Global impacts of land use on terrestrial carbon emissions since 1850

Since the Industrial Revolution, significant changes in global land-use patterns have occurred, which have disrupted terrestrial carbon emissions. However, the disturbance processes, change trends, and distribution patterns are not clear. Therefore, the changes in terrestrial carbon emissions (E_luc) caused by land-use change (LUC) since 1850 were analyzed in this study. The results showed that, owing to the sharp decrease in forestland (-13.39 %; 84.26 × 10⁵ km²) and significant increases in built-up land (+1360.4 %; 7.21 × 10⁵ km²), cropland (+175.8 %; 130.88 × 10⁵ km²), and grassland (+162.6 %; 239.73 × 10⁵ km²), the global E_luc increased from 0.42 Pg C in 1850 to 11.05 Pg C in 2018, with an average annual increase of approximately 3.42 Pg C yr^-1, while the average annual carbon emissions after the 21st century reached 9.65 Pg C yr^-1. Among them, direct E_luc increased by approximately 0.80 Pg C yr^-1 and indirect E_luc increased by 2.62 Pg C yr^-1. In addition, from 1850 to 2018, global E_luc was approximately 578.26 Pg C, with North America, Europe, and Asia being the largest regional sources. Our results highlight the changing trend and distribution pattern of global terrestrial carbon emissions under the influence of LUC since the Industrial Revolution and provide a scientific basis for regional and sectoral formulation of low-carbon emission-reduction policies and planning of low-carbon land-use patterns.