Right on, Dingo. Overpopulation is the root cause and driver of almost every environmental problem. You can throw in greed, stupidity, religions and cultures as aggravating factors. Unfortunately, with overpopulation itself, it is mathematically too late to prevent the crash on the 2040s. Time ran out at the end of last century for one child families universally accepted and obeyed, to have a sustainable population before crashing.
With AGW, we still have 9 years(maybe less) to reduce emissions 90% and avoid thermal maximum and its ELE. That is it theoretically can be done the way Hansen describes in "Storms of My Grandchildren". Knowing people a long time, they will probably do too little too late, and our species will go extinct with millions of others.
Then you have the illogic of the anti-any-nuclear crowd, the illogic of stopping animal cruelty but not caring if they go extinct from AGW. You have green trinket profiteers thinking they are making a real difference, when it is so little as to be a joke. Some just concentrate on on aspect which does need to change, like water use, food waste, soil conservation, green power of various specialties, and educating women for health and family planning. The reduce, re-use, and recycle mantra of sustainable living long term on this planet.
Still, nothing makes much difference after the tipping point of methane turnover in 2023 is fully crossed. Survivors must face a hotter and hotter world with rapidly moving grow lines and ecosystems collapses. Ecosystem services gone, species we rely on extinct, the oceans ruined, and caves, with still cool water, refuges until starvation. Underground fortresses, will they last over 100K years? If they did, would humans be different? Will they be able to survive with so few species left? I think they would end up overheated and starved, too. A multi-generational spaceship to a possible liveable planet? What if it isn't there, or is full of deadly organisms to humans? Will our saved DNA and seeds last over 230K years until conditions are better? Who will unlock the storage and plant them? No, and no one.
"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.
“We do not inherit the earth from our ancestors; we borrow it from our children”
― Chief Seattle