Thousands of years ago, before humans began clearing the forests for croplands and settlements, forests and woodlands covered almost 6.1 billion hectares (15 billion acres) of the earth. By the end of the twentieth century, approximately 16 percent of the forests had been cleared and converted to pasture, agricultural land, cities, and nonproductive land. The remaining 4.6 billion hectares (11.4 billion acres) of forests covered approximately 30 percent of the earth’s land surface.

Salem Press Encyclopedia, 2023. 3p.