My take on these questions is always the same. Avoiding climate catastrophe would have required global cooperation, where everyone agrees to leave all accessible fossil energy into the ground, regardless of how much benefit they could gain from using that resource, and this goes not just for this moment but all time. As the gas is only slowly removed from atmosphere by natural processes, the allowed emission rate is trivial -- maybe something like one hundredth to one thousandth of the rate today.

(Forget about claims made by the net zero people, because I believe this approach can't work, their calculated emission rate must be way too high. The truth is, if the total amount of carbon circulating in biosphere is increasing, that alone will cause a disaster at some timescale. The biosphere's ability to absorb carbon also reduces if temperatures go up, as forests go up in smoke and wetlands dry out, and the CO2 going into oceans is a massive secondary problem that is poised to kill the fish in the oceans. So, net zero as described is never going to work, but is rather something like a scientific fraud. I think even at best, it is an instance of human wistful thinking, manifestation of the hope that there is some way to continue doing what we are doing, albeit at some reduced capacity, when the truth is that industrial civilization must end.)

I also believe that disaster comes from biology and human reproduction allowed by massive growth of machine labor because it made so much food so plentiful, and allowed its global transport creating food rich conditions everywhere that ships could reach, as surplus that could now be ferried elsewhere. However, all this is also based on one-time resource base of minerals and fossil energy, and thus it has a time horizon beyond which it is no longer feasible. We have always tried to reproduce explosively, and I believe it wasn't because some capitalists ordered that it be so -- rather, it is the nature of any species surviving the trials of evolution to make more babies than is needed for replacement. Humans were no exception to this rule, and have until recent times always put out a lot of babies, but high births used to be balanced by high deaths from sickness and lack of food, etc. That this seems to be changing today is little consolation, when human overshoot is probably something like 4 times larger than what can long term survive on the planet at the very minimum. We have already done the overpopulation problem.

The overshoot is the root cause of all our problems, and because overshoot is made possible by fossil energy use, we also can't stop fossil energy use without causing immediate humanitarian global disaster. The time to act was quite a long time ago. It would have been good to stop the population explosion in the 70s at the very latest, and ramp down entire industrial civilization back then, but alas, we did not do so. We are now facing the consequences of over half century of continued delaying action, mounting pollution, and largely unchecked population growth. The attempt has been to extend the easy, comfortable life allowed by machine labor and industrial mass production of food and every other good to the entire world, rather than recognizing that it is fundamentally unsustainable and has a timer beyond where it is no longer feasible. This can probably be laid to some degree at the feet of capitalists, but ultimately the human need and want, and the tantalizing possibility of offering more for everyone, could possibly have created similar industrial production system under any political or economic system.