It's not really a thermodynamics problem. We're not trying to get rid of excess energy in a system, we're trying to get rid of carbon. We need to do something roughly equivalent to growing massive tropical rainforests and burying them over and over again.

Of course it's a thermodynamics problem. It takes less energy to split a hydrocarbon chain into CO2 + Water than it does to capture the CO2 out of the air and turn it back into solid carbon.

In essence, what we have to do is "all the energy output since the industrial revolution--do it again (plus then some), except this time instead of building civilization, capture co2 out of the air. And you must get all that energy from clean sources."

"Growing massive tropical rainforests" just means "inefficiently use solar energy (via photosynthesis) to bind carbon out of the air". We could do the same with solar panels and a carbon-binding chemical process.

But the issue is, again, the sheer magnitude of the problem.

Yes, we are too late.

Emissions affect the climate decades later, some 40 years later. So we're now only seeing the consequences of the emissions from the 70s-80s.

We've emitted more CO2 since the 80s to today, than the previous 150 years.

Too late for what? Yes, there are going to be more impacts. No, it won't mean the extinction of humanity or life on Earth. There still better or worse. Choose better.

If the entire world went to zero carbon emissions tomorrow, the effects would still be serious. Given that's not going to happen, the effects are likely to be catastrophic.

You're right that it won't mean the extinction of life on earth or humanity, but it might turn out to be the end of advanced human civilization if the bad end of the predictions come to pass. If there's not enough arable land left to support the human population, things will get very ugly very quickly.

I doubt it will mean the extinction of humanity, but unless a couple of miracles happen it will mean the end of our current industrial civilization.

If we had started working on this 40 years ago reaching zero emissions would be a realistic goal today, but even that is not enough now. Not only we need to reach zero emissions ASAP, but we also need strong negative emissions. And after that we need to figure out how to slow down the feedbacks (Arctic ice melting, methane, etc).

Maybe if ALL humanity was working towards those goals we would have a chance, but it's not even a priority for the vast majority of humans.