The role of gas in the future of the EU energy sector has been one of the most debated topics in the last few years. As natural gas (NG) makes up less and less of Europe’s energy mix (according to several studies), there is an increasing scope for the development and flexible use of a number of different types of gases (namely biogas, biomethane, synthetic methane (or syngas or renewable methane) and hydrogen. Some of these ‘new gases’ (as we will call them in this paper) may be generated from renewable sources, or from hydrocarbons. A few of these gases are carbon neutral by process; others are responsible for the emissions of greenhouse gases (GHG)1, despite being of 100% biological origin. Some of them are almost identical in chemical terms, but their carbon footprint may vary quite significantly. This complex scenario makes it difficult (and very confusing) to refer to the new gases with non-univocal adjectives such as ‘renewable’, ‘green’ or ‘no-carbon/low carbon’. Therefore, there is a strong need – widely recognised by all the parties in the sector – to agree on a common terminology which could help prevent any misunderstanding when referring to a specific gas; this is even more important in the public debate since the ‘new gases’ are going to be the subject of upcoming EU regulatory measures.