There is something we can do. We can enjoy what we have here and now, for as long as it lasts, for as long as we can.
I'm a transportation cyclist. I mostly ride to save money and improve my physical fitness. The environmental benefits seem to depend on one's diet (mine is about half vegetarian), but seem pretty clear. When talking with some drivers they seem to have the implicit belief that transportation cycling is a "sacrifice" I make for the environment, as if I believe that driving is obviously better. They seem pretty surprised when I tell them that I'd still ride even without the environmental benefits because I enjoy being fit and can put the money to better use. It's not a sacrifice, it's a preference. One I think many folks would agree with if they gave cycling a chance. I think there are quite a few things that people would consider to be massive sacrifices but actually end up being fine.
Though I do agree that cycling is practically impossible for many people, consider this: Just like most people consider their driving commute when choosing where to live, a cyclist needs to consider their cycling commute when choosing where to live. If you optimize for driving, don't expect cycling to be easy. The same applies for jobs: many people won't take a job if they expect the traffic to be a pain. I won't take any jobs that make cycling impossible or even hard. Exact same logic.
Think of all the other mundane ways people die everyday: disease, a bullet, or even just tripping off a sidewalk wrong and hitting your head on the curb. Is that really any better of a fate?