Abstract. Estimates of the annual emissions of carbon from Land Use, Land-Use Change, and Forestry (LULUCF) are important for tracking global, regional, and national carbon budgets, which in turn help predict future rates of climate change and help define potential solutions for mitigation. Here we update a long-term (1850–2020) series of annual, national carbon emissions from LULUCF (Houghton and Nassikas, 2017), based largely, after 1960, on statistics of land use from the Food and Agriculture Organization (FAO) of the United Nations (Faostat, 2021). Those data suggest that rates of deforestation in the tropics (and thus net emissions of carbon) have decreased over the last ten years (2011–2020). The data also indicate that the net loss of tropical forests is greater than the net gain in croplands and pastures, and we explore three alternative interpretations of this apparent forest conversion, one of which is shifting cultivation. We note that LULUCF is not equivalent to LULCC (Land-Use and Land-Cover Change), and suggest that the difference between “land use” and “land cover” may contribute to variation among independent estimates of emissions. The calculated emissions of carbon based on LULUCF approximate the anthropogenic component of terrestrial carbon emissions, but carbon management opportunities exist for unmanaged lands as well.

中文翻译：

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1850-2020 年土地利用、土地利用变化和林业的年碳排放量

摘要。土地利用、土地利用变化和林业 (LULUCF) 的年度碳排放量估算对于跟踪全球、区域和国家碳预算非常重要，这反过来又有助于预测未来的气候变化速率并帮助确定潜在的解决方案减轻。在这里，我们更新了 LULUCF 的长期（1850-2020 年）年度国家碳排放量系列（Houghton 和 Nassikas，2017 年），主要基于 1960 年之后联合国粮食及农业组织 (FAO) 的土地利用统计数据。联合国（Faostat，2021）。这些数据表明，在过去十年（2011-2020 年）中，热带地区的森林砍伐率（因此碳的净排放量）有所下降。数据还表明，热带森林的净损失大于农田和牧场的净增加，我们探讨了对这种明显的森林转变的三种替代解释，其中之一是轮垦。我们注意到 LULUCF 不等同于 LULCC（土地利用和土地覆被变化），并认为“土地利用”和“土地覆被”之间的差异可能会导致独立估算排放量的差异。基于 LULUCF 计算的碳排放量近似于陆地碳排放的人为成分，但未管理的土地也存在碳管理机会。