There are 400 trees for every human on earth
The world distribution and extent of forest trees are necessary to our knowledge of the biosphere. Scientists provide the first spatially continuous world map of forest tree density. This map shows that the global amount of trees is about three trillion, an order of magnitude greater than the earlier estimate. Of these trees, around 1.30 trillion live in tropical and subtropical forests, with 0.74 trillion in boreal areas and 0.66 trillion in moderate regions. Biome-level trends in tree density display climate and topography's influence in controlling local tree densities at more precise scales and humans' overwhelming effect across most countries. According to research over fifteen billion trees are cut down each year, and the world number of trees has fallen by about 46 percent since the origin of human civilization.