How long does Class A have?

The size of the Class A hifi audio amp market literally doesn't move the needle on global environmental impact and the earth's carbon footprint. Much more lower hanging fruit for any activists or policy interest groups to go after first - most obviously a move away from fossil fuels and on to renewables.  It would be much more meaningful to power our societies (including our Class A amps) with offshore wind, solar, waste to energy, etc power sources.  Anyone who cares about policy would be taking this approach and not targeting individual devices.

I hear you, and obviously the vacuum cleaner market is larger, and I’m not sure of your whereabouts but in the EU we had the power of vacuums, lightbulbs etc targeted quite tightly, I just think someone will come along and pick on them, I hope not mind. 

When it comes, and it likely will come, it will come in the form of a consumption tax on electricity. A sin tax if you will. Or maybe a luxury item consumption tax (similar to a gas-guzzler tax). Just a matter of time.

I have solar panels that cover 72% of our family use and I buy energy credits to make up the rest.

Until we get out of gas cars and flying all over the place, Class A amps is a drop in the ocean. 

They sound great. They will continue to be made, sold, and enjoyed. My two cents.

2 days and its history.