What rubbish?

ACCORDING to the Environmental Protection Agency, the United States generates roughly 1,560 pounds of municipal solid waste per person per year. Composition studies of municipal solid waste reveal that it consists of between 34 and 59 per cent degradable carbon. Therefore, America's population of about 269.6 million will have produced in 1997 about 210.3 million short tons of solid waste containing between 71.5 and 124 million tons of degradable carbon.

Other countries have waste-generation rates similar to the United States'. Assuming a world population of 5.8 billion, this implies about 4.5 billion tons of waste containing between 1.5 and 2.7 billion tons of carbon annually. In other words, appropriately constructed landfills could capture roughly 2 billion tons of carbon annually, thus stopping global warming cold.

For many years, biodegradability was considered a good thing --garbage would be reduced to rich dark humus, and landfills would not overrun the earth. But in the process of turning garbage into soil, decomposition returns most of the carbon to the atmosphere as methane and carbon dioxide -- greenhouse gases.

As it happens, though, numerous studies have found that buried garbage is by and large not decomposing. Except for certain components of food and yard debris, which degrade by 25 to 50 per cent over a 10-to-15-year period, the majority of the garbage retains its original weight, volume, and form. Furthermore, recent American regulations governing landfill design tend to ensure preservation of the contents by imposing waterproofing and leachate-removal requirements designed to protect groundwater from contamination. Hence the possibility of sequestering carbon becomes quite realistic.

Space is not a significant constraint; the problem of siting landfills is really a political problem. At current rates of waste generation, a landfill 44 miles square and 120 feet deep could store all of America's garbage for the next thousand years.

Realizing that preservation of garbage is a nobler goal than decomposition points toward new strategies of landfill location and design. It may prove advantageous to pile waste to greater heights. Conceivably, forming trash heaps according to the design of ancient pyramids could improve the aesthetics of such a war against warming. Desert wastelands and permanently frozen places the world over might be perfect for stashing trash. Indeed, with certain modifications to existing international laws, most of the world's garbage could be barged to Antarctica. Garbage might even help insulate the polar icecap if serious global warming occurred despite these efforts, thus protecting us from rising seas.

That citizen-of-the-world spirit that keeps Americans raking recyclables out of their garbage needs to be redirected toward putting more things into the garbage. Citizens could help by putting garbage in watertight bags after taking steps to minimize moisture content. There is much potential for joy in the thought that, in cleaning out the attic, we are not only making our house more livable but also fighting global warming.