Tracing the growth and structural differentiation of carbon neutrality research from 2021 to 2025 through bibliometric analysis

Carbon neutrality research has expanded rapidly since the early 2020s, yet the 2021–2025 period has rarely been examined as a distinct phase in the field’s recent development. To address this gap, this study applies a multi-method bibliometric approach to 2,326 publications on carbon neutrality indexed in the Web of Science Core Collection, including SCI-EXPANDED and SSCI. Combining performance analysis, keyword co-occurrence analysis, Multiple Correspondence Analysis (MCA), source analysis, local citation analysis, and trend topic analysis, the study examines publication dynamics, thematic organization, geographic participation, conceptual structure, and source ecology during this period. The findings show that post-2020 growth was accompanied by increasing structural differentiation. Temporally, 2023 represents both the highest complete-year output and a point of strong terminological concentration, with core terms such as “carbon neutrality”, “CO 2 emissions”, and “emissions” occupying prominent positions. Thematically, keyword and conceptual structure analyses reveal an integrative core linking policy, sustainability, energy transition, finance, and technological innovation, alongside specialized domains related to carbon accounting, sequestration, environmental economics, materials science, and energy-system transition. Geographically, the field shows asymmetric national participation, with China combining a large domestic publication base and substantial international collaboration. Source and local citation analyses further show that productive publication venues and locally influential cited sources do not necessarily coincide. Overall, the study demonstrates that carbon neutrality research during 2021–2025 evolved from rapid expansion into a more structurally differentiated field.