Science News Online - Food for Thought

March 29, 1997

The environment upstream of our supermarket

Most of us stumble through a similar ritual each morning. Bleary eyed, we reach for the coffee can and begin measuring its aromatic contents into the filter of a brewing machine. Precaffeinated thoughts seldom roam far beyond catching up on the overnight news, finding a pair of shoes that match, or making sure the kids don't leave for school without their milk money.

Once the caffeine does kick in -- and the day officially kicks off -- thoughts begin to fly over the day's schedule and a host of unrelated things. But seldom does it focus on the coffee.

Yet there's a history to each scoop. Somewhere, someone cleared a tropical site for their Coffea arabica trees. Farm workers harvested the beans that grew on them, sacked those beans, and then sent them to far off places -- like the United States, where one out of every five cups of coffee is drunk.

John C. Ryan and Alan Thein Durning of Northwest Environment Watch, a nonprofit research center focusing on sustainable-economy issues, have taken a closer look at the chain of activities and resource demands that are linked to common purchases, from coffee and newspapers, to computers and cola. In their new report, Stuff: The Secret Lives of Everyday Things, they now describe -- and, where possible, tally -- the largely hidden environmental, energy, and social costs incurred as these products make their way to our local store. Their prosaic examples illustrate how large and international a "footprint" each of our local purchases can leave upon the planet.

Take coffee. Drinking two cups of java daily requires the purchase of some 18 pounds of beans each year -- or the total annual yield of some 12 coffee trees. So if you're a 2-cup-a-day drinker, somewhere 12 trees have your name on it, dedicated to doing nothing but feeding your personal addiction.

To keep those dozen trees productive, farmers will apply 12 pounds of fertilizer this year, not to mention some pesticides. When the fruit ripens, dollar-a-day pickers remove the trees' pulpy berries by hand and feed them into a diesel-powered crusher that will extract the beans inside. For each pound of beans, two pounds of the pulp wastes will be dumped into a nearby river.

Or consider french fries. Some 90 percent of Idaho potatoes are russet Burbanks, popular with fast-food franchises and makers of frozen fries because these spuds stay stiff after deep-fat frying. A russet Burbank grows on a half-foot-square patch of sandy soil. Over the 150-day growing season, a farmer will apply 7.5 gallons of water to each potato's plot -- water that was probably diverted from the Snake River, Ryan and Durning note.

"Eighty percent of the Snake's original streamside, or riparian, habitat is gone, most of it replaced by reservoirs and irrigation canals" to slake agriculture's thirst, the pair report. Salmon and sturgeon that once migrated back and forth to the ocean over this waterway now confront dams that block their passage. Sturgeon can live a century and grow to 1,000 pounds. "There are undoubtedly sturgeon in the Snake River," the researchers maintain, "that remember the smell of the Pacific Ocean, even though they have not been there for half a century" -- or are likely to ever get back there again.

What about hamburger? Much has been made in recent years about fast-food franchises buying meat from South American ranchers who burned down rainforests to pasture beef for export. In fact, much of the hamburger that Americans now eat comes from steers that grazed for a year on Midwest farms.

Then it's off to the feedlot. There, "workers driving heavy machinery spread the feed mixture in troughs as long as a city block," Ryan and Durning note. It takes 1.2 pounds of feed grain to build up the protein that goes into each quarter-pound burger.

In fact, they calculate, 60 percent of U.S. corn yields -- or about one-quarter of all corn raised globally -- is diverted to feed this livestock. What's more, the row-planted corn contributes substantially to erosion. Indeed, Stuff's authors calculate, growing the corn that's behind each quarter-pound burger permitted "the loss of five times that patty's weight in topsoil."

In the midwestern farm belt, growing the pound of corn behind each quarter pound of beef takes 6 square feet of former prairie and the equivalent of 1 cup of gasoline, the latter primarily to produce fertilizer for that land.

Water, water . . .

Growing a quarter-pounder's worth of corn also requires more than 600 gallons of water, the pair estimate. David Pimentel and his colleagues at Cornell University offer a slightly broader view, noting that it takes roughly 640,000 gallons of water to grow each acre of corn.

However, beef and potatoes are hardly the only agricultural demand on water resources, the Cornell team points out in the February BioScience. Their new accounting notes that globally, agriculture consumes 87 percent of the freshwater used globally.

While high-yielding corn cultivars are undeniably water hogs, the Cornell study shows that they hardly top the list. Each pound of rice that's produced takes 37 percent more water than an equivalent amount of corn, and soybeans 43 percent more water than corn.

But even these hardly hold a candle to meat. Producing 1 pound of animal protein requires roughly 100 times more water than does growing a pound of average vegetable protein. This reflects the tremendous vegetarian appetite of each animal.

At the high end of the spectrum are steers. The Cornell study finds that producing a single pound of beef requires 100 pounds of foraged hay in addition to the fattening-up chow provided at the feedlot. It takes almost 12,000 gallons of water to grow the vegetable protein that will ultimately result in one pound of beef. Producing a pound of broiler chicken, by contrast, takes only 3.5 percent as much water and vegetable resources as an does raising a pound of beef.

Nature's unvalued services

While largely hidden, these resources that are called upon to provide our food can be identified and at least vaguely quantified. As Nature's Services -- a book released this week -- points out, many other resources are devilishly hard to measure, much less to place some economic value on. Yet Gretchen C. Daily of Stanford University has recruited a distinguished team of scientists to argue the merits of trying.

Clearly, there will be no agriculture without soil or water. Yet how does one place a dollar value on each inch of rainfall that may disappear regionally with a global warming, or each inch of topsoil lost as the ground dries and erodes with the wind?

Though conservation of many endangered species has been predicated on the immeasurable richness they contribute to an ecosystem, the loss of these species may also bring an unexpected economic toll. If some increasingly rare flower were the sole enticement for bringing certain important pollinators into a region during the spring, for instance, then crop plants that had depended upon that pollinator's visits may suffer when the floral siren goes extinct.

Similarly, though broad-spectrum agricultural chemicals can kill unwanted crop pests, these chemicals often wipe out beneficial insects as well, including honeybees and other pollinators.

Though dollar estimates of the benefits provided by honeybees are tentative and a bit squishy, they now run to between $5.7 billion and $8.3 billion in increased crop yields within the United States, according to bee experts Gary Paul Nabhan and Stephen L. Buchmann, writing in Nature's Services. But their analyses suggest that native (that is non-honey) bees in the United States, which have all but been ignored in any valuation of pollination services, also offer astounding benefits. In the absence of honeybees, they too can pollinate large number of crops. Compared to yields that would have been realized in their absence, native bees could bring gains worth some $4.1 billion to $6.7 billion a year, Nabhan and Buchmann calculate.

Far less easy to quantify are the natural water-cleansing benefits of woodlands and wetlands or the pollution cleanup services provided by healthy soil microbes and plants (SN: 7/20/96, p. 42). Similarly hard to measure is the cost to our fish of toxic industrial pollutants that rain from the sky or long-range transport of pesticides into the soils and water that nourish our foods (SN: 3/16/96, p. 174).

At a press conference in Washington, D.C., this week, Daily and a number of other prominent scientists -- including Oregon State University zoologist Jane Lubchenco, retiring president of the American Association of the Advancement of Science -- called upon scientists to take up a new campaign: a valuation of Earth's essential natural resources and threats.

Illustration: Don Baker.

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