Yale study estimates 3 trillion trees on Earth

A new study led by Yale's School of Forestry & Environmental Studies has revealed that the Earth is estimated to have over 3 trillion trees. The significance of this is that the figure is over 7.5 times more than previous calculations. However, it is still believed that there has been a 46% decline in the planet's number of trees since the beginning of human civilization. This study, which was recently published in the journal Nature, is said to offer one of the most detailed assessments of the Earth's tree populations.

Researchers were able to come up with the 3 trillion figure by combining forest inventories, satellite footage, and several computer technologies. The result was a worldwide map of tree populations down to a square-kilometer level. The hope is that this data will improve models of systems such as climate change and the distribution of plant and animal species.

"Trees are among the most prominent and critical organisms on Earth, yet we are only recently beginning to comprehend their global extent and distribution," said Yale's Thomas Crowther, the lead author of the study. He mentions that it was surprising to learn the number of trees was in the trillions, but that shows how most people have no idea of the magnitude, yet trees are essential to human life, from their ability to store huge amounts of carbon, to the role they play in the cycling of nutrients, and how important they are to air and water quality.

Two years ago, the estimate was that there were a little over 400 billion trees on Earth, making about 61 trees for each human. The new study, which relied on more ground information and a wider combination of sources, came up with 3.04 trillion trees, making roughly 411 per person.

The study found that boreal forests of sub-arctic Russia, Scandinavia, and North America were home to the highest densities of trees. However, the largest forests are found in the tropics, making up around 43% of the planet's tree population.

SOURCE Yale School of Forestry & Environmental Studies