Experts Explore the Crucial Need for Water Efficiency as World Population Soars
Energy, water, and food are intrinsically connected, and figuring out how to increase availability of one without compromising access to the others will be a demanding policy challenge as global population heads toward 9 billion by 2050, three resource specialists agreed in a wide-ranging discussion at AAAS.
The linkages among energy, water, and food production are everywhere. An estimated 70% of freshwater use goes to agricultural production globally, according to Melissa D. Ho, senior policy advisor for the Bureau for Food Security at the U.S. Agency for International Development (USAID). The remaining 20% goes for industry, and 10% for household use. In less developed nations, she said, 80% to 90% of fresh water can be allocated to agriculture. Use of water to expand agricultural output not only depletes water resources, it also requires energy. In turn, energy—in the form of fossil fuels—is used in production of fertilizers for food crops and to fuel the tractors and other equipment needed to grow and harvest the crops, as well as in the processing of food.
At the same time, substantial amounts of water are required to create energy. It is used to cool power plants fueled by coal, oil, natural gas, and nuclear power, and it is required to generate hydropower. Water also is used in great quantities during fuel extraction, refining and production, including increasing amounts going to hydraulic fracturing for natural gas production.
Each unit of fuel in the future, with few exceptions, “is going to be more water-intense and going to be harder to get,” said Nicole T. Carter, a specialist in natural resources policy for the Congressional Research Service.
Carter, Ho, and Cathleen Enright, executive vice president for food and agriculture at the Biotechnology Industry Organization (BIO), spoke 15 October at the second in a fall series of “Science and Society: Global Challenges” discussions at AAAS. The series is co-sponsored by the AAAS Office of Government Relations, the American Chemical Society, and the Georgetown University Program on Science in the Public Interest. The discussion was moderated by Richard Harris, a science correspondent for NPR.
More Crops with Less Water
Water’s predominant role in agriculture poses tough challenges for a planet on which nearly 900 million people are hungry and nearly 800 million live without access to clean drinking water. Ho noted that agricultural productivity typically is low in developing countries, often because farmers lack access to seed, fertilizer, and water. In sub-Saharan Africa, she said, less than 5% of agricultural land is irrigated, compared to 40% in East Asia, 35% in South Asia and 20% to 35% in the developed world.
In rain-fed, developed nations of the northern temperate zone, Ho said, crop yields are on the order of five to six tons per hectare (2.47 acres), compared to only half a ton to one ton per hectare for developing nations in semi-arid, tropical regions. There is a pressing need to develop technologies that use water more efficiently and increase agricultural productivity, Ho said.
Enright said there are steps that can and are being taken to reduce the amount of water used in agriculture and protect freshwater sources. Farmers are adopting no-till farming methods, she said, that reduce water evaporation, save top soil, and reduce on-farm fuel use. The biotech industry is developing genetically engineered plants that are drought-tolerant, enabling plants to better withstand periods of reduced rainfall.
Ho agreed that biotechnology has great promise for agriculture. But, speaking from her personal experience as a crop physiologist, she cautioned that drought-tolerance is not a single-gene trait. Developing tolerant plants involves a complex interaction of multiple genes, Ho said, and can depend from locale to locale on such environmental factors as rainfall and water availability, relative humidity, and soil type and depth.
USAID supports a wide range of technological solutions for drought and other agricultural constraints, Ho said, but each country should choose the tools that suit it best. Her agency provides technical assistance to developing countries, especially in sub-Saharan Africa, to help them better understand the science behind some of the new technologies and the appropriate regulatory frameworks for their oversight.
Genetically modified crops remain a political hot potato, particularly in Europe. Enright said the European Union’s biotechnology regulations also put pressure on African nations regarding adoption of the technology. Still, she said the value of genetically modified seeds is demonstrated by the increased use of such crops worldwide. An annual survey found that the amount of land planted in biotech crops reached 395.4 million acres in 2011, an increase of 8% over 2010. (The total is the equivalent of an area just a bit larger than Alaska). The United States remained the world leader with 170.5 million acres planted, but Brazil showed the largest year-to-year growth with a 19% increase to 74.9 million acres.
A New Age of Pricing and Policy
The demand for water, both in agriculture and energy production, is driving nations to consider new ways to manage and value water resources, the speakers said. Carter mentioned the experience of Australia, where she studied water issues on a Fulbright fellowship. Australia has moved to a water markets system, with most agricultural water traded as a commodity. The aim is to allocate the continent’s scarce water resources in a way that produces more crop value per drop.
Historically, most Australian states and territories bundled land property titles and associated water entitlements together, according to the website for the nation’s National Water Initiative. As a result of legal reforms undertaken as part of the initiative, most water entitlements are now assets independent of land.
Even as the market system has been improving the value generated from agricultural water, Carter noted, Australian officials are trying to cope with a huge growth in water impacts related to the recent development of coal bed methane. Aquifers are “de-watered” and often hydraulically fractured to access the gas. That produces significant quantities of wastewater. Australia’s states are struggling to account for this use of groundwater in their legal regimes and water markets, Carter said. They also are trying to develop policies for cost-effective treatment, reuse, and disposal of such waters.
Ho said Australia’s water management practices deserve attention. The nation “has now equalized the playing field and come up with a more strategic, comprehensive, sector-wide planning mechanism that actually rations the amount [of water] and optimizes the use across sectors,” Ho said. In the United States, she added, “we’re not quite there yet.”
She contrasted the Australian approach with that of a large American agricultural state: California. The state’s farmers historically have had low-cost access to water, Ho said, paying only about one-fifth what municipalities and other sectors pay. Water rights remain tied to the land, and Ho said farmers sometimes find it more advantageous financially to sell their water rights than to farm the land.
“Whether it’s a good thing or not, the world is changing and [water] is not an infinite resource anymore,” Ho said. “We need to figure how to better manage it.” Ho also noted that “putting a price on it” is one way of valuing and prioritizing the use of water in the future.
Carter agreed that increases in the cost to develop and use water are almost inevitable. “We’re not used to paying a whole lot for water,” she said, and that is changing.
One possible result could be “haves” and “have-nots” globally when it comes to the ability to pay for enough water. Moderator Harris raised the prospect of private-sector entrepreneurs building distribution networks in developing countries and selling water to the highest bidder.
Ho said there are alternatives, and told of a friend who is developing a social enterprise to sell drinking water to the poor for pennies a gallon. She said success depends on using the appropriate technology—a chlorination plant to process the water—and a distribution system that includes street-corner kiosks and delivery by bicycle. Ho called for “creative capitalism,” a phrase that former Microsoft chief executive Bill Gates has used to describe businesses that combine the pursuit of profits with a desire to serve the needs of those who may lack the means to pay for new technologies. Ho urged a creative capitalism that works from the bottom up, not the top down.
Carter stuck an optimistic note. “We have lots of demand for water,” she said. “But we also have lots of ways to treat it.” Water is increasingly reused during oil and gas operations, she said, and reuse of municipal wastewater and desalination of saline waters is becoming more affordable and efficient.
Produce Food, or Produce Energy?
Enright said she was optimistic on another contentious topic: the debate on whether expanding use of biofuels (such as corn for ethanol) will necessarily mean a reduction in the available land devoted to food crops. There has been an ongoing food-versus-fuel debate both in the United States and abroad.
“Here at home, I’m pretty heartened about how it is going to turn out,” Enright said. She said the land now being used to produce biofuels is largely “above and beyond” the land previously available for food production alone. She also noted that the biofuels industry is price-sensitive and cut production this year in the face of drought and rising corn prices.
The food-fuel equation is complex and driven by such factors as government tax incentives and mandates for use of ethanol in gasoline, Ho said. But about 40% of U.S. domestic corn production now is going to biofuels for either domestic use or export, she said, and that percentage represents a significant increase from a decade ago. With increased demand for corn for biofuels and higher commodity prices, Ho said, many farmers have been putting conservation land back into production.
Internationally, Ho said, the food-versus-fuel debate is playing out in “a potentially more ugly way.” She said large tracts of land are being bought or rented by foreign governments and private entities for food and biofuels production in the developing world, especially sub-Saharan Africa. Many of the transactions are not well-documented, she said, and critics question how the outputs and benefits of these investments will be shared with local populations, if at all.
Building Win-Win Policy
More broadly, the speakers agreed that well-crafted policies can encourage efficiency, promote innovation, and ensure sustainable use of resources. But those policies will vary from country to country, Carter said, and even within countries. In the United States, she noted, water resources are managed largely at the state level.
“Some people look to the national government,” she said, “but sometimes the best policy instruments can be refined closer to home.” How water is put to use is largely through private decision-making by individual households, farms, and businesses, she said. And while a national initiative may be appropriate for Australians, Carter said, national policies may be resisted elsewhere, including in the United States.
Ho said that access to water, particularly though backyard wells, long has seemed like a personal right. But if the overall result is a depletion of precious underground aquifers, she asked, “is it your right, or is there a goal for managing a common, shared resource?” She called for cross-sector water planning and sound pricing, citing the example of Seattle where the price of water is inexpensive until a certain threshold of use is passed, after which the price increases substantially.
Water policy always will have to accommodate multiple social goals and engineering approaches, according to Carter. “You don’t make policy choices using one metric,” she said. Scientists have tools and expertise to offer, she said, in the very difficult task of balancing the world’s urgent demands for energy, water, and food.
Read coverage of “Eco-Engineering: Addressing Water Challenges,” a recent forum at AAAS sponsored by Hitachi Ltd.
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