Before people can reduce their carbon footprint, they need to know what actions will most help them do so. Research has shown that this domain of knowledge, known as “carbon competence,” is relatively low among the general public. But until recently there hasn’t been much investigation of why, or how to improve it.
A new study identifies two familiar cognitive biases as psychological barriers to improving carbon competence, “meaning inaccurate understanding of climate impact is not just a knowledge gap but also a behavioral and communication challenge,” says study team member Claudia Schneider, a psychologist at the University of Canterbury in New Zealand.
The team’s findings suggest that simply telling people which climate actions are most effective—until now the gold standard of climate communication—won’t move the needle for everyone. Instead, boosting carbon competence might require an individualized approach.
Schneider and her collaborators conducted an online study of more than 500 U.S. citizens in which they asked participants to estimate what percentage of the average North American’s carbon footprint could be saved by each of 34 different actions.
“Many people misjudge which personal climate actions cut emissions most, often overrating familiar actions like recycling and underrating higher-impact changes such as flying less and eating less red meat,” Schneider says. Those findings are in line with previous studies.
In the new work, people tended to overestimate the effectiveness of actions that were top of mind and those they themselves participated in, and people with higher environmental values were likely to rate all actions more highly, reflecting optimism about the impact they can have as individuals.
Taken together, the results suggest that two well-known cognitive biases, the availability heuristic and motivated reasoning, distort people’s understanding of the effectiveness of climate actions.
The researchers then designed two more studies, each involving about 1,200 participants, to test strategies to overcome these psychological barriers. Reasoning that people like heuristics—rules of thumb used to speed and simplify decision-making—the researchers decided to offer more accurate ones.
They told one group of participants that more effective climate actions tend to have higher costs in terms of time, money, or comfort. Another group was informed that more common climate actions tend to be less effective at reducing emissions. For a third group, the researchers simply listed the four most impactful personal climate actions.
The researchers found some heartening evidence that people are willing to try to overcome a tendency for motivated reasoning: in one of the studies, people who were told that more common actions tend to be less effective were then able to avoid overestimating the impact of their own actions.
But overall, the interventions didn’t improve people’s ability to assess the effectiveness of climate actions as much, or at least as reliably, as hoped. Surprisingly, even straight-up telling people which actions were most effective didn’t necessarily enable them to later identify which actions were most effective.
Instead, the impact of the interventions varied a lot from person to person. “Our data suggests that there is no ‘one-size-fits-all’ solution to overcoming these psychological barriers,” Schneider says.
As well as figuring out how to tailor messages for different audiences, the search for a broadly effective strategy to improve carbon competence needs to continue, the researchers say.
“An important follow up question concerns the factors that drive engagement in climate actions, above and beyond judging their impact,” Schneider adds. She and her collaborators are investigating the role that perceptions of fairness play in these decisions, she says.
Source: Herberz M. et al. “Psychological barriers to improving carbon competence.” Nature Sustainability 2026.
