Rosamond Naylor on Feeding the World

The economist discusses the stresses that climate change and a greater world population will have on our food supply

Rosamond Naylor
Invest in the poorest of the poor, advises Rosamond Naylor. Mark Richards

Rosamond Naylor directs the Program on Food Security and the Environment at Stanford University. An economist by training, she studies the world food economy and sustainable agriculture. Though she says she is deeply worried about climate change and population growth, she described herself as “optimistic” in a conversation with Smithsonian’s Amanda Bensen.

By 2050, there will be an estimated nine billion people in the world. Do we have the land and water to feed them?
The arable land area is certainly not enough to meet those demands unless there are major breakthroughs in terms of crop yields. Agriculture and livestock are by far the largest water users in the world. We could have water shortages in a lot of locations. Farmers are going to have to adopt new technologies and crops to be more conservative in their water use. I look to feedbacks in the system. As we start hitting periods of shortages, there is typically more commitment to invest in agriculture to increase productivity. Agricultural markets are dynamic, prices reflect scarcity, and production and consumption can change. I think these dynamics are going to kick in to help.

How do those dynamics work?
As water becomes more scarce, farmers are probably going to switch to crops that are less water-intensive, or that rely on drip irrigation. Or as food prices rise for consumers, maybe they won’t eat quite as much meat—especially not as much as we do in the United States—and that will have a feedback on the demand side. We can either adjust and start using land and water more efficiently, or people are going to suffer. A billion people are chronically malnourished and can’t afford adequate food right now. If prices go higher, the poor will be among the first to suffer.

You mentioned the need to increase crop yields. How?
There’s a big gap between farmers’ yields and experimental yields, that is, the highest that could be achieved. In places like Nebraska, farmers probably are close to the yield ceiling on corn. But for most of the world—Africa, Asia and Latin America—other constraints are keeping farmers from reaching more than 50 percent of the yields we achieve in the United States. Are there incentives to raise crops in more efficient ways? Are there policies that stabilize prices, so farmers invest in crop productivity? Do farmers need better roads to access markets, or credit to buy fertilizer?

Why are so many people hungry?
Persistent poverty. This is really where the population issue comes in, in a nasty way, because it’s so hard to take care of everybody. Maybe we’re not thinking about it right. Maybe we’re thinking that everything will trickle down to these folks—and it’s not going to. The global community has only begun to focus on what kind of crop investments you need to reach the poorest of the poor. I think the Gates Foundation, the McKnight Foundation and the Rockefeller Foundation are trying to get at that on a big scale now. They’re trying to figure out how to get seed markets going, improve crop marketing for the poor, improve nutrition and make rural economies functional.

How might climate change affect the world’s food supply?
What we know for sure is that temperatures are going to increase, which will cause crop productivity to fall after a certain threshold. People say, well, in the United States, if we have warmer temperatures, won’t that increase corn production, for example? Yes, up to a point—then there is likely to be a huge drop. Temperature affects evaporation and moisture stress on crops. With the temperature increases that are projected for the next 40 to 50 years, we’re going to start to see drop-offs in many parts of the world, particularly in the tropics and subtropics. As the planet warms there may be more moisture in the atmosphere overall, but it won’t necessarily fall where you want it, when you want it.

Can you offer an example of increasing food access in a needy population?
We’re involved in a project right now in Benin, West Africa, where it rains only three to four months of the year. We’re using solar-powered drip irrigation to irrigate small plots of high-value crops for poor farmers. Indigenous legumes that yield more protein and fertilize the soil. Carrots and leafy vegetables that are very nutritious. And the markets are right there in the very poor areas. Farmers are taking their products to market at 5 in the morning and it’s all gone by 5:15. It’s amazing. In villages where we’ve been evaluating these techniques, there’s been a doubling and tripling of income for families involved, and nutrition has improved throughout the communities.

Do you think genetically modified crops are part of the solution?
Traits like heat tolerance and drought tolerance in crops are probably going to be induced much more efficiently by genetic engineering than by traditional breeding. I think both approaches have to be part of it.

What about underutilized conventional crops, or so-called orphan crops?
This is why I’m optimistic. There are a lot of crops already out there that are extremely drought and heat tolerant—we’ve just moved away from them. The agricultural development mentality in the past has been “rice, wheat and corn”—the major staple crops—not “What diversity of crops is more functional, not just ecologically, but economically, for that region?” There needs to be a focus on both nutrition and incomes. The more the global community focuses on food insecurity as being an extremely important issue—and one that will lead to a lot of human suffering if it’s not dealt with—I think all sorts of innovative approaches could come in.

Get the latest Science stories in your inbox.