Reminds me of a little nugget I heard once, that trees grow out of the air not the ground, since they're mostly carbon-y foam which comes from CO2

Part of Richard Feynman's "Fun to Imagine" series, I think. Video link: https://www.youtube.com/watch?v=P1ww1IXRfTA

Plants can often be understood as pumps that pull water from the ground to combine with atmospheric CO2 and sunlight to make sugars that they recombine to make more of themselves.

I felt somehow betrayed when I learned that the oxygen trees release comes off the water that's used for photosynthesis, and not the carbon dioxide directly.

(Of course, the oxygen in the carbon dioxide ends up in new water molecules in a later step of photosynthesis, and that water either immediately or eventually finds itself in another photosynthesis reaction, so that carbon dioxide oxygen finds itself released into air sooner or later, but still.)

And when you lose weight it's mainly in the form of exhaled gas.

I like that a lot! I will remember it next time I’m willing myself not to stop.

It's all a question of time

Oil is ancient solar energy.

I'm curious about this.

The geologic carbon and kerogen cycle looks to be be:

  plankton + plants -> sedimentary rocks -> kerogen -> "liquid and gaseous hydrocarbons [via] catagenesis"

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

However, relatively recently there has also been the discoveries of extraterrestrial sources of kerogen, including in meteorites, Martian samples and planetary nebulae:

https://en.wikipedia.org/wiki/Kerogen#Extra-terrestrial

It's not clear to me how much to attribute to how much terrestrial kerogen could be present during our planetary formation vs that which is continuously replenished during the carbon cycle.

Anyone know of studies of the relative contributions?