A reasonable post on your part.
1a) Is the climate changing at an atypical rate on a geological time scale.
Probably not given historical data of numerous climate shifts over the eons of time, many of them far worse than what we're experiencing.
1b) If so, what's causing it?
Multiple theories, but no absolute certainty with the exception of the lunatics.
2a) Are man's activities significantly affecting climate?
If it's significant it's still a slow roll all on a short time frame, and if significant longer term we're probably long past a tipping point.
2b) If so, how?
I'd say that they have the general idea down of how we are impacting the climate, but given that just how severe that impact is or will be is still unknown the real question is how much sacrifice needs to be made to offset it? That is the big debate and I don't see anyone, including and especially the climate alarmists taking any significant measures on their own part to curb what they can control. If it's all that serious, then get serious and I mean right fucking now. Legislate are fleet vehicles to natty gas immediately. A hundred or more nuke plants to begin construction today. Mandate all electric personal vehicles, today. Limit cross country and cross continent flights immediate. Mandate temperature control on all structures, buildings, homes, everything and no tax penalties to keep the wealthy warm. Nope, everyone puts on an extra sweater. There's more, much more to be done if it's really serious. No taxes, only mandates for change and everyone suffers and sacrifices equally, EVERYONE, WORLDWIDE and it happens today. Those that don't comply are immediately punished with imprisonment. Countries that don't comply are destroyed immediately by whatever means necessary. Got to be that way are we're all gonna die. Ready, set, go, who's in? Yeah, that's what I thought, leading me to believe it ain't all that serious.