Actually fur that has been tanned is no longer biodegradable, that's the whole idea of preserving it. It contains metal salts and other chems to denature the proteins and prevent it breaking down while you wear it.

Better to wear fake fur made from recycled plastic water bottles. Trapping wild animals merely for their skins is cruel and wasteful. Sheepskin coats from meat animals is more humane and less wasteful, if one must have fur of animal origins, but as rockguy stated, the tanning process uses formaldehyde and arsenic, which leach into the ground and are toxic to the environment.

No reputable environmentalist would ever say this about wild animals " it's a renewable resource that can never run out." FYI we are living thru the greatest mass extinction since the time of the dinosaurs and there is no end of species which were harvested to death.

That said, I happened to have watched a very interesting program on pbs last night about the nutria, a giant rat from South America that has become invasive in southern US and is literally destroying the Louisiana coast line. I had no idea! There are people who are marketing the fur as a "green" thing and I think that's a good idea - right now the animals that are killed by bounty hunters are just destroyed and not used so why not use the fur? Which btw is why they were imported from South America in the first place -for their fur which is quite beautiful.

There is a good reason hunters don't use deer fur, it breaks off too easy.