No, you just need fossil fuel energy to be relatively more expensive, not for energy to be more expensive overall. It's happened already but we're currently being held hostage by the coal burners while they scramble to extract the last bit of rent they can.
There is no way to make fossil fuel more expensive without making energy more expensive overall, because fossil fuel is included in the category of "energy overall." The effect of making fossil fuels more expensive is that energy prices will rise. The point of the GP ("Not really. We need polluting energy sources to be charged for their pollution, ie stop using the atmosphere and land as a free sewer, which in turn will put renewables on an equal footing.") is that the goal is not to raise the cost of energy as a whole (even though this is the inevitable outcome of higher fossil fuel prices), but instead to price in the negative externalities generated by fossil fuels.
Put another way, in a world where fossil fuels are no longer consumed, there isn't any reason to limit energy consumption for its sake, since the whole point was to encourage adoption of cleaner technologies. There is a case to be made that this isn't true, since even the "clean" technologies have an environmental impact, but that is tangential to the discussion.
> No, you just need fossil fuel energy to be relatively more expensive, not for energy to be more expensive overall.
Can you explain exactly what you mean? Say (very made up numbers) coal is $1 per day, and a renewable is $2 per day. I raise the price of coal to $3 per day to make it relatively more expensive. Haven't I just increased the price of energy overall to $2 per day?
