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Surviving in a Thirsty World

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Clean, fresh water is an increasingly scare resource in many parts of the world—and that will get worse with climate change. A recent research article reminds us that agriculture is by far the biggest user of fresh water, and calculates that it is responsible for about 92 percent of human water use. The bulk of the water used by crops is directly from precipitation. But even considering only the portion extracted from rivers or wells, or that is polluted and so cannot be readily used for other purposes, agriculture consumes more than twice as much as industry and domestic uses combined. So when we talk about water scarcity, agriculture has to be a big part of the discussion.

Sprinkler Irrigation often wastes water through evaporation. USDA photo by Jack Dykinga

It is noteworthy that different foods have very different water budgets. For example, while cereal crops like corn or wheat average around 1000 cubic meters of water per ton of grain, beef produced in CAFOs (confined animal feeding operations) use on average 15,500 cubic meters of water per ton of meat. This is largely due to the need for multiple pounds of grain to produce a pound of meat.

Eating less meat in countries like the U.S., where we consume an average of a quarter pound per day (4.5 time the global average), can help. So can substituting more-water-efficient meats for beef—like poultry, which consumes about 3,800 cubic meters of water per ton of meat.

Defeatist Rhetoric from Monsanto

Ultimately, we must do what we can to limit climate change. The farther we go down that path the harder it will be to produce enough food and find enough water later in the century, regardless of the agricultural technology.

Adaptation of agriculture will be very important, for example improving ways to capture rainwater and use it more efficiently in irrigation. Using ecologically-based agriculture that improves soil fertility helps too, because fertile soil retains more water for crops to use.

But emphasizing adaptation while suggesting that reducing climate change emissions is futile is unlikely to provide the answers we need—without doing both, and using our ingenuity on both fronts, it will be much harder to prevent an even more thirsty and hungry world.

So it was disappointing to hear a Monsanto scientist throw in the towel on mitigating climate change. Such rhetoric merely provides support for those who want to avoid working to reduce greenhouse gas emissions, even though we already know how to greatly reduce those emissions in economically sound ways.

Fossil fuel companies stand to gain by ignoring the need to adopt climate-friendly energy technologies and conservation. Similarly, it is self-serving for Monsanto and other biotech companies to downplay mitigation when they stand to gain from the need for crops adapted to climate change—that is, if biotech can deliver on its promises.

So Far, Not So Good

Monsanto and other biotech companies have touted their expectation of producing drought tolerant and water efficient crops. But it is not at all clear that Monsanto’s GE crops will be much more than a band aid on a hemorrhaging patient.

Monsanto’s first attempt at a commercial drought-tolerant crop, after years of research and development, is a small step forward. But even if it works as planned, its contribution will be underwhelming. The U.S. Department of Agriculture, which recently approved Monsanto’s new GE drought tolerant corn, found that it provides only about a six percent yield improvement, mainly under moderate drought conditions. That means that instead of, say, a 15 percent yield loss, there would be about a 10 percent yield loss during moderate droughts

And it is only likely to be useful on a relatively small fraction of U.S. (or global) corn acres where moderate drought could be anticipated, not where droughts are occasional but sometimes very important. It is unlikely to have much use during severe or extreme droughts like those that have been oppressing parts of the U.S. Great Plains. Under those conditions this corn would likely die, like any other, or at best produce very low yields.

Meanwhile, our obsession with GE has distracted us from the fact that there are many neglected crops from Africa and elsewhere that begin with a built-in level of drought tolerance much higher than for crops like corn. The big companies ignore these crops because there are no big global markets for most of them, despite their promise and importance to poor farmers. Conventional breeding is making strides—already outpacing GE—with drought tolerance and other traits in these and other crops (including corn) on shoestring public-sector budgets. Public sector breeding can also incorporate meaningful farmer participation, which can help ensure success.

Where are the Water Savings?

What about conserving water? I suspect that many assume that drought tolerant crops use less water, or use it more efficiently than other crops, but that is often not the case. Most often, drought tolerance and water use efficiency (WUE) are different traits, controlled by different genes.

Monsanto has been touting its intention to improve water use efficiency for several years, such as in this video. Elsewhere, one of Monsanto’s VPs said they want to get more crop per drop—a catchy phrase that means using less water to produce our food.

While it may be good PR, there is little evidence that Monsanto’s claim of improving WUE “holds water”. Monsanto is silent about improved WUE for its new drought tolerant corn, and there are no data in its petition to USDA that suggests increased WUE. Similarly, the public record also does not suggest that GE is making any real progress toward improved WUE.

The GE industry can take credit for a baby step forward toward improving crop response to drought. But let’s not get distracted from the much greater need to focus most of our efforts, especially in the public sector, toward the many other approaches that are likely to be much more useful and cost effective. Getting distracted by GE will only leave us thirsty for better solutions.

Posted in: Food and Agriculture Tags: , , , , , , , ,

About the author: Doug Gurian-Sherman is a widely-cited expert on biotechnology and sustainable agriculture. He holds a Ph.D. in plant pathology. See Doug's full bio.

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  • E. Ann Clark

    Doug: I am a long time fan of yours, and applaud much of what is written in this and earlier articles. Would take issue, however, with the comment about water consumption by beef. There are many ways to produce beef, only one of which involves grain. Livestock are, in fact, essential to sustain agriculture into the future, as argued in THE FUTURE IS ORGANIC (but it’s more than organic), a talk which I gave in 2010. The talk has been posted at
    (http://energybulletin.net/stories/2011-03-07/future-organic-its-more-organic) and elsewhere. Not too amazingly, given that cattle are herbivores and evolved to eat grass, it is quite possible to complete the entire beef production cycle (and most parts of pig as well) entirely without grain. Will hope to see acknowledgement of this point in future writings. Thanks for all you do – Ann

    • http://www.ucsusa.org/news/experts/doug-gurian-sherman.html Doug Gurian-Sherman

      Ann, Thanks for the comment. and the link. I appreciate very much all the work you have done on behalf of sustainable ag over the years.

      Yes, you are right, there are several ways to raise livestock, and pasture, especially for ruminants, is a good alternative. In fact, I have written about this in a recent report, “Raising the Steaks” (http://www.ucsusa.org/food_and_agriculture/science_and_impacts/science/global-warming-and-beef-production.html), and several years ago in “CAFOs Uncovered” ( http://www.ucsusa.org/food_and_agriculture/science_and_impacts/impacts_industrial_agriculture/cafos-uncovered.html ). Pasture could have a much lower water footprint when not irrigated (and typically pasture is not). Pasture beef could still use a lot of what the authors of the study I cited call “green water”, essentially precipitation. But that is not necessarily a problem (providing fields are not over-fertilized or over-manured). It is mainly the water extracted from rivers or aquifers for irrigation that is the issue.

      I intentionally specified CAFO beef in my post as a high water user. But I should have been more clear that we are not advocating that people give up eating beef (or other ruminants), only decreasing consumption in countries that consume very large amounts. Ruminants can have an important place on integrated farms. And on range land, where properly managed, can utilize forage where we could not otherwise produce food. But they do convert plant matter to food less efficiently than other livestock, so they require more land per unit of production. And ruminants produce a lot of methane, an important greenhouse gas. So while they should have a place on pastures and integrated farms, we think that this needs to better balanced in some parts of the worls with other food sources.

  • M. Jackson Pond

    Your “neglected crops from Africa” are neglected with good reason – they have proven not to be viable food crops outside small territories encumbered with unique geographic characteristics. They turn in inferior performances alongside what have become our traditional crops for the major global agricultural regions. You obviously are on a childish treasure hunt, assuming any obscure thing with an exotic name must possess magic qualities waiting to be re-discovered. Your arch-nemesis, Monsanto, knows better. That is why they are successful and you are not.

    • http://www.ucsusa.org/news/experts/doug-gurian-sherman.html Doug Gurian-Sherman

      Actually, one of those crops, sorghum, is the fifth most widely grown grain in the world. Millets are grown widely too, as is cassava (which is actually not from Africa, but is now widely grown there, on millions of acres). But because they are mainly used by developing countries, and not widely traded on international markets, they have not received their due attention. Where they occasionally have, they have shown lots of potential for increased productivity. For example, the world food prize was awarded a few years ago to a scientist who did just that with sorghum. Recent cassava varieties have several fold higher yields than older types. But much more needs to be done. I guess I have more confidence in technology’s ability to improve crops than you do, and this has been borne out where some effort has been devoted to these crops.

      The reason Monsanto does not work on these crops is because their markets are small, not for lack of potential. They are often grown by subsistence farmers for their own consumption or local sale, which makes them all the more important. GE is an extremely expensive technology, so a for-profit company can’t use it for important crops like these, where they can’t make a lot of money. This also illustrates the importance of public sector crop breeding programs–which have suffered in recent decades in favor of short-sighted private sector research–for crops and livestock that are not currently seen as highly profitable by big companies.

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