Deforestation

One of the most notable processes by which humankind has affected the Earth's surface is via the conversion of forested land for agriculture, logging, and urbanization, that is, deforestation. Up through the latter decades of the 20th century, deforestation had accelerated and come to be almost totally concentrated in the tropics, almost [Page 696]wholly within developing countries. In the 1990s, the extent of old-growth forests was approximately one fifth of their original cover.

Estimates of land use change over the 20th century (the lion's share of which was concentrated in its last four decades) are crude, but research suggests that though Asia and Africa had a slightly greater percentage of their forests cleared (34% to 38%) compared with Latin America (approximately 28%), a far greater absolute ...