| MadSci Network: Environment & Ecology |
This is one of those debates that may never be solved. There are a number
of these life-cycle environmental impact debates going on today:
The reason that the last one is a favorite (despite the obvious reason in
my email address) is that very few environmental activists have ever
endorsed shopping by mail, but it can be easily shown that the benefit of
less consumer miles traveled far outweighs the paper use impact. After
being on the Internet for a few years myself, I welcome unsolicited mail
that I don't have to pay online user fees for.
Depending whom you ask, you will get answers on either side of your question. If you consider wildfire danger, the lighter probably wins out. The lighter has a much cleaner burn and the solid waste (including littering) load probably evens out because the frequency is much lower but the mass and relative hazardous material impact is much higher with the lighter.
Sometimes these life cycle analyses may surprise you. Dutch scientists once measured the impacts of porcelain, Styrofoam, and paper coffee cups for a fixed number of portions. They were surprised to learn that the porcelain was the worst. This was mostly because of washing. In fact, if you had more than two cups before washing your mug, it tipped the environmental scale back in favor of the porcelain.
I realize that I haven't answered your question, except to tell you that there may not be an absolute answer. If everyone took the time out to think this through like you have, that would truly be the best thing for the environment.
Try the links in the MadSci Library for more information on Environment & Ecology.