They want decisive and ambitious action, you can't get that if we all turn to doomerism.
The bottom 70% of the world's population would have less than $X00 in the bank, and wouldn't have much control over their lifestyle.
The reasons we haven't done this are because China and India are hungrily industrializing, and the Republican Party in the US is captured by fossil fuel companies.
And yes, we do need to give up several aspects of our lifestyles. Meat consumption absolutely must come down. Air travel must come down. Disposable goods, and consumer plastics, must come down. Our lifestyles must change. Capitalism encourages status symbol goods such as beef, travel/tourism, excessive consumption goods, etc.
We need widespread consumer behavioral change before we have any hope of governments listening to people. As long as half of the population doesn't care about the climate then nothing meaningful will get done. For real change to happen people need sunk cost. Right now people have far too many excuses and denials to actually do much. There is always a China to blame, or a company to blame, or a mega rich person to blame.
> As long as half of the population doesn't care about the climate then nothing meaningful will get done.
This is fairly common misconception. At this point the vast majority of people is on board, but the perception is skewed by vocal minority. Big part of the work at the moment is just communication to help closing this perception gap.