Well done and comprehensive. Glad I found it.
Two things that come to mind are:
1. We don't talk about the carrying capacity of humans. Therein lies the rub: humans are an overgrowth predatory species that doesn't have a net useful contribution to our environment. The anthropocentric perspective of our existentialism usually reverts to some bullshit about how smart humans (homo sapiens sapiens) are the 'pinnacle' of evolution/creation, etc.
In fact, we are a very destructive detour from evolution: civilization isolates humans from the risks and responsibilities of the environment that spawned us, and is an evolutionary trap (a nice petri dish) for us to commit growth-suicide.
2. In the debate about fossil fuel-renewables-overshoot-Malthus, etc, we don't have a pragmatic discussion of how to plan for an intentional degrowth-collapse response and survival. You mention a possibility of Greenland/Antarctica survivors, but where are the leaders and plans to get to that point?
My plan is to start building guillotines, but that's only for entertainment of the pitchfork and torch crowds. In reality, those crowds will be mowed down by automatic fire and drones, so the guillotines won't be necessary (I should still be able to sell some before they're ever used, though).
Collapsing populations on purpose (war) is more or less intentional Degrowth.
There's not a file cabinet in Washington full of plans for intentional Regrowth or intentional decivilization. Well, I guess there are the nuclear contingency plans, which would probably cover it for the most part.
There are just endless databases and studies trying to keep the assumption alive that everything in the Economy of Stupid was built and fired by some useful purpose that has to keep going. I.e.:The Economy is burning 100M bbls of oil every day, so it must be necessary and we have to keep it going!
1% of humans produce all of the food. Pretty much every other dollar can be well lost. We have a bloated medical sick care system based on supporting unhealthy people, including all of the construction of gyms and yoga parlors, yet there is no distinction between health insurance and good health, nor why human beings are such inactive, poorly nourished and psychopathic animals living in cages.
We have known this since the end of WWII. Every politician and corporation since then has been doing everything they can to ignore how destructive and useless humans are to the planet.
We have spent the last 2 centuries replacing human labor on the land with fossil fuels and chemicals. There is no plan to reverse this process, because it isn't profitable for the mean Mean 'limited liability' human corporation.
