by Maria Wirth
The most efficient greenhouse gas (GHG) reduction measures may not come only from the energy sector. The extraction, treatment and transport of water, for example, accounts for 8% of worldwide energy generation, according to UN-Water. As population growth and climate change are exacerbating resource scarcity, scientists, infrastructure managers and the private sector are actively searching for solutions beyond sector limits. By 2030, the world will need 30% more water, 45% more energy and 50% more food, according to official United Nations projections. Population growth, urbanization and rising incomes will require development planners to rethink trade-offs among the allocation of increasingly scarce resources. A static perspective of energy, water or food production cannot therefore hold up amid current trends.
The quest for energy security has incentivized biofuel cultivation, which competes with food production for land and water resources to such a degree that it causes malnutrition in affected regions. But coal mining, processing and unconventional fossil fuel sources, such as shale gas and oil sands, as well as the combustion process itself, also require a lot of water. The Ceres Investor Network on Climate Risk found that of the nearly 40,000 oil and gas wells drilled since 2011 in the United States, 55% were in drought-pressured areas, further depleting local water supplies. Beyond process water for steam generation and cooling for condensation, the entire fuel cycle resulted in a global water withdrawal of 583 billion cubic meters for energy production in 2010, according to the International Energy Agency’s (IEA) 2012 report.
Food security requires intensified use of land and water, as well as energy-intensive machinery and nutrient production. Today, over half of the corn produced in the United States is used for ethanol, Greg Koch, managing director of Global Water Stewardship at Coca Cola, told The Guardian. This has led to historically high corn prices, as well as extensive land and water use for cultivation and fuel conversion. “A single variant solution, biofuels for energy security, does not work for a multi-variant problem,” explained Koch. Meanwhile, excessive use of fertilizers entails higher GHG emissions and pollution of surface and groundwater bodies, resulting in higher energy requirements for water purification.
Depletion of groundwater tables necessitates lifting water from even greater depths. Water-scarce countries in the Caribbean, North Africa, the Pacific and the Persian Gulf are increasingly turning to seawater desalination – the most energy-intensive source of water. The UAE is ranked first in this regard, acquiring over 90% of its municipal supply from desalination. Benchmark values issued by the World Water Assessment Program (WWAP) in a 2014 report indicate that energy required to desalinate seawater amounts to up to 100 times that of conventional water production for potable use. At rates such as these, a reduction of end-use water intensity may significantly conserve water, energy and land.
Several South African researchers have called for a “nexus” perspective when it comes to the issue of water, food and energy. As interconnected resources, their joint exploitation should translate into interrelated pricing for water-, energy- and food-related products. As things stand currently, prices and public services themselves challenge nexus-consistent planning. Sonal Pandya Dalal, director of Conservation International’s Business and Sustainability Council, has pointed out that water is not only a salient component of the nexus, it is also the weakest link as a basic human right and free resource. Even private-sector giants Shell, Chevron and Coca Cola have recognized the urgency to plan according to the “bigger picture.” All three are implementing projects to conserve water resources at their production sites in cooperation with local communities, reports Dalal in a blog entry on GreenBiz.
Opportunities to reduce cross-cutting impacts include micro-hydro installations designed to capture energy spent on water conveyance or energy production from wastewater sludge. Researchers have developed tools for a “system of systems” integration to model optimal resource use for water, energy and food production. Broadly speaking, a comprehensive understanding of the nexus will enable robust infrastructure planning, as well as reduced fuel imports, GHG emissions and expenditures.
The Water-Energy-Food nexus is still a relatively loose concept, however, and plenty of uncertainty regarding how successful nexus-based policy should look remains. This was the subject of the first Bonn2011 Nexus Conference, which was followed by subsequent events, reports and development programs issued by several UN institutions, the Intergovernmental Panel on Climate Change (IPCC) and the IEA, as well as a host of research institutions. Still, government departments as isolated “silos” continue to pose obstacles to broad nexus-consistent policy. Thus, although the Water-Energy-Food nexus has certainly outgrown the status of mere buzzword, any real impact on institutional structures may take another decade.