Carbon Balance and Management最新文献

Industry is the core sector with the most challenging task of carbon emission reduction in China. This paper explores how industrial transformation in China's industrial sector affects carbon emissions. We shed light on the effect of industrial sector transformation on carbon emissions, and divide industrial sector transformation into two aspects: industrial structure optimization and industrial spatial layout.We construct socioeconomic panel data for 30 cities in the urban agglomeration in the middle reaches of the Yangtze River from 2000 to 2020, and explore the influence of industrial transformation on carbon emissions in 33 industrial sectors in China from three dimensions: spatial spillover effect, spatiotemporal heterogeneity, and threshold effect. The results show that: (1) In the industrial structure optimization dimension, industrial rationalization has effect on decreasing carbon emissions, while industrial upgrading increases carbon emissions. In the industrial spatial layout dimension, industrial specialization agglomeration can decline carbon emissions, while industrial diversification agglomeration does not reduce carbon emissions but instead increase carbon emissions.(2)Both industrial structure optimization and industrial spatial layout have spatiotemporal heterogeneous impacts on carbon emissions during the study period.(3) Under different levels of economic development, industrial transformation will have different impacts on carbon emissions. In the future, the Chinese government should increase efforts to promote technological progress and innovation, taking technological progress and independent innovation capabilities as the central link in promoting industrial transformation. Those findings not only provide certain environmental research reference for China's industrial economic development and transformation, but also provide a practical reference for carbon reduction in other developing countries that are undergoing economic transformation.

Forests stock up to 90% of the global terrestrial plant biomass carbon (C). Any rise or fall of that stock, but also its utilization for substituting fossil resources can influence the rate of atmospheric CO₂ enrichment. By employing the term 'C sequestration', the ongoing debate suffers, however, from an implicit confusion between (1) processes, rates or fluxes of C (e.g. tree growth) with (2) pools, stores or stocks of forest biomass C. Stock formation is driven by turnover, C duration, residence time, or tree demography, and not by the rate of influx of C, including tree growth. Enhanced tree growth must not be treated as a rise in C stock, without accounting for turnover, also removing often assumed benefits of CO₂ fertilization for stock formation, should tree growth be C limited, another questionable assumption. A carbon 'sink' is a potential volume that can be filled with C, but it does not represent a stock either, without accounting for C residence time. 'Buying time' by lengthening rotation has a cost in terms of reduced utilization of forest products for substitution of fossil resources. Finally, management cessation for biodiversity benefits, should be qualified by its conservation value, rather than by making a case for C storage benefits, without accounting for natural forest gap dynamics, and again, without pricing-in the inevitable cost of the cessation of the substitution of fossil C by renewable C. All this calls for a strict separation of the meaning of carbon fluxes and carbon stocks, and avoiding ambiguous terms such as C sequestration and C sink.

The rapid expansion of the electronics market has led to a sharp increase in waste electrical and electronic equipment (WEEE), intensifying environmental pressure and carbon emissions associated with inefficient recycling systems. Traditional WEEE reverse logistics are characterized by high energy consumption and low resource recovery efficiency, limiting their contribution to carbon reduction goals. To address this issue, this study develops a tripartite evolutionary game model involving the government, consumers, and recycling platforms to analyze strategic interactions and system dynamics in low-carbon WEEE recycling. Numerical simulations are conducted to examine the effects of key parameters on equilibrium stability and convergence behavior. The results indicate that appropriately calibrated government subsidies, consumer participation incentives, and platform-level cooperative benefits accelerate system convergence toward a stable low-carbon equilibrium. However, excessive subsidies generate diminishing marginal effects and potential fiscal inefficiencies. Enhancing long-term cooperative benefits and technological efficiency is shown to improve equilibrium stability and carbon performance. This study contributes to the literature by integrating carbon emission considerations into evolutionary game modeling of WEEE reverse logistics and provides managerial insights into mechanism design for sustainable supply chain coordination.

Carbon, as a key element in urban metabolic processes, has received increasing attention. On the basis of data from 197 Chinese cities from 2005 to 2019, we measure the urban carbon metabolism efficiency (CME) via the super-efficiency slacks-based measure (SBM) model and examines the effects and mechanisms of the low-carbon pilot policy (LCPP) on CME through the two-way fixed effect difference-in-differences (TWFE-DID) model. The results of the study reveal that the urban CME in China generally shows a zigzag upward trend, with the highest efficiency in East China, the second highest efficiency in Central China, and lower efficiency in West China and Northeast China. The implementation of the LCPP can significantly improve CME, and this conclusion holds robust significance following a comprehensive series of endogeneity and robustness examinations. Green technology innovation, industrial structure upgrading, and green finance play important intermediary roles between the LCPP and CME. The LCPP significantly enhances CME in eastern cities, non-resource-based cities, and cities with high marketization, while the impact in other regions is not significant.

Background: Understanding the spatiotemporal dynamics of terrestrial ecosystem carbon sinks, as well as the underlying driving mechanisms, is crucial for guiding regional carbon neutrality policies. Using Moderate Resolution Imaging Spectroradiometer (MODIS) remote sensing data, field measurements data, and multi-source environmental data, we estimated net primary productivity in subtropical zone from 2000 to 2020 with the Carnegie-Ames-Stanford approach (CASA) model, and assessed net ecosystem production (NEP) by subtracting heterotrophic respiration. Regression analysis, coefficient of variation, Hurst exponent, and geodetector were applied to examine the spatiotemporal patterns and driving forces of NEP.

Results: The results identified distinct spatial heterogeneity in NEP across the study area, characterized by a west-south high and east-low gradient, with moderate levels in the north. The NEP exhibited positive persistence (H > 0.5) in 73.2% of the study area. Notably, natural forest areas showed strong persistent improvement (H > 0.65), whereas the Chang-Jiu urban agglomeration was characterized by strong persistent degradation (H < 0.35). The elevation range of 550-750 m exhibited the peak carbon sink capacity (345.6 g C m⁻² year⁻¹); Normalized difference vegetation index and elevation, with the q value of 0.37 and 0.34 respectively, were identified as the key individual factors influencing NEP variation. The strongest interactive effect on NEP variation was detected between soil type and land use type (q = 0.586). This evidence, combined with the impact of the climate-land use interaction on NEP, implies that synergistic management of these factors could enhance carbon sink potential.

Conclusions: Our research reveals that the carbon sink dynamics in subtropical zone are governed by the interaction of topographic, climate, and human activity. Future efforts must implement zonal management strategies (e.g., conserving mountainous areas and promoting forest-grain intercropping on plains) to bolster forest carbon sinks.

Understanding the coordinated changes in soil carbon and nitrogen is essential for evaluating ecosystem responses to environmental change, particularly in ecologically fragile alpine regions such as the Qilian Mountains. In this study, the denitrification-decomposition (DNDC) model was used to assess the spatiotemporal dynamics of soil organic carbon density (SOCD) and total nitrogen density (STND) in the 0-30 cm soil layer from 1975 to 2024. The results revealed that SOCD and STND were higher in the northern and east-central grasslands and lower in the southwestern regions. Both stocks exhibited fluctuating but overall increasing trends, with notable increases aligned with major ecological protection policies in China. To better understand the coupling of soil carbon and nitrogen, we constructed a composite indicator called soil carbon and nitrogen density (SCND) using principal component analysis. This indicator captures the synergistic accumulation of organic carbon and total nitrogen driven by shared ecological processes and was further used to explore its associations with environmental factors, enabling an integrated assessment of soil carbon-nitrogen dynamics. The results revealed that elevation and soil bulk density were the main direct drivers of carbon and nitrogen accumulation, both of which exerted negative effects, whereas the other factors acted through indirect pathways. These findings underscore the importance of topography and soil structure in regulating carbon and nitrogen dynamics. It is recommended to plant deep-rooted grass species, limit heavy machinery, and maintain long-term ecological protection to prevent declines after initial gains from interventions. In addition, the carbon-to-nitrogen (C/N) ratio showed increasing spatial heterogeneity over time, with high values in the western and central regions, where nitrogen input can be enhanced by introducing legumes or applying organic fertilizers. In the northern and southeastern areas, grazing exclusion or low-intensity grazing is recommended to promote organic matter accumulation. Vertically, the C/N ratio decreased with soil depth, indicating strong carbon and nitrogen coupling within the soil profile. Overall, this study highlights the coordinated dynamics of soil carbon and nitrogen in the Qilian Mountain grasslands, providing valuable insights for the sustainable management and resilience improvement of grasslands in this region under changing environmental conditions.

The forest soil carbon pool is a core component of the terrestrial carbon cycle, and its quantity and quality are largely regulated by forest types, thereby influencing the carbon sequestration capacity of forest ecosystems. The Qinghai-Xizang Plateau is one of the regions most sensitive to global climate change, experiencing warming rates higher than the global average and pronounced ecological vulnerability. Among its subregions, southeastern Xizang is characterized by extensive forest cover and prominent ecological functions. Accordingly, elucidating the differentiation characteristics and driving mechanisms of soil carbon pool quantity and quality among different forest types in this region is of great significance for accurately evaluating regional carbon sink capacity. This study focused on multiple representative forest types in southeastern Xizang, including coniferous forests, broad-leaved forests, and conifer-broadleaf mixed forests, to systematically compare the distribution characteristics of soil organic carbon (SOC) and its fractions among different forest stands, and to explore the variation patterns and driving factors of the carbon pool management index (CPMI). The results showed significant differences in soil organic carbon and its fractions among forest types in southeastern Xizang (p < 0.05). The Cupressus gigantea forest exhibited consistently higher levels of soil organic carbon and its fractions, indicating a strong carbon accumulation capacity, whereas both Pinus densata forest and Pinus yunnanensis-Populus davidiana mixed forest showed relatively lower values overall. The carbon pool management index varied markedly among forest types. The Cupressus gigantea forest showed the highest carbon pool index (CPI) and carbon pool management index (CPMI) (p < 0.05), indicating the best soil carbon pool quality. Driving factor analysis revealed that soil organic carbon (SOC) and carbon pool index (CPI) were primarily regulated by available nitrogen (AN), available potassium (AK), electrical conductivity (EC), and soil water content (WC). The carbon pool management index (CPMI) was mainly driven by field capacity (FC) and total nitrogen (TN), whereas carbon pool activity (A) and the carbon pool activity index (AI) were more dependent on available phosphorus (AP) and total phosphorus (TP). Redundancy analysis (RDA) showed that the first two ordination axes together explained 92.8% of the total variation, with the first axis accounting for 88.1% and the second axis for 4.7%, indicating that environmental factors can effectively explain the variation in soil carbon pool quantity and quality. This study revealed the spatial differentiation patterns and distinct driving mechanisms of soil carbon pool quantity and quality in alpine forests, providing a scientific basis for evaluating forest carbon pool quality and guiding regional carbon sequestration enhancement and management.