OK, I'm not sure why you're not convinced. It seems to me that at the heart of it, if we massively increase atmospheric CO2, we know that atmospheric CO2 causes a greenhouse effect, and we do indeed see temperatures rising, then by far the most likely explanation is that the CO2 is causing the warming. We should require good evidence to the contrary to not accept that as at least a working theory. What's more, reducing the atmospheric CO2 will decrease warming, even if there is some other, unknown factor that is also contributing. And given that just a couple degrees of warming will cause mass extinction as well as likely significant human suffering, it would be prudent to act to counter it, even if it were actually unlikely that humans were the cause (which again, I have no reason to suspect).

So, as someone who seems eloquent and informed, your position is truly perplexing to me. The only explanation I can think of is that you have some vested interest in believing as you do, be it conscious or otherwise. Do you feel that accepting human-caused climate change would be betraying your political affiliations? Or is your livelihood, or those of close friends or family tightly coupled to the fossil fuel industry? Do you tend to distrust scientific evidence in other areas?

You don't need to answer these questions, but maybe ask yourself if there might be another reason why you're resistant to the most likely explanation here.