First, this is a classic example of tragedy of commons - if you lower emissions, then you bear all the costs but a tiny fraction of the benefit;

Second, even if coordination can be solved, by and large the groups/areas that can make a meaningful reduction are not the groups/areas that will bear most of the consequences, there's no such thing as a single, aligned direction of interest/benefit for humanity.

I think we can all agree that another mass extinction event and chaotic weather pattern upheavals are both bad things.

This is a different problem known as tragedy of the commons.

What would you, personally, give up to make that happen?

For what it's worth, I've given up my car (I live within easy biking distance of work), live in a small townhouse (heating costs $20/month in the winter thanks to good insulation and neighbors eliminating heat loss to the sides). I purchase few goods, and try to keep most things as long as possible. Most of my entertainment/shopping is within walking/biking distance. I try to limit waste and compost/recycle everything I can.

My electrical usage is so low that I don't think installing solar would be a net win in carbon emissions.

Based on various calculators, my carbon footprint is about half that of a typical American. Now can I ask for a 28% decrease in carbon emissions?

I'm vegan. I ride public transit when possible, and moved next door to my job so I don't need to commute on a daily basis, I buy used whenever possible, and try not to buy stuff I don't need. I take carbon into consideration when making holiday plans (a few plane rides can double a persons carbon footprint). I compost. Future changes I'm trying to make include going to local farmers market and growing more of my own food, switching to solar power. But, realistically, I'm only one person. If everyone went vegan today, gave up cars (for bikes) and planes (for electric trains), and we started growing 51% of our food locally we'd be well on our way to meeting carbon emission reduction goals. The technology has been around for awhile. The will to make the choices has not. Which is why, I'm a pessimist on these issues.

I gave up meat (except fish) 13 years ago. Not because of climate change but I keep it going in part because of it now.

Look into how much water and food you need to grow cows.

Inertia