Speaker: Lester Brown, Earth Policy Insitute


Agriculture as it exists today has evolved over an 11,000-year period of rather remarkable climate stability. Agriculture as it exists today is designed to maximize production with that climate system. But that climate system is no more. It is now changing. This is what makes food projections, decisions by farmers so much more difficult than at any time in the past.

So we have water shortages; we have climate change. We also have soil erosion. In this country we had the Dust Bowl period of the 1930s. Farmers had been plowing and over-plowing grassland in the Southern Great Plains, converting grassland into cropland, and at some point it began to dry out and it began to blow, and we had the Dust Bowl. It was a warning. This was in the 1930s. In response to it, we did, among other things, create the Soil Conservation Service. The Soil Conservation Service had an agent in every county in the United States. The work of that agent was to help farmers devise agricultural practices that would reduce soil erosion—for example, begin alternating strips of wheat and plowed land. You see these strips in fields. That is to control erosion. We planted trees in the Northern Plains, hundreds of thousands of them, designed to slow wind and reduce soil erosion.

So we responded, and we got the Dust Bowl under control. We have done a pretty good job since then of avoiding another Dust Bowl. But in some places in the world there are huge new dust bowls forming now that dwarf the U.S. Dust Bowl of the 1930s. One is in Africa, south of the Sahara. There is a strip of land going across Africa with relatively low rainfall and a lot of cattle and goats. The African population is growing very fast, and the cattle and goat populations are growing at about the same pace. At some point they begin to overwhelm the capacity of the land to support the cattle. So we have, not one dust bowl, but a whole string of dust bowls now forming across Africa just below the Sahara, in what we call the Sahelian zone.

We are also seeing a huge dust bowl develop in northern and western China. To put this in perspective, the United States and China, which are comparable in size geographically, in terms of ability to produce crops and support feed cattle and so forth—the United States has about 100 million head of cows. China has about 100 million head of cows, mostly dairy in both cases, but a lot of beef cows too in the United States. But now we look at sheep and goats. The United States has 9 million sheep and goats. China has 282 million sheep and goats. This is what is creating the huge dust bowl in northern and western China. The same force is at work across the Sahelian zone of Africa. So we have two large areas of the world where we are losing grazing land at a rather rapid rate.

Transcript of entire lecture

Lecture is a discussion of Full Planet, Empty Plates