I guess I missed @MustangMike 's original post.I can believe that, up in colder climates! especially, if one heats with wood. even humid climates such as down here in summer months wood such as oak can last a long time. I have an oak wood pile in my barn and its close to a 1/2 cord +/-... and it is dry and good wood. it is 22 years old! since cut and split. burns great, hot and as one would want. I have been using the 18 year old oak from outdoor woodshed in town of late, burns like been drying for one season. and while it is covered, its sides are open. definitely sees some humid air! I think I got a pix of the wood pile in barn, will post it if so... I may burn some junk now n then in mr Brutus... his appetite is never satiated fully... lol, but both wood piles burn just fine. I can buy into the fact, that due to time effect on the C in the wood, may be down on some BTU's... but from my point of view, and position sitting in front of the fireplace... well, let's just say... I often have to move back! lol ~
If you have wood off the ground and top covered, it will last almost indefinitely even up in the cold climates. We burned 30 year old wood from the back of the pile a few years back when I moved my wood pile from where my dad always stacked it. I know it was that old because we used to have a "bark buster" cone splitter and the wood was all split with that. The back ends of the wood were crumbly but the pieces themselves were solid and the wood on the inside rows weren't even grey.