It's a terrifying problem facing the world and like you said - it definitely could be the case that by the time rapid change starts occurring, it will already be too late. However, it might also be the case that it will just be a slow change that will be more manageable to tackle in time. "Rapid change" when it comes to climate science could mean over the course of a thousand years or over the span of seconds (K-T bolide impact extinction, Ordovician-Silurian (if it was caused by a gamma ray burst)).

The problem is that climate science is an incredibly complex field with an overwhelming number of interconnected factors and so all hypotheses are built on upon assumptions that are built upon assumptions. This is why it often comes down to the verbiage that you see so often in these types of discussions where people "believe" one way or another. The stakes are extremely high though and we can already say for certain that historically rapid change is taking place.

While I personally believe that it is a problem that warrants immediate action, I think it's counter-productive to demonize and strawman all who don't hold one's exact views as climate deniers or (on the other side) climate alarmists. This will only further entrench people in their views, widening the divide between people, and causing them to be more dismissive of anything that doesn't affirm their belief.

If people were more open to actively trying to hear out the other side and find common ground, it will be easier to come to a joint conclusion. By earnestly listening to people, they will in turn be more likely to hear you out as well. The vast majority of people don't actually hold extremist positions but because of the easy amplification of a noisy few, rampant strawmanning is taking place.

(I don't mean to imply you personally are doing any demonizing, or are guilty of the strawmanning, It's just something I often see in comments and wanted to give my two cents)