Razumny - as I have read through your comments - you seem to be arguing that no matter what, there will always be emission so we can never say zero emission. Perhaps this is technically correct but what most are indicating in this thread is that is not the intent of the phrase "zero emision vehicle." We understand it to mean zero emissions when using the vehicle for its intended purposes.
If you are really serious about your definition, we should stop talking about this topic to prevent exhaling - humans are not zero emission. :wink:
We should just say "partial zero emissions", making it clear that the emissions are partially zero, and partially non-zero. Or something. It must make sense, CARB came up with it. ;-)