A semi-drunk question about fossil fuels that came up last night.

[DanTex]

Fossil fuels are made out of long-dead animals and plants. So, in principle, it might be possible to calculate the total amount of fossil fuel energy available on the planet by first computing the total biomass of plants and animals that have died during the history of the earth, then trying to figure out what fraction of those turned into fossil fuels, and stayed in the earth.

Or, since all biological energy basically starts with photosynthesis, maybe compute all the photosynthesis that has ever occurred, then subtract the amount of energy actually expended by organisms.

Obviously, this wouldn't lead to precise numbers, but still it would be an interesting calculation.

Any geologists here? Is this whole line of thinking flawed?

[DK504]

1. Makes me think

Can we recreate photosynthesis products in a lab. Without BigAg adding their toxins to it and doesn't destroy our land.

[DetlefK]

2. That sounds semi-drunk alright.

1. How should we calculate how much plankton in the sea turned into oil? How should we calculate how many trees turned into coal?

2. We can calculate how much light has shone on Earth, but how should we calculate how much of that light was absorbed by plants for photosynthesis?

[DanTex]

3. Don't know the answers, which is why I'm asking.

What I was thinking was, maybe there's some model of how biomass turns into fossil fuels that can estimate that, say, 50% or 5% or 0.005% of trees turn into coal over time. If we have that, we then just need to calculate how many trees have lived in the history of the world.

Or for the photosynthesis calculation, we could start by just assuming that the total amount of photosynthesis per year produced today has been constant throughout history. As a first approximation. Then vary that to account for changes in climate and biomass over time.

Not saying it's easy, but neither was putting a man on the moon.

[NeoGreen]

4. The caveats on the estimated parameters for such an equation would render results...

...that would be meaningless.

+/- multiple orders of magnitude.

Not even worth wasting a used envelope to calculate.

(IMHO as a PG)

[Canoe52]

5. What he said...

No seriously, what neogreen said,

Not all organic matter was trapped in layers to one day become oil, gas, peat, etc. We have no way of knowing the % of that compared to the matter that didn't.

[Danascot]

6. Even if it could be calculated

you'd have to factor in that a significant percentage would be unrecoverable or not worth the effort (cost) to recover.