An urban population should emit less GHG than the same population being spread out. And standard of living is not that much different from Denmark (20% less) or the UK (30% less).

You're right for the Netherlands and the developped countries, of course. I confused this rural pop with developping countries' rural pop, which of course is a lot less energy intensive.

As for the standard of living differences, are those numbers similar to the energy-per-capita differences between the same countries ?

Urburnites claim that city living is cleaner (co2 wise) that living in the country

Living near the people and things you need, walking, cycling, and taking electrified public transport to said things, and multi-family dwellings allowing the use of district heating (or heat pumps powered by renewable energy) can drastically reduce your carbon footprint compared to living in the burbs and driving to everything.

https://www.theguardian.com/environment/2009/mar/23/city-dwe...

Of course, you _can_ have a low carbon footprint in the country, but it's really hard, because those places are hostile to cycling and walking.