Only a luxury good if you are allowed to freeride on society by dumping your dirt on it for free as an alternative to using clean technology.

Indeed it's a luxury only because we've socialized the cost of the externality.

Completely untrue when you look at technologies that can SAVE someone money. It makes sense given increase demand for fossil fuels, to provide a cheaper alternative.

To be fair, I think you're referring to companies that are luxury goods, e.g. carbon offsets, and those could be argued are luxury goods (or rather goods for someone's conscience).

Not all of it. Heating and gasoline prices are expensive. Energy in general is expensive. If it's possible to create a system cheaper than burning stuff we're in good shape.