How Many Trees in the World?

Earth has about 3.04 trillion trees. That number comes from a landmark 2015 study in Nature led by Thomas Crowther at Yale, which combined satellite imagery, forest inventories from over 400,000 ground plots, and statistical modeling. Before that study, estimates ranged wildly from 400 billion to 1 trillion. Three trillion was 7 to 8 times higher than anyone expected.

Three trillion sounds like a lot until you learn that the planet had roughly 6 trillion trees before human civilization began. We have cut down nearly half the trees that once existed. We currently lose about 10 billion trees per year to logging, agriculture, and wildfires, while planting about 5 billion. That is a net loss of 5 billion trees annually, or about 158 trees per second.

Russia has the most trees (642 billion), followed by Canada (318 billion) and Brazil (302 billion). But per square kilometer, tropical forests are far denser. The densest forests are in Central Africa and Southeast Asia. Finland has the most trees per capita (about 72,000 per person) because it has a lot of forest and not many people.

Trees by country (top 25)

Finland has the most trees per person (72,000) because it has massive boreal forests and only 5.5 million people. India has the fewest among large countries (25 per person) because 1.44 billion people share 35 billion trees. China has been planting aggressively: the "Great Green Wall" project has planted over 66 billion trees since 1978, the largest reforestation effort in human history.

Tree loss and gain

Can Planting a Trillion Trees Fix Climate Change?

In 2019, a study in Science estimated that Earth has room for 900 billion additional trees, which could capture 205 gigatons of carbon and meaningfully fight climate change. This launched the "Trillion Tree" movement, with governments and corporations pledging mass planting campaigns. The idea is seductive: trees are cheap, popular, and photogenic. But the science is more complicated.

Critics pushed back hard. Not all planted trees survive: survival rates range from 10% (some corporate programs that plant and walk away) to 80% (well-managed community forestry). Monoculture plantations of fast-growing eucalyptus or pine are not forests. They look green from a satellite but support almost no biodiversity, deplete groundwater, and burn easily. Planting trees in natural grasslands or savannas can actually harm biodiversity by destroying ecosystems that evolved without trees.

The scientific consensus has shifted: protecting existing old-growth forests matters far more than planting new ones. A single old-growth tree stores more carbon than dozens of saplings. Preventing deforestation in the Amazon, Congo Basin, and Southeast Asia would have a larger climate impact than any planting campaign. But "stop cutting trees" is politically harder than "plant a billion trees," so the planting programs get the headlines.

What Are the Biggest and Oldest Trees on Earth?