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) 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 × 10 km) and significant increases in built-up land (+1360.4 %; 7.21 × 10 km), cropland (+175.8 %; 130.88 × 10 km), and grassland (+162.6 %; 239.73 × 10 km), the global E 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, while the average annual carbon emissions after the 21st century reached 9.65 Pg C yr. Among them, direct E increased by approximately 0.80 Pg C yr and indirect E increased by 2.62 Pg C yr. In addition, from 1850 to 2018, global E 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.