Munger made a prediction that has stuck with me for over seven years now: people will someday be mining old landfills to reclaim plastic in order to process it into fuel. After all, plastic is a petroleum product, it burns well, and while we don't have the technology yet (to the best of my knowledge, anyway), I could see this happening at some point.
I feel a bit of guilt when I throw away bottles, cans, and other products that don't rot easily, but I suspect that's residue from propaganda--and I use that word intentionally--I swallowed as a middle schooler. I don't feel as much guilt as I otherwise would, however, because the bottles and cans I'm throwing away are going into a gigantic inventory where they can be recycled and reprocessed when the price is right.
I've seen the claim that recycled aluminum uses 95% less energy than aluminum mined from the ground, but this makes me a bit suspicious: if the 95% energy saving is a free lunch, then we should see a massive market for used aluminum that doesn't have to be subsidized to be viable. Perhaps the energy saving number is accurate, but there are other costs that make using recycled aluminum cost-prohibitive. Here's something to consider, inspired by some recent tweets from Modeled Behavior: if you keep claiming that there's free money on the sidewalk and you don't see anyone stooping to pick it up, the free money probably isn't there.
Are there serious environmental problems? Yes. Is the market for sanitation perfect? Not by a long shot. However, to the extent that there is a solution to these problems it probably isn't sorting our garbage. It's getting the prices right.