Can natural gas warm the climate more than coal?

• Demonstration of the necessity of application of cumulative calculus to evaluate GHG emissions.
• Comparison of direct and life-cycle influence of coal and gas on the climate change.
• Proof that the influence of natural gas on the GHG emissions can be similar as in the case of coal.
• Encouragement for complete and fair comparison of primary energy from the GHG point of view.

Polish energy sector is mainly based on coal. More than 90% of electricity is generated in steam power or heat-and-power plants fired by hard coal or lignite. Obviously, the share of coal fired units in Poland is higher than in EU-15 countries. By taxing CO2 generation EU enforces the development of low carbon technologies. The motivation behind this policy is to limit the global warming effect resulting from energy conversion technologies. However, the implemented system of CO2 taxing accounts practically only for the CO2 produced by direct combustion of fuels neglecting the remaining links of the process chain. The aim of the paper is to give a more complete picture of the influence of the power generation by resorting to the cumulative emission approach.The direct emission of CO2 following from stoichiometry is significantly higher in the case of hard coal or lignite than of natural gas. The result of direct emission analysis are the main argument against coal technologies. As a result, natural gas technologies are treated as much climate friendly than their coal counterparts. Taking into account that in Poland and many other European countries the majority of natural gas is transported by huge distance from Siberia, it is obvious that to have a fair comparison of coal and natural gas technologies, the greenhouse gas emissions associated with transportation of the gas over very long distances and the leakages must be taken into account. The paper shows that when gas leakage at mining and its consumption in compressor stations of the pipeline are taken into consideration, the natural gas technologies exert similar influence on the global climate as its coal competitors.