Meanwhile your "ExtinctionRebellion" phrase seems like a political touchstone that you assume other people know what you're talking about, but I have no clue what it is.
[2] https://en.wikipedia.org/wiki/Extinction_Rebellion_Youth
[3] https://en.wikipedia.org/wiki/School_Strike_for_Climate
Her Holyness [4] https://en.wikipedia.org/wiki/Greta_Thunberg
from 1968 [5] https://en.wikipedia.org/wiki/Club_of_Rome
and 1972 from that same club [6] https://en.wikipedia.org/wiki/The_Limits_to_Growth
and countless dystopian science-fiction literature and movies from that epoch.
edit: https://files.eric.ed.gov/fulltext/ED050960.pdf#page=13
"We have all heard about a population problem in the developing nations of Asia, Africa and Latin America, where death rates have dropped rapidly and populations have exploded. Only recently have we recognized that the United States may have population problems of its own. There are differing views. Some say that it is a problem of crisis proportions — that the growth of population is responsible for pollution of our air and water, depletion of our natural resources, and a broad array of social ills."
SUBTLE
There are no answers given usually, less so convincingly, mostly because the ones demanding scarcity are usually not the ones affected by it.
Just trying to find one member of the working class / blue collar amongst ExtencionRebllion and the like will be a tedious task. Not so much if you look for kids of millionaires, or of bilionaires. Or Millionaires and Billionaires themselves.
As of now I can only see two outcomes:
They either start making these scarcity demands a part of their foreign policy (meaning getting tough on the actual global polluters, not their domestic poor people who barely can afford one cheap vacation to the Balears per year).
Or we just start naming what we would have called it 150 years ago: A top-down class-war.