With the increasing severity of global climate change and environmental degradation, the enhancement of green consciousness has become a focal point of societal concern. Based on event-related potentials (ERP) technology, the influence of carbon labels on the green consciousness of ordinary exhibition visitors and their underlying cognitive mechanisms are explored. Through a brain electrophysiology experiment involving 36 participants,the effects of advertisements with and without carbon labels on the audience's recognition of carbon labels and their green consciousness are analyzed. Behavioral data indicated that advertisements with carbon labels significantly improved the audience's recognition of carbon labels, but had no significant impact on green consciousness. ERP data analysis revealed that the perception of loss, compared to the perception of gain, induced a more positive waveform in the P300 component of the brain electric activity, while advertisements with carbon labels compared to those without induced a more negative FN400 component. However, these differences were not statistically significant. The results show that although carbon labels can effectively enhance the audience's recognition, their role in promoting green consciousness is limited, which implies that future environmental publicity and advertising design need to focus more on education and guidance to stimulate the actual green behaviors of the public.