Back from the Brink

Every year, science teachers instruct students to place celery stalks into dyed water. The students are expected to learn and study how a plant soaks up water, watching the colored liquid rise up the length of the stalk. The basic lesson of this experiment is to show how much water a plant needs and how quickly it drinks it up in order to survive.

The citizens of South Africa are learning this lesson all too well. Growing four times faster than the water supply, 40,000 people have been put to work to preserve diminishing water resources. One way they are doing this is by destroying evasive alien plants, such as the Eucalyptus tree, which on average absorbs 12 gallons of water a day.

If efforts are not enforced now, in 25 years, South Africa will have only half of the water it has today, explains Bill Moyers in his latest special, Earth on Edge, on public television (PBS) stations nationwide (Tuesday, June 19 at 8 p.m.). This new program airs not long after Moyers' latest piece, Trade Secrets, in which he tackled chemical manufacturers and their cover-up of destructive elements in the manufacturing process of such items as plastic. Earth on Edge leads viewers through five different environmental concerns in the two-hour show, beginning in South Africa, with its dwindling water supply.

Viewers are then taken to Vancouver, British Columbia, where clearcutting trees on Clayoquot Sound has given way to more sustainable logging practices, such as flying in loggers, so not to destroy trees to build roads, and flying freshly cut timber out by helicopter.

In two related pieces, Moyers focuses on the grasslands of Mongolia and the farms of Kansas. In Mongolia, due to environmental changes and the way shepherds rotate their herds, grass is growing less year after year and soil erosion is increasing. Due to overgrazing, the grass cannot hold the topsoil, on which it relies so much for regrowth.

In Kansas and the plains of the United States, 20 tons of topsoil disappears each year into water bodies, such as the Mississippi River . However, some farmers are finding ways to work with the environment and make a profit at the same time. On the program, Moyers interviews one farmer about his inventive ways of preserving the farmland for future generations, while continuing with his trade.

The final segment concentrates on reefs off the coast of Brazil and the different efforts people are pursuing in order to preserve them. Without help, the 70 percent of reefs at risk worldwide today will be lost forever. In turn, the world will lose much more than reefs, but also a significant supply of food, because one third of all fish consumed by humans feed off of reefs.

An informative and immediate program, Earth on Edge documents the human footprint on Earth. With excellent commentary, interviews and reporting, Bill Moyers successfully shows viewers what has been done and what still needs to be done in order that humans may go on living, and living on Earth.

This article originally appeared in the May 2001 issue of Environmental Protection, Vol. 12, No. 5, p. 10.

This article originally appeared in the 05/01/2001 issue of Environmental Protection.

About the Author

Heida Diefenderfer is a research scientist and diver with Pacific Northwest National Laboratory's Marine Science Research Operations in Sequim, Wash. ( She served on the Northwest Maritime Center dock design team and as Battelle's project manager for the site surveys and eelgrass restoration. As a biologist with PNNL's Coastal Assessment and Restoration technical group, Diefenderfer conducts applied research for state and federal agencies and other partners for near-shore, wetland, and watershed assessment and restoration.