The problem with relying on the mass of society changing their consumption patterns is that the mass of society is too damn poor to even give a damn, let alone scrounge up the extra money it costs to buy the non-polluting version of the commodity they need.

We’ve been trying to implement bottom-up change for 50+ years, and pretty much the only people who have made any voluntary changes are middle-class yuppies.

On the other hand, top down legislation has had an exponentially larger impact on emissions.