I don't think people understand the scale of the problem. The human race has spent the last few thousand years but especially the last 100+ years squeezing the trigger and now the gun has fired, the bullet is accelerating down the barrel and some people finally decided to stop it. There is absolutely nothing that can be done. The scale of effort required is way beyond the capabilities of the entire human race. Even if everyone spent 100% of their time working on fixing the problem, you would not even put a dent in it in any reasonable amount of time. It might take maybe 1000 years at the current level of technology. The only practical option that might be workable is to invest into the development of certain technologies (such as fission/fusion and robotics/automation/artificial intelligence) to massively multiply capabilities and hope something usable comes out of it. Otherwise, effort would be best used accepting whatever is to come and preparing for it. People are not even able to START living sustainably and within their means and STOP unsustainably depleting all resources, you think they can reverse all damage in a few decades? It takes a huge amount of energy to pull all that carbon out of the atmosphere, who is going to afford that? The likely outcome is that nothing of consequence is done and the parasitic behavior continues until a complete collapse.