I wrote an article on this subject a few years ago for NPN. Hahnemuhle Bamboo is a nice paper, however, Hahnemuhle wouldn't tell me their source for their bamboo. Yes, bamboo is a fast growing weed, but how and where it is grown is important, and if is taken from the wild, that is very bad. Same goes for the sugar cane products. I gave Hahnemuhle the benefit of the doubt in my article. Red River makes Green Pics, a paper made out of 100% recycled material. It is perfect for cards, posters and proofing, but because one never knows exactly what materials are used in the paper, its archival properties are never known. Their is a paper made from stone, but it was terrible and well, stone comes from mining.
I wouldn't stress it too much, inkjet printing is a thousand times better for the environment than traditional chemical output, especially color, which is evil and very toxic.
Use your images for good, that's the best way to help, if you think about it too much, you will realize that photography in general is a massive producer of waste and bad for the environment.