That's not exactly how it works, of course. The people did not lower their quality of life to support the cause, per se, they did it to vanquish Those People. An actual enemy to focus on. And a pretty short timeline. Now you'd ask people to declare war on their own quality of life to fight a consequence which is necessarily vague over a timeline that likely exceeds the remaining lifespan of half of everyone alive today.

Good luck.

In the meantime I sure would like to try some mitigation techniques.