|
A GLOBAL FULL-COURT
PRESS
Chapter 7. Raising Water Productivity
Lester R. Brown, Plan B: Rescuing a Planet Under Stress and a
Civilization in Trouble (W.W. Norton & Co., NY: 2003).
As fast-unfolding water shortages translate
into food shortages, they will signal that we can no longer rely
on incremental business-as-usual change. Three factorsthe
simultaneous drop in water tables, the exponential nature of that
fall, and the globalization of water scarcityensure
that such a response will not be sufficient. As water shocks become
food shocks and as falling water tables translate into higher food
prices, we will realize that the world has changed fundamentally.
As Asit K. Biswas, Director of the Third World Centre for Water
Management, notes, "The world is heading for a water crisis that
is unprecedented in human history. Water development and management
will change more in the next 20 years than in the last 2,000 years."42
Supply-side technological fixes, such as the massive desalting of
seawater, do not hold much hope for food production in the foreseeable
future. Although the cost of desalting seawater is falling, it is
still expensive and thus not yet a viable prospect for irrigation.
At present, it costs between $1 and $2 per cubic meter to desalt
seawater. Even at the lower cost, producing wheat with desalted
seawater would raise its price from $120 to $1,120 per ton.43
Some countries are still focusing on supply expansion when it might
be less costly to focus on demand management. To get water to the
cities in its industrial northern half, including Beijing and Tianjin,
China has devised a plan to move water along three routes from the
Yangtze River basin to the Yellow River basin, since the latter
has only one tenth the flow of the former. These three routes, designated
the East, Central, and West, will cost an estimated $59 billion.
Construction on the East route began in December 2002. For China,
it might be more economical to invest this $59 billion in urban
water recycling and irrigation efficiency in the north rather than
trying to transport water from the south.44
With water shortages now threatening so many countries at the same
time, we need a global full-court press, to borrow an expression
from basketball, to raise water productivity. This begins with improved
irrigation practices and technologies, as described in this chapter.
It also includes boosting crop yields on both irrigated and nonirrigated
land. The former will raise the productivity of irrigation water
and the latter will get more mileage out of existing rainfall. Shifting
to more water-efficient crops also helps raise farm water productivity.
The shift from rice to wheat, already under way in some countries,
can continue wherever it is practical. With feedgrain, shifting
from corn to sorghum may make sense in countries where there is
not enough water for irrigation.
At the dietary level, shifting to more grain-efficient forms of
animal protein can raise the efficiency of grain use, and thus the
efficiency of water use. This means moving from feedlot beef and
pork to more poultry and herbivorous species of farmed fish, such
as carp, tilapia, and catfish. For the world's affluent, moving
down the food chain also saves water.
At the consumer level, switching to more water-efficient household
appliances raises water productivity. For cities and industry, recycling
of water becomes the key to achieving large gains in water productivity.
Finally, and perhaps most important, for water-scarce countries
facing large projected increases in population, accelerating the
shift to smaller families reduces the chance of being trapped in
hydrological poverty.
ENDNOTES:
42. Asit Biswas, "Water Crisis: Current
Perceptions and Future Realities," in Groundwater: Legal and Policy
Perspectives, Proceedings of a World Bank Seminar (Washington, DC:
Salman, 1999), p. 1-11.
43. Calculation based on Peter Wolff and Thomas M. Stein, "Efficient
and Economic Use of Water in Agriculture-Possibilities and Limits,"
National Resources and Development, vol. 49/50 (1999), pp. 151-59.
44. Erik Eckholm, "Chinese Will Move Water to Quench Thirst of Cities,"
New York Times, 27 August 2002; "Per Head Water Resources on Decline
Along Yangtze," Xinhua News Agency, 31 December 2002.
Copyright
© 2003 Earth Policy Institute
|