How have the worlds forests changed over recent centuries?
Forests are naturally dynamic and change over time. Natural climate changes over the millennia prompt forests to advance and recede and change the species makeup over a given area. In recent centuries, however, human influences over forests have become much more profound. Research suggests that only half of the worlds forests cover remains from the last post-glacial era. Harvesting and land-use changeover to agricultural purposes drives much of the loss. In North America, a great deal of acreage has returned to forest cover over the past century. But tropical and subtropical deforestation remains a major concern to climatologists. An estimated 9.6 billion acres of forested lands remain worldwide.
