Posted on 04/02/2010 6:52:16 AM PDT by Diana in Wisconsin
Which costs more, a dollar's worth of sugar or a dollar's worth of paint? That's not a trick question-the sugar costs more, if you count the liters of water that go into making it, according to a new study. Uncovering the water behind the dollars in sectors including cotton farming and movie making could help industries use water more wisely, the study's authors say.
Researchers know little about how much and where water is used. The United States Census Bureau stopped monitoring companies' water consumption in the 1980s, so the most detailed information available is the U. S. Geological Survey's 2000 report on water use in eight broad categories, such as irrigation, public supply, and power generation. But as demand for water increases, it would be useful to know water's relative importance to various industries, says Chris Hendrickson, a civil engineer at CarnegieMellonUniversity in Pittsburgh, Pennsylvania.
To refine the broad categories, Henderson and his colleagues followed the money. They started with the Census Bureau's 2002 economic input-output table, which tracks payments among all 428 industrial sectors, from architecture firms to frozen foods to zoos, and determined how much money each sector spent on water from the public supply. Then they looked at less obvious clues-dollars spent on power, for example, because power plants use massive amounts of water as a coolant. Finally, they used a computer model to quantify the amount of water needed to generate every dollar that flowed from one sector to another. This revealed which sectors used the most water and why.
Not surprisingly, grain and cotton farming top the list, with about 5000 liters of water going into every dollar of the final product. But the model's ability to trace water flow between sectors revealed water where you might not expect to find much. For example, manufacturing $1 of tortillas requires a scant liter of water. But because the process starts with corn or wheat as an ingredient and occurs in factories that run on electricity, that buck's worth of tortilla actually consumes about an additional 500 liters. In a whopping 96% of the sectors analyzed (power generation and agriculture are the two big exceptions), this indirect water consumption outweighed direct water consumption, Hendrickson and colleagues reported 15 March in Environmental Science and Technology. An online version of their model is available [at link].
Unveiling this "virtual water" achieves, for the first time, a true accounting of how much water a sector uses, says Michael Blackhurst, a graduate student at Carnegie Mellon and the study's lead author. "If you just look at [a sector's] purchases, you might miss very water-intensive activity." Knowing exactly where water is used could also help identify where we can conserve, Hendrickson adds.
"It's a very important piece of work," says Arpad Horvath, a civil engineer at the University of California, Berkeley. The next step is to take this study to the level of individual products and regions, which would show states and counties how much water local industries consume and help them decide whether it makes sense, given their resources, to approve new factories or expand farming. For example, "it makes a huge difference whether [a water-intensive activity] happens in Minnesota or California," Arpad says. "That geographic specificity will have to be included in the next piece of work, ... but it's wonderful that the authors have gotten to this point."
Too bad the same reasoning isn’t applied to ethanol ... According to the CARB ethanol produces 2x or more CO2 that regular gasoline does.
If you price water fairly at a market price instead of subsidizing some and punishing others with water prices, then the actual price of the water will be included in the price of the item. You won't then be trying to force deserts to bloom with cheap water and then complaining that too many people are trying to grow lawns in the desert.
But it also generates 5x more agri-welfare than oil ;)
More absurd feel-good faux-conservation.
My favorite example of faux-conservation is the toilets in the airport terminal in Portland, Oregon (PDX). They spent millions to install 2-way valves on the toilet flush mechanism so that users could choose whether to flush just a little or a lot.
Yet, Portland is located in one of the wettest regions of the country, and the Columbia River flows wide, deep and fast just 200 yards away.
Why bother saving water there? Who could use the water if it didn’t go down the toilet?
Gee, and from space it looks like we live on a WATER PLANET.
Let me know when 2/3 of earth looks like a Desert. Call me. I’ll wait.
When are they going to come out with a study that shows how much energy it takes to ship products that could be sold with an “add water” instruction at the end user? Fruit juice, all non carbonated drinks, shampoo, detergent, etc..
Use the finished product size container and just fill up to top and “shake vigrously”. Lazy housewives are costing us a fortune. The “shake vigrously” would also help in weight control and tone up flabby arms.
Sounds like a good project for EPA. If I was a Professor bet I could get a few hundred thousand for a study.
Apply! These days they’ll throw in a bushel of Rainbow Skittles and a Winged Pony along with your cash, LOL!
Just add water!
Hasn’t it been said that the 21st century will see massive wars in the mideast over water diversion?
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