  Combining global gridded population and fossil fuel based CO2 emission data
at 1km scale, we investigate the spatial origin of CO2 emissions in relation to
the population distribution within countries. We depict the correlations
between these two datasets by a quasi-Lorenz curve which enables us to discern
the individual contributions of densely and sparsely populated regions to the
national CO2 emissions. We observe pronounced country-specific characteristics
and quantify them using an indicator resembling the Gini-index. Relating these
indices with the degree of socio-economic development, we find that in
developing countries locations with large population tend to emit relatively
more CO2 and in developed countries the opposite tends to be the case. Based on
the relation to urban scaling we discuss the connection with CO2 emissions from
cities. Our results show that general statements with regard to the
(in)efficiency of large cities should be avoided as it is subject to the
socio-economic development of respective countries. Concerning the political
relevance, our results suggest a differentiated spatial prioritization in
deploying climate change mitigation measures in cities for developed and
developing countries.
