How do systems on earth interconnect and affect the quality of life?

If you refer to solar (or stellar) systems, stars are so far apart that changes in one system will usually NOT affect another system. I would say there are two main exceptions to this: (1) Sometimes stars do get quite close together - especially in global clusters, and in the center of galaxies - and randomly anywhere else. In this case, one star could strip another star of its planets, due to gravitational interactions. (2) If one star explodes as a supernova, it will probably be harmful for life (should there be any) many light-years around it.