Emphasize "methane" and don't use "natural" in language referring to the substance sometimes referred to as "natural gas". In testing the positve and negativ assocations with the phrases “natural gas,” “natural methane gas,” “methane,” or “methane gas”, among Americans, the term “natural gas” evokes much more positive feelings than do any of the three methane terms. Conversely, the terms “methane” and “methane gas” evoke much more negative feelings than does “natural gas.” The hybrid term “natural methane gas” is in the middle — it is perceived more positively than “methane” or “methane gas,” but more negatively than “natural gas.” This pattern was true for both Democrats and Republicans, whereas further research from this team found that the additional terms “fossil gas” and “fracked gas” were more polarizing: viewed favorably by Republicans but very negatively by Democrats. So, if engaging an exclusively left-leaning audience, "fossil gas" or "fracked gas" may be the best choices.