In the collection Counterintuitive facts
Are there more trees on Earth than stars in the Milky Way?
Yes, by current estimates. About 3 trillion trees outnumber the Milky Way's roughly 100 to 400 billion stars, though both figures are estimates.
AI-drafted from web search results, then checked by a second, independent AI that read 4 of its 4 cited pages in full and found the thread supported. No person has reviewed it.
The short answer
Yes. A 2015 study in Nature estimated about 3.04 trillion trees on Earth. Most estimates of the stars in the Milky Way fall between 100 billion and 400 billion. Even the highest star estimate is less than a seventh of the tree count. Neither number has been verified by counting every tree or star, so the comparison rests on estimates. [1] [2]
How trees were counted
The tree figure comes from a paper titled "Mapping Tree Density at a Global Scale," by Crowther and colleagues, published in Nature in September 2015. The researchers used 428,775 field measurements from different biomes and built mathematical models to extrapolate to a global scale, drawing on satellite maps. Of the 3.04 trillion trees, about 1.30 trillion are in tropical and subtropical forests, 0.74 trillion in boreal regions and 0.66 trillion in temperate regions. [1] [2]
The result was an order of magnitude higher than the previous estimate, made in 2005, of about 400 billion trees. The study's authors also estimated that around 15 billion trees are cut down each year. [1]
How stars were counted
Astronomers estimate the number of stars mainly by working out the galaxy's mass, using how it rotates and its spectrum. The next step is deciding how much of that mass is stars, since most of the mass is thought to be dark matter. One calculation gives the Milky Way a mass of about 100 billion solar masses, which translates to roughly 100 billion stars after averaging larger and smaller stars. Other mass estimates raise the figure to 400 billion. NASA's Maggie Masetti has said that higher numbers than that are also sometimes quoted. [1] [3]
Caveats worth knowing
Snopes notes that both figures carry many caveats and limitations, and that the claim holds only insofar as the estimates approximate reality. Its conclusion is that unless a new method yields a much higher star count, trees appear to outnumber stars in the Milky Way. The comparison is also specific to our galaxy: across the whole observable universe, stars vastly outnumber trees. [1] [2]
The tree total works out to over 400 trees per person, according to a World Bank blog post summarizing the study. [4]
Sources
- Are There More Trees on Earth Than Stars in the Milky Way? | Snopes.com (snopes.com) Found by source search. Not checked by a person.
- "There are more stars in our galaxy than trees on Earth." Is it true? · Curious Kea (curiouskea.nz) Found by source search. Not checked by a person.
- Trees Outnumber Stars in Milky Way, Scientists Say (interestingfacts.com) Found by source search. Not checked by a person.
- Five forest figures for the International Day of Forests (blogs.worldbank.org) Found by source search. Not checked by a person.
Questions to follow next
- How do scientists estimate the number of stars in a galaxy?
- How many stars are in the observable universe?
- Has the global tree count been updated since 2015?