting.
I. Manchester. A Certain Future. Our co2llective action on
climate change. Manchester Climate
Change Action Plan.
J. Association of Greater Manchester Authorities (AGMA), Greater
Manchester Climate Strategy
for 2011-2020: http://meetings.gmwda.gov.uk/mgConvert2PDF.aspx?ID=8975