But the human quest for economic development has led to the conversion of billions of hectares of forests into man - made deserts. (climatechangenews.com)
That is a big task, and even harder to do without converting millions more hectares of forests into farmland, contributing to climate change. (wri.org)
Nearly 4 billion hectares of forest cover the earth's surface, roughly 30 percent of its total land area. (earth-policy.org)