Sustainable Use of Water
- Virtual Water Trade
- Water Footprint
- Embodied Energy
Virtual Water
Virtual water concept measures how water is embedded in the production and trade of food and consumer products.
Water Footprint
The water footprint is an indicator of water use that looks at both direct and indirect water use of a consumer or producer. The water footprint of an individual, community or business is defined as the total volume of freshwater that is used to produce the goods and services consumed by the individual or community or produced by the business.
Life Cycle Analysis (LCA) and Water Use
When we analyze a product's life cycle, two of the important factors are the "embodied (or embedded) energy" and "virtual water," both of which are accounting methodologies for establishing the total energy or water required for a product or service to exist in the world, including raw material extraction, transport of parts, disassembly, and decomposition or recycling. From an environmental perspective, a value cannot be accurately placed on a product or service without considering the cost of all of these in-between and indirect phases.
Embodied Energy
Some
researchers have attempted to use the methods of energy analysis, which
aim to produce embodied energy estimates, to derive virtual, or
embodied water estimates.
The Relation Between Consumption and Water Use
The interest in the water footprint is rooted in the recognition that human impacts on freshwater systems can ultimately be linked to human consumption, and that issues like water shortages and pollution can be better understood and addressed by considering production and supply chains as a whole.
Water problems are often closely tied to the structure of the global economy. Many countries have significantly externalised their water footprint, importing water-intensive goods from elsewhere. This puts pressure on the water resources in the exporting regions, where too often mechanisms for wise water governance and conservation are lacking. Not only governments, but also consumers, businesses and civil society communities can play a role in achieving a better management of water resources.
Impact of Virtual Water
Once you add up all the virtual water you eat and in the products that you buy along with the daily use of water out of the tap, you will have a better idea of what your water footprint is. Water footprints are used to give nations a better consumption-based indicator of water use.
The term virtual water describes the amount of water used in the production of a commodity. Some 1,000 litres of water are needed to produce one kilo of wheat, 1,000 litres of water to make a litre of biofuel, 15,000 litres are needed for one kilo of beef, while a pair of jeans requires 4,000 litres, and a cup of coffee uses 140 litres of water to grow, produce, package and ship the beans, and a hamburger needs an estimated 2,400 litres of water.
"Currently, at least 24 nuclear plants in the south-eastern United States face shutdown or drastically limited operations because severe drought conditions have lowered the levels of lakes and rivers that supply cooling water - that's 23% of the nation's 104 nuclear power plants. Last year in Italy, the River Po ran so low there were plans to shut down power plants there. Big ships marooned as a result of the drought in China", according to the UN in January 2008.
Virtual Water Trade
Virtual water trade refers to the idea that when goods and services are exchanged, so is virtual water. When a country imports one tonne of wheat instead of producing it domestically, it is saving about 1,300 cubic meters of real indigenous water. If this country is water-scarce, the water that is 'saved' can be used towards other ends. If the exporting country is water-scarce, however, it has exported 1,300 cubic meters of virtual water since the real water used to grow the wheat will no longer be available for other purposes.
The contrast in water use can be noticed between continents. In Asia, people consume an average of 1,400 litres of virtual water a day, while in Europe and North America, people consume about over 4,000 litres. About 70 per cent of all water used by humans goes into food production.
Among the biggest net exporter countries of virtual water are the U.S., Canada, Thailand, Argentina, India, Vietnam, France and Brazil. Some of the largest net import countries are Sri Lanka, Japan, the Netherlands, South Korea, China, Spain, Egypt, Germany and Italy.
Water-scarce countries like Israel discourage the export of oranges (relatively heavy water guzzlers) precisely to prevent large quantities of water being exported to different parts of the world.
In recent years, the concept of virtual water trade has gained weight both in the scientific as well as in the political debate. The notion of the concept is ambiguous. It changes between an analytical, descriptive concept and a political induced strategy. As an analytical concept, virtual water trade represents an instrument which allows the identification and assessment of policy options not only in the scientific but also in the political discourse. As a politically induced strategy the question is, whether virtual water trade can be implemented in a sustainable way, whether the implementation can be managed in a socially, economically and ecologically fashion, and for what countries the concept offers a meaningful option.
The data that underlie the concept of virtual water can readily be used to construct water satellite accounts, and brought into economic models of international trade such as the GTAP Computable General Equilibrium Model. Such a model can be used to study the economic implications of changes in water supply or water policy, as well as the water resource implications of economic development and trade liberalization.
In sum, virtual water trade allows a new, amplified perspective on water problems: In the framework of recent developments from a supply-oriented to a demand-oriented management of water resources it opens up new fields of governance and facilitates a differentiation and balancing of different perspectives, basic conditions and interests. Analytically the concept enables to distinguish between global, regional and local levels and their linkages. This means, that water resource problems have to be solved in problem sheds if they cannot be successfully addressed in the local or regional watershed. Virtual water trade can thus overcome the hydro-centricity of a narrow watershed view. According to the proceedings of a 2006 conference in Frankfurt, Germany, it seems reasonable to link the new concept with the approach of Integrated water resources management.
Saving Water Saves Energy, Water in Terms of Protecting the Generating Resource
The energy and water industries have been looking more closely at the complex interconnection between two resources, as water use consumes 8 percent of the USA's energy for treatment, transportation and heating. The energy needed for these functions is the “embodied energy” in water use and is measured in kWh/gallon.
Likewise, powerplants require "embodied water", expressed in gallon/kWh, to cool systems. Add the fact that these functions occur mostly during peak use hours, and it becomes clear that water conservation also carries embodied energy-saving opportunities.
Water and energy conservation are often stove-piped as separate programs, but planners are starting to see the value of a systems approach. It is important to communicate the water/energy connection to residential end-users. Customers are not as likely as utilities and large industrial customers to see significant direct savings from integrated conservation plans, but people don't pay for water they don't use, so there is some immediate savings potential. Water's embedded energy costs get passed on to consumers in their water bills.
Making a Difference
People need to be educated about the situation that exists with virtual water. Since the world is becoming more water stressed, all possible remedies need to be investigated. Raising awareness of virtual water and green water is essential. If people are not informed nothing will be changed. Also, if the revelation of the amount of water actually consumed by each person was made known people might attempt to become more water wise.
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