Good question. I haven't looked. If the company that compresses, bags, and ships these shavings can do it so cheap that I pay $6 for one, they must be pretty efficient with their energy use.
I'm not very interested in sustainability, or just being "not dead" like Paul W says.
I purchased this compressed wood from a mercantile shop 10 minutes from my place and they offer other items I may purchase like bales of hay, and split wood for burning if I don't have enough cured by next winter. I'm unsure how many people the mercantile employs, but if I buy some stuff from them, it helps their business make money and they can hire more clerks who make money too.