Tuesday, April 19, 2011

waterfootprint?



In class we are looking a our carbon footprints, but understanding and considering ecology is important too. This waterfootprint.org website is dedicated to understanding the connection water consumption and human needs.
You can determine your waterfootprint here. Water is important for consumption but it is also used to make products like paper and ethanol.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,” says Professor Arjen Y. Hoekstra, creator of the water footprint concept and scientific director of the Water Footprint Network. "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."

How much water does it take to make 1 kg of beef, a cup of coffee? Which countries are using the most water per capita?

  • The production of one kilogram of beef requires 16 thousand litres of water. There is a huge variation around this global average. The precise footprint of a piece of beef depends on factors such as the type of production system and the composition and origin of the feed of the cow.

  • To produce one cup of coffee we need 140 litres of water. This, again, is a global average.

  • The water footprint of China is about 700 cubic meter per year per capita. Only about 7% of the Chinese water footprint falls outside China.

  • Japan with a footprint of 1150 cubic meter per year per capita, has about 65% of its total water footprint outside the borders of the country.

  • The USA water footprint is 2500 cubic meter per year per capita.

Remember, statistics can only provide data based on what was entered in. The average consumption of water will vary a lot more than what is reported on a per capita basis. For instance, the US has several industrial plants and research labs consume a very large amount of water. The high consumption will greatly increase the per capita average. The average consumption level of each person is therefore greatly exaggerated due to outliers in industry. For example, ethanol plants consume anywhere from 4-6 gallons of water to make one gallon of ethanol. A plant making 100 million gallons of ethanol would require 400 millions gallons of water. Such a large sum of water means that only states, like Nebraska with large reserves of water are able to produce ethanol. This large demand on natural resources is depleting the aquifer faster than it is able to replenish itself. Overtime, it has become clear that Nebraska will need to conserve its water supply by prohibiting additional irrigation systems and ethanol plants. These outliers contribute to countries overall water and ecological footprint. I wonder, how many gallons of water does UGA consume a day?




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