By 1968, ninety-five percent of the redwoods had been cut down.
People need wood for many things, of course. So they cut down trees. The larger the human population, the more trees are cut down. "In Kentucky," writes Greene, "the Daniel Boone National Forest is being converted by the U.S. Forestry Service into a regulated tree farm, and the Appalachians are under siege. More than half of the world's boreal forests have been reduced to junk mail and catalogs. The rain forests of South and Central America, Africa, and Indonesia, including the magical cloud forests; the enchanted Danube basin; the Black Forest; the monumental Russian Tiaga — all are falling, falling."
Massive trees are made of a massive amount of carbon. In the absence of the trees, the carbon is in the atmosphere, warming the planet.