Water-short world will need 'more crop per drop' - experts

Megan Rowling

Water must be used more efficiently to meet rising food demand from a growing population amid climate-change pressures, experts say.

MARSEILLE, France (AlertNet) - Water must be used more efficiently and its waste reduced if the world is to meet rising food demand from a fast-expanding population amid the pressures of climate change, experts have said ahead of World Water Day.

Marked each year on March 22, the United Nations hopes the 2012 event will focus attention on water's critical role in feeding the world.

The U.N. Food and Agriculture Organization (FAO) says the world will have to produce up to 70 percent more food to feed a global population expected to reach 9 billion people by 2050, from the current 7 billion. That will require better management of water, boosting farmers’ resilience to climate shifts, and cutting food and water waste.

Water consumption by agriculture is estimated to rise 19 percent by 2050, but the figure could be much higher if crop yields and production efficiency don't improve dramatically, warns the latest U.N. World Water Development Report.

Water scarcity already affects more than 40 percent of people on the planet, and two-thirds could be living under water-stressed conditions by 2025, according to the FAO.

"Agriculture has to be more efficient in water use - which means more crop per drop - otherwise the demand cannot be met and we will run into a big, big competition between water for agriculture, water for industrial purposes and water for municipalities," Alexander Müller, FAO's assistant director-general for natural resources and the environment, told journalists at the World Water Forum in Marseille, Paris, last week.

"If we don't find solutions for water and agriculture, we will not find solutions for the other sectors," he added.

In a guide to water and food security issues for World Water Day, the FAO points out that farm irrigation accounts for 70 percent of all water withdrawn from "blue water" sources such as rivers, lakes and aquifers. Only a fifth of the world's cultivated land is irrigated, but it contributes 40 percent of total food production.

Gao Zhanyi, president of the International Commission on Irrigation and Drainage, said this makes agriculture a vulnerable sector. "With the rapid development of urbanisation and industry, a lot of water previously used for irrigation in agriculture is now shifting to other sectors... So we have to use non-conventional water," he urged.

Non-conventional sources include water that is safe for reuse, treated waste water and desalinated water. Over 80 percent of waste water worldwide is not collected or treated, according to the U.N. water report.

ADAPTING TO CLIMATE CHANGE

Climate change is clouding the outlook further, because its main impacts are on water resources, the FAO says.

A warming planet is widely predicted to result in more extreme weather patterns, bringing more frequent and intense droughts, flooding and heavy rainfall events. And the Mediterranean Basin and semi-arid areas of the Americas, southern Africa and Australia are expected to experience further reductions in water availability and quality.

"Climate change can be seen as a multiplier of already existing risks. Where people are vulnerable today, they will be even more vulnerable tomorrow," said FAO's Müller. "In the agriculture sector, adaptation to climate change is of the utmost importance, and water very often is at the centre of adaptation to climate change."

Zhanyi said more water storage facilities should be provided to help farmers regulate an increasingly erratic water supply. "We have to upgrade the system with more resilience to variations in precipitation and run-off," he argued.

Other methods outlined in the FAO World Water Day briefing include conservation agriculture, which protects the soil; small-scale irrigation techniques like treadle pumps and drip irrigation; changing rice cultivation so it uses less water; and farming fish in rice paddies.

Zhanyi said smallholder farmers in Asia and Africa will need government support to utilise new techniques, otherwise they will start abandoning their land and head to cities to look for work.

INTEGRATED APPROACH

A key consensus reached among ministers and government officials attending the water forum in France was on the need for stronger cooperation and policy integration between water, food and energy.

Today, a lack of joined-up thinking across these sectors, as well as between consumers and policymakers, is causing major problems for poor communities in some parts of the world.

In Mali, for example, farmers who live downstream of major dams and sluices on the Niger and Bani rivers have been deprived of the annual floodwaters they rely on for rice-growing, fishing and grazing, as water is diverted upstream, according to Wetlands International.

Its CEO, Jane Madgwick, said this is more to blame for the drought now affecting the region than low rainfall.

"If this situation continues, and if the additional hydropower dams that will also support irrigation go ahead, then catastrophic drought years will become a regular event," she warned.

But that could be avoided with the adoption of water efficiency models, increased use of solar rather than hydro-power, and consultation with downstream farmers, she added.

Many experts believe a more holistic, collaborative approach to water resource management is the only way to avoid social conflict as demand for water grows.

Some fear that if policymakers don't follow their advice, the outcome could be unrest of the kind that erupted during the food price spike in 2007-2008.

"Demonstrations and riots in urban areas put a lot of pressure on governments," said FAO's Müller. "This might also happen with water in the near future. The competition has already started."