It is surprising, harmonized views on the concept of carbon footprint and its calculation are not reached. This concept is being further manipulated depending on who uses it, and even according to the type of calculation and use is given. It's not an empty statement, we have only to realize how it is used, when interested, equating carbon footprint to environmental impact. Anyone in the environmental world (and many others) are well aware that they are very different concepts, and that only in certain cases you can set a certain unification in its assessment. Moreover, there are over 100 methodologies for calculating the carbon footprint, so in practice it is not possible to compare between companies, sectors, etc, as there is no unified criteria, but even when assessing footprint resulting from electricity generation, which mix would we use? Would we use a mix-country? Maybe a mix-supply company? many variables without defined criteria for its determination or calculation, that should de unified in order to make comparisons between companies in the markets, and in the same way in order to evaluate the different labels, of which today there is at least one by country in the EU.