As a monist and non-believer, or at least a skeptic of supernatural things, I am not a big fan of individual karma the way it is thought of in the West. It is a pop-word by now, coming from Eastern religions which is completely misunderstood (as the whole individualism in the West) - no, I don’t believe that somewhere in the Akashic Records my entire life history is stored and at any point in time Reality balances out my deeds; if it were true, I would probably be getting lots of pranks done on me the way I did it on my neighbors. Anyways…
I am a big believer in collective karma though – that our actions influence the environment around us as well as the lives of our descendants and the beings that we share planet Earth with. It is super simple, it is actionable and doesn’t involve anything supernatural. That’s Feedback 101 and Failure of Feedback is one of the 4 cardinal sins preventing us from having good futures. You want your children to have good enviroment, friends and prospect of good future? Well, then simply participate in society, form groups and influence the present.
Some people have Housing Theory of Everything, I go one step back: Failure-of-Feedback Theory of Everything.
Collective karma is simply a feedback loop propagating in time to our environment and our descendants.