There are perfectly acceptable, even scientific arguments against CO2-induced climate change theory. Not only that, but even if we accept the premise that CO2 is inducing climate change, we can debate about to what degree, and whether or not it is "an existential crisis" as some have argued. Further still, if we accept that it's a crisis, we can also debate on the trade-offs civilization should make in order to contend with it. All of those positions should be perfectly acceptable to take up. We do not know with anywhere close to 100% confidence what the climate will do over the next few decades. It is a non-linear, dynamic, chaotic system that by definition becomes exponentially unpredictable as a function of time: https://en.wikipedia.org/wiki/Chaos_theory