When I was a boy scout in the late 70s and early 80s, LNT was just gaining traction. Although I did hear about LNT in the 80s, the Boy Scouts were still using a simpler version: Leave nothing but footprints; take nothing but pictures. Now, every wilderness entry permit I have seen in years has promoted LNT, and it is the prevailing ethic among those who spend time backpacking.
There are seven priciples of LNT:LNT.ORG website.
LNT is one of the reasons I prefer hammock camping. A tent requires a relatively flat area to be cleared and smoothed, whereas a hammock can be hung above uneven, uncleared surfaces. In addition, I use straps to attach to the trees, which prevents the rope from cutting into the bark. By treading lightly, I can leave my campsite looking as if no one has ever been there. Additionally, this flexibility in campsite choice makes it easier for me to avoid already damaged areas, giving them more time to recover. Tents often end up being pitched in the same location repeatedly, because it is the only good spot in the area.
Similarly, I have long avoided building new fire pits. In the old days, we used to dig a hole for the fire, and then after it was out cold, we would simply fill it back in with the original turf over the top. While this seemed to hide the traces of fire, it ignored the fire debris that inevitably gathered around the edges, and it was not good for what lives in the soil, so the turf patch woulf usually die and the spot would turn to bare earth. I like a fire as much as the next person, but if there is no established fire pit at my campsite, I am perfectly happy just using my stove.
There is only one area where I find LNT troublesome: it encourages us to pack out used toilet paper out of the woods with us. While I agree that “TP flowers” (wads left on the ground with a small pile of refuse) are nasty, I’m not too hot on the idea of putting all my used TP into a ziploc bag and putting that in my backpack to take home. Instead, using fast degrade TP, I dig a cathole, do my business, throw the used TP in the hole, add a small amount of water to wet the paper and hurry it’s disintegration, and then bury it all. I know that in some wilderness areas, you are expected to pack out not only the TP, but the solid wastes as well. When I visit such a place, I’ll have to confront my squeamishness, but for everywhere else, this procedure will be good enough for me. Please don’t judge me.
Beyond that one exception, I fully support and practice LNT on all of my outings.