Global spatially explicit carbon emissions from land-use change over the past six decades (1961–2020)

Abstract

Land-use change (LUC) is a major source of global anthropogenic carbon emissions that contribute to climate change. However, current estimates of LUC-induced emissions vary widely with differences in data and models, making it challenging to identify and manage emissions hotspots by location and LUC activity. Here, we estimated spatially explicit carbon fluxes associated with global major gross land-use transitions based on a new bookkeeping model (i.e., LUCE). Between 1961 and 2020, LUC induced 215 and 142 Pg C of global carbon emissions and removals, respectively, resulting in average net emissions ( E LUC ) of 1.21 Pg C year −1 . Latin America, Southeast Asia, and Sub-Saharan Africa dominated global E LUC with 69% of 60-year cumulative emissions, or about 86% between 2001 and 2020. Forest-related LUC activities (e.g., deforestation, reforestation) contributed largely to both regional and global carbon fluxes. Our findings shed new light on identifying LUC-induced emissions hotspots and managing land for climate mitigation and conservation. • Global land-use change has resulted in large carbon emissions • Deforestation and reforestation greatly affect regional carbon fluxes • Latin America, Southeast Asia, and Sub-Saharan Africa dominated global net emissions • Land-use change should be well examined for climate and conservation actions Land-use change (LUC) that broadly refers to the transformation of land use and management (e.g., deforestation, reforestation, and grazing) has become a major global environmental issue. Historically, LUC has led to increased emissions of carbon dioxide (CO 2 ) that contribute to climate change. Examining past LUC activities allows us to identify location, time, and land-use types that have been regulating regional and even global CO 2 emissions and removals. Tropical regions were most heavily affected by LUC, which led to strong emissions. Deforestation by converting forest to other land uses was one of the major causes of global emissions. It is critical for developing quantitative approaches including modeling to understand “the rise and fall” of historical LUC emissions and guide future actions of climate mitigation and conservation that involve LUC. Land-use change (LUC) is a main driver of global anthropogenic carbon emissions, yet LUC emissions modeling is still challenging. With a newly developed model, this study managed to estimate carbon fluxes associated with temporal and spatial changes of land uses, which enables us to identify LUC emission hotspots by location, time, and land-use type. The findings of this work underscore the importance of land management in climate mitigation and nature conservation.

Topics & Concepts