I can't find the answer and i was hoping someone else knew itPlease cite your source if you know!
There is a lot that might need more definition within the wording of your question. What is a greenhouse gas? There are many. Water vapor is a greenhouse gas. Carbon dioxide is a greenhouse gas. Methane is a greenhouse gas. Do you think that anyone has measured the amount of sweat put out by workers building fuel cells? Or how many times per minute and how much carbon dioxide they have exhausted while breathing. There may be some measurement of the amount of energy (other than human) that has been used to build fuel cells but what of all the components that have come to that point. What about the pollution released in transporting each component to the point where it is used. The problem with these kinds of calculations is that at some point they become just conjecture or defined so narrowly that they become meaningless. Perhaps if you could give some idea of where you were heading with this information it might be easier to make some guesses. Although this is supposed to be the information age, I doubt any realistic information actually exists on this.
