Different names for “natural gas” influence public perception of it

Highlights

• Americans have strong positive feelings for the term “natural gas”.

• Americans have negative views of the alternative terms “methane” and “methane gas”.

• They associate natural gas with “clean” and methane gas with “pollution”.

• The alternative terms “fossil gas” and “fracked gas” are politically polarized.

Abstract

In many countries, natural gas is perceived more favorably than other fossil fuels. Here, we experimentally test (N = 2931) how perceptions of natural gas vary depending on what it is called. We find that Americans have stronger positive feelings for the term “natural gas” than “natural methane gas” (d = 0.59), “fossil gas” (d = 0.80), “fracked gas” (d = 0.81), “methane” (d = 0.94), and “methane gas” (d = 0.96). Democrats and Republicans both reported more positive views of “natural gas” than “natural methane gas” or “methane [gas].” But the patterns for the two political parties differed for perceptions of “fossil gas” and “fracked gas,” which were both viewed relatively positively by Republicans but negatively by Democrats. Analyses of open-ended word associations found that many participants associated methane with words like “pollution” and “global warming,” whereas they associated natural gas with words like “clean.” The results suggest that the terms used for this fossil fuel have very different meanings among the public, which may affect people's risk perceptions, consumer choices, and support for related policies.

Introduction

Natural gas is primarily (70–90%) composed of methane, a greenhouse gas. Methane has approximately 25 times more global warming potential than carbon dioxide for a time horizon of 100 years, meaning that 1 ton of methane absorbs approximately 25 times more energy (i.e., traps more heat or causes more radiative forcing) than 1 ton of carbon dioxide (Environmental Protection Agency, 2020; Forster et al., 2007). In 2015, the amount of methane that leaked from oil and natural gas production in the United States (U.S.) was estimated to be equivalent to about 2.3% of gross production (i.e., 7.6 million tons leaked vs. 33 million tons produced; Alvarez et al., 2018). Over a 20-year time horizon, the global warming impact of annual fugitive methane emissions from the oil and gas supply chain in the U.S. is roughly equivalent to the carbon dioxide released from all U.S. coal-fired power plants operating in 2015 (Alvarez et al., 2018). In other words, methane leaks “substantially erode the potential climate benefits of natural gas use” (Alvarez et al., 2018, p. 3).

Yet, whereas coal is viewed by many Americans as a harmful energy source, perceptions of natural gas are much more positive. A majority (76%) of the American public have favorable attitudes toward natural gas (Climate Nexus et al., 2020), and this is consistent across many countries around the world (Kennedy et al., 2020). The American public's attitudes toward natural gas are closer to their attitudes toward wind and solar (82% and 87% in favor; Climate Nexus et al., 2020) than to coal (39% in favor), even though electricity production from natural gas is responsible for 10–44 times more greenhouse gas emissions than electricity produced from wind and solar (Schlömer et al., 2014, Table A.III.2). On average, 62% of Americans (57% of Republicans and 76% of Democrats) think coal is harmful to human health, compared to only 29% (22% of Republicans and 35% of Democrats) who think natural gas is (Leiserowitz et al., 2018). In contrast, when asked about landfill methane gas as an energy source, 42% of Americans (39% of Republicans and 50% of Democrats) think it is harmful to human health, suggesting that the term “landfill methane gas” is perceived more negatively than “natural gas” (although this may be driven in part by the word “landfill”). This finding of diverging perceptions of similar energy sources (i.e., natural gas and landfill methane gas) raises the question of whether people's favorable perceptions of natural gas change depending on whether it is called “natural gas,” “methane gas,” or some other alternative label.

Labels function as shorthand symbols that help convey meaning, and they can work similarly to emphasis framing when they highlight different underlying aspects of an issue at the expense of other aspects (Cacciatore et al., 2016; Clarke et al., 2015; Entman, 1993). Names or labels can influence public opinion about an issue by making certain attributes of a product, object, event, or phenomenon more salient, thus activating different sets of affect and emotions, mental models, and risk perceptions (Clarke et al., 2015, Leiserowitz & Smith, 2017; Schuldt, 2016). When names or labels activate different perceptions of risk, they can profoundly shape consumer preferences, public policy support, and activism (Slovic, 1999). For example, the American public is more supportive of hydraulic fracturing when it is called “shale oil or gas development” than when it is called “fracking” (Clarke et al., 2015). Similarly, many studies demonstrate that food products labeled with the word “natural” are perceived to be better for the environment, healthier, tastier, and more moral (Asioli et al., 2017; Chambers et al., 2018; Sörqvist et al., 2015). Further, using a natural analogy to describe geoengineering technology (“like an artificial tree”) increases support for this technology (Corner & Pidgeon, 2015).

In a prior study, a small group of Americans (N = 94) were asked about the images they associate with “natural gas,” and whether those images were positive or negative. “Natural gas” elicited mostly neutral images (e.g., fire, pipe, gas appliances; Truelove, 2012). However, the sample was small, and the affective measure used may have obscured some important nuances, such as whether Americans hold ambivalent attitudes toward either natural gas or some of the images they associated with natural gas. This has important implications because ambivalent attitudes are less stable over time and are more susceptible to persuasion (Conner & Armitage, 2008). Ambivalent attitudes are also weaker predictors of behavioural intentions compared to non-ambivalent attitudes (Costarelli & Colloca, 2004). Further, this prior study did not address other important questions, such as how people respond to alternative terms for natural gas (e.g., methane gas), and how much people's perceptions are driven by these word choices (such as the use of the word “natural”). The current study addresses these questions in a large, randomized experiment (N = 2931).

This study assesses positive and negative affect associated with six different names for natural gas. The name “natural gas” refers to a fossil fuel gas mixture that contains 70–90% methane. It was named as such to differentiate it from artificial or manufactured gas, which was used throughout the nineteenth century (Castaneda, 2001; Waples, 2012). More recently, the natural gas industry has branded it as “cleaner energy,” “the cleanest fossil fuel,” and has promoted cooking with gas as being “synonymous with speed and efficiency” (American Gas Association, 2021a, 2021b; Enbridge, 2021). Although “methane gas” is not frequently used in public discourse to refer to natural gas, it is included in this study as an alternative term that emphasizes the primary compound in natural gas. Although not a term widely used in current discourse, “natural methane gas” is included to isolate the labeling effect associated with the word “natural.” Similarly, “methane” is included to isolate any potential effects related to the word “gas.” Climate advocates have started using the terms “fracked gas” (e.g., Sierra Club, 2018; #frackedgas on Twitter) and “fossil gas” (Global Witness, 2021) as alternative names for natural gas. The term “fossil gas” emphasizes that natural gas, like coal and oil, is a fossil fuel. The term “fracked gas” emphasizes a method of natural gas extraction using hydraulic fracturing or fracking, and aims to activate mental associations related to fracking, which tend to be more negative than positive (Clarke et al., 2013, 2015). Because these are currently contested terms, it is important to subject them to empirical tests.

Little is known about how people feel about the different terms that can be used to describe natural gas or whether different terms elicit different reactions among Republicans and Democrats. We tested three hypotheses. First, we predicted that “natural gas” would be viewed more positively than “methane” or “methane gas.” Second, we predicted that “natural methane gas” would be viewed more positively than “methane” or “methane gas.” Third, we predicted that Republicans would have more positive attitudes overall compared to Democrats, similar to the aforementioned political party differences in perceived harm to health (Leiserowitz et al., 2018). The terms “fossil gas” and “fracked gas” were also included because these terms are increasingly being used by climate advocates, but we made no specific predictions about the feelings and images associated with these two terms.

Another objective of this study was to better understand what comes to mind when people think of natural gas and other names for it. Affective image analysis and word association techniques provide unique insights because they help reveal the mental representations held by a population in a way that is “unfiltered, relatively context-free, and spontaneous” (Leiserowitz & Smith, 2017). We conducted exploratory analyses to answer the following questions: What associations (words or phrases) come to mind most often in each condition? Do these associations generate positive or negative affect? Finally, we examined how people perceive the relationship between natural gas and methane to determine whether the American public understands that natural gas is comprised primarily of methane.