Electric heating is rarely used; there are many other heat sources available. There are no other energy sources available for cooling (passive cooling design aside), so comparing a heating-dominated climate to a cooling-dominated one will inevitably show more electric consumption in the hot zone. Has nothing to do with efficiency.

This left me curious and just checked that in EU, 50% of emissions are due heating and cooling [1] whereas in the US 20% of residential electricity [2] is used for air conditioning. I'd like to have better stats, but assuming numbers are correct this indicates that the difference of CO2 emissions between US and EU per capita are due other reasons than a/c use in US.

[1] http://ec.europa.eu/smart-regulation/roadmaps/docs/2015_ener...

[2] https://www.theguardian.com/environment/2010/oct/08/air-cond...

It's much, much better to burn fossil fuels for heat than to burn fossil fuels to spin turbines, transmit the electricity long distances, and then run it "back" through heating elements. Stages one and two are pretty lossy.

Particularly when electricity is from coal and natural gas power plants, using it for heating is a staggeringly bad idea.

True, but electric powered heat exchangers can give a 2-8x advantage since it's not generating the heat, just moving it from one place to another.

I think you're right about house sizes, but there are a lot of the US that needs both summer AC and winter heating - like the midwest, the north east, and probably the west coast east of the mountains (inland Washington, Oregon).

Insulation is key. From what houses I've seen in the US vs Europe, the former are mostly wood-based (or similar material) and thin-walled, whereas Europe's houses are often stone- or concrete-based, thicker walls and/or (at least for newer/refurbished houses) very good insulation.

Combine that with some (more or less) clever thermal management and you need way less for both cooling and warming the house. There's also multiple government programs/incentives to improve housing energy consumption efficiency.

Do people need air-conditioning or is it just a luxury?

I guess now the globe is heating up there is more need for one, but I've always thought of it as borrowing from the future a little, a viscous cycle. More AC, More emissions, needs more AC.

I'm in Indonesia right now and sure the houses are built for the tropics but with locals, AC is rare and people manage to get plenty of good sleep and have loads of energy.

It's rarely productive to talk about "need". Do you really need indoor plumbing? Do you need a private bedroom? A broad variety of foods? After all, plenty of people in the less developed parts (and in the near past in the more developed parts) of the world get by without those just fine.

The history of civilization is largely the history of the taming of nature to better suit the needs (and wants!) of humans.

People get used to heat and humidity. If all you know is a more temperate climate or ubiquitous AC then it's hard to image sleeping in tropical heat.