Global Carbon Budget 2021
Global Carbon Budget 2021
复制标题
DOI：
10.5194/essd-14-1917-2022
复制
发表时间：
2022-04-26
影响因子：
11.4
通讯作者：
Zeng, Jiye
中科院分区：
文献类型：
--
作者：
Friedlingstein, Pierre;Jones, Matthew W.;Zeng, Jiye
准确评估人为二氧化碳（CO2）排放及其在气候变化中在大气、海洋和陆地生物圈中的重新分布，对于更好地理解全球碳循环、支持气候政策的制定和预测未来气候变化至关重要。在这里，我们描述和综合数据集和方法来量化全球碳预算的五个主要组成部分及其不确定性。化石CO2排放量（E-FOS）依据的是能源统计和水泥生产数据，而土地使用变化（E-LUC）排放量（主要是毁林）依据的是土地使用和土地使用变化数据以及簿记模型。大气CO2浓度直接测量，其增长率（G（ATM））是根据浓度的年变化计算的。海洋CO2汇（S-OCEAN）是用全球海洋地球化学模式和基于观测的数据产品估算的。用动态全球植被模型估算了陆地CO2汇（S-LAND）。由此产生的碳收支不平衡（B-IM），即估计的总排放量与估计的大气、海洋和陆地生物圈变化之间的差异，是对当代碳循环不完善数据和理解的一种衡量。所有不确定性报告为+/- 1 sigma。第一次，一种方法被证明可以调和我们的E-LUC估计值与国家温室气体清单的差异，支持对集体国家气候进展的评估。化石排放量为9.5 +/- 0.5 GtC yr（-1）（当包括水泥碳酸化汇时，为9.3 +/- 0.5 GtC yr（-1）），E-LUC为0.9 +/- 0.7 GtC yr（-1），人为CO2排放总量为10.2 +/- 0.8 GtC yr（-1）（37.4 +/- 2.9 GtCO（2））。此外，2020年，G（ATM）为5.0 +/- 0.2 GtC yr-1（2.4 +/- 0.1 ppm yr（-1）），S-OCEAN为3.0 +/- 0.4 GtC yr（-1），S-LAND为2.9 +/- 1 GtC yr（-1），B-IM为-0.8 GtC yr（-1）。2020年全球大气CO2平均浓度达到412.45 +/- 0.1 ppm。2021年的初步数据显示，E-FOS相对于2020年反弹+4.8%（4.2%至5.4%）。总体而言，1959-2020年期间全球碳预算各组成部分的平均值和趋势是一致估计的，但CO2通量的年至半十年变率的代表性存在高达1 GtC yr（-1）的差异。对多种方法和观测的估计值进行比较表明：（1）土地利用变化排放量的估计值持续存在很大的不确定性;（2）不同方法对北方热带以外地区陆地CO2通量大小的一致性很低;（3）不同方法对过去十年海洋汇强度的估计值之间存在差异。这一动态数据更新记录了这一新的全球碳预算中使用的方法和数据集的变化，以及与该数据集以前的出版物相比，对全球碳循环的理解进展（Friedlingstein等人，2020，2019; Le Quere等人，2018 b，a，2016，2015 b，a，2014，2013）。在这项工作中呈现的数据可在（Friedlingstein等人，2021年）。
Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize datasets and methodology to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (E-FOS) are based on energy statistics and cement production data, while emissions from land-use change (E-LUC), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (G(ATM)) is computed from the annual changes in concentration. The ocean CO2 sink (S-OCEAN) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO2 sink (S-LAND) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (B-IM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as +/- 1 sigma. For the first time, an approach is shown to reconcile the difference in our E-LUC estimate with the one from national greenhouse gas inventories, supporting the assessment of collective countries' climate progress.For the year 2020, E-FOS declined by 5.4 % relative to 2019, with fossil emissions at 9.5 +/- 0.5 GtC yr(-1) (9.3 +/- 0.5 GtC yr(-1) when the cement carbonation sink is included), and E-LUC was 0.9 +/- 0.7 GtC yr(-1), for a total anthropogenic CO2 emission of 10.2 +/- 0.8 GtC yr(-1) (37.4 +/- 2.9 GtCO(2)). Also, for 2020, G(ATM) was 5.0 +/- 0.2 GtC yr-1 (2.4 +/- 0.1 ppm yr(-1)), S-OCEAN was 3.0 +/- 0.4 GtC yr(-1), and S-LAND was 2.9 +/- 1 GtC yr(-1), with a B-IM of -0.8 GtC yr(-1). The global atmospheric CO2 concentration averaged over 2020 reached 412.45 +/- 0.1 ppm. Preliminary data for 2021 suggest a rebound in E-FOS relative to 2020 of +4.8 % (4.2 % to 5.4 %) globally.Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959-2020, but discrepancies of up to 1 GtC yr(-1) persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows (1) a persistent large uncertainty in the estimate of land-use changes emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extra-tropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living data update documents changes in the methods and datasets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this dataset (Friedlingstein et al., 2020, 2019; Le Quere et al., 2018b, a, 2016, 2015b, a, 2014, 2013). The data presented in this work are available at (Friedlingstein et al., 2021).