In his recent book, pioneering environmental analyst Lester R. Brown takes on the world of food. Full Planet, Empty Plates: The New Geopolitics of Food Scarcity provides a look into food scarcity, falling water tables, eroding soils and rising temperatures, and what that means for communities, companies and countries. I’ve been following Brown since the 1980s, more than a decade after he founded the Worldwatch Institute, a globally focused environmental research organization based in Washington, D.C. In 2001, he left Worldwatch to establish the Earth Policy Institute, dedicated to "planning a sustainable future and providing a roadmap of how to get from here to there." At age 79, Brown remains as prolific and passionate as ever.

I spoke with him recently about the challenges and opportunities in a world with a growing demand for food, a rising population and climate change. The conversation has been edited for clarity and length.

Joel Makower: Let's start with the notion that we take the premise of your book as valid — that, as you put it, food is the new oil and land is the new gold. Looking at this from a business perspective, what do you think the proper business response should be?

Lester Brown: I think the important thing is to recognize that there are several trends converging during this decade, the second decade of the 21st century, that are going to make it more difficult for us to keep up with what has become, in the last few years, record growth in the demand for grain. We're looking at a situation where the cropland area is not going to increase very much in the future. In some countries, it's decreasing already, either because of slow erosion or because of a loss of irrigation water in some cases.

And they're also looking at a tightening water supply worldwide. Almost everywhere you look in the world today, countries have gone beyond the supply of surface water available from the traditional dams and rivers, to turning to underground water. And we look at the big three countries, for example, that account for half of world food production — China, India, the United States. All three are over-pumping.

China is over-pumping under the North China plain, which produces half of its wheat and the third of its corn. India does not have any limits on the drilling of irrigation wells. As a result, we've seen the number of wells soar in recent years. They now have 26 million irrigation water pumps pulling water from underground, with the result that the water table's falling very fast and some of these wells are already starting to go dry.

In the United States, we have been pumping heavily in the western Great Plains, the Texas panhandle, Oklahoma, Kansas and southern Nebraska from the Ogallala aquifer. The Ogallala happens to be a fossil aquifer like the one under the North China plain. That is, it does not naturally recharge, so it's like an oil field. Once you've pumped it out, it's gone, and we're already seeing wells go dry in western Kansas, Oklahoma, the Texas Panhandle and so forth. So, water is becoming a real issue where world food production is concerned.

Makower: I'm still not sure I've heard you describe the business response. What should companies be doing?

Brown: What's happening is that we're seeing a tightening of food supplies. We're going to see much higher food prices in the future. We've actually seen world grain prices double since early 2007 and that increase is going to continue in the future. And not only is that rise in prices likely to continue, it may well accelerate because we're pressing against the limits in so many parts of the world.

The land supply is now more or less fixed. We're not going to be adding much to the world's cropland in the future. And with water, we're over-pumping water, so there's a water bubble there that's going to burst one of these days when the wells go dry.

The third thing, of course, is climate change. Farmers have always had to deal with the vagaries of weather but climate change is something very different, and that is going to take its toll because agriculture, as it exists today, has evolved over an 11,000-year period of rather remarkable climate stability. Suddenly, the climate system is changing and with each passing year, the climate system and the food production system will be more and more out of sync with each other. This means tighter supplies and higher prices and I don't see any way at this point of avoiding that.

Makower: So if I'm a Unilever or a Tyson’s or McDonald's or Procter & Gamble, how should I be thinking differently? What should I be doing?

Brown: First is what you do at the corporate level. The other is what you do at the global level and beyond narrow corporate interests. That's the easy one. We need to be thinking about how to raise water productivity in the same way that we started focusing on raising land productivity around 1950, when we suddenly realized there really wasn't much more cropland to be had in the world and since then, we've tripled grain yields and thereby tripled world grain harvests.

We have to ask ourselves, "Can we do something like this with water?" We don't know the answer, but that's the challenge. And from a more narrow corporate point of view, the question is whether supplies will be adequate — whether it's McDonald's or Unilever or what-have-you — whether it's grain or vegetable oils. And if they're going to be tighter, how do we go about dealing with this in a way that's not politically destabilizing, in a way that doesn't create social unrest? This, I think, is the bottom-line issue on the world food front today.

Makower: How much do you think this is a technology solution, where we learn how to use water much more efficiently as we have with cropland, and increasingly with energy, or how much do you think it's a policy solution in terms of pricing water at a more reasonable level that reflects its true value or cost?

Brown: If I were to pick one thing that I think we need to do on the water front, it is to put a price on water that reflects its current value. Water a half-century ago was essentially a free resource, and in many parts of the world it still is. Farmers who are irrigating in California and in large parts of China and elsewhere have never been charged the full cost of the water they're using, so we've treated it as a free good. It's no longer free and it's no longer cheap, but we have not yet made that adjustment.

Makower: What about the role of technology? Do you see technologies that are being used now or that are coming online that can dramatically reduce water use, whether it's for food or for human use?

Brown: There are some things that can be done. The Israelis have been a leader in developing drip irrigation, for example, and that's good for intensive vegetable production, or orchards of fruit trees, but it doesn't work very well with wheat and corn production and that's what most of the world's cropland is used for. I think we're going to have to do in the food area what we started doing with oil a generation or so ago, and that is begin looking at the demand side, not just the supply side, and ask ourselves, "What can we do to reduce demand?"

We now all know about the importance of having more fuel-efficient cars and we've been making a lot of progress on this front in recent decades, but we now need to ask, "How can we produce food more efficiently?" Is it the irrigation technology? In some cases, that can be helpful. Is it shifting to less water-intensive crops? It takes roughly twice as much water to produce a ton of rice as a ton of wheat, so maybe we should be producing less rice and more wheat. These are the kinds of questions we need to be asking and they need to be part of the public policy debate, but you really don't hear very much about them.

Now, you hear about the water shortages when they occur. We see the economic effects of water shortages showing up in higher food prices, but we've yet to really engage this issue in a meaningful way. There's very little work on linking food prices and CO2 levels, for example. But any meteorologist will tell you that if CO2 levels keep rising, food prices are going to rise also.

Makower: What about the role of biotech here? Obviously, it's controversial. The biotech companies are making strong cases that theirs is the solution to a world with more mouths to feed and less water to grow crops. Is that a solution that you see?

Brown: The advances or the applications of biotechnology, thus far, have been confined to increasing the insect resistance of a crop, like the new cotton varieties that are naturally resistant to the boll weevil, so you don't have to douse them with insecticides, as in the past. Another example would be corn varieties that are resistant to the boll weevil. Those are the sort of things that we've been able to do with biotechnology.

What we've not been able to do is to dramatically increase yields using biotechnology and the reason is because plant breeders had already done almost everything we could think of to do to raise yields before biotechnology arrived on the scene.

Makower: So, you're not seeing anything in the biotech world that's going to start to increase yields?

Brown: That's correct. And the reason is because we are currently pressing against the limits of photosynthesis in large parts of the world. That is, corn yields in the United States, rice yields in Japan and China, wheat yields in France and Germany and the UK — these are crops where yields, after rising for decades, have plateaued within the last decade or so and are no longer rising, and these crops where yields have plateaued now account for about 40 percent of the world grain harvest. And with each passing year, that 40 percent keeps rising. In another few years, it'll probably be 50 percent. But we have not yet, at the public policy level, realized that we are increasingly pushing against the limits of photosynthesis with grain yields.

And once you've reached that level, there's really no place to go. Once you've eliminated the nutrient constraints on yields and once you've eliminated the moisture constraints insofar as you can, then photosynthesis is the only remaining constraint, and that's what we're pushing against now and that's why yields are starting to plateau after several decades of rise.

Makower: So is there any optimism here? Is there a pathway that you see to take us out of this downward spiral around food?

Brown: One of the things we’re beginning to realize is that we have some slack in the system with biofuels, and if push comes to shove, my guess is that food's going to win over biofuels in terms of the response to prices; so that's one.

Makower: So you're talking about switching some cropland that's used for biofuels over to food?

Brown: That's correct. To food or feed, one or the other.

A second source of security in the system is there are a lot of us, probably close to a billion people in the world, who can move down the food chain and who would probably benefit from moving down the food chain because we're living too high on the food chain for our own health. We're consuming too many fat-rich livestock products. So that also provides a question of sorts.

Makower: I want to end this where I started this, which is: If you were the CEO of a multinational company in the food sector — part of Big Food, if you will — how would you start to rethink or realign your company for a world where we have a full planet with empty plates?

Brown: What we've seen governments begin to do in the last few years, particularly governments in food-importing countries, is they have begun to look for land in other parts of the world that they could use to produce food for themselves. This will become a temptation in the corporate world, where companies that depend heavily on grain or vegetable oils or what-have-you will begin to look for ways that they can assure the supplies they will need to, in effect, stay in business, at least on a scale comparable to where they are today.

This is a new situation because historically, we never had to worry — we could always produce more. Sometimes it would take a jump in grain prices, but we always had the slack there. We don't have that anymore. I mean, if you go back over the last half-century, back to the mid-20th century, we had large areas of grain set aside in the United States because we were producing too much. But that idle cropland, under government programs, disappeared about 1985, so we don't have that anymore.

We used to have huge stocks of grain in the world; enough carryover stocks when the new harvest began to feed the world for 100 days. That's now down to 61 days. So, we're living much closer to the edge and a poor harvest next year, for example, in a situation where reserves are so low and prices are already high, would create a lot of instability in world grain markets. And that instability, I'm afraid, is going to become part of the agricultural landscape in which agribusiness firms will be doing business — it's something they're going to have to begin to integrate into their policymaking. They’ll have to think about building up their reserves in a way that they've not had to do before.

Image of Brown courtesy Earth Policy Institute