Saving the planet shouldn't be up to the consumer.

Until we can accurately build in negative externalities (probably never) it will always be cheaper to pour industrial waste in the river, spew sulphur dioxide into the air, chop down ancient forests, overfish the oceans, and drive cars based on cheap fossil fuels that warm the planet.

We endow the government with the right to make long-term decisions that are good for society, even if they are less profitable to us in the short-term. (Not that the government always does a good job of it, but that is one of its mandates.)