Originally Posted by
genejockey
From what I can find online, CO2 for dry ice or for inflation is a byproduct of other industrial processes, rather than being made on purpose, so you might arguably even remove the 16g of CO2 in the cartridge from the calculation.
The canisters are a much bigger problem than the content. I stopped using them for that reason. I bought a nice thrifty Silca frame pump instead.