Why should I believe your assessment that a huge chunk of fossil fuel use by the rich world went to "relatively small marginal gains in quality of life"? I think they went to massive quality of life gains for huge numbers of people, and that suddenly removing fossil fuels as an energy source would be catastrophically bad for huge numbers of people, and not obviously worse than the effects of global warming over a comparable timeframe.
I never suggested we should suddenly remove fossil fuels as an energy source, that is a huge exaggeration. We wouldn't have needed to do anything suddenly 40-50 years ago when we started to understand that there was a problem, and we won't suddenly remove fossil fuels in the upcoming few years either.
But that is also a false choice: Not all CO2 emissions in the past 40 years were net beneficial. I firmly believe humanity would have done better with fewer (not zero, fewer) flights, less (not zero) beef, and fewer (not zero) fossil fuel car journeys. All while continuing to raise people from poverty and providing real improvements, of course.
If you raise people from poverty, they'll want to spend the money they now have as non-poor-people on things like taking airplane flights, cars, and eating beef, because those now no-longer-impoverished people consider access to those things to be part of their good quality of life. In particular all of these things happened to over a billion people in China as China has gotten less impoverished over the past half-century. Another way of looking at it is that causing there to be fewer flights, beef, and fossil fuel car journeys is literally the same thing as making most people poorer - the only way to make there be fewer of those things is to make them drastically more expensive so that even people who are generally getting richer (like, for instance, the average person in China) find it harder to afford them.
