Photograph by Gene J. Puskar, AP
Published February 26, 2010
This story is part of a special series that explores the global water crisis. For more clean water news, photos, and information, visit National Geographic's Freshwater Web site.
Save Water … Drink More Beer. The irony of this drinker's joke isn't lost on experts calculating our global use of H2O.
Like their cousin the carbon footprint, water footprints are one of the latest methods scientists and policy makers are using to assess humanity's impact on the planet. And now businesses are starting to use water footprinting as well.
A water footprint measures the total amount of water it takes for a company to manufacture and transport a product, or for a city, country, or business to operate.
Calculating water footprints can help businesses and communities better understand and prepare for the impacts of global water scarcity, according to experts.
And if this so-called embedded water information ends up on a product label—somewhat similar to the U.S. government's Energy Star label that indicates energy efficiency, or the U.S. Environmental Protection Agency's WaterSense label, which measures water efficiency—consumers may be able to choose products based on water footprints as well.
Exceptionally water-intensive products and food items include beef, coffee, and cotton. For example 2 pounds (1 kilogram) of beef requires 4,227 gallons (16,000 liters) of water to produce, once you consider the water needed to grow feed and process the meat, according to WFN. Likewise, 776 gallons (2,900 liters) of water is needed to make a cotton shirt.
The U.S. has the biggest water footprint per capita, at 766,098 gallons (2.9 million liters) per person each year, according to WFN. And across the Pacific, 65 percent of Japans total water footprint comes from beyond its borders in the form of imported products, the group says.
Now major corporations are warming to the idea of working with WFN and its partner organizations to measure the footprints of their operations and manufacturing processes
Beer giant SABMiller, one of the first to sign on, unveiled the first detailed corporate water footprint at this year's World Water Week conference in Stockholm, Sweden. The company said it will use the results to help manage its water use.
Global conservation organization WWF, a WFN partner, analyzed SABMillers operations in South Africa and the Czech Republic, measuring water inputs required to produce bottled beer—including the bottle itself. The analysis found that for each liter of beer brewed in South Africa, 41 gallons (155 liters) of water were used. But in the Czech Republic a liter of beer has a water footprint of 12 gallons (45 liters).
The much higher water cost of SABMillers South African operation was largely due to the country's more arid climate and greater reliance on crop irrigation, versus a cooler, rainier Czech Republic, according to WWF.
More than 98 percent of the beers footprint in South Africa was from the cultivation of raw ingredients such as barley.
Such data allows companies to identify potential water savings and plan for future shortages due to factors such as population growth and climate change, according to the SABMiller report's authors.
In most cases companies pay for municipal water or water rights, so increasing water costs are of concern as well.
Andy Wales, SABMiller's head of sustainable development, said in a statement that water footprinting will enable the brewer to understand which specific parts of the supply chain might face water scarcity, or poor water quality, in the future.
The Coca-Cola Company has also now water-footprinted one of its products—the 0.5-liter bottle of Coca-Cola Classic. Armed with the new knowledge, the company hopes to improve water efficiency by 20 percent before 2012, Coca-Cola water-sustainability manager Denise Knight said during World Water Week.
Knight wouldn't say what the Coca-Cola Classic's water footprint was, but she said that agricultural inputs were the largest contributor.
Knight also highlighted the impact of sugar beets and other crops that may require a lot of water, used to sweeten the drink. We recognize that across the globe that sweetener is going to be a key component of our water footprint, Knight said.
New findings will be used by WFN, based at the University of Twente, Netherlands, to standardize the way water footprints are calculated.
Applying a standard to water footprinting is crucial, said Stuart Orr, WWFs freshwater-footprint manager. That's because the complex ecological analysis, which involves identifying and measuring multiple water inputs, is "confusing everybody right now," he said.
But, footprinting represents the best tool for reducing water demand in already severely water-stressed countries that will have to support some 3 billion people by 2025.
"We cant screw this up," he added. "There is no Plan B with water. Lets be clear about that."
University of Twente's Arjen Hoekstra, creator of the water footprint concept, said the current confusion is not in the methodology but in "people who for the first time [are starting to] consider the issue."
"There are many questions raised which leads to confusion," he said. "There is a demand for practical guidelines—for tools that can be easily used by business. That is where the development will be."
A new manual due out later this month by WFN will spell out the method for calculating water footprints, whether its by individuals, businesses, or governments, Hoekstra added.
Some environmental groups are pressing for water footprinting information to be included on food labels so consumers can also play their part in choosing low-water-impact foods.
But WWF has said that its still too early in the water-footprint movement to provide label information. The group notes the complexities of comparing water footprints.
Meanwhile, many manufacturers remain skeptical of putting water footprint information on labels.
Donna Jeffries is sustainability manager at U.K.s Unilever, which has a large portfolio of household brands, such as Lipton tea and Ben & Jerry's ice cream.
She said detailed water footprint labels are an unrealistic prospect "when you have many thousands of products. We'd get so bogged down in measuring everything."
Sylvain Lhôte, of Austria-based plastics manufacturer Borealis, said the company was completely opposed to the idea of water footprint labels on its products.
"We think it is totally meaningless and misleading to talk about a product's water footprint," Lhôte said, adding that a products true ecological impact isnt revealed by water volume alone.
Two U.K.-based organizations that promote sustainable farming practices›:Sustain and the Food Ethics Council›:this summer proposed a flower-shaped eco-label that would have water as one of its key "petals."
Each petal would represent a different environmental concern.
Rather than showing water liters per kilogram, the food and drink stickers would show if a company practiced "good water stewardship."
This year the Finnish food company Raisio, for instance, introduced a label showing the amount of water used to produce a packet of its oat flakes.
Companies have plenty of incentive for providing such information, according to Hoekstra.
"Corporate image is an issue," he said. "It may damage their corporate image if they don't have a clear story to tell."
Special Ad Section
Our new Phenomena space blogger, Nadia Drake, will be bringing you tales from beyond our home planet.
Video of the Day
When the trembling stops, the disaster is only the beginning. Learn the basics about earthquakes.