The Age has an interesting piece on how Sweden is on its way to becoming (mostly) carbon-free. "Today, Sweden's annual greenhouse gas emissions are just over five tonnes per capita, compared with Australian and US levels in the high 20s and climbing." The country's aiming to end its oil dependency by 2020. And they've managed to do it without suffering economic ruin and abject poverty. Quite the concept.
Now granted, it's not clear how closely other countries could follow Sweden's example--the Swedes seem to use a lot of biomass to generate electricity, for instance, and there's probably not enough biomass to power the entire planet--but it does suggest that a carbon tax (Sweden slapped down a hefty one way back in 1991) plus various other policies can go a long way toward curbing emissions. Most notably, the government's done a lot of work to convince people to drive less and "encourage high-density living over urban sprawl," although the piece is a bit vague on how they managed to do that.