I sort of disagree; the governments might be (as usual) the crucial element of the solution - they're the only actors on this planet capable of forcing a decision on masses, even if it goes against the wishes of the market. But getting the government to do the right thing sooner rather than later - that's the hard part. Especially that nations are market players themselves, and doing the right thing in case of climate change means handicapping the whole country on the international market.
I think both the ultra rich and governments can be useful in funding more R&D on clean technologies. The goal here should be developing technologies that ultimately let you go carbon-neutral while sacrificing as little as possible compared to the old methods. Doing the right thing is painful for people, and by extension the governments, so whatever can be done to ease that pain increases the chance that the right things will start being done.