The water footprint
of consumption in the UK
Prof. dr. Arjen Hoekstra
University of Twente – the Netherlands
www.waterfootprint.org
Overview
- Freshwater scarcity & pollution
- The water footprint of
- our daily commodities
- meat
- bio-energy
- What can we do?
Signs of global water scarcity
Strawberries for export
Coto Doñana National Park, southern Spain
Signs of global water scarcity
Cotton for export
Former Aral Sea, Central Asia
Signs of global water scarcity
Soybeans, deforestation,
Mato Grosso, Brazil
It takes 1430 million m3 of water per year to
produce soybean in Brazil for export to the UK.
(equiv. to more than 0.5 million Olympic
swimming pools)
Signs of global water pollution
The total water footprint of a consumer in the UK
► about 3% of your water footprint is at home.
150 litre/day
► about 97% of your water footprint is ‘invisible’, it is
related to the products you buy in the supermarket.
3400 litre/day for agricultural products
1100 litre/day for industrial products
► about 60 to 65% of your
water footprint lies abroad.
The water footprint of a product
Green water footprint
► volume of rainwater evaporated.
Blue water footprint
► volume of surface or groundwater
evaporated.
Grey water footprint
► volume of polluted water.
Global water footprint of UK consumption
62% of the UK water footprint
is outside its own borders
[Chapagain & Orr, 2008]
[Hoekstra & Chapagain, 2008]
[Hoekstra & Chapagain, 2008]
[Hoekstra & Chapagain, 2008]
99% of the total refers to water
consumed in producing the feed
[Hoekstra & Chapagain, 2008]
[Hoekstra & Chapagain, 2008]
[Hoekstra & Chapagain, 2008]
Meat versus vegetarian diet
Meat diet
Industrial
countries
Developing
countries
kcal/day
litre/kcal
litre/day
Animal
origin
950
2.5
2375
Vegetable
origin
2450
0.5
Total
3400
Animal
origin
350
Vegetable
origin
2350
Total
2700
Vegetarian
diet
kcal/day
litre/kcal
litre/day
Animal
origin
300
2.5
750
1225
Vegetable
origin
3100
0.5
1550
3600
Total
3400
2.5
875
Animal
origin
200
2.5
500
0.5
1175
Vegetable
origin
2500
0.5
1250
2050
Total
2700
2300
1750
Meat versus vegetarian diet
Meat diet
Industrial
countries
Developing
countries
kcal/day
litre/kcal
litre/day
Animal
origin
950
2.5
2375
Vegetable
origin
2450
0.5
Total
3400
Animal
origin
350
Vegetable
origin
2350
Total
2700
Vegetarian
diet
kcal/day
litre/kcal
litre/day
Animal
origin
300
2.5
750
1225
Vegetable
origin
3100
0.5
1550
3600
Total
3400
2.5
875
Animal
origin
200
2.5
500
0.5
1175
Vegetable
origin
2500
0.5
1250
2050
Total
2700
2300
1750
Meat versus vegetarian diet
Meat diet
Industrial
countries
Developing
countries
kcal/day
litre/kcal
litre/day
Animal
origin
950
2.5
2375
Vegetable
origin
2450
0.5
Total
3400
Animal
origin
350
Vegetable
origin
2350
Total
2700
Vegetarian
diet
kcal/day
litre/kcal
litre/day
Animal
origin
300
2.5
750
1225
Vegetable
origin
3100
0.5
1550
3600
Total
3400
2.5
875
Animal
origin
200
2.5
500
0.5
1175
Vegetable
origin
2500
0.5
1250
2050
Total
2700
2300
1750

Grazing systems
Water footprint:
• mostly green
• local
Water footprint:
• green & blue
• local
Mixed systems
Water footprint:
• green & blue
• partly imported
Industrial systems
Water footprint of biofuels from different crops [litre/litre]
[Gerbens-Leenes, Hoekstra & Van der Meer, 2009]
Water footprint of transport when fueled with bio-energy
Transport mode
Energy source
Crop source
WF (litre per
passenger km)
Biodiesel
Rapeseed
236-492
Bio-ethanol
Sugar beet
65-136
Biodiesel
Rapeseed
109-355
Bio-ethanol
Sugar beet
36-212
Biodiesel
Rapeseed
111-154
Bio-ethanol
Sugar beet
31-43
Train
Bio-electricity
Maize
8-19
Electric car
Bio-electricity
Maize
11-13
Walking
Sugar
Sugar beet
4.4
Bike
Sugar
Sugar beet
1.7
Airplane
Car
Bus
What can we do?
Reducing humanity’s water footprint – Companies
•
Shared terminology & calculation standards
•
Product transparency
•
Benchmarking
•
Quantitative footprint reduction targets
•
for both own operations and supply chain
Global standard
Feb. 2011
Reducing humanity’s water footprint – Government
•
Embed water footprint assessment in national water policy making.
•
Promote coherence between water and other governmental policies:
environmental, agricultural, energy, trade, foreign policy.
•
Reduce the own organizational water footprint
•
Promote product transparency
Stop waste of ‘blue water’
Full water recycling
in industries
Towards precision irrigation
Make better use of ‘green water’
Increase water
productivity in
rain-fed
agriculture
Grey water footprint  zero
Towards organic farming
Towards zero emission