Banking on Disaster.

VHS VIDEO: Banking on Disaster. Produced and directed by Adrian Cowell. Bullfrog Films, Oley, PA 19547. 78 minutes, in three 26-minute parts. Institutional purchase price, $450; conservation groups may buy for $1 00.

If you read this magazine's November/december issue, you would agree with one of this film's main assumptions: that the destruction of tropical forests is the greatest single threat to the stability of the world's environment. That fact fuels the zeal with which producer Adrian Cowell treats his topic, filmed over a decade in the Brazilian state of Rondonia, site of the world's largest rainforest.

The film's three parts (an arrangement ideal for classroom use) focus on "penetration road" BR364, financed partly by the World Bank. It was built and then paved to help hundreds of thousands of colonists to move into the region to farm, and to reduce social conflict in other parts of Brazil. The first part follows a typical family for five years, and documents vividly their efforts to fell the forest and burn it off to create farmland, only to find that, in the settler's own words, "The land is not good-nothing grows. "

Part 3 follows the work of Francisco "Chico" Mendes, leader of a union of local rubber tappers, an articulate and effective foe of rainforest destruction by cattle ranchers and landless peasants. Just after this film's completion, Mendes was murdered at his home. The American Forestry Association's Fernow Award for 1989 will be awarded posthumously to Mendes.

This is a disturbing film-both because it portrays the enormous scope of the rainforest devastation and because it unravels the serpentine trail of international social, economic, and other causal factors whose reversal seems almost impossible. It is too long for the casual viewer. But it is easily long enough to bestir people who understand that we are all on this planet together.-bill ROONEY