Not sure why you are downvoted. I've been thinking about this as well. One individual change probably can't do much but, what I've been trying to do:
- consume less food
- eat more vegetables
- less red meat
- spend less in eating out or buying drinks out
- if I do buy drinks, I try to get paper cup
- stick with boring phone and mac and don't chase shiny toys
- use less plastic
- drink water vs coffee/tea
- use public transportation
- travel just once a year
- use more efficient language (i.e., Rust)
- if I have a home one day I'll be filling it with plants