Well no, but it's either pedantic or meant to mislead. If we're in agreement we need to do something about CO2, then we both know we're talking about human sources of CO2, so why be pedantic?

Also part of my point is that we do not have to focus on human emission as the only lever. We can also focus on sequestration of natural emission (or sequestration of atmospheric carbon as a whole).

Telling people to not emit carbon dioxide from, say, a health related usage (sanitation) IMO is foolish when we can choose to sequester from other areas. Frankly I think we need to focus on the decarbonization of energy, rather than regulating human behavior.

What's a non human source of CO2 emissions that we can reasonably prevent?

For one thing, because it's important to know the lower bound of success in order to identify the reasonableness of the proposed solution, competing its perceived costs with its perceived benefits.

That entire sentence means nothing, and is entirely irrelevant to my comment and the discussion at hand.