Do you use natural gas? Petroleum? Electricity? Geothermal? Wood-burning?

If you have electric heating and cooling, the way to make it clean is to buy 100% clean electricity. We are big fans of geothermal heating and cooling systems, which pull heat from below ground, where the temperature is pretty constant throughout the year. You can read more about these in the Your Thermostat section. As far as hot water (and some space heating), solar hot water is a great option. If you currently have, or are thinking about using biomass (wood burning) for heating, check out our FAQ question on it to see if it is actually a clean option for you.

If you already have one of these systems, congratulations, you're done. If not, do what you have to to get your home comfortable without using CO2. It may simply be a matter of completing another guide on this site (like 100% clean electricity). If it's not that simple, then consult with an HVAC specialist and see if an upgrade of your existing system to a clean one is reasonable (it may even end up saving you money). Just be sure to take a hard look at each of the different technologies out there and keep them in mind when it's upgrade time.