Brian Fagan's review of Michael Williams' Deforesting the Earth reminds us that the Earth's forests were not unaltered by humanity before the Industrial Age. In China,

persistent population pressure and the demands of agriculture destroyed forests everywhere. Europe broke out of the cycle with the Black Death and the Age of Discovery, which took some pressure off tree clearance. China never had such epidemiological or environmental safety valves.

It sounds like Fagan thinks that's a bad thing. Anyway, what's the big deal about saving farms, those despoilers of what is "natural"?