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Transcript of Www.merseyforest.org.uk Green Infrastructure and Climate Change Dr Susannah Gill The Mersey Forest...
www.merseyforest.org.uk
Green Infrastructure and Climate Change
Dr Susannah Gill
The Mersey Forest
www.merseyforest.org.uk
Overview
• Green infrastructure• Climate change• Green infrastructure for adaptation in
urban areas• Policy relevance in the UK• North West Climate Change Action Plan• Conclusions
www.merseyforest.org.uk
Green Infrastructure
• Life support system – the network of natural environmental components and green and blue spaces that lie within and between our cities, towns and villages and provide multiple social, economic and environmental benefits
• http://www.greeninfrastructurenw.org.uk
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Our Climate is Changing
(source: IPCC, 2007)
• Warming of the climate system is unequivocal
• Coherent changes in many aspects of the climate system not just temperature
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Changes go beyond natural variability
Temperature change in last 50 years is very likely (>90% chance) due to increase in anthropogenic greenhouse gas concentrations
(source: IPCC, 2007)
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Global climate change projections
(source: IPCC, 2007)
(rel
ativ
e to
198
0-99
)
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What does this mean for the UK?
• UKCIP02– 4 emissions scenarios– 3 time slices– 50 km outputs (some 5 km)
• UKCIP08– Probabilistic scenarios– 25 km output– Due October 2008
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UK Climate Changes• Average temp increases• High temp extremes increase in frequency• Low temp extremes decrease in frequency• Sea-surface temp warms• Thermal growing season lengthens• Winter precipitation increases• Winter precipitation intensity increases• Greater contrast between summer & winter• Snowfall decreases• Summer soil moisture decreases• Sea-level rises
UKCIP02 High Confidence Levels
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Greater Manchester Average Maximum Summer Temperature
Data from the UK Met Office and UKCIP02
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Greater Manchester Summer Precipitation
Data from the UK Met Office and UKCIP02
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Greater Manchester Winter Precipitation
Data from the UK Met Office and UKCIP02
Baseline (1961-90)
2050s Low emissions
2050s High emissions
2080s High emissions
Manchester(Mean Annual Temp)
Slide courtesy of Mark Broadmeadow
Baseline (1961-90)
2050s Low emissions
2050s High emissions
2080s High emissions
Manchester(monthly mean temp, diurnal temp range & precipitation)
Slide courtesy of Mark Broadmeadow
Matt Cardy/Getty Images
Source: The Guardian website
Daniel Berehulak/Getty Images
Kate Gillon/Getty Images
Source: Stott et al, 2004
June-Aug temp anomalies (relative to 1961-1990 mean)
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Climate Change Management
Smit et al (1999)
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Mitigation Role of GI
• Carbon sequestration & storage
• Direct fossil fuel substitution
• Material substitution
• Local food production
• Reducing need to travel
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Adaptation Role of GI
• Moderating temperature extremes
• Decreasing rate and volume of rainwater runoff
• Providing wildlife corridors
• Providing recreation spaces e.g. high capacity, less sensitive landscapes
Key Stakeholders
Town & Country Planning Association (Chair)
Association of British Insurers
Environment Agency
North West Climate Group
Office of the Deputy Prime Minister
Royal Town Planning Institute
South East Climate Group
http://www.k4cc.org/Members/Claire/BKCC-Results-Publication.pdf
ASCCUE MethodologyASCCUE Methodology
• Two case study areas– Greater Manchester – Lewes, Sussex
• Three exposure units– Integrity of the built
environment– Human comfort– Urban greenspace
• Two case study areas– Greater Manchester – Lewes, Sussex
• Three exposure units– Integrity of the built
environment– Human comfort– Urban greenspace
Urban GreenspaceUrban Greenspace
• Urbanisation alters – Micro-climate – increased temperatures – Hydrology – increased rate & volume of surface
runoff
• Climate change alters temperature & rainfall patterns
• Urban greenspace can moderate ‘urban heat island’ effect and reduce rate & volume of runoff
• Therefore urban greenspace has potential to adapt cities to climate change
• Urbanisation alters – Micro-climate – increased temperatures – Hydrology – increased rate & volume of surface
runoff
• Climate change alters temperature & rainfall patterns
• Urban greenspace can moderate ‘urban heat island’ effect and reduce rate & volume of runoff
• Therefore urban greenspace has potential to adapt cities to climate change
Urban Morphology TypesUrban Morphology Types
Urban CharacterisationUrban Characterisation
Greater Manchester Urban Morphology TypesGreater Manchester Urban Morphology Types
UMT Surface CoverUMT Surface Cover
‘Evapotranspiring’ Surfaces ‘Evapotranspiring’ Surfaces
‘Urban’ Tree Cover‘Urban’ Tree Cover
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
woodlandmineral workings & quarries
formal recreationformal open space
informal open spaceallotments
major roadsairports
railriver, canal
energy production & distributionwater storage & treatment
refuse disposalcemeteries & crematoria
high density residentialmedium density residential
low density residentialschools
hospitalsretail
town centremanufacturing
officesdistribution & storage
disused & derelict landremnant countryside
UM
T
Percentage of all 'urban' tree cover
Surface Cover and Residential DensitySurface Cover and Residential Density
Modelling environmental functionsModelling environmental functions
• Use surface cover data as one input into surface temperature and runoff models
• Series of model runs– Current urban form
• Baseline and future climate
– ‘Development scenarios’• Baseline and future climate
• Use surface cover data as one input into surface temperature and runoff models
• Series of model runs– Current urban form
• Baseline and future climate
– ‘Development scenarios’• Baseline and future climate
Maximum Surface TemperaturesMaximum Surface Temperatures
For a day occurring on average twice per summer
Residential ± 10% green coverResidential ± 10% green cover
High density residential
15
20
25
30
35
40
1970s 2020sLow
2020sHigh
2050sLow
2050sHigh
2080sLow
2080sHigh
Time period and scenario
Max
su
rfac
e te
mp
(°C
)
current form
-10% green
+10% green
High density residential
15
20
25
30
35
40
1970s 2020sLow
2020sHigh
2050sLow
2050sHigh
2080sLow
2080sHigh
Time period and scenario
Max
su
rfac
e te
mp
(°C
)
current form
-10% green
+10% green
If grass does not evapotranspire…If grass does not evapotranspire…
• Maximum surface temperatures increase by– 4.7-5.7°C in high
density residential areas
– 13.8-15.6°C in schools
• Maximum surface temperatures increase by– 4.7-5.7°C in high
density residential areas
– 13.8-15.6°C in schools
(Manchester Evening News, 2006)
Occurrence of Drought for GrassOccurrence of Drought for Grass
Months/year when grass water stressed
Adaptation in the Public RealmAdaptation in the Public Realm
Surface temperature in tree shade here was 13°C cooler than in sun – large mature tree canopies provide more shade
Surface RunoffSurface Runoff
56% more rain results in 82% more runoff
For a precipitation event occurring on average one day per winter, with normal antecedent moisture conditions
Infiltration CapacityInfiltration Capacity
A case for ‘Conservation
Areas’?
Climatic adaptation via the green infrastructureClimatic adaptation via the green infrastructure
Corridor
Patch
Matrix
Corridor Patch Matrix
Flood storage
• • • • • •
Infiltration capacity
• • • • • •
Evaporative cooling
• • • • • •
Shading • • • • • •
Functional importance of urban greenspace needs to be reflected in plans, policies, strategies
Summary of FindingsSummary of Findings
• Greenspace moderates temperatures through evaporative cooling & shading– Mature trees critical for shading
• Most effective in regulating surface runoff on high infiltration soils
• Increase rainwater storage
• Opportunity to use for irrigation in times of drought
• Greenspace moderates temperatures through evaporative cooling & shading– Mature trees critical for shading
• Most effective in regulating surface runoff on high infiltration soils
• Increase rainwater storage
• Opportunity to use for irrigation in times of drought
Policy ImplicationsPolicy Implications
• Work across administrative boundaries & disciplines
• Protect critical environmental capital• No net loss of green cover• Creative greening• Take opportunities in new development /
restructuring• Ensure water supply
• Work across administrative boundaries & disciplines
• Protect critical environmental capital• No net loss of green cover• Creative greening• Take opportunities in new development /
restructuring• Ensure water supply
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Increasing Policy Relevance
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NW Climate Change Action Plan
• “Undertake scoping studies to assess future regional risks, opportunities and priorities for the potential for green infrastructure, including regional parks, to adapt and mitigate for climate change impacts and commence implementation of findings”
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GI functions for climate change
Mitigation Adaptation
Biofuels production
Timber production
Food production
Carbon storage
Recreation
Green travel routes
Shading from sun
Evaporative cooling
Shading from sun
Evaporative cooling
Water storage
Water interception
Water infiltration
Soil stabilisation
Storm protection
Habitat for wildlife
Corridor for wildlife
Recreation
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Conclusion
• Climate change mitigation role limited but important
• Climate change adaptation role substantial
• GI is a good adaptation strategy as it has other functions and benefits
• To maximise this need strategic planning at all levels, with functionality in mind
• Protect, create, enhance, and maintain