What are the CO2 emissions by source or sector of human activity in the world?
Sources: IEA, IPCC and Jean-Marc Jancovici
Depending on the source and the analysis used, we will see that the proportions vary enormously.
Global CO2 emissions by source of activity

Global CO2 emissions by source of activity including electricity and energy in the end use source
Emissions of all greenhouse gases in addition to CO2 (methane, N2O and halocarbons) by sector of final activity

Geographical distribution of the top 12 CO2-emitting countries in the world and ranking according to sector
More details: Manicore