Yale scholars contribute to study highlighting importance of word choice ‘in climate change discourse’

A new study published in the journal Environmental Communication has found that the terms "carbon emissions" and "carbon pollution" are more effective at communicating the causes and impacts of climate change than the term "greenhouse gas emissions." 

The study, conducted by Francis Commerçon, Matthew Goldberg, Karine Lacroix, Jennifer Carman, Seth Rosenthal, and Anthony Leiserowitz of Yale, analyzed how Americans interpret and respond to different terms used to refer to the two main causes of global warming, carbon dioxide and methane emissions.

“In communication, it is important to use terms that are understood by and resonate with one’s audience,” the study authors wrote. “Word choices can influence people’s thoughts and feelings, policy support, and even behavior. In climate change discourse, greenhouse gas emissions, carbon emissions, and carbon pollution are often used interchangeably.”

Study respondents were randomly assigned to one of three conditions with identical questions except for the key terms greenhouse gas emissions, carbon emissions or carbon pollution. 

Measured outcomes included respondent’s feelings associated with the term, beliefs about environmental and health harms of each term, and the understanding between fossil fuels and climate change. Respondents' top-of-mind associations to their assigned term were also collected and coded into eight categories.

“We found that the terms carbon pollution and carbon emissions are more strongly associated than the term greenhouse gas emissions with harm to human health, the environment, and poor air quality,” the study authors wrote.“Respondents were also more likely to understand that burning fossil fuels generates carbon emissions than that fossil fuels generate greenhouse gas emissions. 

"This suggests that carbon emissions and carbon pollution are stronger terms than greenhouse gas emissions for conveying the causes and impacts of climate change,” they added.

The study states respondents' top-of-mind associations with the different terms also varied with carbon pollution evoking more negative images of harm, carbon emissions evoking more negative images of pollution and greenhouse gas emissions evoking more images of climate change. 

Carbon emissions also evoked more images of fossil fuels and cars compared to greenhouse gas emissions. However, greenhouse gas emissions evoked more positive feelings than the other terms, as well as more neutral images, such as gardening and plants.

The study concludes the terms carbon emissions and carbon pollution appear to communicate the causes and harm of climate change better than greenhouse gas emissions, although the latter term is best suited for scientific and technical discussions as it includes non-carbon based compounds that cause climate change.