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Mole's Progressive Democrat

The Progressive Democrat Newsletter grew out of the frustration of the 2004 election. Originally intended for New York City progressives, its readership is now national. For anyone who wants to be alerted by email whenever this newsletter is updated (usually weekly), please send your email address and let me know what state you live in (so I can keep track of my readership).

Location: Brooklyn, New York, United States

I am a research biologist in NYC. Married with two kids living in Brooklyn.

  • Help end world hunger
  • Thursday, August 06, 2009

    Your Water Footprint

    Just as everyone is getting used to their carbon footprint and trying to reduce it, we now have to consider our water footprint. Actually, this is not a new problem, but the idea of quantifying it this way is new.

    Fresh water is a precious commodity. Most Americans are not really aware of how scarce fresh water can be, unless you are a farmer in a drought struck area. But in many parts of the world, fresh water is hard to come by and, although I don't believe any modern international conflict can be comlpetely attributed to conflicts over water, water rights play a role in the conflicts between Israel and its neighbors, between India and its neighbors and in Central Asia...and probably elsewhere. Population growth and industrialization (increased demand) combined with pollution and deforestation (both of which reduce the supply of fresh, clean water) create frequent local crises that can then lead to regional conflicts.

    I should note that at times the conflict aspect of water scarcity is overstated. There is an interesting exchange of opinions this year in the scientific journal Nature where one article asserts water scarcity is more a driving force for cooperation, and three responses, one from an Israeli expert on water usage issues and one from Polish agricultural experts and one from former World Bank vice-president Ismail Serageldin, give different views on this.

    Another view is presented in a Current TV piece:

    I tend to view water scarcity not necessarily as THE deciding factor in two nations going to war, but it does create tensions between nations that can and will exacerbate existing tensions.

    The possibility/probability of water increasing world tensions has led some people to advocate the idea of a water footprint as a measure of a person's water usage. From Water Footprint.org:

    People use lots of water for drinking, cooking and washing, but even more for producing things such as food, paper, cotton clothes, etc. 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.

    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."

    You can calculate your water footprint here.

    Not surprisingly, some of the same consumption habits that lead to a high carbon footprint also lead to a high water footprint. Eating beef, for example, is among the most carbon intensive activities, AND uses 15500 litres of water per kg of beef. Eating cheese is not much better in terms of carbon footprinnt, but is better in terms of waterfootprint: 5000 litres of water for 1 kg of cheese. By comparison, eating chicken is far less carbon intensive than beef or cheese, and uses 3900 litres for 1 kg of chicken meat (much less than beef, slighly less than cheese). Pork is somewhere in between in terms of both carbon and water footprint. Eggs take 200 litres of water for one egg. So eggs are a good option compared with any meat. Milk takes 1000 litres of water for 1 litre of milk. I should re-emphasize that in terms of carbon footprint, chicken and eggs are MUCH better than beef, milk or cheese. And, of course, chicken is healthier. So...when making choices about meat, chicken and eggs are the best way to go. As another comparison, soybeans takes 1800 litres of water for 1 kg of soybeans. So in terms of water footprint, though not necessarily carbon footprint, eggs are better than tofu.

    Among grains, wheat requires 1300 litres of water for 1 kg of wheat. So does barley. Corn is better with 900 litres for 1 kg of maize. Millet is high for grain: 5000 litres for 1 kg of millet, about the same as for pork or cheese and a bit higher than chicken. Rice, as you'd expect given how it is grown, takes a lot of water: 3400 litres for 1 kg of rice. Not as bad as millet.

    Some more comparisons. Wine: 120 litres of water for one glass of wine. Beer: 75 litres of water for one glass of beer. Coffee: 140 litres for 1 cup of coffee. Tea: 30 litres of water for one cup of tea. So...it is more water intensive to have a coffee habit than a wine or beer habit. But tea is the most benign from this point of view.

    What I never see anyone take into account is tobacco use. Smoking has a carbon AND water footprint, as well as supporting some of the most irresponsible and right wing companies in America. Yet rarely is this mentioned.

    Next to meat consumption, industrial usage is the largest component of an American's water usage. This means the clothes and electronics and other products we buy actually are a much bigger component of our water usage than what we drink or shower with. This averages out to 80 litres of water per US$ of industrial product. So if you buy something that costs $100, on average 8000 liters of water went into producing it. Keep in mind that is a huge oversimplification, but worth keeping in mind.

    Of course consumption is just part of the problem. Pollution of our waterways as well as deforestation (which reduces the capacity of a region to store water after rains, creating flood/drought cycles like Bangladesh sees every year) reduce the supply of potable water. Groups like Riverkeeper work to preserve our waterways. And the group Trees, Water, People combines the need for fresh water, reforestation and development in a very intelligent way (I support them every year).


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