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...