Environmental Surprises: Planning for the Unexpected

Article excerpt

Environmental futurists are finding new ways to anticipate the effects of complex trends.

The process of environmental decline usually seems gradual and predictable. We are comforted by the thought that even if we have not turned the trends around there will be time for our children to rise to the challenge.

But this way of thinking is like sleepwalking. To understand why, you have to look at decline close up. Here is how it has happened in one small country, with big implications.

The Honduran Predicament

In the early 1970s, Honduras was caught up in a drive to build agricultural exports. Landowners in the south increased their production of cattle, sugarcane, and cotton. This more-intensive farming reduced the soil's water absorbency, so more and more rain ran off the fields and less remained to evaporate back into the air. The drier air reduced cloud cover and rainfall. The region grew a lot warmer.

As the land became less productive, people began to leave. Many moved north to work on newly developed plantations or to carve their own small farms out of the area's rain forests. Much of this northern agriculture was devoted to export crops, too, primarily bananas, melons, and pineapples.

But it is difficult to mass-produce big, succulent fruits near rain forests--even badly fragmented rain forests--because there are so many insects and fungi around to eat them. So the plantations came to rely heavily on pesticides. From 1989 to 1991, Honduran pesticide imports increased more than fivefold, to about 8,000 tons.

The steaming, ragged forest was a perfect habitat for malaria mosquitoes. Around the plantations, the insecticide drizzle suppressed them for a time, but they eventually acquired resistance to a whole spectrum of chemicals. As a result, the mosquitoes were basically released from human control. When their populations bounced back, they encountered a landscape stocked with their favorite prey: people. And since these people were from an area where malaria infection had become rare, their immunity to the disease was low. Malaria rapidly reasserted itself: From 1987 to 1993, the number of cases in Honduras jumped from 20,000 to an estimated 90,000.

The situation was brought to light in 1993 by a group of researchers concerned about the public health implications of environmental decline. But their primary interest was not in what had already happened -- it was in what might happen next. Some very nasty surprises might be tangled up somewhere in this web of pressures. They argued, for example, that deforestation and changing patterns of disease had made the country vulnerable to climate change.

They were right. In October 1998, Hurricane Mitch slammed into the Gulf Coast of Central America and stalled there for four days. Nightmarish mudslides obliterated entire villages; half the population of Honduras was displaced, and the country lost 95% of its agricultural production.

Mitch was the fourth-strongest hurricane to enter the Caribbean in the twentieth century, but much of the damage was caused by deforestation: If forests had been gripping the soil on those hills, fewer villages would have been buried in mudslides. And in the chaos and filth of Mitch's wake there followed tens of thousands of additional cases of malaria, cholera, and dengue fever.

Complexities of Change

It is hard to shake the feeling that "normal change" --even change for the worse--should not happen this way. In the first place, too many trends are spiking. Instead of gradual change, the picture is full of discontinuities--very rapid shifts that are much harder to anticipate. There is a rapid warming in the south, then an abrupt expansion in deforestation in the north, as plantations are developed. Then malaria infections jump. Then the mudslides, in addition to killing thousands of people, cause a huge increase in the rate of topsoil loss. …