Recently Todd over at Today's Green Construction asked "Is Bamboo Flooring Green?". I asked a similar question last year about the greenness of different flooring options. I hadn't heard about widespread clear cutting of old-growth forests to plant bamboo but he indicated there were many references about it if I searched on Google. I don't know about "many" since I had to search for a while, but the upshot of my searching suggests that much of the bamboo flooring currently available is not green, particularly the cheap stuff (sorry, Home Depot and Lowe's). But if you're careful to get bamboo made with non-VOC glues, properly aged, and now FSC certified, it can be.
There's still the issue of shipping it from China or Vietnam to the U.S., which is a non-trivial problem. Though cork mostly comes from Portugal, linoleum from Canadian linseed, and tile from Italy or Mexico, so there's no 'free lunch'. As with many things these days, it's a balancing act, finding the right products for your needs and finding the greenest option available. Linoleum looks pretty good these days, though only has a life expectancy of 30 to 40 years.
The other thing that came up during my recent searching were questions about the durability of bamboo. Some people report lots of dents and dings, and some report gaps between the boards. The first is more common with darkened bamboo, because it's darkened by heating it and that weakens it. But it's much more common to have dents and dings because it's cheap. Bamboo grows very quickly (it can be harvested in as little as 3 years), but if it's not aged for a couple of years, it doesn't harden (lignify). The problem with gaps is generally an installation problem. Bamboo (which is a grass), like wood, expands and contracts depending on the moisture content. So the first thing to do before installing bamboo or wooden flooring is to let it sit in the area where it will be installed, to acclimate to the moisture. Obviously there will still be changes in moisture, particularly in places with hot, humid summers and cold, dry winters, but skipping the acclimation is pretty much guaranteed to cause problems.
While our bamboo floor isn't from FSC-certified bamboo, it's made using non-VOC glues, and has thus far been very resistant to dents and scratches. It's beautiful, and we've been very happy with it so far. So is bamboo flooring green? It can be, but not all bamboo flooring that's available is green, so shop wisely.