Climate Change and the Water Cycle Richard Harding Centre for Ecology and Hydrology
Jan 04, 2016
Climate Change and the Water
Cycle
Richard HardingCentre for Ecology and Hydrology
Drivers of Global Change:
• Increasing population
• Increasing water consumption
• Land cover/use change
• Increasing greenhouse gases
Stern Review (2006)
Water Consumption - after Shiklomanov 2000
0
500
1000
1500
2000
2500
3000
1900 1920 1940 1960 1980 2000 2020 2040
Co
nsu
mp
tio
n,
km3/y
ear
Agriculture
Industry
MunicipalneedsReservoir
Total
Assessment
Forecast
Areas of physical and economic water scarcity (IWMI, 2006)
We represent the earth by a grid of squares, typically of length 150 km or smaller.
The atmosphere and oceans are divided into vertical slices of varying depths.
To predict the future we need the climate models
FIGURE SPM-6. Relative changes in precipitation (in percent) for the period 2090–2099, relative to1980–1999. Values are multi-model averages based on the SRES A1B scenario for December to February (left) and June to August (right). White areas are where less than 66% of the models agree in the sign of the change and stippled areas are where more than 90% of the models agree in the sign of the change.
IPCC 2007
Smoothed annual anomalies for precipitation (%) over land from 1900 to 2005; other regions are dominated by variability.
Land precipitation is changing significantly over broad areas
Increases
Decreases
Climate change scenarios – the changing seasons
• UK winterWetter: Up 10% by 2020s, up to 30% by 2080s
Drier: 20% by 2020s, up to 50% by 2080s
• UK summer
30-yearevent
12-yearevent
4-yearevent
30-yearevent
12-yearevent
4-yearevent
Climate change scenarios – changing extremes
Percentage change in
flows for the 20-year return
period
Climate change scenarios – impact on flows
10km
Glacier melt in the Himalayas
1989
2000
1978
1996
SAGARMATHA: Snow and Glacier Aspects of Water Resources Management in the Himalaya
-80
-60
-40
-20
0
20
40
60
0 1 2 3 4 5 6 7
Decade
% c
han
ge Uttarkashi
Haridwar
Kanpur
Allahbad
%change in decadal mean flow for Ganges from
regional climate model output (RCM2)
http://www.nwl.ac.uk/ih/www/research/SAGARMATHA/
WATCH
WB7
Assessing the vulnerability of water resources
WB6
Past, present and future population, LUCC and
water demand
WB2
Extremes and scales of
hydrological events
WB4
Feedbacks in the climate hydrological
system
WB5
21st Century Global water cycle
20th Century Global water cycle
WB3
WB1
Management, training anddissemination
WATCH
WB7
Assessing the vulnerability of water resources
WB6
Past, present and future population, LUCC and
water demand
WB2
Extremes and scales of
hydrological events
WB4
Feedbacks in the climate hydrological
system
WB5
21st Century Global water cycle
20th Century Global water cycle
WB3
WB1
Management, training anddissemination
WB7WB7
Assessing the vulnerability of water resources
WB6
Assessing the vulnerability of water resources
WB6
Past, present and future population, LUCC and
water demand
WB2
Past, present and future population, LUCC and
water demand
WB2
Extremes and scales of
hydrological events
WB4
Extremes and scales of
hydrological events
WB4
Feedbacks in the climate hydrological
system
WB5
Feedbacks in the climate hydrological
system
WB5
21st Century Global water cycle
20th Century Global water cycle
WB3
WB1
21st Century Global water cycle21st Century Global water cycle
20th Century Global water cycle20th Century Global water cycle
WB3
WB1
Management, training anddissemination
The WATCH Integrated Project:
25 European partners: hydrology, climate and resource scientists
13m euros of effort
International programme
research, workshops, training, dissemination
Thank You