Carbon Dioxide (CO2) Emmissions - Greece. Million Tonnes of carbon dioxide. Carbon emissions reflect only those through consumption of oil, gas and coal, and are based on standard global average conversion factors. This does not allow for any carbon that is sequestered, for other sources of carbon emissions, or for emissions of other greenhouse gases. The data is therefore not comparable to official national emissions data. The table is compiled on the basis of carbon content: oil - 73,300 kg CO2 per TJ (3.07 tonnes per tonne of oil equivalent); natural gas - 56,100 kg CO2 per TJ (2.35 tonnes per tonne of oil equivalent); coal - 94,600 kg CO2 per TJ (3.96 tonnes per tonne of oil equivalent).