Streams and rivers emit substantial amounts of nitrous oxide (N₂O) and are therefore an essential component of global nitrogen (N) cycle. Permafrost soils store a large reservoir of dormant N that, upon thawing, can enter fluvial networks and partly degrade to N₂O, yet the role of waterborne release of N₂O in permafrost regions is unclear. Here we report N₂O concentrations and fluxes during different seasons between 2016 and 2018 in four watersheds on the East Qinghai-Tibet Plateau. Thawing permafrost soils are known to emit N₂O at a high rate, but permafrost rivers draining the East Qinghai-Tibet Plateau behave as unexpectedly minor sources of atmospheric N₂O. Such low N₂O fluxes are associated with low riverine dissolved inorganic N (DIN) after terrestrial plant uptake, unfavorable conditions for N₂O generation via denitrification, and low N₂O yield due to a small ratio of nitrite reductase: nitrous oxide reductase in these rivers. We estimate fluvial N₂O emissions of 0.432 − 0.463 Gg N₂O-N yr⁻¹ from permafrost landscapes on the entire Qinghai-Tibet Plateau, which is marginal (~0.15%) given their areal contribution to global streams and rivers (0.7%). However, we suggest that these permafrost-affected rivers can shift from minor sources to strong emitters in the warmer future, likely giving rise to the permafrost non-carbon feedback that intensifies warming.

Electric power material warehouses are critical to optimizing power grid supply chains and reducing carbon emissions, aiding the power sector’s decarbonization and climate goals. Nevertheless, to our knowledge, there are no comprehensive assessments of the life cycle carbon emissions associated with storage warehouses, so the emission reduction potential of the ever-increasing number of automated technologies is still unknown. This study presents an extensive life cycle carbon footprint assessment model tailored for electric power material warehouses, and it encompasses both traditional and automated frameworks. Utilizing a process-based life cycle assessment (LCA) methodology, carbon emissions across five distinct stages are examined: storage buildings and facilities, loading and unloading, transportation, packaging, and information management systems. For this purpose, warehouses in Jiangsu Province, China, are employed as a case study. The results show that automating warehouses can achieve a reduction in total carbon emissions of 42.85% compared with traditional warehouses, with total life cycle emissions of 39,531.26 tCO₂, and the transportation stage is identified as the predominant contributor. This research not only offers actionable recommendations for strategies, including renewable energy integration, intelligent control systems, and standardized packaging protocols, but also establishes a framework for future investigations of refining carbon accounting methodologies—particularly in underexplored domains such as packaging.

Agricultural soils are a significant source of nitrous oxide (N ₂ O) emissions. The application of biochar to soil offers a synergistic approach to establishing stable organic carbon (C) storage while reducing greenhouse gas (GHG) emissions, particularly through effective reductions in N ₂ O emissions. However, current biochar application strategies often lack consideration of locally tailored application rates and biochar properties, limiting its N ₂ O mitigation potential. Here, we conduct a spatially explicit analysis to investigate the N ₂ O mitigation potential of straw-derived biochar in China’s croplands, exploring optimal application strategies under both ideal and realistic conditions. The key drivers that influence the spatial patterns of straw-derived biochar’s mitigation potential and application strategies are also revealed. We find that applying biochar with optimal strategies could avoid approximately 50% and 36% of nationwide cropland N ₂ O emissions under ideal and realistic conditions, respectively. The optimal biochar application rate and properties required to achieve the maximum N ₂ O reduction potential exhibit significant spatial variability, differing among biochar types. Key factors determining the optimal biochar application rate in various regions include N fertilizer application rates and soil organic carbon (SOC) content, while water input—including precipitation and irrigation water input—is the primary factor determining the optimal biochar properties. These findings may inform the development of site-specific biochar application strategies aimed at enhancing the N ₂ O mitigation efficacy in croplands across China. Graphical