We live in a world that is more and more desert by almost any measure. The challenge is to devise ways of living that minimize desertification in an ever more crowded globe. PNS editor Franz Schurmann, professor emeritus of history and sociology at UC-Berkeley, has traveled widely in the Middle East and reads the Arab- and Farsi-language press.

We live in a world that is more and more desert by almost any measure. The challenge is to devise ways of living that minimize desertification in an ever more crowded globe. PNS editor Franz Schurmann, professor emeritus of history and sociology at UC-Berkeley, has traveled widely in the Middle East and reads the Arab- and Farsi-language press.

China will have to abandon its capital, Beijing, if it cannot control the desert according to a recent interview in Newsweek with Chinese prime minister Zhu Rongji.

Bone-dry sand dunes, common all over northwest China, are moving southward at a rate of 2.1 miles every year. They are now 66 miles north of the capital, which means the first dunes could reach Beijing in 16 to 17 years.

Many environmentalists hold that desert spread, called "desertification," does not result from uncontrollable natural processes but from human practices that create fragile ecosystems. However, historical and archaeological evidence indicates that desertification has been going on relentlessly for some 5000 years in one particular swath of the globe.

Maps show most of the world's deserts lie within two bands. One is between 20 and 40 degrees north latitude, and includes the American southwest and northern Mexico in our hemisphere and the Sahara, Arabian, Iranian, Baluchistan, Sindh and Rajasthan deserts in the Eastern Hemisphere.

A similar band between 30 and 50 degrees north latitude contains the Takla Makan and Gobi deserts. Beijing is at the eastern extreme of this band.

Cave paintings an estimated 5000 years old have been found in the Sahara Desert that show not only vigorous vegetation but animals like elephants, hippopotamuses and rhinoceroses that need large quantities of water. Many researchers now believe that most humans who lived in the region escaped desertification by migrating southward into the Niger River region and eastward toward the Nile.

Biblical accounts and archaeological evidence also indicate that there was much more water in the Middle East 3000 years ago than there is today, but desertification was already evident.

Accounts of Buddha's birth 2600 years ago, at Lumbini in Nepal, tell of a lush and rich region. Today it is dusty and virtually treeless. Archeologists have also found much evidence that the Gobi desert -- the one moving toward Beijing -- was once green and widely inhabited by people practicing agriculture.

Now, the Middle East, from Egypt through Pakistan, is suffering the worst drought in a century. In some areas in Israel, Jordan, Syria, Iraq, Iran, the rains have not come for four years. Imams again and again chant special prayers for rain.

So serious is the shortage of water that many Afghan refugees are returning home despite the terrible conditions there. UN figures show nearly 75,000 Afghans returned from Iran -- these are mostly Shi'a and side with the opposition to the Taliban. Evidently living in danger but with water is better than the reverse.

Another 54,000 have returned from Pakistan. Most of them lived on the edges of the great Sindh Desert. In Afghanistan they will become even poorer, because women will not be able to bring in income but will have water to drink from its many mountain springs.

A Cairo-based workshop, "Water Management in Africa and the Middle East," reports that annual renewable freshwater per capita in the Middle East has declined by half since 1950. As a result more and more nations in the region, notably Egypt, Israel and Jordan, are turning to treated and recycled sewage water.

From the late 1800s to the mid-1900s it was widely held that deserts could be reclaimed through great water projects. Without such projects, California today would likely have a population the size of Belgium's.

But while technology can bring water to deserts it evidently cannot stop their spread. And when droughts lessen the amounts of water falling on mountains then the rivers and aquifers, too, will dwindle.

But the 5000 years of desertification have given rise to great cultures -- along the Niger, Nile, Euphrates, Tigris, Indus, Mekong, Yangtze and Yellow rivers. In all these settings, village-based agriculture flourished. In most of them towns arose and in some great cities -- some with urban plumbing close to modern standards.

Over the millennia urban populations have waxed and waned. Yet farm and town have kept coming closer and closer together. Villagers tend the rivers and streams that supply drinking water to the cities. The townspeople repay them by supplying the technology and products of advanced civilizations.

Like it or not we are all going to be living at closer and closer quarters. The nearer agriculture comes to the cities the easier it is to resolve water shortages, even if it means recycling.