MEASURING WATER USE IN A GREEN ECONOMY - UNEP

Measuring water use in a green economy
Broadly speaking, the goal of assessing water
footprints is to comprehensively quantify total
and actual water consumption at a specific time
and place and to assess the sustainability of
the water consumption. The information gained
through these two steps can then be used to
identify and prioritise appropriate response
strategies.
4.4.2 Production and consumption
perspectives
The water footprint can be used to understand
the water consumption related to the
production of goods and services and their
consumption. Production water footprint
accounts show the allocation of water in a river
basin, nation or a business to different goods
or services. The water footprint of production
is temporally and geographically based on
the time and location of the production. The
water footprint of consumption relates to all
the water used in the production of the goods
and services consumed by an individual or
a group of individuals. The water footprint
of consumption is related to the location of
the consumer which may or may not be in
the same location as the production of these
goods or services. The water footprint of
consumption links the consumer, through
the water embedded in non-local products
consumed, to the water footprint of production
in river basins around the world. In both the
water footprint of production and consumption,
the focus is not limited to promoting wateruse
efficiency at field level but extended to
wise water governance in supply chains as a
whole (Kuiper et al., 2011). By integrating the
water footprint of production and consumption
in water resource management, the true
potential for using water more efficiently and
meeting new challenges and opportunities that
globalisation creates for water management,
can be assessed.
4.4.3 Sustainability assessment in water
footprinting
The three components of the water footprint
– green, blue and grey – need to be assessed
for environmental, social and economic
sustainability. The aim of the assessment is to
identify where water consumption and pollution
violate sustainability boundaries. In the case
Box 4.3 Water footprint and virtual water trade in China
There has been a strong increase in per capita water footprint in China in recent decades, from
255 m 3 cap −1 yr −1 in 1961 to 860 m 3 cap −1 yr −1 in 2003 (Liu and Savenije, 2008) (Fig. 4.2). This was
caused mainly by a shift of food-consumption patterns towards protein-rich Western diets. Meat
used to be luxury food in China, and its consumption remained at low levels (< 13 kg cap -1 yr -1 )
prior to 1980. However, meat consumption has risen rapidly, by a factor of 3.7 from 1980 to 2003,
mainly as a result of a rapid increase in per capita income, urbanisation, and market expansion.
In contrast, the consumption of cereals has not changed much, and the consumption of the two
staple food, rice and wheat, peaked in the late 1990s and has declined slightly since then. In
China, it takes 2 400–12 600 litres of water to produce a kilogram of meat, whereas a kilogram
of cereal needs only 800–1 300 litres (Liu et al., 2007). The recent rise in meat consumption
has pushed China's annual water footprint for food production up by a factor of 3.4. Compared
with China's population growth by a factor of 1.9 over the same period, this suggests that
dietary change is making a high demand on water resources.
Changing food-consumption patterns are the main cause of worsening water scarcity in China
(Liu et al., 2008). Trends indicate that the future per capita water footprint will increase
further in the next few decades, which will doubtless create high pressures on the limited water
resources of China, particularly in the north.
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