Congratulations, environmentalists, tree-huggers, and people who enjoy breathing oxygen: the Earth has seven times more trees—approximately 3 trillion—than previously estimated, according to a new study in Nature. Scientists from around the world created the first "data-driven global tree census" by combining satellite images with tree counts from around the world, coming up with an estimate that amounts to about 422 trees per person, Gizmodo reports. The most tree-dense forests (nearly 25% of all trees) were in North America, Scandinavia, and Russia, while the most trees (more than 40%) were found in tropical and subtropical forests, notes Nature.
Now here's why the grand total, though bigger than expected, isn't necessarily a cause for celebration. The study shows that approximately 15 billion trees are lost every year, and there are only about half as many trees as there were when humans first started farming 12,000 years ago. "The scale of human impact is astonishing," Thomas Crowther, one of the researchers behind the count, says in Nature. "We're not saying, 'Oh, everything's fine.'" Gizmodo points out that trees are integral to providing the Earth with clean water and good soil while lessening the impact of carbon emissions. "Simply put, a future with fewer trees is a future less secure for humans." (A famous California redwood isn't as old as thought.)