> So maybe people really just don’t care

I think so. Everyone is always selfish. There are only selfish reasons. Some of us happen to selfishly feel good about helping others, but not always, not with everything, not when it's just inconvenient enough. If you want people to stop worsening the climate, you have to frame it in a way that convincingly portrays it not as something that is happening but as something that is noticably worse for them individually. Is global warming noticably worse for me individually? Not where I live at my salary. So what then do you say to convince?