Most Americans greatly underestimate their carbon footprint

When you ask Americans how to reduce carbon emissions, you’ll likely hear answers like “switch to LED light bulbs” or “recycle more.” These are familiar habits, but they’re not the most effective ways to shrink your carbon footprint.

A new study from researchers at Stanford University and New York University shows just how far off public perception is.

People tend to overestimate the impact of small, visible actions and underestimate the power of major lifestyle changes – like cutting back on flying or eating less beef.

“People are very misinformed around how their actions can translate into actual impact in terms of reducing carbon,” said study senior author Madalina Vlasceanu.

“We think, ‘I have to recycle this and it will help the planet.’ It’s less likely you will hear that if you fly less, that’s the best you can possibly do, lifestyle-wise.”

Knowledge about carbon footprints

The study included nearly 4,000 U.S. participants who completed an online survey. They were divided into three groups. One group actively rated 21 common behaviors – like biking to work or using energy-efficient appliances – on how much they thought each reduced emissions.

After submitting their guesses, the individuals received feedback comparing each action’s impact.

“We compared the actions to each other – not tons of carbon. That’s something nobody understands. It’s so abstract, you’ll forget it immediately,” Vlasceanu said.

Another group passively received the same information without first guessing. A third group received no information at all.

Then, all participants were asked about their willingness to adopt the same 21 behaviors, as well as five larger system-level actions, such as voting for climate-focused politicians or attending a protest.

Informed but disengaged?

After the exercise, many participants showed a shift in thinking. They expressed stronger intentions to take meaningful steps, like choosing lower-carbon meats. Poultry, for example, has a far smaller climate impact than beef.

“Participants found this can be really easy to do, and has one of the highest impacts that has been actually documented,” Vlasceanu said.

Those who had the biggest gaps between perception and reality showed the most change. The clearer the feedback, the more likely they were to say they would make high-impact changes.

But there was an unexpected downside. When the study focused only on personal actions, participants were less inclined to support collective efforts – like voting or joining demonstrations.

Even with better understanding, they became less likely to engage in actions that drive systemic change.

“These interventions also decreased commitment to collective action, where you’re really trying to influence some sort of policy, and this is a problem,” Vlasceanu said.

The personal vs. political dilemma

This finding highlights a key challenge in climate communication: encouraging individuals to act without making them forget the power of public pressure and policy change.

“Now we have to go back and understand how we would better design these interventions so we don’t have those negative spillovers,” Vlasceanu said.

Individual actions are easier to measure. For instance, skipping one long flight can significantly cut your personal carbon emissions. But broader actions – like voting – may be harder to quantify even though they’re incredibly powerful.

One previous analysis found that a single vote in a Canadian national election was over 20 times more effective than skipping a long flight, in terms of climate impact.

“If you extrapolate from that, you can conclude that all the collective actions are way more effective than all the lifestyle changes you can do, although this still remains to be empirically quantified,” Vlasceanu said.

The carbon choices we make

The study also revealed a deeper truth regarding how people make decisions about their lifestyle choices and carbon footprint.

“People will engage in lifestyle changes when they think it’s easy to do. It’s less important to them if it’s effective,” Vlasceanu said. “For collective action, it is more important to people that the action they engage in will actually result in a meaningful change.”

The research included a broad political spectrum: about half of participants identified as Democrats, 22% as Republicans, and 26% as independents or others.

“Democrats were more sensitive to incorporating what they learned into their behaviors compared to Republicans,” Vlasceanu said.

Simple tools to change human behavior

The researchers weren’t trying to push an agenda. Their goal was to learn more about how people think and how simple tools might help change behavior.

“Our job as academics is not to be activists or fight for a particular cause,” Vlasceanu said. “These are research questions we scientifically care about that uncover essential processes about the human mind.”

This work is part of a larger research effort looking at how low-cost, scalable interventions can influence people’s choices. Climate change presents a perfect test case.

“We pick the context in which we apply these investigations such that they are societally relevant,” Vlasceanu said.

“If we understand how the mind works in this context, then we can document ways in which practitioners, policymakers – people whose job it is to address this crisis – can most effectively address it.”

Lifestyle changes and carbon footprints

Future studies might explore other ways to boost both personal and public engagement – such as using stories or emotional messages instead of facts alone.

“In order to meaningfully address climate change, experts have agreed that we will need lifestyle change and collective action,” Vlasceanu said. “This is a critical part of the pathway to net zero.”

Understanding how people perceive carbon impact isn’t just about correcting facts. It’s about shaping better conversations.

When education focuses on both personal habits and collective responsibility, it can build a more balanced response to climate change.

Getting carbon literacy right could be one of the most powerful tools we have – not just for reducing emissions, but for encouraging meaningful action on every level.

The full study was published in the journal PNAS Nexus.

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