What are the effects/outcomes of sending emissions deep into the ground, instead of into the atmosphere?

Question

Hi guys! I was in the shower this morning and I had one of those thoughts, so now I’m here.

So, I want to start at the beginning of my thought process.

When plants and animals die, they are decomposed by microbes into chemicals, including carbon dioxide.

To make a long process short, I’ll just say that oil humanity currently consumes was originally from the death of plants and animals hundreds of millions of years ago.

Now, I don’t know the exact process for how CO2 becomes petroleum (CnH2n+2), but I do know that energy cannot be created or destroyed, so the Carbon in our emissions is the same Carbon molecule that was stored underground in the liquid form petroleum, and ultimately are the same carbon molecules that made up plants and animals millions of years ago. So if we funneled the Carbon Dioxide that we currently emit into the atmosphere (from something like power plants, cars probably wouldn’t work) back into the ground, would nature/geology not continue it’s regular process of turning the gas CO2 back into crude oil over hundreds of millions of years?

I understand there may be more to this process. For example, the fact that crude oil contains Hydrogen tells me there is likely water involved in the process, but I don’t understand why something like that would be a factor. The only potential issues I could see are the possibilities that injecting gases deep into the ground could make the ground unstable, or the gases may slowly leak out through the Earth (in which case, at least SOME of the Carbon Dioxide would still be absorbed into the ground).

Please help me understand! And thank you ahead of time.

TLDR; What would be the effects of returning emissions to where the fuel came from?

In: Other

Answer 1

Carbon capture and storage is a thing. However, it is both expensive and unreliable. There are a lot of concerns about the ability to avoid leakage in the process.

It is, generally speaking, way less expensive to get energy in a way that emits less carbon than to try to capture and store the carbon that comes from a dirtier energy source.

As for the long term impacts on the CO2 of storing CO2 underground I’m not sure. Generally, the main way CO2 leaves the atmosphere is when it is fixed through photosynthesis. The fossil fuels we use weren’t created from CO2 trapped underground, but other hydrocarbons (i.e. the material from ancient plants).