Interesting points, pbev, although I think they ultimately show that people have to do different things to save the earth depending on their circumstances. Thinking about this issue got me thinking how elegant, effective, and liberating a carbon tax would be. No snobbery, niceties, or guilt trips about other people's lifestyles. Just make people pay for their carbon output and watch them find ingenious ways to reduce it in order to avoid the cost.
Anyway, here are my answers to your remarks:
I live on the sixth floor of a New York apartment building and dispose of my trash by dumping it into a garbage shoot. Plastic, water and tear-resistant bags are necessary because if the bag breaks in the shoot the garbage could sit there for a long time, attracting rodents. Suffice it to say my neighbors would hate me.
I can see how not using trashbags could be doable in the suburbs or the
country, as long as you didn't have a mouse/insect problem. It would be especially practical if you also had a compost pile for organic waste (which tends to be 99% of the especially icky wet garbage). But it won't work in Manhattan.
I console my conscience by the fact that living in Manhattan allows me the ultimate environmental virtue: not owning a car.
Canvas is heavier than plastic, so packing your shoes in canvas means more weight for you and the carbon-burning airplane to carry. Of course, you can argue that the extra emitted by plane carrying an extra canvas bag is infinitisimal, but then, so is the carbon emitted in the production of a plastic bag for each of my shoes (but note to environmentally conscious women everywhere--YOU CAN MAKE A DIFFERENCE BY NOT PACKING 5 OUTFITS AND A GALLON OF COSMETICS FOR EACH DAY OF YOUR TRIP!).