China is the world’s largest carbon dioxide (CO2) emitter and a major trading country. Both anthropogenic and natural factors play a critical role in its carbon budget. However, previous studies mostly focus on evaluating anthropogenic emissions or the natural carbon cycle separately, and few included trade-related (import and export) CO2 emissions and its contribution on global warming. Using the CarbonTracker CT2019 assimilation dataset and China trade emissions from the Global Carbon Project, we found that the change trend of global CO2 flux had obvious spatial heterogeneity, which is mainly affected by anthropogenic CO2 flux. From 2000 to 2018, carbon emissions from fossil fuels in the world and in China all showed an obvious increasing trend, but the magnitude of the increase tended to slow down. In 2018, the radiative forcing (RF) caused by China’s import and export trade was ‒0.0038 W m‒2, and the RF caused by natural carbon budget was ‒0.0027 W m‒2, offsetting 1.54% and 1.13% of the RF caused by fossil fuels that year, respectively. From 2000 to 2018, the contribution of China’s carbon emission from fossil fuels to global RF was 11.32%. Considering China’s import and export trade, the contribution of anthropogenic CO2 emission to global RF decreased to 9.50%. Furthermore, taking into account the offset of carbon sink from China’s terrestrial ecosystems, the net contribution of China to global RF decreased to 7.63%. This study demonstrates that China’s terrestrial ecosystem and import and export trade are all mitigating China’s impact on global anthropogenic warming, and also confirms that during the research process on climate change, comprehensively considering the carbon budget from anthropogenic and natural carbon budgets is necessary to systematically understand the impacts of regional or national carbon budgets on global warming.
Carbon fluxes are essential indicators assessing vegetation carbon cycle functions. However, the extent and mechanisms by which climate change and human activities influence the spatiotemporal dynamics of carbon fluxes in arid oasis and non-oasis area remains unclear. Here, we assessed and predicted the future effects of climate change and human activities on carbon fluxes in the Hexi Corridor. The results showed that the annual average gross primary productivity (GPP), net ecosystem productivity (NEP), and ecosystem respiration (Reco) in the Hexi Corridor oasis increased by 263.91 g C·m-2·yr-1, 118.45 g C·m-2·yr-1 and 122.46 g C·m-2·yr-1, respectively, due to the expansion of the oasis area by 3424.84 km2 caused by human activities from 2000 to 2022. Both oasis and non-oasis arid ecosystems in the Hexi Corridor acted as carbon sinks. Compared to the non-oasis area, the carbon fluxes contributions of oasis area increased, ranging from 10.21% to 13.99% for GPP, 8.50% to 11.68% for NEP, and 13.34% to 17.13% for Reco. The contribution of the carbon flux from the oasis expansion area to the total carbon flux change in the Hexi Corridor was 30.96% (7.09 Tg C yr-1) for GPP, 29.57% (3.39 Tg C yr-1) for NEP and 32.40% (3.58 Tg C yr-1) for Reco. The changes in carbon fluxes in the oasis area were mainly attributed to human activities (oasis expansion) and temperature, whereas non-oasis area was mainly due to climate factors. Moreover, the future increasing trends were observed for GPP (64.99%), NEP (66.29%) and Reco (82.08%) in the Hexi Corridor. This study provides new insights into the regulatory mechanisms of carbon cycle in the arid oasis and non-oasis area.
Accurate spatio-temporal land cover information in agricultural irrigation districts is crucial for effective agricultural management and crop production. Therefore, a spectral- phenological-based land cover classification (SPLC) method combined with a fusion model (flexible spatiotemporal data fusion, FSDAF) (abbreviated as SPLC-F) was proposed to map multi-year land cover and crop type (LC-CT) distribution in agricultural irrigated areas with complex landscapes and cropping system, using time series optical images (Landsat and MODIS). The SPLC-F method was well validated and applied in a super-large irrigated area (Hetao) of the upper Yellow River Basin (YRB). Results showed that the SPLC-F method had a satisfactory performance in producing long-term LC-CT maps in Hetao, without the requirement of field sampling. Then, the spatio-temporal variation and the driving factors of the cropping systems were further analyzed with the aid of detailed household surveys and statistics. We clarified that irrigation and salinity conditions were the main factors that had impacts on crop spatial distribution in the upper YRB. Investment costs, market demand, and crop price are the main driving factors in determining the temporal variations in cropping distribution. Overall, this study provided essential multi-year LC-CT maps for sustainable management of agriculture, eco-environments, and food security in the upper YRB.
Changes in production-living-ecological spaces (PLES) profoundly affect the global carbon cycle, further challenging socio-ecological system sustainability. However, the impacts of PLES changes on carbon balance have been insufficiently discussed under a spatial heterogeneity perspective, resulting in an inadequate understanding of green development. This paper quantified the dynamics of PLES using the transfer matrix method and assessed the carbon balance computed by the ecological support coefficient of carbon emissions (ESC) in Shandong province from 2000 to 2020. The impacts of PLES changes on ESC were further investigated using a geographically weighted regression model. On this basis, carbon balance zones were delineated through cluster analysis. The results indicated that both production and ecological spaces decreased while the living space increased during 2000-2020. Carbon emissions increased and its sequestration decreased. As a result, ESC initially increased and then decreased, exhibiting apparent spatial clustering. The impact of different PLES transfer changes on ESC varies across county sites, with production→living space having the most significant impact on regional ESC and ecology→living space having the most negligible impact. Finally, six types of carbon balance zones were established to reduce carbon emissions. The findings are expected to support policy implementations for reducing carbon emissions and optimizing territorial development through low-carbon land use.
This study explores the impact of intergenerational differences on farmers’ terrace abandonment in response to increasing intergenerational differentiation among rural households and the practical issue of terrace abandonment. Logit and Tobit models are employed to conduct empirical analysis and it is found that terrace abandonment increases sequentially among the new, middle, and old generations, confirming that intergenerational differences significantly influence whether farmers abandon terraces and the terrace abandonment scale. Village characteristics and government subsidies significantly influence farmers’ terrace abandonment. An increase in the number of migrant workers in the village increases terrace abandonment among new and middle generation farmers, whereas an increase in the distance from the village to the county significantly increases terrace abandonment among old generation farmers. An increase in the village’s total population significantly reduces terrace abandonment among new generation farmers. An increase in government subsidies significantly reduces terrace abandonment among middle and old generation farmers. The impact of intergenerational differences on terrace abandonment is more pronounced in low-altitude areas. To reduce terrace abandonment, it is necessary to promote terrace transfer, develop characteristic agriculture, improve terrace farming subsidies, and propose targeted strategies for the different generations of farmers.
Social networks are vital for building the livelihood resilience of rural households. However, the impact of social networks on rural household livelihood resilience remains empirically underexplored, and most existing studies do not disaggregate social networks into different dimensions, which limits the understanding of specific mechanisms. Based on 895 household samples collected in China’s Dabie Mountains and structural equation modeling, this paper explored the pathway to enhance livelihood resilience through social networks by disaggregating it into five dimensions: network size, interaction intensity, social cohesion, social support, and social learning. The results indicate that: (1) Livelihood assets, adaptive capacity and safety nets significantly contribute to livelihood resilience, whereas sensitivity negatively affects it. Accessibility to basic services has no significant relationship with livelihood resilience in the study area. (2) Social networks and their five dimensions positively impact livelihood resilience, with network support having the greatest impact. Therefore, both the government and rural households should recognize and enhance the role of social networks in improving livelihood resilience under frequent disturbances. These findings have valuable implications for mitigating the risks of poverty recurrence and contributing to rural revitalization.
Agriculture, significantly impacted by climate change and climate variability, serves as the primary livelihood for smallholder farmers in South Asia. This study aims to examine and evaluate the factors influencing smallholder farmers’ adaptive capacity (AC) in addressing these risks through surveys from 633 households across Nepal, India, and Bangladesh. The findings reveal that AC is influenced by various indicators categorized under eight principal factors. The first three factors, which explain about one-third of the variance in each country, include distinct significant indicators for each nation: in Nepal, these indicators are landholding size, skill-development training, knowledge of improved seed varieties, number of income sources, access to markets, and access to financial institutions; in India, they encompass access to agricultural-input information, knowledge of seed varieties, access to markets, access to crop insurance, changing the sowing/harvesting times of crops, and access to financial services; in Bangladesh, the key factors are access to financial institutions, community cooperation, changing the sowing/harvesting times of crops, knowledge of improved seed varieties, and access to agricultural-input information. Notably, indicators such as trust in weather information, changing sowing/harvesting times of crops, and crop insurance were identified as important determinants of AC, which have been overlooked in previous studies.
The perfection of the cross-border regional innovation system of the Pearl River Delta (PRD) and Hong Kong remarkably underpins the construction of the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) towards an international technological innovation hub. This paper focuses on the relational characteristics of the usage of technological innovation functions and elements, including labor force, technology, and producer services from Hong Kong by high-technology firms in the PRD, and probes into the influencing factors by integrating the objective perspective on the impact of firm-level socioeconomic attributes and subjective perspective on the open interpretations on the reasons by using or not using technological innovation functions and elements from Hong Kong by various stakeholders in high-technology domains in the PRD. Key research findings are fourfold. First, Hong Kong’s technological innovation functions primarily ride on its institutional advantages under the “One Country, Two Systems” framework to empower high-technology firms in the PRD by expanding their international market, international business operation, and financing, but cross-border investment and entrepreneurship has retrieved to a relatively marginalized position. The degree of supply-demand relations of producer services is the highest, followed by labor force and technology. Second, Hong Kong-invested, large-sized, and long-standing high-technology firms in the PRD are more inclined to use technological innovation elements from Hong Kong, while domestic, small-and-medium-sized, and start-up high-technology firms in the PRD are in turn, gradually unhooked from the supply of technological innovation elements from Hong Kong. Third, Hong Kong enjoys both advantages and disadvantages in supplying labor forces, technologies, and producer services to high-technology firms in the PRD, with advantages in competitiveness, international linkages and visions, and disadvantages in high cost, lack of more profound mutual understanding between Hong Kong and the PRD, and the imperfect cooperation mechanisms. Fourth, interactions among the transitioning role of Hong Kong in the macro-level global and national economic development landscape, meso-level cross-border regional specificities under the “One Country, Two Systems” framework, and micro-level heterogeneous practices and capabilities of firms influence the usage of technological innovation functions and elements from Hong Kong by high-technology firms in the PRD.
Globalization has resulted in a notable rise in the flow of high-skilled talent from emerging countries to developed nations. Current research on transnational talent flow mainly focuses on the destination countries, with less attention given to the perspective of the sending countries, particularly lacking a dynamic discussion on its impact on technological evolution in the origin countries. Based on the OECD REGPAT database, this paper aims to explore how talent groups migrating to developed countries facilitate the return of knowledge and technology to emerging countries and achieve breakthroughs in their technological evolution paths, while further discussing the potential mechanisms involved. The findings of this paper are as follows: (1) The technological development of emerging countries is a path-dependent process, where countries often branch into new technologies related to their preexisting knowledge base. Consequently, knowledge feedback from high-skilled talents increases the likelihood of sending countries developing unrelated technologies. (2) The mobility of talents across borders fosters more international collaborations and citations for patents that are unrelated to the local knowledge base, thus enriching the technological paths of sending countries. (3) The mobility of high-skilled talents primarily affects complex technologies, which have significant economic effects that encourage imitation by other countries. However, the effect on novel technologies is less significant due to their strong geographical stickiness. In general, this paper addresses the gaps in existing research on talent outflow and the technological evolution of origin countries, providing empirical evidence for the positive role of transnational talent mobility in the technological catch-up of emerging nations. Besides, it offers recommendations for talent export, import, and innovation policy formulation in these countries.
An appropriate spatial structure of a power battery supply network is crucial for the specialization and scale development of key components in new energy vehicles, accelerating the transformation and upgrade of the industry. This paper investigates the cooperative relationships among supply chain enterprises from the perspective of complex networks. Employing methodologies such as the gravity model and Moran’s I analysis, it explores the spatial structural characteristics and correlation patterns of the power battery supply network in China and discusses the influencing factors using the quadratic assignment procedure, revealing the mechanisms behind the differences in the spatial distributions of the power battery supply network. The results indicate that the distribution of power battery enterprises is densely concentrated in the eastern and southern regions, whereas the western region has a sparse distribution. The spatial supply network consists of a four-tier linkage system, encompassing 135 prefecture-level cities, with Chongqing, Shanghai, Nanjing, and other cities particularly prominent. Overall, the degree of agglomeration is low, with coastal cities dominating the landscape and inland cities serving as complementary regions. Most areas are characterized as insignificant or low-high regions, and the regional linkage effect of core cities is not pronounced. There is a notable lack of significance and high spatial heterogeneity. Four types of factors—spatial factors, market factors, agglomeration economies, and innovation levels—jointly influence and shape the spatial structure of the power battery supply network.
