Climate - truthful information about climate, related activism and politics.

I've done energy models for houses here in Saskatchewan (~560 tCO2e/GWh) and at the moment, they are not cleaner than heating with natural gas, which is the typical primary heat source. Obviously, it would depend on grid carbon intensity, so there is a level of grid 'cleanness' where heat pumps would become cleaner, but that tipping point depends on a number of factors.

You could do a rough estimation with the seasonal heating efficiency of a heat pump based on the heating-degree-days of your location versus a certain efficiency of natural gas furnace. Burning natural gas is about 0.18 kgCO2e/kWh. So, if you have a heat pump that's 200% seasonally efficient, you'd need the grid carbon intensity to be about 0.38 kgCO2e/kWh (380 tCO2e/GWh) to be equivalent to a 95% efficient natural gas furnace.

Maybe not in the article, but I've heard in other places that a carbon heavy grid still gets enough energy to the heat pump that the heat pump's efficiency can offset that increase.

You're also installing a system that is easier to decarbon in the future, which isn't the case for natural gas.

I think the point is to compare the heat pump with an electricity heater, there may be other ways that generate less carbon footprint of course