They've all had their whole lives to make climate conscious lifestyle decisions, they could all stop eating meat tomorrow, but they ain't done squat. Not as individuals nor as a group. The few who have are weirdos who live at the margins.
This is why so many free-market, minimal-state absolutists are so prone to putting their fingers in their ears and pretending climate change is not a problem, or if it is, that individuals as free agents are responsible for creating it and therefore fixing it. They cannot accept the logical conclusion of the necessity of state action, as it contradicts their core beliefs.
The whole situation is as deterministic as two celestal bodies moving according to Newtonian physics. Technological progress was inevitable, and so was the resulting population bomb in the last century, and so is the nearing Collapse of the civilization in the coming decades, due to ecological overshoot. Read the Industrial Society and Its Future by Ted Kaczynski.