Edwards wrote:In the present I think using twigs and a Kelly Kettle is mush more sustainable to make a cup of tea.
The main principles off Bushcraft as in respect for nature and do not take to much food items is certainly one we should all adopt.
As regards a fire, it is possible to have a very small cooking fire and leave no trace at all plus not do lasting damage to the countryside. Only if it is done with respect an awful lot of thought and planning.
As has been said using a gas stove is not very sustainable, but at times needs must, so I have only my conscience to deal with.
While I think there are stoves like the KK which are comparably efficient to using a gas stove, I can't believe an open fire is anywhere near comparable. When on the road I use only a tiny fraction of the gas (and almost everything else) I would use at home. Even a small open fire has to be vastly less efficient than a small and controllable alcohol, gas, or petrol stove used properly. And again...who's wood is it?
I agree that some bushcrafters do have a deep understanding and respect for the environment. Although most of the ones I know have been doing it since before the term was popularised and wouldn't wish to be called it. I also know from my own travels that there are increasing amounts of people, inspired perhaps by Mears and co and the growing bushcraft industry who haven't.
It should also be remembered that so far, we have only considered one end of the er... "food chain".
(some good info on fuel efficiency and lots of other stuff about stoves here:-
http://zenstoves.net/StoveChoices.htm#Efficiency)