I just gave you an example of how something on a microbial scale has affected the climate.. You're welcome to say "that didn't happen on a human timescale, so it doesn't really concern me" which I would agree with. But you can't just say "I fail to see how any action today on this front will change anything later. At all." It's objectively false.
The medical/health claim is accurate, as we were shown with the scamdemic.