There Are More Trees on Earth Than Stars in the Milky Way

Quick Answer

Earth is home to roughly 3.04 trillion trees, according to a landmark 2015 study published in Nature. The Milky Way galaxy contains an estimated 100 to 400 billion stars. That means our planet has roughly 7 to 30 times more trees than our galaxy has stars. This finding shocked scientists -- previous estimates had placed Earth's tree count at around 400 billion, a number that was off by nearly an order of magnitude.

The Number That Broke Everyone's Intuition

When most people hear "more trees than stars," they assume it must be wrong. We can see the stars. The Milky Way is immense -- 100,000 light-years across, containing the mass of hundreds of billions of suns. Surely a single planet cannot compete with that?

But it can, and it does. The problem is that our intuition for large numbers is terrible, and we wildly underestimate how many trees cover the Earth's land surface.

The 2015 study, led by Thomas Crowther at Yale University (now at ETH Zurich), combined satellite imagery with ground-level forest inventories from every continent except Antarctica. The team used data from over 400,000 ground-based tree density measurements, correlated them with satellite observations, and built a model that estimated total tree count for the entire planet.

The result: approximately 3.04 trillion trees. That is 3,040,000,000,000 individual trees currently alive on Earth.

Previous estimates, based primarily on satellite data alone, had suggested around 400 billion -- already more than the low-end estimate for Milky Way stars. The ground-truth data revealed that satellites were dramatically undercounting trees in dense forests, where canopy cover makes it impossible to distinguish individual trees from above.

How Do You Count Stars in a Galaxy?

The star estimate for the Milky Way comes from a completely different methodology, for obvious reasons. Nobody has counted individual stars. Instead, astronomers estimate the galaxy's total mass (from gravitational observations and rotation curves), subtract the estimated mass of gas, dust, and dark matter, and divide the remaining stellar mass by the average mass of a star.

This gives a range of 100 to 400 billion stars. The uncertainty is enormous -- a factor of four -- because the average stellar mass is itself an estimate, and the Milky Way's total mass is still debated. Most astronomers settle on "a few hundred billion" as the working figure, with 200 to 250 billion being common middle estimates.

Even taking the highest star estimate of 400 billion, Earth's 3 trillion trees outnumber them by a factor of about seven.

Where Are All These Trees?

The distribution is not what you might expect. Russia alone has about 640 billion trees -- more than any other country. Canada follows with roughly 318 billion. Brazil, despite having the largest tropical rainforest, comes in third with about 302 billion. The United States has approximately 228 billion.

The boreal forests of Russia, Canada, and Scandinavia are the planet's great tree reservoirs. These vast, cold forests of spruce, pine, and larch stretch across millions of square kilometers, and their tree density is high even if individual trees are relatively small.

Tropical forests have fewer trees per hectare than many people assume, partly because large tropical trees have massive canopies that shade out competition, and partly because tropical forests contain enormous biodiversity of non-tree plants that fill the understory.

The country with the highest tree density relative to land area is Finland, where trees outnumber people by roughly 16,000 to one.

The Sobering Flip Side

The Crowther study also estimated how many trees have been lost since the dawn of human civilization. The answer: roughly 46 percent. Earth once had an estimated 5.6 trillion trees. Human activity -- agriculture, logging, urbanization -- has cut that nearly in half over the past 10,000 years.

Currently, the planet loses approximately 15 billion trees per year to deforestation and land-use change. About 5 billion are planted or naturally regenerate, leaving a net loss of roughly 10 billion trees per year.

At that rate, we are losing the equivalent of the Milky Way's entire star count in trees every 10 to 40 years, depending on which star estimate you use. The comparison cuts both ways.

Tip

Despite the net loss trend, some regions are gaining trees. China's massive reforestation programs have increased its forest cover significantly since the 1990s. Parts of Europe have more forest now than they did a century ago, as agricultural land has been abandoned and reforested. The net global loss is driven primarily by tropical deforestation in South America, Africa, and Southeast Asia.

Why This Matters Beyond the Fun Fact

The 3 trillion tree number was not just a curiosity. It fundamentally changed how scientists model the global carbon cycle. Trees are the largest land-based carbon sink, and having seven times more of them than previously estimated meant recalculating how much carbon the world's forests store and exchange with the atmosphere.

The Crowther study estimated that Earth's trees collectively store about 400 gigatons of carbon in their trunks, branches, and roots. Understanding this number accurately is essential for climate models, deforestation impact assessments, and reforestation planning.

It also provided a baseline for global restoration targets. The Trillion Tree Campaign, launched by the UN Environment Programme, aims to plant or restore one trillion trees by 2030. The Crowther study showed that this is ambitious but represents roughly a 33 percent increase in the current count -- achievable in theory if land is available and political will exists.

Whether you find hope or alarm in these numbers depends on which direction you look. Three trillion trees is extraordinary -- a number that dwarfs the stellar population of our galaxy. But 5.6 trillion minus 3 trillion is a loss of staggering proportions, and 10 billion per year is a pace that should concern anyone paying attention.

For now, though, sit with the headline: there are more trees on your planet than stars in your galaxy. Earth is more forested than the Milky Way is starred. That is a fact worth knowing.