I assume when people are concerned about the future, they are concerned about the prospective quality of life specifically for themselves and their descendants.

No one is claiming humanity will go extinct. But during that ice age there were probably less than 100k living in the whole world. With technology and our current spread, we won't go so low, but a planet 3-4 degrees hotter is nowhere near able to sustain 7B people. Not to mention the terrible migration and resource wars we'll see as hundreds of millions if not billions of people have to leave places where temperatures routinely rise over livable standards.

Couldn’t disagree harder on every single count. Humanity will adapt. We could sustain 10x population (70 billion) with the correct technology - the vast majority of land on earth is totally empty. There will be no resource wars and no migration. You are thinking delusionally.