Yes, I read a bit on this (apparently real after all) business and I saw CO2 is the carbon source. It just confused me the promotional website does not even mention CO2. When they called Solein carbon neutral, I assumed they are talking about the product and process, not the entire cycle (in the same way you might call planting trees CO2-emission negative), though this makes sense. In any case, I still find it to be a pretty strong misrepresentation to call this protein synthesis out of "thin air".