China’s carbon sinks from land-use change underestimated

Abstract

The size and attribution of the regional net carbon flux from land-use change (LUC) activities (ELUC) are often highly debated, especially in regions such as China, which has experienced decades-long extensive reforestation activities. Here, using a LUC dataset incorporating remote-sensing and national forest inventory data with two modelling approaches, we show that ELUC in China shifted from a carbon source to a sink in the 1990s, contributing to a net cumulative CO2 removal of 2.0 Pg C during 1981–2020. From 2001 to 2020, the average ELUC was −0.14 Pg C yr−1, accounting for over one-third of the national land carbon sinks. Forest-related LUC activities contributed greatly to national carbon fluxes, while non-forest-related activities played a dominant role in certain areas. Our findings suggest that the carbon sinks from LUC activities in China may be largely underestimated in global assessments, underscoring the need to develop region-specific modelling for evaluation and potential regulation. The terrestrial carbon flux—sources and sinks—under land-use change (LUC) is difficult to quantify. Here, using a LUC dataset drawing on remote sensing and forest inventory data, the authors show that in China the carbon sink from LUC (such as afforestation) may be underestimated.