So does any activity that produces CO2, including natural forest fires, and breathing. The whole idea that CO2 is harmful, came from modern scientific knowledg

So does any activity that produces CO2, including natural forest fires, and breathing. The whole idea that CO2 is harmful, came from modern scientific knowledge - also part and product of the economy/society. The same economy could come up with solutions e.g. carbon taxes or other tech advances. You are taking a complex issue, CO2, the economy and its planetary effects, and turning it into a simplified concept of "harm". Humans have consumed some amount of CO2 forever, it's only an issue now because there are significantly more humans (who also create more CO2, but that's beside the point of the first). In order to survive in growing numbers, humanity will need to manage its CO2. Incidentally this isn't the first time something like this has happened: https://en.wikipedia.org/wiki/Great_Oxidation_Event https://en.wikipedia.org/wiki/Great_Oxidation_Event Nothing about this the hobo lifestyle suggests it will produce a solution to this problem beyond the fact that it's unlikely to support communities of a certain size for other reasons.