Deforestation, clearance, clearcutting or clearing is the removal of a forest or stand of trees from land which is then converted to a non-forest use. Greatly accelerated by human activities since 1960, deforestation has been negatively affecting natural ecosystems, biodiversity, and the climate. 

Multiple factors, either of human or natural origin, cause deforestation. The primary driver of deforestation is the expansion of agriculture. Natural factors include natural forest fires or parasite-caused diseases which can result in deforestation.

The UN’s Food and Agriculture Organization estimates the annual rate of deforestation to be around 1.3 million km2 per decade.