Estimating the number of trees on our planet or the number of stars in our galaxy may seem like an unthinkable task. Such gigantic figures are impossible to conceptualize and compare. Yet thanks to the efforts of researchers in numerous scientific disciplines, we have rough estimates for both, and the results may surprise you.
According to an exhaustive study published in the journal Nature in 2015, there are an estimated 3.04 trillion trees on Earth. This figure was reached by collecting hundreds of thousands of field measurements of tree density in different regions and biomes and then using mathematical modeling to extrapolate the total number of trees on Earth. Incredibly, the updated estimate was a full order of magnitude higher than the previous estimate of 400.25 billion trees, made in 2005.
Even if the earlier estimate had been correct, the number of trees would probably still exceed the number of stars in our galaxy, which is estimated to be between 100 and 400 billion stars. This wide-ranging estimate was reached by calculating the entire mass of the galaxy and then determining how much of that mass comes from stars as opposed to dark matter. These figures were reached by analyzing the galaxy’s rotation and light spectrum and measuring the color and brightness of stars. Accounting for stars that are bigger or smaller than our sun, one widely used calculation suggests that the Milky Way has a mass of around 100 billion solar masses, or roughly 100 billion stars. Other estimates have put the number at 400 solar masses or even higher, which equates to at least 400 billion stars.
Of course, despite being as accurate as current methods allow, these estimates are still very approximate. Given the immensity of the subjects being studied, we will likely never know the precise figures. However, it does seem that there is a clear winner, and it’s the trees!
Not seeing the forest for the trees:
- The 2015 Nature article, entitled “Mapping Tree Density at a Global Scale,” found that 1.3 trillion of the Earth’s trees are found in tropical and subtropical forests.
- An estimated 15 billion trees are cut down each year, while several billion are planted annually.
- When comparing trees on our planet to stars in the universe, there’s simply no contest. It’s estimated that the universe contains over one septillion stars (1 followed by 24 zeros). This figure is based on estimates of around 10 trillion galaxies, assuming that each has around 100 billion stars, like the Milky Way.
