OK, so there are some things that many environmentalists don't seem to get. So let's see what's really environmentally sound.
1) Nuclear power. It's simple really, coal is horribly dirty, releases lots of mercury in the air. Nuclear waste (and I'm talking about the stuff that's truly dangerous, not the 'has been in a radioactive environment garbage' like radiation suits are considered after one use, etc) is not only small and easily containable, but can be recycled into more power via pebble bed reactors, and used until it has fissioned into non radioactive isotopes to keep producing electricity.
2) Buying Used 4 cylinder cars, not new hybrids/electrics. The amount of pollution that goes into making almost any new car is very, very high. The amount of pollution produced by a used 4 cylinder car that's simply kept tuned and in good working condition is low.
3) Buying antiques for furniture, vintage clothing at Estate sales and such. If it's at all feasible to wait and shop for it at some place that sells used, do so. Kitchen items? Estate sales and flee markets. Furniture? Antique shops, estate sales, sometimes garage sales or flea markets. Shop Craigslist, maybe Ebay. Every time you buy used instead of new, you help the environment. Even fur is fine to purchase Vintage, as the purchase does not increase or encourage the killing of animals. That money never goes to the original fur makers, and in some cases, said company might be out of business already.
4) Helping countries develop industrially is actually good for the environment. There is a short term increase in carbon emissions and such, but a properly industrialized country requires an educated populace, to keep up with the other modern countries. This combines with a push to spend time working, and both partners working, leading to a decrease in population growth over the long term, as well as greater interest by individuals to be environmentally sound. This develops into being better for the environment in the long term.
And I'm sure there's even more I'm missing. Think out of the box, in all things!