Preparing for The Worst

By Philip Elmer-DeWitt

If the nations of the world take immediate action, the destruction of the global environment can be slowed substantially. But some irreversible damage is inevitable. Even if fossil-fuel emissions are cut drastically, the overall level of carbon dioxide in the atmosphere will still increase -- along with the likelihood of some global warming. Even if toxic dumping is banned outright and that ban is strictly enforced, some lakes and aquifers will be tainted by poisons that have already been released. Even if global population growth could somehow be cut in half, there would still be more than 45 million new mouths to feed next year, putting further strain on a planet whose capacity to sustain life is already under stress.

Sooner or later the earth's human inhabitants, so used to adapting the environment to suit their needs, will be forced to adapt themselves to the environment's demands. When that day comes, how will societies respond? How well will the world cope with the long-term changes that are likely to be in store?

To help answer those questions, political scientist Michael Glantz of the National Center for Atmospheric Research has pioneered the use of a technique known as "forecasting by analogy" to predict the effects on society of future climatic change. In a series of case studies, Glantz and his colleagues analyzed the response of state and local governments to actual environmental events across the U.S., from a 12-ft. rise in the level of Utah's Great Salt Lake to the depletion of the aquifer that supplies groundwater to eight Great Plains states.

When Glantz's forecasting technique is applied to the rest of the world, two things become clear. One is that virtually every long-term environmental change is occurring in miniature somewhere on the planet, whether it is a regional warming trend in sub-Saharan Africa or the vanishing coastline in Louisiana. The other is that Homo sapiens is an immensely resourceful species, with an impressive ability to accommodate sweeping change. In countries and regions hit by climatic upheavals, people have come up with a variety of solutions that are likely to have broad applicability to the global problems of tomorrow.

How would societies respond, for example, if the oceans were to rise by 3 ft. to 5 ft. over the next century, as some scientists have predicted? One option would be to construct levees and dikes. The Netherlands, after all, has flourished more than 12 ft. below sea level for hundreds of years. Its newest bulwark is a 5.6-mile dam made up of 131-ft. steel locks that remain open during normal conditions, to preserve the tidal flow that feeds the rich local sea life, but can be closed when rough weather threatens. Venice is beginning to put into place a 1.2-mile flexible seawall that would protect its treasured landmarks against Adriatic storms without doing ecological damage to the city's lagoon.

Shoring up cities such as New York, Los Angeles, Paris, London and Rio de Janeiro would require equally monumental measures. In the U.S. the Environmental Protection Agency estimates that the cost of protecting developed coastal areas could reach $111 billion. Southern Louisiana, which is losing land to the Gulf of Mexico at the alarming rate of one acre every 16 minutes, has already drawn up an ambitious mix of programs. In the biggest project, a $24 million pumping station would divert millions of gallons of silt-rich Mississippi River water onto the coastline to help stop saltwater intrusion and to supply sediment that will build up the eroding land. At least one parish is considering plans for a backstop dike to give residents time to escape should the sea finally reach their doors.

Poorer countries have fewer options. Wracked by periodic floods, Bangladesh cannot simply evacuate the "chars" -- bars of sand and silt in the Ganges Delta -- where millions of people have set up camp. But the government has drawn up plans for a network of raised helipads and local flood shelters to facilitate the distribution of emergency aid if, as seems inevitable, disaster strikes again. Meanwhile, the country can only appeal to its Himalayan neighbors to do something about the root cause of the flooding: the deforestation of watersheds in India and Nepal that has turned seasonal monsoons into "unnatural disasters."

The problems of agriculture are likely to be critical in the next century, as growing populations, deteriorating soil conditions and changing climates put even more pressure on a badly strained food-supply system. In parts of sub-Saharan Africa, that system has broken down periodically over the past 20 years, resulting in the familiar TV images of children with swollen bellies and relief camps filled with hungry people.

What is not so well known is that hundreds of grass-roots organizations in Africa are taking action to cope with environmental change. Somalia has launched a vigorous antidesertification drive that includes a ban on cutting firewood. In Burkina Faso villagers have responded to steadily dwindling rainfall by building handmade dams and adapting primitive water-gathering techniques. Even so simple a trick as putting stones along the contour lines of a field to catch rainwater can make the difference between an adequate harvest and no harvest at all.

Necessity has spawned invention in marginal farmlands around the world. The Chinese, threatened by a desert that is spreading at the rate of 600 sq. mi. a year, are planting a "green Great Wall" of grasses, shrubs and trees 4,350 miles across their northern region. In Peru archaeologists have revived a pre- Columbian agricultural system that involves dividing fields into patterns of alternating canals and ridges. The canals ensure a steady supply of water, and the nitrogen-rich sediment that gathers on their floors provides fertilizer for the crops.

Perhaps no one is better prepared for hot, dry summers than Israel's farmers. The Israelis, using drip irrigation and other techniques, have made plants bloom on land that has been barren for millenniums. Portions of the arid Negev, an area once written off as largely uncultivable, today grow fruit, flowers and winter vegetables eagerly sought by European markets. Through a process known as "fertigation" -- dripping precise quantities of water and nutrients at the base of individual plants -- crops can be grown in almost any soil, even with brackish water.

Plant genetics is another option that needs to be energetically pursued. At / the University of California at Riverside, plant physiologist Anthony Hall is working on a way to make cowpeas more tolerant to heat. Other scientists are using genetic engineering to transfer genes from bacteria that act like natural insecticides. But though they have tried, scientists have not yet been able to develop farm crops that are drought resistant. Says Hall: "You can't grow plants without water."

There are things people can do if the well runs dry. Several communities located near the sea have built desalinization plants. Denver, meanwhile, has pioneered the unsavory concept of turning sewer water into drinking water. In 1985 the city opened an experimental plant that produces 1 million gal. a day of high-quality H2O from treated effluent.

Some scientists have suggested that the depletion of the ozone layer could be counteracted by a variety of Star Wars-like techniques. They include lofting frozen ozone "bullets" into the upper atmosphere and blasting apart ozone-depleting molecules in the air with huge terrestrial laser beams. But such grandiose schemes would be unreliable and could change weather patterns in unpredictable ways. In the end, it may be safer and cheaper, if inconvenient, to cope with ozone depletion by wearing wide-brimmed hats, sunglasses and sunscreen.

Man has always shown a great capacity for adjusting to change. Past generations have survived floods and ice ages, famines and world wars. But when dealing with the environment, there is a grave danger in relying on adaptation alone: societies could end up waiting too long. Many of the global processes under way, like the wholesale destruction of species, are irreversible. Others, like global climate changes caused by man, are so profound that if allowed to progress too far, they could prove to be overwhelming. Simple prudence suggests that taking forceful preventive action now -- to save energy, to curb pollution, to slow population growth, to preserve the environment -- will give humanity a much better chance of adapting to whatever comes in the future.

With reporting by J. Madeleine Nash/San Francisco