from Hacker News

Are there more trees on Earth than stars in the Milky Way? (2016)

by alexmolas on 1/1/25, 11:20 PM with 90 comments

• by dataflow on 1/2/25, 5:29 AM

  Remember it's a lot easier to visualize these numbers if you take the cube or square root. A trillion is 10^12 which is 10^4 cubed or 10^6 squared. That means a cube with 10,000 items along each dimension, or a square with a million items on each dimension.

• by Sniffnoy on 1/2/25, 6:40 AM

  Meanwhile, there are estimated to be possibly a quadrillion individuals of bristlemouth species in the genus Cyclothone... https://en.wikipedia.org/wiki/Cyclothone

• by chrisfosterelli on 1/2/25, 1:45 AM

  This made me think "wow, maybe the universe isn't so big after all", and then I remembered there are somewhere between 200 billion and 2 trillion other galaxies out there.

• by amai on 1/2/25, 9:40 AM

  The national debt of the USA stands at 30 trillion dollars. This is more than stars in the milky way and all trees on earth combined:

  https://en.wikipedia.org/wiki/National_debt_of_the_United_St...

• by twothamendment on 1/2/25, 2:41 AM

  That is kinda crazy to think about. I see the milky way and a lot of trees where I'm at. How big does the tree have to be to be counted as a tree? In spring we had a carpet of Douglas fir trees starting. I could put my hand down and cover 20 or so!

  I spoke to the forester yesterday about the plans to thin. They are all marked out now and I'm the spring it goes to auction. And IF for some reason it isn't stopped by legal action, it will get cut in the next 1-5 years!

  My property borders the public land in question and we'd love to see the fire risk reduced and stronger, healthier trees remain. I can't believe how long it takes and that people might want to stop this. We can thin it and take care of it or watch it all burn.

• by izzydata on 1/2/25, 1:52 AM

  While fun to think about big numbers at these scales this fact seems entirely arbitrary. You can fit a million Earths into our singular sun. 200 billion stars is still quite a bit more impressive than 3 trillion trees.

• by A_D_E_P_T on 1/2/25, 9:55 AM

  On land, most biomass is in trees.

  In the oceans, it's mostly in arthropods and fish! (Bacteria aside, that is...)

  Biomass distribution of Earth estimates: https://www.pnas.org/doi/10.1073/pnas.1711842115

  Trees outweigh everything else, and:

  A worldwide census of the total number of trees (32), as well as a comparison of actual and potential plant biomass (17), has suggested that the total plant biomass (and, by proxy, the total biomass on Earth) has declined approximately twofold relative to its value before the start of human civilization. The total biomass of crops cultivated by humans is estimated at ≈10 Gt C, which accounts for only ≈2% of the extant total plant biomass (17).

  Humans haven't yet put such a dent into fish biomass, but we're getting there.

• by bohare1 on 1/2/25, 1:59 AM

  Thankful for heartwarming posts like this, especially on a day like this. Thank you, sincerely.

• by deadbabe on 1/2/25, 5:30 AM

  It’s crazy that we don’t think of wood being so much more precious than gold considering how long it takes for the universe to produce the amount of wood we have on earth compared to gold which has just always been around

• by shireboy on 1/2/25, 1:19 PM

  Starting with 3 trillion trees, the reduction needed to reach 400 billion trees is 3,000,000,000,000−400,000,000,000=2,600,000,000,000 trees. Given that 15 billion trees are lost each year, the number of years required is 15,000,000,000 / 2,600,000,000,000 =173.33 years. Therefore, it would take approximately 173 years to reduce the number of trees to 400 billion if no new trees are added and 15 billion are lost annually.

  Of course trees are added, and it’s not clear if the 15 billion number is net loss. Assuming not, the number of years could stretch to infinity.

• by shahzaibmushtaq on 1/2/25, 6:49 AM

  > an estimate for the number of trees on Earth of 3.04 trillion

  We still need more trees to fight climate change in the 21st century and according to the United Nations since the 1800s, human activities have been the main driver of climate change, primarily due to the burning of fossil fuels like coal, oil and gas.

• by drzaiusx11 on 1/2/25, 3:20 PM

  Reminds me of a realization I had in undergrad with some back of the envelope math:

  There are more unique combinations [1] of a 16x16 1-bit grid/bitmap than there are:

  * Cells in your body (10^13)

  * Stars in the known universe (10^24)

  * Atoms that make up our solar system (10^56)

  1. 2^256 == ~1.2x10^77

• by K0balt on 1/2/25, 7:55 AM

  I wonder how that compares to the number of transistors we have made so far.

• by grahamj on 1/2/25, 5:06 AM

  Neat! I wouldn't have guessed we had that many trees.

• by domoregood on 1/2/25, 2:21 AM

  How long before Snopes debunks this Snopes article?

• by brundolf on 1/2/25, 2:57 AM

  > One popular fact included on numerous list of "science facts that sound wrong"

  Amazing

• by 1zael on 1/2/25, 4:53 AM

  This is an analysis of 3-dimensional space. I'm waiting for the 4-dimensional analysis, which I'm sure will push it by orders of magnitude more

• by MrVandemar on 1/2/25, 2:18 AM

  ... for how much longer?

  Population pressure and agriculture and industry means that land is continually being cleared.

  I urge anyone with the ability, plant a tree this year — maybe even a couple! You'll feel good about it, and it may well outlive you. The birds and insects and other life will be happy about it.

  The best time to plant a tree is 10 years ago; the second best time is right now.

• by lupire on 1/2/25, 1:37 AM

  (maybe, estimated)

• by Archelaos on 1/2/25, 7:35 AM

  What counts as a tree in the behind-a-paywall Nature study? Also each little sapling? What about these very tiny artic trees, like salix herbacea?

• by BugsJustFindMe on 1/2/25, 2:00 AM

  Comparing numbers of things is itself an odd thing to do. Humans poop as many poops as there are trees on the planet every year. Why not compare those to stars as well? And so what?