This is somewhat old news, but it is still good news.

Raincoast Books is the company that is publishing the Harry Potter books for Canada is very eco-conscious. The books have been/continue to be printed on 100% post-consumer recycled paper. 30,000 tress may be saved as a result. BoingBoing has more info.

From the link:

Raincoast isn’t the only publisher seeking to put a green tint on the wildly popular Potter books. Publishers from Germany, Italy, Britain, and Israel also comitted to printing Harry Potter and the Half-Blood Prince on large percentages of recycled paper and/or “ancient forest friendly” paper.