Climate change - future droughts Kent Water Summit Thursday 29th June 2006 East Malling Conference Centre, Kent www.futuredrought.org.uk Steven Steven Wade, Wade, Jean-Philippe Jean-Philippe Vidal Vidal11 HR HR Wallingford Wallingford Acknowledgements: Acknowledgements: Defra Defra (Global (Global Atmospheres), Atmospheres), Environment Environment Agency, Agency, UKWIR, UKWIR, UKCIP, UKCIP, Project Project partners partners ~~ Met Met Office, Office, Lancaster Lancaster University, University, Entec Entec UK, UK, CRU, CRU, CEH, CEH, BGS, BGS, Anglian Anglian Water, Water, Southern Southern Water, Water, Veolia Veolia
HR Wallingford History 1947 1982
2005
Hydraulics Research Organisation is formed Privatisation to create Hydraulics Research Ltd New Froude Modelling Hall opened
Water
Floods
HR Wallingford Coasts
Maritime
Energy
Page 2
1
Outline Introduction\Background Global warming Modelling climate change Impacts on UK future drought:• Rainfall drought • Hydrological drought (River flows, reservoirs, groundwater levels) • Water resources
Conclusions Page 3
Global warming
2
Global warming: evidence Combined global land and marine surface temperature record from 1856 to 2004 (Source: Climate Research Unit, University of East Anglia).
Temperature change ºC
Page 5
1.0
Evidence: Warming can not be explained by ‘natural’ forcing factors observed
model simulation
0.5
0.0
-0.5 1850
1900
1950
2000
Page 6
3
Evidence: Warming can be explained when anthropogenic forcing included Temperature change ºC
1.0 observed
model simulation
0.5
0.0
-0.5 1850
1900
1950
2000
Page 7
Climate modelling
4
30km 2.5 lat
Global models e.g. The Hadley Centre third coupled model – HadCM3 Page 9
3.75 long
19 levels in atmosphere 1.25 1.25
20 levels in ocean HadleyCentre
-5km
Global temperature change (°C) to 2100
Page 10
5
The UK Climate Impacts Programme Climate change scenarios SUMMER
winter
UKCIP98 300km
UKCIP02 50km
BIC03 25km
UKCIPnext ??km
Page 11
Climate change in the South East Essex County Wide Action Plan (HR Wallingford, 2005)
Main projections for Essex by the 2080s: •Winter temperatures will increase by 2-3°°C •Summer temperatures will increase by 3-5°°C •Winter precipitation will increase by 13-25% •Summer precipitation will decrease by 24-47% •Average sea levels will increase by 26-86cm* •Extreme sea levels will increase by 80-140cm* *including regional isostatic subsidence as well as climate change Page 12
6
Impacts of climate change on Essex Precipitation change Water resources Flooding (inland) Temperature increase Heat stress during summer Risk to river/wetland ecologies Heating of buildings Cooling of buildings Demand for water Page 13
Why should we be considering climate change? Climate change is happening and will impact on water There is high confidence in this fact. There is less confidence in the extent of change, But we can still plan for the potential consequences.
What can we do to limit the consequences? ADAPTATION – reducing impacts of climate change. MITIGATION – reducing future climate change.
Why do this if the projections are so uncertain? NO and LOW regret actions - benefits now. ‘Climate proof’ future infrastructure development
Principles for adaptation to climate change • Rigorous science + practical solutions + social engagement (Hunt, 2006) Page 14
7
Future Droughts Impacts of climate change on water resources
Background: Water Availability & Supply
CEE
SEE
Public Water Supply
Ground water
Surface Water
Anglian Water
50%
50%
Thames Water
25%
75%
Southern 80% Region
20%
Water Availability (Groundwater): (Environment Agency, 2001). Page 16
8
Background: Water Availability (Surface Water) Summer
Winter
(Environment Agency, 2001).
Page 17
The development & impacts of UK drought Climate change
Climate variability
High temperatures Increased evapotranspiration
DURATION
Reduced ‘effective’ rainfall Less runoff and recharge Increase soil moisture deficits Lower groundwater levels Reduced river flow Reduced habitat areas
Plant water stress Reduced biomass/yield Increased demand for water
‘Threatened’ or actual water supply shortage Drought Permits/Orders Page 18
Environmental Impacts
Social Impacts
Economic Impacts
DROUGHT Rainfall--Agricultural-- Hydrological-- Water Resources
Rainfall deficits (amount, timing, severity)
Socio-economic change
9
Potential impacts of climate change Rainfall drought
Change in monthly average rainfall 2020s _ River Medway Rainfall Factor Indicators
10 5
%
HadCM3 CGCM2 CSIRO-mk2 CCSR/NIES GFDL-R30 ECHAM4/OPYC3 Average of GCM factors
0 -5 -10 -15 -20 Average
Spreadsheet of 2020s monthly rainfall and PET factors for % all UK catchments (UKWIR/EA, 2006)
Page 20
Winter
Summer
Climate models
UKCIP02 LOW UKCIP02 MEDIUM UKCIP02 HIGH
15
PET Factor Indicators 25 20 15 10 5 0 Average
Winter
Summer
10
Medway: Changes in monthly rainfall 2020s Monthly rainfall factors Percent change from 1961-90
40
WETTER WINTERS
WETTER WINTERS
30 20 10 0 -10 -20 -30
DRIER SUMMERS
-40 Jan Feb Mar
Apr May Jun
Jul
Aug Sep Oct
Nov Dec
Page 21
Medway: Changes in monthly PET 2020s Monthly PET factors 40
MORE EVAPORATION
Percent change from 1961-90
35
MORE TRANSPIRATION
30
GREATER WATER LOSSES FROM PLANTS, SOIL and OPEN WATER
25 20 15 10 5 0 Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
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11
Development of extreme scenarios based on climate models (HR Wallingford, 2005) Direct use of monthly RCM data to estimate changes in frequency of severe droughts (6 months & 2 year) Regional analysis of 9 grid squares Comparison of GCM outputs (6 models) to place RCM in context
NS ES
SS NI
NEE
NWE
CEE
SWE
SEE
Defra Cross-Regional Climate change programme
Page 23
Changes in precipitation patterns based on HadRM3 Defra Cross-Regional Climate South East of England change programme Possible changes in precipitation 3 summer months (JAS) 200
Total rainfall July-Aug-Sept (mm)
180 160 140 120 100 80 60 40 20 0 1960
1970
1980
Control run 1961-1990
1990
2000
2010
Low Emissions
2020
2030
2040
Medium High Emissions
2050
2060
2070
2080
2090
2100
High Emissions
Page 24
12
Changes in precipitation patterns based on HadRM3 South East of England Possible changes in precipitation 3 winter months (OND) 450
Total rainfall Oct-Nov-Dec (mm)
400 350 300 250 200 150 100 50 0 1960
1970
1980
Control run 1961-1990
1990
2000
2010
Low Emissions
2020
2030
2040
2050
2060
Medium High Emissions
2070
2080
2090
2100
High Emissions
Page 25
Defra Cross-Regional Climate change programme
Changing patterns of seasonal rainfall 2080s Medium High Emissions scenario compared to 1961-1990
Change in frequency of extreme dry conditions
East Scotland
South East England
1 in 20yr Dry Winter
23 yrs
18 yrs
1 in 10yr Dry Winter 1 in 20yr Dry Summer
12 yrs 9 yrs
10 yrs 7 yrs
1 in 10yr Dry Summer
5 yrs
4 yrs
Comments (--) No significant change
(x2) More dry summers
Page 26
13
0
0
2020s 2050s 2080s 2020s 2050s 2080s HadRM3 (A2) - Increase in1970s the frequency of ‘short’ rainfall ES SS droughts
1970s
25 Defra Cross-Regional Climate change programme 20 25
15
5 0
1970s
25 20
10 5 0
10
5
5
0
0
1970s
1970s
2020s 2050s NS
2020s 2050s 25 NEE
2080s
15
10
10
5
5 2020s 2050s NI
0
2080s
25
25
20
20
15
15
10
10
2080s
5
1970s
10 5
5 1970s
2020s 2050s ES
1970s
25 20
Page 27
15
2080s
15
2020s 2050s SWE 0
20
10
0
20
1970s
25
15
15
10
0
15
20
2020s 2050s CEE
0
1970s
2020s 2050s 25 NWE
2020s 2050s SS
2080s
2080s
20 15 10
20
5
1970s15 2020s 2050s NEE
1970s
2020s 2050s NWE
2080s
25 20
5
15
0 1970s
0
2080s
10
5
2080s
0
2080s
25
No. droughts in 30 yrs
10
20
25
HadCM3 HadRM3-a HadRM3--b HadRM3--c
20
15
25
Number of 6 months extreme droughts
10
1970s 2020s 2050s SWE
2020s 2050s 5 SEE 0 2080s
1970s
Time period
2080s 2020s 2050s SEE
2080s
HadRM3 (A2) - Increase in the frequency of ‘long’ rainfall droughts Defra Cross-Regional Climate change programme
Number of 24 months extreme droughts 5
5
4
4
3
3
2
2
2
1
1
1
0
0
5 HadCM3 HadRM3-a HadRM3--b HadRM3--c
4 3
Page 28
1970s
2020s 2050s NS
2080s
1970s
2020s 2050s ES
2080s
0
5
5
5
4
4
4
3
3
3
2
2
2
1
1
1
0
0
1970s
2020s 2050s NI
2080s
1970s
2020s 2050s NEE
2080s
0
5
5
5
4
4
4
3
3
3
2
2
2
1
1
1
0
0
1970s
2020s 2050s CEE
2080s
1970s
2020s 2050s SWE
2080s
0
1970s
2020s 2050s SS
2080s
1970s
2020s 2050s NWE
2080s
1970s
2020s 2050s SEE
2080s
14
Potential impacts of climate change River flows
Runoff factors based on UKCIP02 scenarios for the 2020s (UKWIR, 2003) Anglian 5
% change
0 -5
J
F
M
A
M
J
J
A
S
O
N
D
-10 -15 -20 -25 -30 low
medium
high
Southern & Wessex
Thames 10
10
J
F
M
A
M
J
J
A
S
O
-20 -30
N
D
% change
% change
0 -10
0 -10
low
medium
F
M
A
M
J
J
A
S
O
N
D
-30 -40 low
-40
J
-20
medium
high
high
Page 30
15
Change in river flows: 2020s UKWIR/EA CL-04 Medway@Teston (40003) 50 90% confidence intervals 50% confidence intervals median
40
Change in monthly flows (%)
30 20 10 0 -10 -20 -30 -40 -50 Page 31
J
F
M
A
M
J
J
A
S
O
N
D
Potential impacts of climate change Reservoirs
16
HadRM3H – perturbation to estimate source yields
Page 33
EA Severe Droughts Project
Potential impacts of climate change Groundwater
17
Change in recharge 2020s Itchen@AllbrookHighbridge (42010) 50 90% confidence intervals 50% confidence intervals median
40
Change in monthly recharge (%)
30 20 10 0 -10 -20 -30 -40 -50
J
F
M
A
M
J
J
A
S
O
N
D
Page 35
UKCIP02 Impacts on groundwater levels – Average changes in chalk in SE England (Bloomfield & Wade) 0.00 -0.20 -0.40 -0.60 -0.80 -1.00 Mean
-1.20
1 in 20 year
Point 3 ditto
08 0s H2
0s H
20 8
08 0s M
M
L2
H
20 5
0s
20 20 s H
0s 20 2 H M
M L2
L2 Page 36
02 0s
-1.40 02 0s
Change in groundwater level (metres)
Change in Minimum Groundwater Levels
Scenario
18
Water resources systems
Impacts of change on water resources Climate variability & Climate Change (UKCIP02 & HadRM3 Extremes)
Social & economic change (Foresight scenarios) •Population growth •Economic growth •Land use change •Social change •(Lifestyle & attitudes) Policy responses •Regulation •Investment •CAMS •WFD
Stakeholder responses •Business strategy •Risk “appetite” •Guidelines
Temperature Winter precipitation Summer precipitation PET Variability
Environment
Responses
SUPPLY
DEMAND
Supply-demand balance •Risk •Uncertainty •(Headroom) •Least cost
Page 38
19
Water resources planning 260.00
Supply/Demand Ml/d
250.00
Planned schemes
Resources (no climate change)
Demand (climate and socio-economic change)
240.00 230.00 220.00
A
Increasing Deficit
D
19
25
B
210.00
Resources (with climate change)
200.00 190.00 1
3
5
7
9
11
13
15
17
21
23
Year
Demand
Page 39
Demand plus Headroom
Supply (Do Nothing)
Water futures for the SE: 2020s 80.0 Water Supply Agriculture Environment
Requirements Ml/d
70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 Page 40
WMLE
WMHE
NEMHE GSLE Scenario
GSHE
Planned
20
Water futures for the South East 2020s Small increase in the demand (2%) for water due to climate change Large increases in demand for water in ‘growth areas’ due to increasing population/households Potential supply-demand deficits of 4 to 15% in the SE. Potential for additional investment ca. £50M per water resources zone in development ‘hot-spots.’
2050s Increase in demand (4%) due to climate change Increases in demand depending on socioeconomic scenario Potential supplydemand deficits of 7 to 32 % in SE
Water Futures: 2080s resource requirements =f(climate change, socio-economic change)
160.0
350.0
140.0
300.0
120.0 100.0 Water Supply Agriculture Environment
60.0 40.0
250.0 200.0 150.0 100.0 50.0
20.0
Page 41
Requirements Ml/d
Requirements Ml/d
Water Futures: 2050s resource requirements =f(climate change, socio-economic change)
80.0
2080s Further increases in demand due to climate change Overall increases depending on socio-economic scenario Potential supplydemand deficits of 16 to 46% in SE
0.0 WMLE
WMHE
NEMHE Scenario
GSLE
0.0
GSHE
WMLE
WMHE
NEMHE
GSLE
GSHE
Scenario
Management measures
Page 42
Supply
Demand
Environmental
National
National transfers (North to South) Research Monitoring of trends in rainfall, river flow and recharge
Educational projects Research into water saving technology Improved Building Regulations
Environmental Directives Implementation of the WFD New legislation on drought management
Regional
New reservoirs Reservoir raising Canal transfers Drought forecasting Conjunctive use Emergency planning
Tariffs for measured charges Restrictions to discretionary use
Negotiated environmental agreements Habitat corridors Regional Spatial Strategies
Local
Bankside storage Collective storage reservoirs Desalination Wastewater re-use Artificial recharge of aquifers Flexible licensing Insurance against crop failure
Waste minimisation Dual flush toilets Metering Leakage control Rainwater use Greywater use White goods subsidies Change crop types Improved irrigation technology
Abstraction controls & trading Emission controls Recreation and restoration of wetlands areas Rehabilitation projects
21
Multi-Criteria Analysis of Options Figure 3.3: Scatter Plot of Score versus Cost for the East of Scotland Case Study 100% 90% 80%
WW reuse (indirect pws)
WW reuse (direct pws)
Abstraction trading
WW reuse (direct non-pws)
70%
WW reuse (indirect non-pws)
Weighted Score
Educational projects Rainwater use
Tariffs
White goods subsidies
Retrofit of toilets
60%
Metering (domestic)
Pipeline transfer
Canal transfer
50%
Improved leakage control
40% Greywater use
30% Winter storage (farm consortium) Winter storage (single farm)
20%
Waste minimisation
Change crops
Change irrigation
10% 0% 1
10
100
1000
3
Cost (p/m )
Page 43
Conclusions: Climate change impacts •Three of the worst five rainfall droughts in the UK since 1914 have occurred since 1990 •‘Short’ droughts, lasting one or two seasons, will increase significantly by the 2050s and be commonplace by the 2080s •The chance of a ‘dry winter’ will remain unchanged •Pressures on public water supply, agriculture and the environment will increase •Public water supply-demand deficits of 4 to 15 % developed by the 2020s and deficits of 16 to 46 % by the 2080s for the baseline or ‘do nothing’ case. Page 44
22
Conclusions: Adaptation
Page 45
•improvements to drought risk management •variable water charges •changes to agricultural irrigation practices inc. small on-farm reservoirs • mandatory changes to land use planning and building regulations • as well as the ‘twin-track’ water resources planning approach of developing new resources alongside demand management schemes. •selecting adaptation measures to meet environmental, social and economic objectives (MCA)
23
