I agree with you that eventually governments are the only entitles that could implement solutions on a big enough scale. However it will be too late if this only happens when they are forced to act by social upheaval, mass starvation and economic collapse.

I challenge the ultra rich to put a substantial portion of their assets to work in funding large scale R&D on clean technologies, and simultaneously funding powerful lobbying of governments to act on climate change.

Another thought is that for better or worse we now have the tools for "social engineering" and campaigns might be funded to sway public opinion to support governments that support clean technologies.