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The Weight of Life

2022-11-29 · explainer · John · 4:00 · watch on YouTube

Topic: Science & nature · mode: Personal essay

Following Hank's mammal biomass video, John says humans are a rounding error in Earth's biomass (plants over 80%, bacteria 12%, animals under 1%) and argues that, though powerful, we should see ourselves realistically: the danger is not ending life but making Earth less habitable for us and other complex life.

What is said

The parts of the video and what is said in each (★ — how much it matters to the video).

00:00:00 — Reply to Hank's mammal biomass video; humans as a rounding error; what biomass measures

  • ★★ John recalls Hank's recent video: humans and their livestock together make up over 90% of mammal biomass. — 00:00:00 · Hank Green
  • ★★★ John says that compared with non-mammals too, humans by weight are sort of a rounding error. — 00:00:00

00:00:29 — Shares of animal and total biomass: humans, livestock, fish, arthropods, viruses, bacteria, plants

  • ★★ John explains biomass: bacteria far outnumber humans, but humans are larger and more complex, so biomass asks how much of all the carbon in living things is human, microbial and so on. — 00:00:29
  • ★★★ John says humans are about 2.5% of animal biomass, wild mammals 0.3%, livestock such as cows and pigs about 4%, and aquatic invertebrates like coral and jellyfish another 4%. — 00:00:29
  • ★★★ John says fish are 29% of animal biomass, more than 10 times humans' weight, and arthropods about 42%, so most animal life by biomass is fish or arthropods. — 00:00:58
  • ★★★ John says animals are a tiny part of the story: much less than 1% of Earth's biomass. — 00:00:58
  • ★★ John says humans weigh a lot less than viruses. — 00:01:27
  • ★★★ John says bacteria are 12% of Earth's biomass and together weigh about 200 times more than humans. — 00:01:27
  • ★★★ John says humans are also outweighed by fungi, protists and above all plants, over 80% of Earth's biomass: a plant planet with a scattering of other life. — 00:01:27

00:01:56 — Human self-aggrandizement versus real power; Indiana's forests; the ginkgo's age; Earth as a habitat; sign-off

  • ★★★ John says humans are a little self-aggrandizing, placing themselves at the center of Earth's story, which he grants is justified in some ways. (hedged) — 00:01:56
  • ★★ John says humans differ from other life because writing, video and other communication technologies let them share knowledge across space and time. — 00:01:56
  • ★★★ John says humans currently have outsized power: their behavior is causing extinctions and reshaping the climate and habitats. — 00:01:56 · climate change
  • ★★ John says Indiana, thought of as endless cornfields, was all hardwood forest 400 years ago: a forest land terraformed for corn. — 00:02:26 · Indiana
  • ★★★ John says humans are very powerful and changing the biosphere, but should not exaggerate their power: we are just a form of life, a very small part of a very big world. — 00:02:26
  • ★★ John says a ginkgo tree looks much like ginkgos of the Jurassic over 150 million years ago, while humans have existed about 300,000 years, 0.2% of the ginkgo's history. — 00:02:55
  • ★★★ John says Earth and life on Earth will be okay without us; Earth has recovered from far greater shocks than humans. — 00:02:55
  • ★★★ John wants humans to stay around: in a somewhat countercultural opinion he is broadly in favor of humans, finding them more interesting than viruses. — 00:02:55
  • ★★★ John says we should see the situation less egotistically: the danger is not destroying life on Earth but, without better choices, making Earth less habitable for us and other complex life. — 00:03:24
  • ★★ John says what is most valuable about Earth is not that it is a planet but that it is a habitat hosting a huge array of life. — 00:03:24
  • ★★ John says Earth's life contains around 550 gigatons of carbon, of which humans are about 0.01%. — 00:03:24

In the description and comments

  • ★★ Answering a viewer in a channel comment, John says about 31% of Earth's carbon is biomass and 69% is stored in soil. — video description
  • ★★ The description says that from ginkgo trees to E. coli, we should remember we are rare, fragile and profoundly interdependent. — video description

Threads in this video

Mentioned

Central: Biomass (ecology)

Also: Concepts: arthropod · Bacteria · Cattle · climate change · extinction · Ginkgo biloba · human impact on the environment · Plant · Virus

Places: Indiana

Only in the description or credits: Our World in Data

Also centred on Biomass (ecology): How Much Does Humanity Weigh?

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