How Many Trees Are on the Planet?

Deforestation is occuring at a frightening rate, but, until recently, no one could say just how many trees there are on earth. Using satellite images, scientists previously estimated the number to be around 400.25 billion, but a new census produced a number more than seven times that. 

According to a recent study published in Nature, there are 3.04 trillion trees on planet earth. The data was gathered by Thomas Crowther, who's now an ecologist at the Netherlands Institute of Ecology, and his team of researchers while working at Yale University. He was inspired by a friend who was a part of a group that aimed to plant one billion trees to combat global warming. The problem was that no one knew whether one billion trees was a significant amount or just a drop in the global bucket.  

When Crowther went digging for hard figures on the number of trees on earth, he was surprised to learn that no one really had an answer. All he could find was the estimate of over 400 billion trees based on satellite pictures, but this number was dubious because another census based on ground-sourced data showed there were 390 billion trees in just the Amazon basin. 

In a quest for more accurate numbers, Crowther gathered information sourced from ground surveys. His team compiled data from the detailed national forest inventories maintained by nations around the world. After looking at information from approximately 400,000 forest plots over the course of two years, they finally came up with their massive estimate. The areas with the highest tree densities were Russia, Scandinavia, and the boreal forests of North America. The thin conifers that grow there account for 24 percent of the world's total tree count. 

Though three trillion trees is almost too many to comprehend, Crowther asserts this is no excuse to continue the decimation of the world’s forests. Before the inception of agriculture 12,000 years ago, there were nearly twice as many trees as there are today. Every year, the gross number of trees that are lost due to human activity is around 15 billion. In light of the new data, the conservation group that inspired Crowther has upped their goal to one trillion trees. 

[h/t: NPR]