Why People Unknowingly Share Climate Misinformation Online

Climate Misinformation on Social Media: How False Information Spreads and Why People Believe It

Climate change represents one of humanity’s most pressing challenges, yet social media platforms continue to serve as breeding grounds for misinformation that undermines scientific consensus and environmental action. A groundbreaking new study published in Cogent Social Sciences reveals the psychological mechanisms behind why users believe and share false climate information online, providing crucial insights for combating this growing problem.

The research, co-authored by visiting scholar Dr. Muhammad Ittefaq and colleagues from Arizona State University and the University of South Carolina, examined how social media users evaluate the credibility of climate-related content they encounter online. With most users lacking expert climate knowledge, the study found that people rely heavily on mental shortcuts, or “heuristics,” when determining what information to trust.

“Even well-meaning social media users can unwittingly amplify false claims that ultimately harm efforts to tackle climate change,” the researchers note in their findings. This amplification effect creates cascades of misinformation that can significantly impact public opinion and policy support.

The study presented 320 participants with various X-style (formerly Twitter) posts containing false climate information while manipulating three key credibility cues: professional expertise signals, message style, and popularity indicators—often referred to as “bandwagon cues.”

Professional expertise emerged as a powerful influence, with participants rating posts seemingly from experts (identified by titles like “Dr.” or “PhD”) significantly more credible than identical content from non-experts. Credibility ratings jumped from 3.70 to 4.72 out of 7 when expertise indicators were present, with sharing intention similarly increasing from 3.54 to 4.53.

Message length and style also played a critical role in perceived trustworthiness. Longer, more detailed posts were deemed more credible (4.94 versus 3.47 for shorter posts) and generated stronger sharing intentions among participants (4.73 versus 3.34).

Perhaps most concerning for social media platforms was the significant impact of popularity signals. Posts displaying high numbers of likes and shares were substantially more trusted, with credibility ratings rising from 3.45 to 4.97 and sharing intention more than doubling from 3.13 to 4.94. This finding suggests that misinformation can gain momentum through what researchers call a “bandwagon effect,” where perceived popularity creates a self-reinforcing cycle of credibility.

The combination of these factors proved even more potent. Posts featuring both substantial length and high popularity received the highest trust and sharing ratings in the study. Similarly, content appearing to come from experts that also showed popularity indicators saw credibility ratings soar from 3.95 to 5.50.

One particularly troubling discovery was that participants sometimes indicated willingness to share content they personally doubted—if it appeared many others had already shared it. This suggests social validation can override personal skepticism, further accelerating misinformation spread.

“The bandwagon effect can be especially powerful for brief messages that might otherwise be dismissed,” explained the researchers. “Short posts that appeared popular saw sharing intentions jump from 2.37 to 4.32, indicating how quick, simple falsehoods can gain traction through perceived social approval.”

Interestingly, the study found that combining all three credibility cues—expertise, length, and popularity—did not produce higher ratings than strong combinations of just two factors, suggesting there may be a ceiling effect to perceived credibility.

These findings arrive at a critical moment for climate communication. As social media platforms face increasing pressure to address misinformation, understanding the psychological mechanisms behind user behavior becomes essential for developing effective countermeasures.

For climate scientists, communicators, and social media platforms, the research highlights the importance of addressing not just the content of misinformation, but also the contextual cues that make it seem believable. Potential solutions may include improved verification systems for expertise claims, better tools for users to evaluate source credibility, and algorithms that don’t amplify content based solely on popularity metrics.

As climate policy decisions gain urgency worldwide, ensuring that public discourse is grounded in accurate information has never been more important. This research represents a significant step toward understanding and ultimately addressing one of the most pervasive challenges in climate communication today.