Just spitballing here, aside from CO2, has anyone considered that maybe all the heat we are making is making things warmer?
Yes
And?
The dynamic of a greenhouse gas is the heat radiated from the earth that they capture and then emit back to the earth. 99.9% of this energy comes from the sun.( I don't know the exact percentage off the top of my head, but it is the vast majority). Without it, well, the earth would be a pretty cold place and we wouldn't be here. So any heat generated by us on top of what the sun gives and what the earth itself generates is either captured by a greenhouse gas and emitted back to us, or escapes into space. Water Vapor, CO2, Methane, etc.. CO2 has a relatively small wavelength window in which it acts as a greenhouse gas.
None of that can be argued. That's the general science behind why life as we know it is even possible here. I think the dissenting arguments fall on three lines of thought, "I don't believe in global warming" < just don't know how earth cycles work "That CO2 isn't coming from humans and we can't affect our planet like that" < not heard as much anymore, since those not in group 1 probably now realize that we do contribute to increased CO2 in the atmosphere even if they disagree on the amount. And the more common, "So what, we don't believe that the increase in temperature is anything to really worry about, or don't think it is as much as the scientists say" < can actually be argued.