Scenarios In China Research Articles

Predicting the Distribution of the Invasive Species Atractosteus spatula, the Alligator Gar, in China

The Alligator Gar (Atractosteus spatula) is a very dangerous species that has an extremely destructive impact on the ecological environment in aquatic areas. As a kind of ornamental fish, it is spreading rapidly all over the world. In order to avoid or delay the spread of Alligator Gar in China, it is urgent to further monitor and clarify its distribution range within the country. In this study, a maximum entropy model (MaxEnt) and geographical information system (ArcGIS) were used to identify suitable regions under climate change scenarios in China, and the significance of environmental factors that shape this species’ distribution were evaluated. According to the geographical distribution data of Alligator Gar and selected environmental variables, the potential habitat area of Chinese Alligator Gar under four climate scenarios in the present (2000s) and future (2050s and 2070s) was predicted. (1) The main environmental variables affecting the potential geographical distribution of Alligator Gar are temperature factor variables (the mean temperature of the warmest quarter and the mean temperature of the coldest quarter), precipitation factor variables (precipitation in the driest month and in the driest quarter), and altitude. (2) Under the current climate conditions, the suitable breeding areas of Alligator Gar are mainly concentrated in the Guangxi Zhuang Autonomous Region, Guangdong Province, and Hainan Province. Under the four future climate scenarios, the distribution area of the total suitable area of Alligator Gar will gradually decrease, and the suitable area of Alligator Gar will spread to high latitudes.

A new assessment framework to forecast land use and carbon storage under different SSP-RCP scenarios in China

The vision of achieving “carbon neutrality” has created new requirements for the projection of land use and land cover (LULC), as well as the carbon storage (CS) of terrestrial ecosystem. Global-scale LULC scenario assessments with coarser resolution introduces uncertainties to national and regional-scale studies, which in turn has a negative impact on CS analysis based on land use perspective. Therefore, we proposed a new framework for scenario-based assessment that integrates the global-scale Land Use Harmonization (LUH2) dataset, Patch-generating Land Use Simulation (PLUS) model, and Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model, which we called LUH2-PLUS-InVEST (LPI) model. Our aim is to investigate the potential impacts of the combinations of Shared Socioeconomic Pathways (SSPs) and Representative Concentration Pathways (RCPs) on China's future LULC and CS. By calibrating the demands, we generated structural predictions that were consistent with the actual land use. Furthermore, we explored the spatial heterogeneity of potential land use changes using 500 m × 500 m downscale simulations. Additionally, we developed a quantitative evaluation of CS from a spatiotemporal perspective and made recommendations on potential ecological threats. Our findings indicate that the basic characteristics of LULC and CS are determined by the natural context and that the prospects of land use distribution and carbon sequestration capacity are influenced by global emission pressure, regional competition, and China's unique development pattern. The results demonstrate that the LUH2-PLUS-INVEST model can provide an effective method for modeling the feedbacks of LULC and CS to the climate-society system.

The decarbonization pathway of power system by high-resolution model under different policy scenarios in China

Emission reduction from the coal power sector is vital for achieving carbon mitigation targets in China. In this study, we explore feasible pathways and economic cost of power system transition under different policy combination scenarios. We use a high-resolution power system model which is coupled with capacity planning and operation simulation to project the transition. We find that: (1) Without other policies, the single carbon market policy will lead to a potential rebound in emissions during the transition of the power industry. After 2045, a reduction in the proportion of free quotas and an increase in emission cost will enhance the emission reduction effectiveness of the market. (2) When policy measures are not sufficiently robust, even with a high proportion (80%) of renewable energy deployment requirement, there is a risk of rebound in coal power investments and subsequent emissions after 2050. (3) The achievement of carbon neutrality can only be realized by constraining the carbon budget within the boundaries of climate goals and other policy constraints. And carbon neutrality, compared to a high proportion (90%) of clean energy constraints, would increase total costs by at least 6%.

Willingness to pay for cancer prevention versus treatment in China: implications for cost-effectiveness threshold

ABSTRACT Background Empirical support for the appropriate cost-effectiveness threshold (CET) in China remains sparse. Objective This study aimed to estimate the willingness to pay (WTP) for cancer prevention and treatment from the perspective of healthcare policy-makers (i.e. supply side) and to investigate whether there is a difference between the estimated WTP in two scenarios. Methods We conducted a web-based survey from May to July 2022 among experts who offering consultation to the government. We surveyed 79 experts from a national think-tank (84.81% response rate) using contingent valuation method, a method for estimating the monetary value that individuals place on a non-market service. Results The mean WTP for two scenarios were estimated at 1.29 times of per capita Gross Domestic Product (GDP) of China and 1.90 times of per capita GDP, respectively. There was a difference between the WTP in the two scenarios and the WTP for treatment was significantly higher than prevention. Conclusion The findings suggest that though there is a smaller gap between the two scenarios in China as compared to other countries, the WTP may vary under different scenarios. So there’s a need to further refine the development of CET by adding parameters like prevention instead of defining one universal threshold.

Unlocking Dysprosium Constraints for China's 1.5 °C Climate Target.

Some key low-carbon technologies, ranging from wind turbines to electric vehicles, are underpinned by the strong rare-earth-based permanent magnets of the Nd, Pr (Dy)-Fe-Nb type (NdFeB). These NdFeB magnets, which are sensitive to demagnetization with temperature elevation (the Curie point), require the addition of variable amounts of dysprosium (Dy), where an elevation of the Curie point is needed to meet operational conditions. Given that China is the world's largest REE supplier with abundant REE reserves, the impact of an ambitious 1.5 °C climate target on China's Dy supply chain has sparked widespread concern. Here, we explore future trends and innovation strategies associated with the linkage between Dy and NdFeBs under various climate scenarios in China. We find China alone is expected to exhaust the global present Dy reserve within the next 2-3 decades to facilitate the 1.5 °C climate target. By implementing global available innovation strategies, such as material substitution, reduction, and recycling, it is possible to avoid 48%-68% of China's cumulative demand for Dy. Nevertheless, ongoing efforts in REE exploration and production are still required to meet China's growing Dy demand, which will face competition from the United States, European Union, and other countries with ambitious climate targets. Thus, our analysis urges China and those nations to form wider cooperation in REE supply chains as well as in NdFeB innovation for the realization of a global climate-safe future.

The underappreciated role of transboundary pollution in future air quality and health improvements in China

Abstract. Studies assessing the achievability of future air quality goals in China have focused on the role of reducing China's domestic emissions, yet the influence of transboundary pollution of foreign origins has been largely underappreciated. Here, we assess the extent to which future changes in foreign transboundary pollution would affect the achievability of air quality goals in 2030 and 2060 for China. We find that in 2030, under the current-policy scenario in China, transboundary contributions to population-weighted PM2.5 in China would be reduced by 29 % (1.2 µg m−3) as foreign countries transition from the fossil-fuel-intensive to the low-carbon pathway. By 2060, the difference would be increased to 45 % (1.8 µg m−3). Adopting the low-carbon instead of the fossil-fuel-intensive pathway in foreign countries would prevent 10 million Chinese people from being exposed to PM2.5 concentrations above China's ambient air quality standard (35 µg m−3) in 2030 and 5 million Chinese people from being exposed to PM2.5 concentrations above the World Health Organization air quality guideline (5 µg m−3) in 2060. Meanwhile, China adopting the carbon-neutral pathway rather than its current pathway would also be helpful to reduce transboundary PM2.5 produced from the chemical interactions between foreign-transported and locally emitted pollutants. In 2060, adopting a low-carbon pathway in China and foreign countries coincidently would prevent 63 % of transboundary pollution and 386 000 associated premature deaths in China, relative to adopting a fossil-fuel-intensive pathway in both regions. Thus, the influence of transboundary pollution should be carefully considered when making future air quality expectations and pollution mitigation strategies.

Public health impact of 2-, 4-, and 9-valent HPV vaccination in females on cervical and noncervical diseases in men and women under different coverage scenarios in China: A simulation study

ABSTRACT The high prevalence of human papillomavirus (HPV) infection in China suggests there would be a substantial positive health impact of widespread vaccination against HPV. We adapted a previously described dynamic transmission model of the natural history of HPV infection and related diseases to the Chinese setting to estimate the public health impact in China of 2-valent (with and without cross-protection), 4-valent, and 9-valent HPV vaccination strategies. The model predicted the incidence and mortality associated with HPV-related diseases, including cervical and noncervical cancers, genital warts, and recurrent respiratory papillomatosis (RRP), based on the various vaccination coverage rate (VCR) scenarios, over a 100-year time horizon. The public health impact of the 4 vaccination strategies was estimated in terms of cases and deaths averted compared to a scenario with no vaccination. Under the assumption of various primary and catch-up VCR scenarios, all 4 vaccination strategies reduced the incidence of cervical cancer in females and noncervical cancers in both sexes, and the 4-valent and 9-valent vaccines reduced the incidence of genital warts and RRP in both sexes. The 9-valent vaccination strategy was superior on all outcomes. The number of cervical cancer cases averted over 100 years ranged from ~ 1 million to ~ 5 million while the number of cervical cancer deaths averted was ~ 345,000 to ~ 1.9 million cases, depending on the VCR scenario. The VCR for primary vaccination was the major driver of cases averted.

Comparative environmental impacts of different hydrometallurgical recycling and remanufacturing technologies of lithium-ion batteries considering multi-recycling-approach and temporal-geographical scenarios in China

Although recycling retired lithium-ion batteries (LIBs) can alleviate global warming and the energy crisis, the environmental impacts of different recycling routes require further assessment. The multiple environmental indicators, such as carbon footprint and cumulative energy consumption for three hydrometallurgical recycling and remanufacturing routes of LIBs in China are quantified and compared using life cycle assessment methods. Then, the potential of reducing environmental impacts by battery remanufacturing with recycled materials is assessed. Moreover, the sensitivity of battery recycling and remanufacturing to temporal and geographical variations in electricity generation is determined. Results reveal that: (1) Differences in chemical reagents, energy consumption, and processes lead to differences in environmental indicators of battery recycling, with a gap of up to 29.3 kg CO2 eq./kWh in carbon footprint. (2) Due to avoiding raw material mining and processing, battery manufacturing with recycled materials can reduce the endpoint environmental categories by more than 18.4% compared to that with raw materials. (3) The environmental impacts of LIBs remanufacturing through a multi-recycling-approach will gradually decrease and reach to a constant, with the lowest carbon footprint of this route being only 61.1 kg CO2 eq./kWh. (4) The carbon footprint of LIBs manufacturing in China in 2050 can be more than 37.5% lower than that in 2021. Battery recycling and decarbonization of energy systems can reduce environmental impacts and contribute to the sustainable development of the transportation industry.

Encourage or impede? The relationship between trust in government and coproduction

ABSTRACT Coproduction has been widely advocated for, but there are theoretical and empirical disagreements as to whether trust in government can encourage coproduction. This study proposed external and internal efficacy as potential moderators to further understand this relationship. We designed a questionnaire with 537 citizens, and a 2 × 2 × 2 between subjects survey experiment with 375 citizens to test our hypotheses in four urban governance scenarios in China. The findings provide solid empirical evidence for theoretical disagreements about coproduction and new ideas for mobilizing it.

Multidimensional climatic niche conservatism and invasion risk of Phenacoccus solenopsis.

The cotton mealybug Phenacoccus solenopsis, a globally invasive insect, is listed as a national quarantine pest in agriculture and forestry, which seriously threatens biological safety of China. Niche conservatism is a key assumption of species distribution model. An evaluation of the applicability of using ecological niche models to assess the invasion risk of cotton mealybug, and further optimizing model complexity, are of both theoretical and practical significance. Based on 706 occurrence records and key bioclimatic variables, we used n-dimensional hypervolume niche analysis method to quantify the climatic niche hypervolumes of this pest in both native and invasive sites, and further tested the niche conservatism hypothesis. MaxEnt model parameters were optimized to predict the invasion risk of the mealybug under current and future climate scenarios in China. The results showed that four climatic variables (annual mean temperature, mean temperature of wettest quarter, mean temperature of warmest quarter, and precipitation of driest quarter) were the key climate factors affecting the distribution of cotton mealybug. Compared with native climatic niche (hypervolume volume, HV=40.43), the niche hypervolume of cotton mealybug in the invasive areas was significantly reduced (HV=6.04). Niche contraction (the net differences between the amount of space enclosed by each hypervolume was 0.84) explained 98.8% of niche differentiation, whereas niche shift (the replacement of space between hypervolumes was 0.01) contributed less than 2%. The direction of climatic niche contraction of the pest in different invasive areas was not exactly consistent. The default parameters of MaxEnt model were unreliable (ΔAICc=14.27), and the optimal parameter combination was obtained as follows: feature combination was linear-quadratic-hinge-product and regularization multiplier was 0.5. The most suitable habitats of cotton mealybug were concentrated in the south of Huaihe River-Qinling Mountains line, and the north-central provinces contained a large area of low suitable habitat. The increase of suitable habitat was not significant at the end of 21 century (SSP1-2.6: 1.7%, SSP5-8.5: 0.7%). The multidimensional climatic niche of P. solenopsis was highly conservative. The species distribution model was suitable for analyzing its invasion risk. The northward spread was obvious, and climate change had less impact on the pest.

Impact assessment of river sand resource shortage under different policy scenarios in China

More than half of the annual global concrete materials were produced in China due to the rapid developing construction industry, which partly led to the shortage of river sand. However, mining rate exceeds the natural replenishment rate of river sand recently, resulting in depletion of natural river sand accumulation. The increasing demand of river sand influences lots of aspects including altered landforms, increasing carbon emissions, ecological deterioration, international trades and disputes. To face the river sand resource shortage in China and to propose possible coping strategies, the data of river sand for construction in China and other related data were collected, and it is suggested that effective policy measures should be taken right now to protect river sand and strictly manage sand mining. Professional solutions for river sand shortage can be summarized as “5Rs” principle, which includes reduce, recycle. reuse, replace and recover. System dynamic model is established to predict the trend of river sand shortage and it was predicted that the gap between river sand supply and demand will come up to 63%. The impact of three policy scenarios is tested in the model, and the gap can be reduced to 35% by single policy scenario, while the scenario with all policy measures is able to reduce the contradiction between supply and demand to 4%. Suggestions are proposed from the aspects of structural and material technology, policy measures and international alliances. Attention should be paid to the shortage of river resources, to realize the sustainable development of the construction industry and other related industries, and to promote the harmonious coexistence of human and nature.

Projecting the excess mortality due to heatwave and its characteristics under climate change, population and adaptation scenarios.

Heatwaves have significant adverse effects on human health. The frequency, duration, and intensity of heatwaves are projected to increase dramatically, in the context of global warming. However, there are few comprehensive assessments of the health impact of heatwaves considering different definitions, and their characteristics under climate change scenarios. We aimed to compare future excess mortality related to heatwaves among different definitions under climate change, population, and adaptation scenarios in China and further explore the mortality burden associated with heatwave characteristics. Daily data during 2010-2019 were collected in Guangzhou, China. We adopted nine common heatwave definitions and applied quasi-Poisson models to estimate the effects of heatwaves and their characteristics' impact on mortality. We then projected the excess mortality associated with heatwaves and their characteristics concerning climate change, population, and adaptation scenarios. The relative risks of the nine common heatwave definitions ranged from 1.05 (95% CI: 1.01, 1.10) to 1.24 (95% CI: 1.13, 1.35). Heatwave-related excess mortality will consistently increase in the future decades considering multiple heatwave definitions, with more rapidly increasing rates under the Shared Socioeconomic Path5-8.5 and non-adaptability scenarios. Regarding heatwave characteristics, the intensity is the main factor involved in the threat of heatwaves. The increasing trend of characteristic-related mortality burden is similar to that of heatwaves, and the mortality burden caused by the duration of the heatwaves was the largest among all characteristics. This study provides a comprehensive picture of the impact of heatwaves and their characteristics on public health under various climate change scenarios, population changes, and adaptive assumptions. The results may provide important public health implications for policymakers in planning climate change adaptation and mitigation policies, and implementing specific plans.

Research on Capacity Allocation Method for Multi-scenario Rural Integrated Energy System

As an significant part of China’s energy system, rural energy has ushered in significant development opportunities in the national strategy of Rural Revitalization and new urbanization construction. On account of the differences in the geographical location of China, different rural areas have different economic statuses and characteristics, so it is essential to allocate the corresponding comprehensive energy system for different regional advantages, which is that the energy supply system can satisfy the load demand in rural areas. To solve the above problems, the investigation on the development scenario of village energy differentiation, considering economic, environmental protection and energy saving, puts forward the optimization allocation method of comprehensive rural energy under the differential scenario. The capacity allocation method of the rural comprehensive energy system put forward in this text is verified by selecting three villages with typical scenarios in China.

Diverging destinies: changing trends of induced abortion in China

In the era of the second demographic transition, “diverging destinies” theory states that women with the most economic opportunities often obtain gains while women with the least economic opportunities suffer from losses. Using nationally representative data from the 2017 China Fertility Survey, we attempted to examine if diverging destinies theory can explain differences in the incidence of induced abortion among women with differing economic opportunities. We found that women with good economic opportunities (i.e., well-educated and holding urban hukou) were more likely to have induced abortions between 1980 and 2010 and less likely to do so between 2015 and 2017. Moreover, younger cohorts were far more likely to have induced abortions at a younger age and before marriage. These findings provide supportive evidence for diverging destinies in induced abortion scenarios in China. We thus advocate that sexual and reproductive health policy making shows an overarching concern for the interests of disadvantaged groups.

Construction and influencing factors of an early warning system for marine ranching ecological security: Experience from China's coastal areas

Marine ranching has been widely considered as a new mode of marine fishery production. Marine ranching ecological security (MRES) is the basis and premise to ensure the sustainable utilization of marine ranching functions. In this study, an MRES early warning system was constructed based on comprehensive marine ranching ecological security index (CMRESI) and system dynamic model to reveal the main factors affecting the development of marine ranching and explore the changes in MRES under different future development scenarios in China's coastal areas from 2011 to 2035. The results showed that (1) the mean CMRESI of China was only 0.3265 and spatial heterogeneity was significant, showing a general security state; (2) coupling and coordination degree of MRES subsystems was high in Jiangsu, Fujian, Shandong, and Guangdong, and resources was a major constraint on the coordinated development of MRES in the study area (63.6%); (3) Under the ecological priority development scenario, the CMRESI will be the highest in 2035; however, 27% of MRES (in Jiangsu, Fujian, and Hainan) will continue to issue serious early warnings. This study could provide a reference for construction planning, management maintenance, and decision-making of marine ranching.

Life cycle assessment of carbon reduction potential of EoL wind turbine blades disposal scenarios in China

It is estimated that there will be 85,000 tons of End-of-Life (EoL) wind turbine blades in China by 2050. How to disposing discarded blades has become a significant problem restricting the development of wind power industry in China. To this end, a life cycle assessment (LCA) is performed to measure the carbon reduction (CR) potential of four disposal scenarios of EoL LM 37.3 P2 blades. The contribution of each scenario to reduce the carbon emission intensity of a specific wind farm is further evaluated. At the same time, the critical transportation distance to maintain the CR potential of each scenario is estimated. The results show that: firstly, the disposal scenarios with the greatest and smallest CR potential are producing concrete by EoL blades instead of cements and producing concrete by EoL blades instead of aggregates, respectively. The former one is determined as the baseline scenario, which can reduce 4516 kg CO2-eq carbon emissions per functional unit. Secondly, the critical transportation distances for incineration for electricity, co-processing and producing concrete by EoL blades instead of cements are 895 km, 3309 km and 9716 km. Finally, a reasonable recycling strategy can reduce the life-cycle carbon emission intensity of Datang Zhaluteqi 49.5 MW Wind Farm from 12.51 g CO2-eq/kWh to 9.22 g CO2-eq/kWh. This study not only quantifies the CR potential of different scenarios, but also offers important implications to promote blade disposal technology and improve the wind turbine blade recycling management.

The Climate Response to Global Forest Area Changes under Different Warming Scenarios in China

The Climate Response to Global Forest Area Changes under Different Warming Scenarios in China

Effect of Climate Change on the Potentially Suitable Distribution Pattern of Castanopsis hystrix Miq. in China.

Climate warming poses a great threat to ecosystems worldwide, which significantly affects the geographical distribution and suitable growth area of species. Taking Castanopsis hystrix Miq. as the research object, the potentially suitable cultivation regions under present and future climatic emission scenarios in China were predicted based on the MaxEnt model with 360 effective individual distributions and eight environmental variables. The min temperature of coldest month (bio6), precipitation of driest month (bio14), and precipitation of warmest quarter (bio18) are three leading factors affecting the geographical distribution area of C. hystrix Miq. The suitable cultivation regions of C. hystrix Miq. range from 18°-34° N, 89°-122° E in central and southern China and cover an area of 261.95 × 104 km2. The spatial pattern of C. hystrix Miq. will migrate to the southern region of low latitudes with a decreasing suitable area when in ssp1-2.6, and to the southwestern region of low latitudes or expand to the northeast region at high latitudes in ssp5-8.5, with an increasing suitable area; no significant change on the spatial pattern in ssp2-2.4. For ssp1-2.6 or ssp2-4.5 climate scenarios, the southern region of high latitudes will be appropriate for introducing and cultivating C. hystrix Miq., and the cultivation area will increase. For ssp5-8.5, its cultivation will increase and expand to the northeast of high-latitude areas slightly.

Significance of achieving carbon neutrality by 2060 on China's energy transition pathway: A multi-model comparison analysis

China has proposed to achieve carbon neutrality by 2060. Although previous studies have assessed net-zero emissions pathways in China, the diversity observed in these studies in terms of model construction and parameter setting has led to inconsistent conclusions on some key issues, such as energy transition. This study employs a multi-model comparison method to examine the significance of China's carbon neutrality target on its energy systems by assessing 67 carbon neutrality scenarios in China that are collected from the ADVANCE database, and identifying the differences between energy transition pathways under BEF60 scenarios (i.e. scenarios realising carbon neutrality by 2060) and AFT60 scenarios (i.e. scenarios realising carbon neutrality after 2060). Results show that China needs a larger deployment of low-carbon electricity, a higher electrification rate and more carbon sequestration amount under BEF60 scenarios than those under AFT60 scenarios. Meanwhile, the magnitude of the difference between the two categories of scenarios varies significantly in terms of different outcome indicators. Those that present significant disparities include the deployment scale of solar power (increasing by 160%), the electrification rate of the building sector (increasing by 27%) and the carbon sequestration amount of biomass power with carbon capture and storage (increasing by 380%). In addition, this study selects six indicators to present the technological and economic characteristics of various energy systems of China at the point of net-zero emissions. Exploring the relationships between characteristics, this research identifies the common features among various net-zero energy systems. A great share of non-biomass renewable power generation is always associated with a relatively high per capita energy use, implying that high renewables penetration may relax restrictions on energy consumption, which should be addressed for China when making efforts to promote energy transition.

Cell-level coupling of a mechanistic model to cellular automata for improving land simulation

ABSTRACT The land use and land cover change (LUCC) process is crucial for climate and environmental change studies. Cellular automata (CA) models based on machine learning techniques have commonly been used to simulate LUCC. However, conventional CA models can only capture the historical relationship between driving forces and LUCC through statistics. Climate change significantly affects LUCC, especially natural vegetation. The statistical relationship between driving forces and LUCC may change with the climate. Furthermore, the existing coupled models of CA and mechanistic models are only loosely coupled in terms of the quantity of land demand provided by mechanistic models, which denotes that mechanistic models do not directly guide CA models in simulating spatial land dynamics. Thus, herein, a novel model that couples Lund Potsdam Jena (LPJ), a mechanistic model, and CA at the cell level is proposed to consider the mechanisms and statistics in LUCC simulations. The proposed coupled model (LPJ-FLUS) is validated by comparison with two historical LUCC simulations in China from 2001 to 2010 and 2015. The results show that the proposed coupled model affords higher simulation accuracy, especially on natural vegetation, compared to the two conventional CA models. The overall Figure of Merit value of the LPJ-FLUS model in the historical LUCC simulations is about 5% higher than that of the conventional CA model, reaching 23.37%, and is even 8% higher for some natural vegetation types. The proposed model is employed to predict the future LUCC under two SSP-RCP scenarios in China from 2015 to 2100. The simulation results show that the proposed model effectively combines the strengths of LPJ and CA, retaining the high spatial resolution of CA while representing the spatial possibilities of LUCC under different future climate scenarios assessed by LPJ. The quantitative validation results show that the simulation results of the LPJ-FLUS model are more spatially correlated with the LPJ model than those of conventional CA models. The proposed LPJ-FLUS model is a valuable attempt toward tightly coupling mechanistic and CA models at the cell level. Additionally, it has promising potential for high spatial resolution LUCC simulations and environmental impact analysis under future extreme climate scenarios.