There is some debate as to how much more green and friendly digital photography is to film and chemicals. However, Ink cartridges, large amounts of lead in computers, the power needed to run printers and monitors (I know people with broadband who never log off) and a throw away society constantly looking for the latest spec upgrade probably make it all much of a muchness.
I'm not exactly a tree hugging hippy (I love tyre munching fast motorbikes too much for that) however I keep my used chemicals and have them taken away for ethical disposal. I live in the South of England where every drop of water counts so I print onto RC paper rather than fibre based as the wash time for each photograph is greatly reduced, and I always switch the light in the loo off after use. The latter has no effect on my photographs but it does save electricity!!!