Why your daily fix can fix more than your head: coffee, if grown right, can be one of the rare human industries that actually restore the Earth's health.

• Author: Halweil, Brian

Take a deep breath.

If you are in a coffeeshop--or you've just brewed your own java--you are inhaling microscopic particles of coffee, which carry some of the 800 naturally occurring chemicals that give coffee its seductive aroma. These are the same chemicals, by the way, that can jumpstart your central nervous system--caffeine being the most famous one.

When these molecules enter the nostrils and stimulate the olfactory nerve, it may be hard to think about much more than getting that first swallow. Drinking coffee quickens the heartbeat and makes a person more energetic and alert. Regular coffee drinkers can even experience withdrawal symptoms, if they don't get their fix at the expected time. So if you're starting your day and just want that first cup, it may be hard to muster much interest in where the coffee actually comes from.

But where it comes from has surprising importance for the future of life on a destabilized planet. Coffee is one of those tropical exports that are produced exclusively in the Third World and consumed almost entirely in the First World. (Cocoa, vanilla, and bananas are some other examples.) The beans that are brewed for people in Geneva, Los Angeles, and Tokyo all grow in that waistband of tropical rainforests that girdles the planet between the Tropic of Cancer and the Tropic of Capricorn. At this point, there are basically two ways to grow coffee--in a manner that helps to preserve and restore rainforest, or in a manner that destroys rainforest. And as biologists have stressed, rainforest happens to have disproportionately high value to the Earth's ecological health.

Until a few decades ago, most of the world's coffee was grown in the understory of rainforests, with farmers looking after the rainforest trees as a natural part of managing their coffee. But now, more and more coffee is produced in what was rainforest-- clear-cut tracts of land without shade, that give off the dry, burning scent of ammonia fertilizer. Over 40 percent of the coffee area in Colombia, Mexico, Central America, and the Caribbean has been converted to "sun" coffee, with an additional one-quarter of the area in conversion. It's a pattern that is emerging everywhere coffee is grown.

In the short term, this conversion may boost yield because larger numbers of coffee plants can be crowded together in the space where great wild fig trees once stood. But the long-term effect is another story. From an ecological point of view, this conversion is simply another form of tropical deforestation, along with the slash-and-burn clearing by settlers, or the bulldozing by cattle farmers looking to expand grazing range. When a shade coffee farm is converted to full-sun cultivation, the diversity and number of organisms in the area crashes. The various orchids, mosses, frogs, salamanders, and birds that inhabit a rainforest nearly all need a shady and moist area to build their homes, get food, and survive.

Ornithologists have found that in full-sun plantations, the number of bird...