News

2025.11.28

Global Carbon Budget 2025 is published

On Thursday, 13 November 2025, the Global Carbon Project (GCP) released the Global Carbon Budget 2025. WPI-AIMEC researcher, Dr. Hiroaki Tatebe (Senior Researcher, JAMSTEC) participated in the preparation of this report.

The Global Carbon Budget (GCB), coordinated by the Global Carbon Project under the auspices of Future Earth, provides a comprehensive assessment of the global carbon cycle. In this assessment, several different approaches are combined to understand how much carbon dioxide (CO₂) enters and leaves the Earth’s system as a whole.

Specifically, the evaluation integrates “bottom-up” methods—such as national and regional emission inventories, simulations of land-use and ecosystem changes, and models that calculate how carbon moves within the ocean—with “top-down” methods that estimate surface CO₂ fluxes so that they are consistent with observed atmospheric CO₂ concentrations. By using these complementary approaches, the assessment quantifies CO₂ emissions from fossil fuel combustion, emissions associated with land-use change such as deforestation, the rate of increase in atmospheric CO₂, and the amounts of CO₂ absorbed by the land and ocean.

For the 2025 edition, by a bottom-up assessment based on integrated simulations that combine observations with an Earth system model capable of representing global climate change and the biogeochemical cycles involving carbon, Dr. Hiroaki Tatebe contributed.