Are scientists sure about how many trees grow on Earth?

Researchers using new satellite-imaging techniques to count trees in west Africa suggest there may be more trees growing on the planet than have previously been estimated.

The study, published in October 2020, suggests there could be further increases to a 2015 global estimate of 3 trillion trees, which marked a sevenfold jump from the previous estimate of 400 billion. That study focused on data from forests. It estimated that 15 billion trees are cut down each year while 5 billion trees are planted or sprouted, calculating that the global tree count has fallen by “approximately 46% since the start of human civilization.”

The new study notes that trees outside forests “are not well-documented.” New mapping technology counted “quite a few hundred million” trees where few were expected, an author told the Guardian. Earlier estimates have been “extremely far away from the real numbers.”