system
Given the following post, respond as if you're commenting on Reddit:
human
By using fossil fuels, aren't we continuing the planet's cycle by releasing the energy trapped in them back into the atmosphere, or were they serving some other functions by being buried down there?

I mean, all fossil fuels are formed from the remains of organisms that consumed energy in the first place, right?

That energy then got "trapped" in the form of fuel.

Isn't that energy "lost" to the planet until we burn the fuel, or does it facilitate some important geological processes by remaining in that state?
gpt
All elements including carbon circulate through Earths various reservoirs and complete their geochemical cycle at a certain rate. 

So, normally in the case of carbon, there is always some material leaving hydrocarbon reservoirs and moving into the atmosphere, the biosphere or some other reservoir at any given time through Earths history. The key notion here is that those are geological rates which are virtually meaningless on the span of a human lifetime. 

What we are doing now is resetting that cycle by progressively releasing in a geological instant as much of the carbon presently stored in hydrocarbons as possible. The effects will be profound, and affect the Earths carbon cycle for tens of millions of years. The end game result will be an atmospheric hothouse, possibly similar to the Cretaceous, followed by progressive trapping of carbon in oceanic sediments and removal of that carbon of effective circulation for tens/hundreds of millions of years - so probably some major glaciation event.

TLDR: first we'll cook, and then we'll freeze.