Adapting to the effects of climate change

on water supply reliabilityNigel Arnell and Matt CharltonWalker Institute for Climate System Research,

University of Reading

School of Geography, University of Southampton

Living with climate change: Are there limits to adaptation? London, February 7-8 2008

Research questions

Are there limits to our ability to adapt to climate change in a particular place?

…and what controls those limits and barriers?

Water supply reliability in southern England

Outline

• Water resources in southern England

• A conceptual framework

• The case study

• Potential adaptation options

• Barriers to implementation

Water resources in southern England

Surplus or deficit in 2009-10?

Environment Agency (2001)

Increasing demands

…and add climate change

Change in summer runoff, UKCIP02 medium-high scenario, 2020s

No newresources

Somecompany-proposedschemes

some demand management

much demand management-30-20-10

0102030405060S

uppl

y -

dem

and

(Ml/d

)

Medium population growth

Adaptation options

Eastern South East England

Supply-side options

Demand-side options

A conceptual framework

Generic barriers apply to the adaptation challenge

- is the need for adaptation recognised?

- can the need for adaptation be defined?

- can potential adaptation options be identified?

- can adaptation options be evaluated?

- can an option be selected?

Specific barriers apply to individual options

- are there physical limitations on the performance of the option?

- are there financial constraints on the adoption of the option?

- are there socio-political constraints on its adoption?

- are there institutional factors within the organisation or its regulatory / market context that constrain the adoption of the option?

The case study catchment

River Medway catchment, Kent

Multiple “ownership”

Complicated resource management

Multiple stakeholders

Water supply companiesEnvironment AgencyLocal councilsSEERACPREWildlife TrustAgricultureWater consumers

Change in the catchment

Medway at Teston: change by 2020s

-40

-30

-20

-10

0

10

20

30

40

J F M A M J J A S O N D

% c

han

ge

fro

m 1

961-

1990

Change by the 2020s

Potential adaptation options

Supply side Demand side

Bulk transfers Reduce leakage

Effluent re-use Metering and tariffs

Aquifer storage and recovery Water efficiency

Desalination Licence trading

Local resources - enlarge Bewl Bridge - new Broad Oak / Clay Hill - winter flood storages - new sources

Public education

Reduce rate of growth

Increased connectivity

No one option is likely to meet targets

Barriers to implementation

Generic barriersIs the need recognised? Yes…

Can the need be specified? Strategically - yes…

Can potential options be identified? Yes…

Can options be evaluated? Not sure yet…

Can an option be selected? Not sure yet…

Specific barriers to individual options

Supply side Physical Financial Socio-political

Institutional

Bulk transfers

Effluent re-use

Aquifer storage and recovery

Desalination

Local resources - enlarge Bewl Bridge - new Broad Oak / Clay Hill - winter flood storages - new sources

Increased connectivity

Preliminary assessment

Strong Medium Weak ?

Specific barriers to individual options

Demand side Physical Financial Socio-political

Institutional

Reduce leakage

Metering and tariffs

Water efficiency

Licence trading

Public education

Reduce rate of growth

Preliminary assessment

Strong Medium Weak ?

Specific barriers

• Major physical barriers for most supply-side options (environmental constraints, reliable yield etc)

• Physical barriers for demand-side options relate to uncertainty over effectiveness

• Significant pressure-group objections to many supply-side options

• Significant customer barriers to many demand-side options

What next?

• Explore characteristics of different adaptation options with stakeholders

• How can portfolios of adaptation options be implemented?– Multiple ownership of the challenge of coping

with water resources deficits

Thank you

www.walker-institute.ac.uk