The world doesn't have to reduce its standard of living to shift to clean energy. And it doesn't have to cause a disproportionate drop in the standard of living in the poorer countries, which stifles wealth creation there and also dampens the prospects for developed countries. (Everyone is better off if people everywhere can make and afford to buy goods and services.)
Some people getting electricity for the first time are getting it from clean energy - particularly solar. Their living standard has improved without continually adding carbon.
Lots of jobs creation and growth in emerging clean energy industries - particularly wind and solar. A lot lower health costs as polluting industries disappear.
What happens in the next few decades will be heavily influenced by decisions made this decade.
If we leave the shift to clean energy too much longer, then I agree it will cost a lot more and will adversely impact prosperity everywhere, but especially those countries that are most vulnerable to climate change (the poorer countries that can't afford to adapt). That will have a flow on effect to wealthier countries. It's in our best long term interest to not let that happen.
Whatever the case, the issue is not simple and straightforward. I agree with you that other huge problems like global warming and resource depletion generally, have to be factored in to considerations of population.
