National CO2 Budgets (2015-2020) inferred from atmospheric CO2 observations in support of the Global Stocktake

This is a pilot dataset of country-specific net carbon exchange (NCE) and terrestrial carbon stock changes aimed at informing countries’ carbon budgets. These estimates are based on “top-down” NCE outputs from version 10 of the Orbiting Carbon Observatory (OCO-2) modeling intercomparison project (MIP), wherein an ensemble of inverse modeling groups conducted standardized experiments assimilating OCO-2 column-averaged dry-air mole fraction (XCO2) retrievals, in situ CO2 measurements, or combinations of these data. The OCO-2 MIP NCE estimates are combined with “bottom-up” estimates of fossil fuel emissions and lateral carbon fluxes to estimate changes in terrestrial carbon stocks, which are impacted by anthropogenic and natural drivers. These flux estimates are reported annually (2015-2020) as both a global 1ox1o gridded dataset and as a country-level dataset.

本数据集为面向特定国家的净碳交换（net carbon exchange, NCE）与陆地碳库变化试点数据集，旨在为各国碳预算制定提供参考依据。
该估算结果基于轨道碳观测站2号（Orbiting Carbon Observatory-2, OCO-2）模式比较计划（modeling intercomparison project, MIP）第10版的“自上而下”NCE输出成果：该计划中，多支反演模式团队开展标准化实验，同化OCO-2柱平均干空气摩尔分数（column-averaged dry-air mole fraction, XCO2）反演数据、原位CO₂测量数据，或两类数据的组合数据集。
研究人员将OCO-2 MIP的NCE估算结果与化石燃料排放、横向碳通量的“自下而上”估算结果相结合，以此估算陆地碳库变化——该变化受人为活动与自然驱动因素共同影响。
本通量估算成果以年度数据形式覆盖2015至2020年，同时提供全球1°×1°网格化数据集与国家级数据集。