Ask MetaFilter: what practical difference can I make for the environment?

From Ask MetaFilter: What can I do, from the big changes on down to the minutae, to make a difference to the environment?

It's a great thread of practical advice which is probably best that you just read instead of me summarizing it. Some of these things I've already started to talk about - eliminating bottled water and using energy-efficient lighting were two of the first suggestions - while others, such as home insulation, "food miles," flying, and all kinds of other things are topics which I plan to cover in the future.