Divergent shifts in public ecological attention following the COVID-19 pandemic

Public engagement is critical for environmental action, but its dynamics were disrupted by the COVID-19 pandemic. Whether this acute pandemic crisis eclipsed or paradoxically amplified long-term ecological concerns remains uncertain. Here, we analyze a massive (2014-2025) longitudinal social big data archive from Republic of Korea, comparing 18 ecological keywords pre- and post-pandemic. Our tripartite analysis reveals a complex restructuring, not a simple uniform shift. The pandemic suppressed public interest in 'fine dust' (83,481 ± 65,110 to 45,610 ± 19,525 mentions) while accelerating 'climate crisis' (185 ± 424 to 7,526 ± 3,741 mentions). Sentiment analysis showed a critical divergence: 'climate crisis' discourse became significantly more negative (57% to 38% positive), while 'microplastic' discourse became more positive (40% to 57%). Most profoundly, semantic network analysis revealed a structural "re-wiring." A sparse, fragmented pre-pandemic network was reorganized into dense clusters, forging a novel, dominant link between 'COVID virus' and 'fine dust' (public health-environment axis) and a new 'climate-action' cluster ('climate change,' 'carbon neutrality,' 'environmental movement'). The COVID-19 pandemic acted as a powerful semantic catalyst, fundamentally altering the cognitive landscape of public ecological perception. It did not just change what people discuss, but how they frame and connect issues. This transformation creates new opportunities for integrated policy (e.g., public health and environment) but also highlights persistent gaps, as fundamental and ecological functional concepts like 'food web' remain isolated from public discourse. These findings are critical for designing effective post-pandemic environmental communication.