Mahatma Ghandi once said about human appetites that there is enough for every person's need, but not for some people's greed. Unfortunately, the world's population has practically doubled since Ghandi's time. Greed or no, there may not be enough to meet the needs of the planet's next arrivals, let alone the 11 to 14 billion the United Nations predicts will inhabit the earth when human population finally stabilizes.

This is the case made by Paul and Anne Ehrlich, outspoken population experts, in their latest book, The Population Explosion. Reckless resource use, compounded by human numbers, account for the fact that we are already devouring our home and pushing out other life forms. If international cooperation cannot be mustered soon, say the authors, nature will end the population explosion for us--in very unpleasant ways--well before a population of 10 billion is reached.

The Ehrlichs spend the better part of their book making the case that the entire planet and virtually every nation is already vastly overpopulated. They do this by providing a cold, factual account of disap- pearing resources, injured ecosystems, a threatened atmosphere, intractable poverty, and endangered human health.

Overpopulation, in the authors' estimation, is not measured in sheer numbers, but in homo sapiens' im- pact on the environment. The Ehrlichs have developed a loose formula for measuring this value Impact = Population x Level of Affluence x Prevailing Technologies' Effect on the Environment. Using this tool, the authors contend that the United States is currently overpopulated, due more to the high value of the country's affluence and technology factors than to the size of its population. South Florida, with its pollution, evicted wildlife, and disrupted hydrology, is