Enhanced forest carbon gains from stronger protection in China's protected areas

Protected areas (PAs) are central to China's forest conservation strategy, yet their effectiveness for carbon storage across governance and management contexts remains unclear. A clearer understanding of their current and future carbon benefits is essential for informing conservation and climate policy. Here, using 1-km GEDI satellite data, we show that forests within China's PAs store on average 68.29 ± 0.17 Mg C ha⁻¹ - about 13% more than matched unprotected forests. Carbon gains are highest in national parks (18.19 ± 0.69 Mg C ha⁻¹) and in managed naturally regenerating forests (9.85 ± 0.36 Mg C ha⁻¹), although some PA categories underperform. To assess future potential, we integrate GEDI observations with CMIP6 climate projections and find that under the high-emission SSP5-8.5 climate scenario, strongly protected areas could retain an additional ~600 ± 36.39 Tg C by 2100. These results show that strong protection and optimized management substantially enhance China's carbon sink, offering major opportunities for climate mitigation and biodiversity conservation.