Stone house and air source heat pump

[fernicarry]

the improved energy efficiency reduces the potential benefits for planet earth of swapping out to an ASHP

Thats actually a very good point. The thermal improvements are a prerequisite to making a HP effective. But having done the thermal improvement your gas usage will be half of what it was. Thats already a pretty good result. A stunning result actually. It makes the additional cost of a HP a much less obvious investment.

Similarly EV's. Since I switched to a PHEV my petrol usage has easily halved. It doesn't rely on billions being invested in charging infrastructure, just a 13A plug. And I don't have nearly so much blood on my hands for the minerals that were extracted to go into the modestly sized battery as compared to a full fat BEV. Half the benefit for a tiny fraction of the cost.

 

[Flyfisher]

Well, yes, but at the risk of going off topic, we can't really be a bit sustainable, or rather we can but it only kicks the can down the road rather than solving the ultimate problem. As someone once said, you can't be a little bit pregnant.

I've definitely reduced my carbon footprint (battery EV, solar PV reducing my average annual consumption by about 90%, home heating at least 50% wood) but I'm under no illusion that my lifestyle is ecologically sustainable or that it could be enjoyed by everyone on the planet, and that's the real issue; global population. I suspect this is essentially an unsolveable problem before something catastrophic happens. Meanwhile, we are immensely privileged to to live as luxuriously as we do.