Heat pumps are different than traditional HVAC and water heaters in two primary ways:
1. They run on electricity.
2. They are way more energy efficient.
The fact that they run on electricity is important because even if we got our grid to 100% renewable energy tomorrow, we'd still have hundreds of millions of tons of emissions from gas, oil, and propane heating systems.
Technically speaking we could replace all those fossil fuel heaters with electric furnaces.
But that'd be a terrible idea.
Why? Because electric furnaces use a lot more electricity than heat pumps.
More electricity demand means we have to build more solar, wind, batteries, and transmission lines.
And building stuff is hard!
It's also expensive.
And you have to deal with NIMBYs and (oddly) sometimes environmentalists.
Heat pumps will help us avoid some of that.
As a climate solution, heat pumps are also unique in that:
1. The technology is already production-ready.
2. A lot of people can save money by switching to a heat pump.
Compare that to something like direct-air capture, which is also all the rage these days.
That technology is nascent and still years or even decades from being production-ready.
Or compare it to going vegan.
I've been vegan for the last two years and every time I tell people they say something like "Oh I could never do that. I'd miss [insert_meat_of_choice] too much."
It's perceived by most as a sacrifice.
Switching to a heat pump on the other hand can save you $10-20k over the lifespan of the unit.
The personal finance blogger Mr. Money Mustache said he expects a 15% annual return on his investment.