WATER AND FOOD Charles R. O’Melia Johns Hopkins University After Alexander Zehnder

Sustainability as the Driver of Innovation Alexander J.B. Zehnder

Challenges in the Water Area  Waterborne disease, with emphasis on developing countries  Water for agriculture  Water infrastructure  Pesticides, hormonally active agents, pharmaceuticals, etc.  Water and ecosystems

Water availability and cereal import comparison between 1980–84 and 1995–99 From Yang et al. 2003

5 Water availability and cereal import comparison between 1980–84 and 1995–99 Adapted from Yang et al. 2003

Annual water requirement per capita for household, services, industrial activities (average 1990–95)

7 Annual water requirement per person Sufficient>1700 m 3 Water stress m 3 Scarcity m 3 Extreme scarcity< 500 m 3 From Falkenmark & Widstrand, 1992

8 Water availability and cereal import comparison between 1980–84 and 1995–99 Adapted from Yang et al. 2003

9 Estimated annual world water use total and by sector 1900–2000 From Postel, 1992

Water needed to produce 1 kg of plant material (dry weight) 10 Sorghum250Liter Corn350Liter Clover460 Liter Wheat500Liter Potatoes636Liter Cucumber713Liter Alfalfa900Liter Partially from Muller, 1974

11 Meat production Animals convert 5 to 15 % of the energy content of plant material into meat. The average is 10 percent.

12 Projection of water availability From Zehnder, 1999

Relationship of water-use efficiency to grain yield Grain yield (ton/ha) Water use efficiency (kg/m 3 ) Irrigated Dryland Y=0.259X – 0.016X 2 R 2 =0.88 From: Musick et al. 1994

Crop yield Yields of selected cereals (ton/ha) average AustraliaChinaEU (25)USA Barley Maize Rice Wheat According to FAO, 2004

Situation 2000 From Zehnder, 2002

Virtual water flows by regions (average over the period 1997– 2001) Unit: cubic km From Yang et al. submitted ExporterImporter N America73E Asia149 30C America64 22N&W Africa58 17M East55 27Others71 S America30W Europe26 21E Asia25 18M East35 12N&W Africa21 15Others38 Oceania15E Asia20 11S-E Asia24 10M East14 13Others24

Situation 2025 From Zehnder, 2002

18 Virtual water as part of a country‘s water resource ET ~8.4 Fossilgroundwater0.2 Desalination0.21 Virtual water exp. approx Virtual water imp. approx. 6.0 Rain9.2 Discharge0.5 External supply 1.03 Israel Singapore Rain1.7 ET1.3 from Malaysia 0.58 Desalination0.15 Virtual water imp. approx. 4.0 Run-off0.15 Discharge0.34 Numbers are in km 3 /yr

Water (Woda) by Wislawa Szymborska A drop of rain fell on my hand, condensed from the Ganges and the Nile, from the heavenward ascending hoarfrost on the whiskers of a seal, from the water of broken jugs in the cities of Ys and Tyre. On my index finger the Caspian Sea is the open sea, and the Pacific meekly flows into the Rudawa, that very same river that floated as a cloud over Paris in the year of seventeen hundred and sixty four on the seventh of May at three in the morning. There are not lips enough to utter your fugitive names, O water. You were in baptismal fonts and in the baths of courtesans. In shrouds, in love-enshrouded kisses. Eating away at stones, nourishing the rainbows. In the sweat of dew and pyramids, of lilacs. How much lightness there is in a drop of rain. How delicately does the world touch me. Whatever whenever wherever has happened is written on the water of Chicago.

Someone was drowning, someone dying called for you. That was long ago and that was yesterday. Houses you extinguished, houses you carried off like trees, forests like towns. Someone was drowning, someone dying called for you. That was long ago and that was yesterday. Houses you extinguished, houses you carried off like trees, forests like towns. Someone was drowning, someone dying called for you. That was long ago and that was yesterday. Houses you extinguished, houses you carried off like trees, forests like towns. You were in baptismal fonts and in the baths of courtesans. In shrouds, in love-enshrouded kisses. Eating away at stones, nourishing the rainbows. In the sweat of dew and pyramids, of lilacs. How much lightness there is in a drop of rain. How delicately does the world touch me. Whatever whenever wherever has happened is written on the water of Babel [Chicago].

Conclusions  Water is increasingly becoming an economic driving force.  Economic and political interdependence is growing.  Economic power of less developed countries needs strengthening.  Increased use of herbicides, insecticides, nutrients, genetically modified crops.  Significantly more water reuse can be expected.

Closure Environmental problems and their solutions involve complex technological, societal, cultural, economic, and political aspects. Environmental engineers and scientists must be comfortable traversing both the technical and the complex social terrain. Environmental science and technology can help to alleviate global environmental crises and contribute to world stability. We should do much more to save the lives of millions of children who die from easily preventable water-borne diarrheal diseases.

24 6 great challenges in the water area Good water quality for a growing population Enough food for all Water infrastructure (distribution & collection) Solution for water conflicts and fair water share for all Distribution between humans and ecosystems Water induced disasters Disaster protection