Solving the Growing Global Water Scarcity

The study pro­vides the most com­pre­hen­sive pic­ture of the global water prob­lem to date, look­ing at monthly rather than annual changes and dig­ging into the actual causes of water depletion—agricultural, indus­trial, and domestic—in our ecosys­tems. While the find­ings aren’t rosy—more than 2 bil­lion peo­ple are affected by water short­ages each year—coau­thor Richter says there are still rea­sons to be hope­ful … read on to the end of this Q&A with him to find out what they are.

Q. Why is this study so impor­tant? Your num­bers seem to cor­rob­o­rate pre­vi­ous findings—water is scarce and get­ting more so, affect­ing bil­lions of peo­ple world­wide.

A. Previous stud­ies only looked at the amount of water with­drawn from fresh­wa­ter sources, not tak­ing into account the fact that much water is returned after use. For exam­ple, cities use a lot of water, but 80-90 per­cent of that water is returned to the orig­i­nal water source after use. If it’s returned in good qual­ity, it doesn’t deplete the water source and the water is avail­able for oth­ers to use and to sus­tain aquatic life.

Even with this dis­tinc­tion between water con­sump­tion and deple­tion, our study shows that it’s get­ting very dif­fi­cult to meet water needs in more than half of the river basins in the world—potentially affect­ing some 2.7 bil­lion people.

And we found that 92 per­cent of this water deple­tion glob­ally is tied to agriculture.

Q. So it sounds like ag is the place to start in order to solve the water prob­lem. Can we change our farm­ing prac­tices? 

A. Unlike cities, most water used to irri­gate farms is not returned to the ecosys­tem. On aver­age, more than half of that water is lost to the atmosphere—it either passes through the plant dur­ing growth or evap­o­rates from the soil. So cities use more water than crops on a per-area basis, but it’s impor­tant to note that irri­gated agri­cul­ture occu­pies four times as much land as cities do.

We need to help farm­ers imple­ment state-of-the-science irri­ga­tion meth­ods and improve the pro­duc­tiv­ity of rain-fed farms as soon as possible. We are going to have to pro­duce more food with less water. If we can’t do that, we can’t add another 3 bil­lion peo­ple to our planet. No way. And we will kill our rivers and lakes in the process.

Q. Tell us more about the impacts of water shortages—who or what will be hit the hardest?

A. We would expect that places with scarcity at some time dur­ing the year are already expe­ri­enc­ing eco­log­i­cal degra­da­tion in rivers or lakes, per­haps with recur­rent fish die-offs. In places with mul­ti­ple months of scarcity, they are likely expe­ri­enc­ing seri­ous com­pe­ti­tion for water, and dur­ing droughts they’ll have eco­nomic impacts in agri­cul­ture, power pro­duc­tion, or other industries.

For exam­ple, dur­ing the 2007-8 drought in Georgia, a severe reduc­tion in hydropower gen­er­a­tion cost the Southern Company elec­tric­ity provider more than $33 mil­lion. Water short­ages in California in 2009 dev­as­tated the state’s agri­cul­tural indus­try, lead­ing to an esti­mated loss of 21,000 jobs and more than $1 bil­lion in revenue.

The com­pe­ti­tion for water between cities and farms is get­ting rather intense. If you’re liv­ing in an area where the avail­able water is already being heav­ily depleted, it makes it very dif­fi­cult and expen­sive for a city to access addi­tional water needed for its growth. That’s why cities are spend­ing bil­lions to import water from far-distant rivers or remove the salt from seawater.

Q. There’s been lots of talk about com­pa­nies label­ing their products—from food to wine to clothing—with infor­ma­tion about the “water foot­prints” of those prod­ucts. Do you see this as a ben­e­fi­cial step? How close are we to it?

A. Labels could be very mis­lead­ing and not very use­ful if they aren’t done right. The real­ity is that it takes dif­fer­ent amounts of water to pro­duce the same con­sumer item in dif­fer­ent parts of the world, so just telling the con­sumer how much water was used in the prod­uct is not very useful.

What is far more impor­tant is whether the com­pany pro­duc­ing that good is using water as effi­ciently as pos­si­ble, and whether they are con­tribut­ing to sus­tain­able man­age­ment of the shared water resources wher­ever they operate. That’s what the Alliance for Water Stewardship (AWS) will be seek­ing to cer­tify begin­ning in 2013; if they decide to put out a label, it would be extremely use­ful because con­sumers could have con­fi­dence that the cer­ti­fied com­pany they’re buy­ing from is a good water steward.

Q. You also sug­gest that trade for agri­cul­tural prod­ucts can help by import­ing water-intensive prod­ucts from more water-rich areas—are loca­vores going to be up in arms over this?

A. When you know where your food is being grown and who’s grow­ing it, you have a bet­ter chance of under­stand­ing any prob­lems that might be caused by agri­cul­ture and you can help resolve those problems. So it’s good to try to buy our food from the closest-possible sources.

But buy­ing every­thing locally sim­ply isn’t pos­si­ble for everyone. When you’re buy­ing a food prod­uct from some dis­tant part of the world, you want to ensure that the water used to pro­duce it is being used sustainably—that’s what an AWS label could communicate.

Q. In your study you note that  an increas­ing demand for bio­fu­els is a fac­tor wors­en­ing water scarcity—how big of a deal are biofuels?

A. It takes 10,000 gal­lons of water to pro­duce one gal­lon of biofuel. That’s the most water-intensive way to pro­duce energy. In the process, you’re trad­ing off the use of a lot of water and land that could be used for pro­duc­ing food or sup­ply­ing water to cities. We need to take a much harder look at those trade-offs.

Click here to read the rest of this arti­cle at Grist.org.