The importance of water
Photo: Jessica Sain-Baird
I see water everywhere, embedded into everything. This concept of virtual, or embedded, water is one I learned from my friend and colleague Tom Kostigen. The co-author of the New York Times best-seller The Green Book, Tom first explained the concept of virtual water in a 2008 Discovery magazine article, "Everything You Know About Water Conservation Is Wrong." At the time, the concept did not hold much interest for me. I was more concerned with the water I could see than the virtual water it took to make things. But Tom's latest book, The Green Blue Book, makes it clear that virtual water must be a priority too.

The book details tips for water conservation in our daily lives by revealing the water that is visible (in, say, a dripping tap) and the water that is embedded (the water it takes to make the tap itself). By understanding that a chicken requires about 468 gallons of water to process, while an egg contains about 23 gallons of virtual water, we can start to make smarter, systemic decisions about how to conserve our most precious resource.

Our water crisis is local and global. During a time when one in six people around the world does not have access to enough safe drinking water, and 45 of the 50 United States report "water stress" conditions, we have the opportunity to use less and do better. I interviewed Tom in honor of World Water Day—and the release of his book—to garner greater insights on what we need to do differently and why this issue requires our attention.