True, but irrelevant. 1 and 3 are part of the carbon cycle, by which carbon goes in and out of the atmosphere but the total in the ecosystem does not change significantly.
Very much like the hydrologic cycle, by which water changes phase and location but not in quantity.
Fossil fuels are ancient parts of the carbon cycle that got isolated from the ecosystem. When they are burned they increase the total of carbon, not just move it around. Even a slow, gradual increase in a constituent of the atmosphere may eventually result in a significant effect.
There are lots of good arguments for why the "global warming" thing is exaggerated, but this isn't one of them.
That is the key unproven assumption. No one knows how much is too much and when the effects of human activity may cause real global consequences. All we have are a bunch of computer models made by bombastic scientists, claiming that the end is near.
The other poster was noting that human addition of CO2 to the atmosphere is trivial in magnitude compared to natural sources. That is a true statement.
So the hydrocarbons in the ground are not part of the ecosystem. How did they get isolated? They were once part of the living flora or fauna that got buried. In geologic time they were certainly part of the ecosystem. We, through their conversion, are bringing them back.
In the distant past CO2 levels have been orders of magnitude higher than today and yet life survived and we are all here.
Hydrocarbons like methane are found in distant heavenly bodies. How did they get there? Methane is a much more powerful green house gas than CO2 and there is a moon out there with a methane atmosphere.
Green house gases are part of the natural universe, and the atmospheric processes here on earth have adjusted to that without our intervention.
See my post 35.