Surviving in a Thirsty World

March 6, 2012
Doug Gurian-Sherman
Former contributor

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.