FLICKR, SCOTT WYLLE
Researchers have used on-the-ground measurements and satellite imagery from around the world to approximate the global number of trees. The resulting estimate, published yesterday (September 2) in Nature, is about 3 trillion—or 422 trees for every person, with a human population of 7.2 billion.
An international team linked more than 400,000 ground measurements with satellite imagery, generating tree-number estimates across wide areas and on every continent except Antarctica. “All of the information that went into our models was generated from people standing on the ground counting numbers of trees in a given area. And so we could relate this information to what the satellites are telling us,” study coauthor Thomas Crowther told NPR’s Goats and Soda.
The data show that the highest numbers of trees ...
