However, it's a lot easier to passively heat a house then to passively cool a house. We could easily upgrade building envelope standards, incorporate a heat pump, and reduce the heating-associated CO2 emissions to a fraction. If we did that, I think on net the Houston C02 emissions might be larger, since there really aren't equivalent ways to passively cool space.
There is no evidence this is really possible. Houston homes cooling a house 25 degrees will still be significantly less than maintaining a 100 degree difference in Minneapolis during a -30F snap. Don’t forget that there is significantly less daylight to work with in the winter for this “passive heating” too.
There's plenty of evidence. One example is Passive House standards (which can be applied to commercial contexts as well), which reduce heating loads by 90% using the methods I discussed. There's a lot of factors you're not accounting for:
1. Waste heat from lights, equipment, and people is constantly offsetting the heating energy, and contributing to cooling energy. There's so much equipment in office/commercial buildings, it's common to need air conditioning all through winter.
2. It's not just air temperature difference, it's also about solar radiation gain. Even in cold climate zones the peak load for cooling is significantly higher then the peak load for heating.
Passive house standards don’t cut it. Reducing 90% doesn’t matter if many of those energy improvements also apply to cooling.
> Waste heat from lights
Use LEDs and this is irrelevant for a home.
> people is constantly offsetting the heating energy
Insignificant in the scheme of things. Humans can’t even keep themselves warm when holding still in 50F.
> it's also about solar radiation gain.
Do you realize how little sun cities in the north get during the winter? Conversely, solar electricity can conveniently capture plenty of electricity quite near the time it’s required in the South.
Peak air con time is when there is solar radiation. Peak heating time is in the dead of night.
Be careful here since it gets complicated between energy efficiency differences in heating vs. cooling, but also in greenhouse impact of the units themselves. For example, R410A used in modern A/C units is over 2000x more potent as a greenhouse gas than straight CO2, and A/C units leak quite frequently as they age. You also need to factor the greenhouse impact of the energy source of the local power grid during the season when heating/cooling are needed. It's hard to make a solid claim either way without looking at quite a bit of data.
This works both ways! You can clean the grid in the the Northeast[1], and the clean energy would go a lot further to condition your (properly energy-retrofitted) houses then a house in Houston.
[1] For example in Toronto, Ontario, the electric grid is fueled from hydro (and we get passive cooling from lake water). And yet, Toronto's urbanization is so intense (and still growing) so the city still needs to reduce the energy consumption of it's buildings to manage it's peak power consumption. And I would argue this still has a huge impact on CO2 emissions given the reduction of transportation emissions associated with high density areas.
Okay, the power company is named Toronto Hydro, but it buys electricity from whatever is available on the grid, be it hydro, gas, nuclear (Darlington wasn't built to power Ottawa...), wind (hello Chatham farmland!) or solar.
