The status of carbon neutrality of the world's top 5 CO2 emitters as seen by carbon satellites

China, the Unite States (US), the European Union (EU), India, and Russia are the world's top 5 fossil fuel and cement CO₂ (FFC) emitting countries or regions (CRs). It is very important to understand their status of carbon neutrality, and to monitor their future changes of net carbon fluxes (NCFs). In this study, we implemented a well-established global carbon assimilation system (GCAS, Version 2) to infer global surface carbon fluxes from May …