Search

This paper proposes a novel aviation CO 2 emissions reduction method by introducing a market-based incentive mechanism. An aviation carbon emissions prediction model is proposed to characterize both the microscopic flight dynamics and the macroscopic air traffic demand trend. Based on emissions prediction, a linear climate response model is applied to evaluate the environmental impact of the aviation carbon emissions. Finally, a market-based framework for aviation CO 2 emissions reduction is established based on a two-phase carbon trading model, which provides a piecewise charge method through emission taxation and cap-and-trade. A case study is carried out to demonstrate the effectiveness of the proposed framework using a real-world dataset from the Hefei Air Traffic Control Zone in China. Three scenarios are defined to describe the possible development speed of sustainable aviation fuel application in the future: not applied, medium-speed development, and high-speed development. The results show that the carbon peak will be reached in 2025 in the high-speed development scenario, when the emission amount and associated environmental impact will be reduced by 23.7% and 22.3%, respectively. Thus, the market-based framework proposed in this paper can effectively reduce aviation CO 2 emissions and mitigate the effects of global warming. • An aviation CO 2 emissions prediction model is proposed considering both microscopic flight dynamics and macroscopic traffic demand. • A more efficient market-based CO 2 emission reduction framework is developed based on a two-phase carbon trading model by means of taxation and cap-and-trade. • Case study shows that the proposed method has a more optimal incentive for CO 2 emission reduction. [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) emissions from wetlands have exacerbated global warming, attracting worldwide attention. However, the research process and development trends in this field remain unknown. Herein, 1865 papers related to wetlands GHG emissions published from January 2000 to December 2023 were selected, and CiteSpace and VOSviewer were used for bibliometric analysis to visually analyze the publications distribution, research authors, organizations and countries, core journal and keywords, and discussed the research progress, trends and hotspots in the fields. Over the past 24 years, the research has gone through three phases: the "embryonic" stage (2000–2006), the accumulation stage (2007–2014), and the acceleration stage (2015–2023). China has played a pivotal role in this domain, publishing the most papers and working closely with the United States, United Kingdom, Canada, Germany, and Australia. In addition, this study synthesized 311 field observations from 123 publications to analyze the variability in GHG emissions and their driving factors in four different types of natural wetlands. The results suggested that the average carbon dioxide (CO 2), methane (CH 4), and nitrous oxide (N 2 O) fluxes in different wetlands were significantly different. River wetlands exhibited the highest GHG fluxes, while marsh wetlands demonstrated greater global warming potential (GWP). The average CO 2 , CH 4 and N 2 O fluxes were 60.41 mg m−2·h−1, 2.52 mg m−2·h−1 and 0.05 mg m−2·h−1, respectively. The GWP of Chinese natural wetlands was estimated as 648.72 Tg·CO 2 -eq·yr−1, and CH 4 contributed the largest warming effect, accounting for 57.43%. Correlation analysis showed that geographical location, climate factors, and soil conditions collectively regulated GHG emissions from wetlands. The findings provide a new perspective on sustainable wetland management and reducing GHG emissions. [Display omitted] • A 24-year bibliometric analysis of GHG emissions from wetlands was conducted. • The historical evolution and future trends in the field were summarized. • River wetlands exhibited the highest GHG fluxes. • GWP of China's wetlands was estimated to be 648.72 Tg·CO 2 -eq·yr−1. • CH 4 emissions contribute 57.43% to the GWP value in China's wetlands. [ABSTRACT FROM AUTHOR]

Reducing greenhouse gas emissions is urgent for the global community with rising climates. Considering the importance of renewable energy in mitigating climate warming, forecasting renewable energy generation is vital for the Chinese government's future low-carbon and green development plan. This paper proposes a novel multivariable grey model based on historical data on China's renewable energy generation and three industries. A novel information accumulation mechanism with two adaptive factors is designed to improve the traditional multivariable grey modeling defect. Based on the proposed mechanism, this paper optimizes the initial and background values and nonlinear model structure with the whale optimization algorithm. The forecasting results show that the fitting MAPE is 1.13%, comprehensive MAPE is 2.60%, MSE is 50.86, and RMSE is 7.13, which significantly improve the forecasting accuracy of traditional GM(1,N) and are better than other compared models. The forecasting results show that China's renewable energy generation will gradually increase to 5834.02 TWh. The Chinese government should keep the previous Five-Year Plans rising trend of the three industries in the future Five-Year Plans to support renewable energy industries. In China's future energy system, it is necessary to promote incentive policies and capital investment for actively accelerated development to make renewable energy the leading force. [ABSTRACT FROM AUTHOR]

Global warming, mainly caused by rising carbon dioxide (CO 2) emissions in the atmosphere, has led to severe effects worldwide. Hence, reducing carbon emissions has become an urgent need to mitigate the adverse effects. To do so, accurately forecasting CO 2 emissions is crucial for policymakers in formulating climate and energy policies. Existing CO 2 emission forecast models rely on various longitudinal economy, energy or environment data collected at the same periods, e.g., yearly, as indicators. However, these data usually come from diverse sources with different sampling frequencies, e.g., monthly vs. daily. Therefore, in this paper, we introduce for the first time a Mixed-frequency data Sampling Grey system Model (MSGM) that can exploit the potential information in high-frequency sampling (HF) data of economic and social indicators to effectively forecast annual CO 2 emissions. In MSGM, (1) we directly model low-frequency CO 2 emissions and HF economic-energy influence indicators without undertaking same-frequency conversion, thereby avoiding potential information loss and enhancing prediction accuracy; (2) we introduce polynomial weight functions to address the frequency mismatch, and its parameters are obtained through search optimization algorithms; (3) unlike existing grey system models, the whitening equation of MSGM adopts a reduced-order form to address the exponential explosion issue caused by HF data accumulation; (4) the time and cumulative terms are also introduced separately to explore the effects of temporal development and historical data on future CO 2 emissions. Extensive Monte-Carlo simulations show that MSGM exhibits high accuracy on both training and testing datasets and outperforms many other state-of-the-art rival techniques like MIDAS, AR-MIDAS, AMTGM, MLRM, BPNN, SVR, ARIMA and TVGBM. We further demonstrate the potential of MSGM to forecast China's CO 2 emissions under three distinct scenarios. Out-of-sample forecasting results indicate that only under a tight-contraction scenario does the growth rate of CO 2 emissions decrease. To the best of our knowledge, the MSGM is the first technique that can exploit different frequency data to effectively forecast CO 2 emissions. [Display omitted] • A novel grey system forecast model based on mixed-sampling frequency is proposed. • Introducing more higher frequency data from economic and social indicators. • Selecting popular local search algorithms to find optimal unstructured parameters. • The CO 2 emission forecast for 2022–2026 is carried out under three distinct scenarios. [ABSTRACT FROM AUTHOR]

The battery electric vehicle (BEV) industry, commanding over half of the global market share in China, has garnered significant attention in response to escalating concerns about climate change. NCM (LiNi x Co y Mn z O 2) batteries, prized for their high energy density, are pivotal in this industry. However, their production relies on critical metals, posing environmental challenges. Recycling processes aim to address this issue by recovering critical metals from end-of-life batteries. The industry is updating from NCM 111 to NCM 811 batteries to enhance energy density and reduce costs, but the key factors influencing the material flows and environmental impacts remain uncertain. This paper aims to identify the key factors contributing to the potential differences in material flows and environmental impacts introduced by the NCM battery upgrading in China. Following the new energy vehicle sales projections in China until 2035, a dynamic material flow analysis was employed to calculate material demands, recovered amounts, and substitution rates for various upgrading scenarios. The study reveals that the majority of retired batteries until 2035 were sold between 2022 and 2029. Material substitution rates prove to be more sensitive to the upgrading scenario than the lifetime and growth rate of BEVs. Faster NCM 811 penetration results in over 2.5 times more saved cobalt demand compared to additional nickel demand. A life cycle assessment of NCM batteries reveals a 39% lower global warming impact for NCM 811 compared to NCM 111, highlighting environmental benefits from increased energy density and reduced cobalt consumption. The energy density improvement contributed 85%, while the alteration in material composition contributed 15% to the global warming reduction in NCM 811. Recycling emerges as a crucial strategy in mitigating environmental impacts across all categories, particularly addressing eutrophication, previously deemed challenging due to the difficulty in recovering Li 2 CO 3. [ABSTRACT FROM AUTHOR]

Pterophyllum, an extinct plant of Bennettitales, constitutes a significant component of the Mesozoic flora. In this study, we identified four fossil species of Pterophyllum from the Middle Jurassic Yaojie Formation in the Yaojie Basin and the Baojishan Basin in Gansu Province, Northwest China. Through analysis of macroscopic and macroscopic characteristics, these specimens were identified as Pterophyllum xinjiangensis Zhao, P. subaequale Hartz, P. ptilum Harris, and P. angustum (Braun) Gothan. These findings bridge gaps in the study of Bennettitales fossils in the region, affirming the warm and humid climate of the Yaojie Basin and the Baojishan Basin during the Middle Jurassic. Moreover, a comprehensive analysis of 598 reported Pterophyllum fossil records in China revealed that their occurrences from the Late Triassic to the Early Cretaceous was constrained by ancient climates and tectonic. The Late Triassic exhibited the highest diversity, with 83 species, which were widespread across warm-humid and tropical-subtropical zones in China; however, their diversity decreased sharply in subsequent periods, increased slightly in the Early Cretaceous, and then disappeared. In this paper, we further examined the habitat characteristics of this genera based on its spatiotemporal distribution and the paleogeographic and paleotectonic features of its origins, elucidating the coupled relationship between its distribution and ancient geographic and tectonic factors. • Four species of Pterophyllum in Yaojie Formation are described. • 598 records of 157 species of Pterophyllum reported in China are provided. • Distribution of Pterophyllum during the Mesozoic in China is provided. • Most of the occurrences of Pterophyllum represent warm and humid climate types. • Restricted conditions of Pterophyllum distribution & evolution are discussed. [ABSTRACT FROM AUTHOR]

Abstract With the development of China's economy, the use of fossil energy has become more and more, resulting in increasing carbon emissions. CO 2 emissions have caused global warming, threatening humans and creatures on Earth. In order to effectively suppress the growth of carbon emissions, it is necessary to analyze the influencing factors of carbon emissions and apply them to predict carbon emissions. This paper presents sixteen potential influencing factors and uses grey relational analysis to identify the factors that have a strong correlation with carbon emissions. The principal component analysis (PCA) is used to extract the four principal components, which reduce the redundancy of the input data. The long short-term memory (LSTM) method is established to predict carbon emissions in China. We use back propagation neural network (BPNN) and Gaussian process regression (GPR) to compare LSTM method. The simulation results show that the prediction accuracy of carbon emissions based on LSTM is better than that of BPNN and GPR, indicating the effectiveness of PCA and LSTM in prediction of carbon emissions. Finally, this paper provides the theoretical basis for China to reduce carbon emissions by studying prediction of carbon emissions. Highlights • Grey correlation analysis is applied to identify factors associated with carbon emissions. • Principal components analysis is used to simplify input variables and obtain the main factors affecting carbon emissions. • The long short-term memory model is used for the first time to predict carbon emissions. • The direction of reducing carbon emissions in China is given by analyzing the prediction results. [ABSTRACT FROM AUTHOR]

With the aggravation of carbon emissions and global warming, the probability of various natural disasters and environmental risks will increase significantly. Therefore, carbon emission reduction and low-carbon development have become the focus of environmental economic research. This paper uses the information about the opening of high-speed railway (HSR) in China to comprehensively explore the effect of infrastructure construction on urban carbon total factor productivity (CTFP) in China, which is calculated by the novel non-parametric method named biennial non-radial Luenberger productivity indicator (BLPI). Our results reveal that in China, an extra HSR line significantly improves the CTFP of local cities by 0.63%, while the CTFP of related surrounding cities increases by 6.3%. We confirm the robustness of our empirical findings and perform the mechanism analysis from several aspects. The mechanism analysis shows that the HSR improves the CTFP of local cities mainly via industrial upgrading and technological progress, and improves the CTFP of surrounding cities via industrial agglomeration and factor spillover. Besides, the impact of the HSR is more pronounced for the core cities, large cities, and innovative cities. Our results suggest that the HSR makes cities more carbon efficient, which is a non-negligible advantage of infrastructure construction in reducing environmental risks. • Governments around the world have been committed to reducing external environmental risks by adopting urbanization. • This paper analyzes the spillover effect of the onening of HSR on CTFP in China. • This paper provides a novel framework, which uses the LPI combined with the BNDDF to measure CTFP. • An extra HSR line significantly improves the CTFP of local cities by 0.63% and surrounding cities by 6.3%. • The mechanism analysis reveals four channels, including industrial upgrading, technological progress, industrial agglomeration, and factor spillover. [ABSTRACT FROM AUTHOR]

• Transition zones are the hotspots of bioclimatic changes under global warming. • Global warming extends growing season lengths but increases heat and water stresses. • Sustainable grasslands in China shrink and shift northwestward with global warming. Bioclimatic response to global warming is a key linkage between anthropogenic climate change and ecosystem sustainability, particularly for the impact-prone climate transition zones. This paper examines changes in heat-water conditions from 2006 to 2100 across China, using the fifth generation climate reanalysis from the European Centre for Medium-Range Weather Forecasts (ERA5) and bias-adjusted climate projections by the Coupled Model Intercomparison Project Phase 5 (CMIP5). We then assess the effects of these changes on habitat suitability for responsive ecosystems using a species distribution model. The results reveal significant changes in bioclimatic environments across dry–wet climate transition zones under the present-day climate and the RCP8.5 scenario. By the end of the 21st century, local growing season length (GSL) could extend by 60 days and 30 % of the GSL could be under heat stress. Water conditions worsen overall in both the air and the soil, despite some improvements in the middle parts of transition zones. With altered heat-water conditions, sustainable grasslands shift northwestward, with a reduction of approximately 131 million km2 (46.6 % relative to 2006–2010) in total area. These changes primarily arise from alterations in winter and spring heat-water conditions. Our findings highlight the climate transition zones as hotspots of ecosystem vulnerability demanding particular attention in impact assessment and adaptation studies. [ABSTRACT FROM AUTHOR]

Cross-front transport is a vital process in the offshore transport of terrestrial materials. The factors influencing cross-front transport are multifaceted and exhibit regional variability. As important factors regulating material transport patterns in the shelf seas of eastern China, the East Asian Winter Monsoon (EAWM) and Kuroshio current (including its branches) vary on multiple time scales, yet their role in controlling offshore transport is not fully understood. In this paper, cross-front offshore transport in the North Yellow Sea is chosen to investigate the aforementioned issue using numerical simulation. By excluding other potential processes for offshore transport, frontal instability is identified as the primary mechanism for offshore transport, which is triggered by winter storms (bursts of the EAWM); hence, the intensity of offshore transport is highly associated with the strength of winter storms on synoptic scales. However, on the inter-annual scale, the intensity of offshore transport is more likely regulated by the strength of the Kuroshio current, and a warming Kuroshio facilitates offshore transport. Although the role of each factor in controlling the intensity of offshore transport is delineated, the interactive effects of the EAWM and Kuroshio current on offshore transport are quite intricate, and how to quantitatively estimate their roles on multiple time scales remains a challenge using modelling. The results obtained from this study can be applied to analyse cross-front transport throughout the eastern China seas and bear significant implications for future studies on pollutant diffusion, nutrient distribution, and sediment transport in the coastal area. • Cross-front transport around the Shandong Peninsula was revealed using a numerical model. • EAWM and Kuroshio affect the strength of cross-front transport on different time scales. • With global warming, the temperature of Kuroshio might gradually become the primary control of cross-front transport. [ABSTRACT FROM AUTHOR]

• Significantly changes of LAI and GPP mostly occurred in eastern and southern China. • Divergence between LAI and GPP were found in regions with dense vegetation coverage. • The importance of VPD, SM, and PT to vegetation indices increased as latitude decreases. Climate change notably boosts terrestrial hydraulic redistribution pattern, which could directly affect the spatiotemporal evolution characteristics of vegetation productivity. However, the spatiotemporal evolution pattern of long-term hydrometeorological controls of vegetation productivity is still not fully understood. This paper comprehensively explored the impacts of hydrometeorological controls on leaf area index (LAI) and gross primary productivity (GPP) in China during 1982–2015 using both satellite observations and reanalysis. Vapor pressure deficit (VPD), evapotranspiration (ET), precipitation (PT), and soil moisture (SM) were used as representative indicators during investigation. The dynamics of LAI and GPP displayed increasing trends on the whole. And significantly changes mostly occurred in eastern and southern China, accompanied by moderate to dense vegetation coverage. An accelerated increasing trend for LAI could be observed since September 2003 (+0.175 per decade), while the growth rate of GPP (+16.76 g C/m2 per decade) basically maintained stable. In terms of hydrometeorological controls, VPD and ET showed consistently increasing trend and SM presented falling trend in the context of warming climate. Through analysis of feature importance index established by Random Forest, the importance of VPD, SM, and PT obviously increased as latitude decreases, which implied the high sensitivity of vegetation in semi-humid\humid regions to water availability. Additionally, divergence between LAI and GPP can be found in southern Tibet Plateau region and coastal regions, which provides compelling evidence that in the case of high LAI, increasing LAI could weaken the improvement effect on GPP. Findings of this study is expected to promote the understanding of long-term vegetation responses to hydrometeorological variations. [ABSTRACT FROM AUTHOR]

For China, greenhouse gas emissions increased by 0.075 gigatons (Gt) in the period of 1995–2000 and increased by 4.23 Gt from 2000 to 2009, then reached the amount of 8.61 Gt in 2009. Different from the traditional analysis focused on accounting sectors’ greenhouse gas emissions under the production-based responsibility, this paper investigates sectoral GHG emissions in China in the period of 1995–2009 from the perspective of consumption-based and income-based responsibility. We found that different metrics yield very different GHG emission responsibilities. The sector of electricity, gas and water supply has the highest GHG emissions responsibility based on the production and income metrics, while the sector of construction is the largest emitter under the consumption metric. In the light of the key driver analysis of GHG emissions from 1995 to 2009, based on the consumption metric, the change in the final demand volume is the largest driver of increase in China's consumption-based GHG emissions (+17.18 Gt). The changes in the production structure and the final demand structure are other contributors (+0.53 Gt, +1.46 Gt). The improvement to the intensity of GHG emissions is the main force for GHG emissions mitigation (−14.86 Gt). According to the income metric, the contributions of input volume changes, input structure changes and GHG intensity changes are similar to the effects of consumption-based responsibility (+19.11 Gt, +1.13 Gt, −14.95 Gt). The difference is that the change in the production structure is another force that offset GHG increase (−0.98 Gt). Results in this paper can give some recommendation on mitigating GHG emissions in China for policy-makers from production-side, demand-side and supply-side. [ABSTRACT FROM AUTHOR]

In recent years, the rapid development of transportation industry brings economic benefits, at the same time, the problem of environmental pollution is becoming more and more serious. The emission of CO 2 intensifies the trend of global warming. How to measure the development of environment and economy is a huge challenge for us. This paper proposes a data envelopment analysis (DEA) method based on slacks-based measure (SBM) to evaluate the environmental and economic performance of the transportation industry from 2015 to 2017. According to the economic region, 30 provinces in China are divided into northeast, east, central and western regions for efficiency analysis. The model can determine the low efficiency decision units and finally put forward improvement suggestions for the low efficiency areas. [ABSTRACT FROM AUTHOR]

This paper presents projections of climate extremes over China under global warming of 1.5, 2, and 3 °C above pre-industrial (1861–1900), based on the latest Coupled Model Intercomparison Project phase 6 (CMIP6) simulations. Results are compared with what produced by the precedent phase of the project, CMIP5. Model evaluation for the reference period (1985–2005) indicates that CMIP6 models outperform their predecessors in CMIP5, especially in simulating precipitation extremes. Areal averages for changes of most indices are found larger in CMIP6 than in CMIP5. The emblematic annual mean temperature, when averaged over the whole of China in CMIP6, increases by 1.49, 2.21, and 3.53 °C (relative to 1985–2005) for 1.5, 2, and 3 °C above-preindustrial global warming levels, while the counterpart in CMIP5 is 1.20, 1.93 and 3.39 °C respectively. Similarly, total precipitation increases by 5.3%, 8.6%, and 16.3% in CMIP6 and by 4.4%, 7.0% and 12.8% in CMIP5, respectively. The spatial distribution of changes for extreme indices is generally consistent in both CMIP5 and CMIP6, but with significantly higher increases in CMIP6 over Northeast and Northwest China for the hottest day temperature, and South China for the coldest night temperature. In the south bank of the Yangtze River, and most regions around 40°N, CMIP6 shows higher increases for both total precipitation and heavy precipitation. The projected difference between CMIP6 and CMIP5 is mainly attributable to the physical upgrading of climate models and largely independent from their emission scenarios. [ABSTRACT FROM AUTHOR]

China has set an ambitious national determined contributions target to peak CO 2 emissions by 2030 and aims to be carbon neutral by 2060. One of China's top energy consumers and CO 2 contributors, the steel industry accounts for 13% of the country's total consumption and 15% of CO 2 emissions. In response to the present global warming trend, there is an urgent need to cut energy consumption and CO 2 emissions to promote low-carbon growth. This paper attempts to provide a detailed analysis of the steel industry's CO 2 emission reduction path to carbon neutrality. Further efforts in terms of industrial structure, material efficiency, energy efficiency, and low- or zero-carbon technologies are required to achieve a low-carbon transition. Given that decarbonization is a significant priority in the steel industry in many countries, this study focuses on the goals and technological paths of low-carbon emissions projects to optimize existing technology priorities and propose development directions. Deep decarbonization is also projected to be achieved by combining CCUS and hydrogen metallurgy technologies. The steel industry requires collaborative efforts to standardize CO 2 emission accounting methodologies and establish a carbon trading system to strengthen carbon emission management. • The steel industry is one of the key contributors to carbon neutrality which needs to accelerate decarbonization. • Reducing energy consumption and CO 2 emissions to keep up with the current global warming trend are reviewed. • This paper selects low-carbon emission projects to optimize current technology priorities and provide development directions. • Policy recommendations and next steps for low-carbon transition are given. [ABSTRACT FROM AUTHOR]

In this era of global warming the importance of climate risk cannot be understated, and finding ways to reduce climate risk is a topic worthy of study. In this paper, we innovatively examine the role of renewable energy technology innovation on climate risk in China. In addition to their linear relationship, we also investigate the asymmetric and heterogeneous impact, detect the impact channels, and find that (1) increased renewable energy technology innovation can effectively alleviate the climate risk situation. Accordingly, the development of renewable energy technology innovation can make a significant contribution to CR abatement. (2) Pronounced impacts of renewable energy technology innovation on climate risk can be observed in the higher quantiles (75th and 90th) of climate risk. (3) Renewable energy technology innovation is a powerful weapon for eradicating climate risk in provinces with a higher level of government fiscal expenditure. And (4) renewable energy technology innovation has an impact on climate risk by facilitating energy consumption efficiency, which is a necessary mediator. These conclusions inspire us to put forward several corresponding policy implications for better climate risk governance and renewable energy technology innovation development. [ABSTRACT FROM AUTHOR]

• The extent of flooding in China is greater than in any other country. • Nearly 66% of China's landmass is submerged by flooding. • Financial toll of flooding accounts for approximately 1.42% of the annual GDP. • Various forms of climatic change contribute to flooding. The extent of flooding in China is more significant than in any other country. Our research reveals that approximately 66 % of China's landmass is submerged by flooding, affecting about 50 % of the population. Furthermore, the financial toll of flooding now accounts for approximately 1.42 % of the annual gross domestic product (GDP), which is almost 40 times higher than the corresponding figure for the United States. We have observed that Zhengzhou city in Henan province, which faced a devastating flood in 2021, received a significant amount of rainfall, specifically a total of 552.5 mm within a 24-hour period. The floods in Henan province in 2021 caused considerable damage, including impacting nearly 15 million people, resulting in almost 400 deaths, damaging over 10,000 square kilometers of agricultural land, causing almost $19 billion in economic losses, and leading to the collapse of over 35,000 households and damage to various properties. In a similar manner, the significant flooding that occurred in southern China in 2020 impacted approximately 7.1 million individuals across eight provinces and resulted in 54 fatalities, the collapse of 6,700 houses, and incurred a direct economic loss of US$3.33 billion. We found that rainstorms have significantly increased to 10 % in the last 60 years in China. In this paper, we delved into exploring the existing published articles, reports, and government and authoritative legal texts to analyze the causes and impacts of flooding in China's flood-prone regions and potential mitigation strategies to reduce the repercussions of distressing flood events. We believe this study will help policymakers by providing new insights while formulating policy to reduce the loss caused by high-level flooding. [ABSTRACT FROM AUTHOR]

[Display omitted] • The drought pattern in China is closely related to the basin distribution and multiple teleconnection factors. • The intensity and frequency of drought in China exhibited an increasing trend. • The ENSO-AO had important positive effects in the major basins in China. • Multiple wavelet coherence helps identify the processes controlling drought changes. Due to increasing global warming and the frequent occurrence of severe drought risk in recent decades, many studies have investigated drought in China. However, the spatiotemporal heterogeneities of droughts are complicated, and a comprehensive analysis of the driving forces has not been thoroughly explored. In this paper, we studied the temporal and spatial patterns of drought in China from 1960 to 2018 and disclosed its relationship with multiple teleconnection factors on different time scales. The results show that (1) Drought in China has exhibited a fluctuating increasing trend over the past 59 years, with a standardized precipitation–evapotranspiration index (SPEI) rate of change of –0.12/10 a, and the most severe droughts occurred during 2000–2010. (2) There was a significant abrupt change in China's meteorological droughts induced by climate change around 1997. (3) The trend in China was characterized by drought in spring and autumn and humidification in winter, while the trend in the Southwest River Basin was characterized by drought. (4) A combination of factors can best explain the drought variations from basin to basin, and the El Niño-Southern Oscillation (ENSO)-Arctic Oscillation (AO) was most commonly the best predictor. The use of multiple wavelet coherence helps to identify the dominant drought change processes. [ABSTRACT FROM AUTHOR]

This study explores the impact of political uncertainty on sustainable urban development by examining carbon emission trading systems (ETS) in four major markets in China (Beijing, Shanghai, Guangdong, and Hubei) from 2014 to 2022. As an alternative to carbon taxes, carbon ETS markets have become increasingly popular due to their success in reducing greenhouse gas emissions. However, their effectiveness is often hindered by political instability and uncertainty. Utilising logistic regression and AR(1)-GARCH estimations, we identify a negative relationship between political uncertainty and carbon trading volume. Our study also reveals significant variations in the responses of these markets to political uncertainty. The paper contributes to the understanding of how ETS markets operate in a complex and constantly changing political environment. We suggest that policymakers need to consider the impact of political uncertainty on carbon trading when designing and implementing urban policies that promote sustainable development. Additionally, our research contributes to the development of urban policies that can be effectively implemented in both developed and developing regions. • Local government official turnovers are used as the measurement of political uncertainty. • Daily transaction data from four carbon ETS markets (Beijing, Shanghai, Hubei and Guangdong) in China • Considered the probability and proportion of zero transaction day • Logistic regression and AR(1)-GARCH estimations • A negative relationship between political uncertainty and carbon transaction volume [ABSTRACT FROM AUTHOR]

In recent years, studies have found that drought can occur rapidly under anomalous atmospheric circulation patterns and underlying surface conditions. This type of drought is defined as "flash drought". It is more sensitive to global warming compared to traditional drought and may become a common drought phenomenon in the future and require intensive research. But the characteristics and development mechanism of flash drought in northern China has been studied much less than in southern China, and thus deserve further study. Based on the daily station data and GLDAS grid data from 1978 to 2020, this paper identified the flash drought in northern China, analyzed its evolution of temporal-spatial characteristics and explored the meteorological driving factors of flash drought. The main results are as follows: (1)The frequency of flash drought in the year is the highest in WNW (West of Northwest), followed by ENW (East of Northwest), NC (North China) and NE (Northeast China), while the frequency in the plant growing season is the highest in the south of NE and the south of NC, and low in the other regions. (2)The hotspot areas of flash drought showed an obvious eastward trend from WNW to ENW in northern China from the 1980s to 2010s. (3) There is a good relationship between soil moisture and precipitation in WNW and ENW, while the soil moisture is affected by both temperature and precipitation in NC and NE. (4) Flash drought could occur all through the year in WNW and NC, while it mainly occurred in the summer half-year and summer in EWN and NE. The main high occurrence period of flash drought in each region is in late spring and early summer, while a second high occurrence period appears from early September to late October in WNW. (5) From the perspective of the driving of water vapor changes, the flash drought in WNW and ENW is mainly driven by water vapor advection, while that in NC and NE is mainly driven by wind field divergence. • The hotspot areas of flash drought showed an obvious eastward movement from WNW to ENW in northern China. • The main high occurrence period is around early May to early July in northern China, with a second one in WNW. • Flash drought in WNW and ENW (NC and NE) is mainly driven by water vapor advection (wind field divergence). [ABSTRACT FROM AUTHOR]

The increasing contribution of refrigeration systems to global warming has led to widespread demand for low global warming potential (GWP) refrigerants as alternatives. This paper proposed a comprehensive environmental assessment method for evaluating the carbon footprint of units charged with low-GWP refrigeration. Experimental and numerical studies were used to investigate the carbon footprint impact of using alternative refrigerants at different ambient temperatures in China. Initially, the model was validated through experimental case studies on the use stage of cold storage units. Subsequently, a comparison was made between the cooling capacity (CC) and energy efficiency ratio (EER) of cold storage units charged with different refrigerants. Additionally, the impact of alternative refrigerants in the use stage was analyzed by numerical calculations, and the adaptability of the cold storage unit to the ambient temperature and the national energy structure was also studied. The results indicate that among the four stages of the cold storage unit, the use stage is the hotspot of carbon footprint due to the large amount of energy consumption and the existence of refrigerant leakage and other behaviors. Utilizing low-GWP alternative refrigerants could significantly reduce the carbon footprint of the cold storage units' use stage by 10.56%–16.39%, thereby lowering the whole stage carbon footprint. Furthermore, the ambient temperature and national energy structure could also effectively reduce the carbon footprint of cold storage units' whole stage by 1%–27.17%. Furthermore, after adopting low GWP refrigerants, the life-cycle cost (LCC) of the units have also decreased by 6.1%–12%. Taking into account both environmental impact and economic considerations, it is recommended to directly replace R404A with R448A in the units in regions where the average ambient temperature is above 15 °C. • A carbon footprint evaluation model for the units was established. • Influencing factors of carbon footprint are studied numerically and experimentally. • By GHG assessments, the optimal refrigerant and external conditions were determined. • Alternative refrigerants reduce carbon emissions for cold storage units by 8.8%–24.92%. [ABSTRACT FROM AUTHOR]

As climate warming intensifies, reducing greenhouse gas emissions has become a national consensus for many countries. Green finance plays an important role in promoting energy efficiency and lowering such emissions, but there is scant literature that analyzes the impacts and mechanisms of green finance on energy efficiency. Based on China's provincial panel data from 2010 to 2018, this research measures the green finance index using the panel entropy weighting method and systematically evaluates the relationship between green finance and energy efficiency using the fixed-effects model. The results show the following. (1) Green finance significantly contributes to energy efficiency and remains the same after a series of robustness tests such as endogeneity treatment, replacement of explanatory and interpreted variables, and replacement of regression models. (2) Green technology innovation and energy structure optimization are the transmission mechanism of green finance for energy efficiency, which means that green finance improves energy efficiency by promoting green technology innovation and energy structure optimization. (3) There is regional heterogeneity, temporal heterogeneity, and industry heterogeneity in the impact of green finance on energy efficiency. The positive effects of green finance on energy efficiency are more pronounced in resource-dependent regions, regions with irrational industrial structure, north regions, industrial sectors, and after 2013. The conclusions of this paper offer some policy recommendations, including promoting the development of green finance, building a cooperation platform for green finance and technological innovation, enhancing the depth and breadth of renewable energy utilization, and building differentiated green finance strategies according to local conditions. [ABSTRACT FROM AUTHOR]

The efficient and effective new energy vehicles (NEVs) power batteries recycling (PBR) plays a critical role in reusing scared metal resources, decarbonizing the transport sector and climate warming mitigation. The policy consistency from up to down in a big country lays a solid foundation for sustainable recycling. However, quantitative comparison or evaluation of power batteries recycling policies (PBRPs) from various levels of government is insufficient in the existing literature. In this paper, text mining technology and the Policy Modelling Consistency Index (PMC-Index) model are used to evaluate the longitudinal and horizontal consistency level of China's 13 central PBRPs as well as 25 local PBRPs from 2016 to 2022. The findings demonstrated that: (1) Longitudinally, the local governments present a high consistency level with the central government in the objective and content of PBRPs via comparison analysis of high-frequency words, which embodies the local governments firmly advocating the national strategy for retired battery recycling. (2) Horizontally, the number of central PBRPs with excellent and good consistency is five and seven, respectively, while the number of local PBRPs with excellent and good consistency is six and seven, respectively. One central and twelve local PBRPs are of acceptable consistency, indicating significant disparity in local governments' policymaking ability. (3)The drawbacks of those acceptable policies attribute to the policy tendency of traceability management, policy timeliness, policy content in terms of incentives and business recycling model. Finally, management implications were summarized to optimize China's PBRPs system and PBR performance based on the empirical result, an overview of PBRPs and recycling practices in developed countries. [Display omitted] • We evaluate the China's central and local power batteries recycling policies. • The PMC-Index model is used to quantitative analysis of policy consistency. • The longitudinal and horizontal consistency of battery recycling policies is good. • We outline the power battery recycling policies and practice in the EU and the U.S. • Carbon footprint requirements should be added in China's battery recycling polices. [ABSTRACT FROM AUTHOR]

The terrestrial Yanliao Biota in northeastern China represents a Jurassic biodiversity hotspot. Abundant and diverse fossils include the oldest known representatives of several groups of plants, invertebrates, and vertebrates that thrived in a forest ecosystem under a humid and warm climate. Since the early 21st century, discoveries associated with the Yanliao Biota have significantly improved our understanding of Jurassic terrestrial ecosystems. However, a robust chronostratigraphic framework is required to calibrate the biota with key evolutionary events and to improve understanding of possible links between evolution and tectonism. In this paper, we report novel 40Ar/39Ar ages for two tuff layers (161.4 ± 0.8 Ma and 161.6 ± 0.6 Ma) positioned directly above the less-studied but salamander fossil-rich beds in Reshuitang, near Lingyuan, Liaoning Province, China. These new age data improve knowledge of the timing of diversification of early salamanders. We also review all reported age data and summarize significant fossils from classic Yanliao outcrops. Our study indicates that the Reshuitang fossil beds were deposited slightly later than the well-known Daohugou fossil beds situated ∼15 km away in Inner Mongolia and somewhat earlier than the Linglongta fossil beds in western Liaoning Province. These findings advance understanding of the Jurassic world during an episode of pronounced climatic warming. • We provide detailed age calibration for the Jurassic Yanliao Biota. • Our study allows us to understand Jurassic terrestrial ecosystems. • A robust chrono-stratigraphy reconstructs the link between life and climate. [ABSTRACT FROM AUTHOR]

Global warming caused by the excessive combustion of fossil fuels has become the focus of the international community. China's carbon emission reduction policy plays a vital role in international climate change, carbon emission neutrality and domestic environmental pollution control. This paper summarises the progress of China's Emission Trading Scheme (ETS) pilots from 2011 to 2021, including trading volume, carbon emissions price, and the effect of carbon emission abatement. By calculating the carbon emissions intensity decrease rate of China's ETS pilot and non-pilot regions, the ETS and carbon emissions tax are compared in terms of emission reduction effectiveness, emission reduction cost and implementation resistance to provide theoretical support for the Chinese government to select and develop carbon emission reduction tools. The development of the Clean Development Mechanism in China is also compared with China Certified Emission Reduction (CCER), and the offsetting rules of CCER are summarised. After the whole analysis and assessment, the results show that from 2013 to 2018, the average carbon emissions intensity decline rate in the ETS pilots was 7.3% and that in non-pilots was 4.29%. Some problems of China's carbon emissions trading market are also concluded. The trading volume is small (only 43.4 × 106 t in 2020) and is discrepant greatly in the different ETS pilots. The carbon emissions price is low (only 33.45 Yuan/t in 2020), with high volatility and large price differences among the ETS pilots. Based on the existing problems, this paper proposes some suggestions for improving China's emission trading market and provides theoretical and decision-making support for promoting carbon emission reduction and neutralisation for China. [Display omitted] [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • We incorporate a variety of principles and indicators into an improved ZSG-DEA model. • We conduct a multi-criteria allocation of China's CEA by 2030 to provincial shares. • We measure the total and per capita space for carbon emissions by province. • All provinces reach the DEA frontier with different CEA ranging from 4.21 to 16.77 Gt. • Differentiated provincial reduction policies are the key to achieving China's INDCs. Abstract Accelerating global warming has suggested the importance of controlling greenhouse gas emissions associated with human activities. In striving to fulfill the Paris Agreement, China has announced its Intended Nationally Determined Contributions (INDCs) aimed at reducing its carbon dioxide (CO 2) emission intensity by 60–65% in 2030 against the level of 2005. However, China's INDCs cannot be fulfilled without formulating appropriate schemes for the allocation of carbon emission allowance (CEA) at sub-national scales. To help close the gap in our knowledge, this paper starts with measuring the overall CEA of China by 2030, and then proposes a science-based scheme for CEA allocation by developing an improved zero sum gains-data envelopment analysis (ZSG-DEA) model. It demonstrates that the final CEA of some northern provinces can be cut down as compared to their initial shares and, conversely, most southern provinces experience an increase in their CEA. Comparing the final share of CEA by province with current carbon emissions, we observe that provinces with abundant energy reserves, such as Shanxi, Inner Mongolia and Shaanxi, tend to be operating in a state of overshoot in terms of space for carbon emissions (SCE). In contrast, there remains SCE when it comes to Guangdong, Hunan, Fujian, etc. The remaining provinces, such as Heilongjiang, Hebei and Ningxia, are close to the break-even point. In view of the differing SCE of individual provinces, common but differentiated policies for CO 2 emission control would be the key to achieving China's INDCs. The research findings lay a scientific basis for the Chinese government to make its INDCs come true through inter-provincial collaboration on emission reduction, but also serve as a reference for fueling further scientific discussions and development of schemes for the allocation of responsibility for carbon emissions at multiple scales within and beyond China. [ABSTRACT FROM AUTHOR]

This paper presents a decomposition analysis of energy-related CO2 emission in China for the period 1991–2006 divided into three equal time intervals. The complete decomposition method developed by Sun is used to analyze the nature of the four factors: CO2 intensity, energy intensity, structural changes and economic activity. The results show that economic activity has the largest positive effect in CO2 emission changes in all the major economic sectors and China has achieved a considerable decrease in CO2 emission mainly due to the improved energy intensity. However, the impact of CO2 intensity and structural changes is relatively small. Structural changes only exhibit positive effect to the CO2 mitigation in agricultural sector, and CO2 intensity also contributes to the decrease of CO2 emission in transportation sector. Moreover, a formula about CO2 mitigation is presented in this paper, which shows that China has made a significant contribution to reducing global CO2 emission. [Copyright &y& Elsevier]

High-latitude permafrost peatlands are sensitive to global warming, and understanding their paleohydrological evolution is critical for assessing future hydrological and environmental changes. This paper presents a diatom record from a peat deposit covering the past 3300 years to reconstruct the moisture and acidity conditions in the Tuqiang permafrost peatland in the northern Greater Khingan Mountains of northeast China. Our findings are integrated with previously published records of plant macrofossils, palynology, and geochemistry from the same profile. From 3300 to 2800 cal yr BP, planktonic and benthic diatoms were equally abundant, indicating relatively high moisture conditions, while the low abundance of acidophilous diatoms reflects relatively high pH during this interval. Pollen data show dominance by sedges with input from the surrounding Pinus forest, while LOI data and lithology suggest that the site was a non-peat accumulating wetland. During the period 2800–1100 cal yr BP, the dominance of planktonic diatoms indicates a wetter local environment, concurrent with the dominance of peat-forming sedges (Eriophorum), indicating the development of a peatland. Between 1100 and 500 cal yr BP, a short-lived increase in acidophilous diatoms (Eunotia) marks a decrease in pH. Since 500 cal yr BP, the dominance of benthic diatoms reflects a drier environment, while a vegetation shift from an Eriophorum -dominated rich fen to a Sphagnum- and Ericaceae-dominated poor fen. An increase in Eunotia diatoms prior to the Sphagnum peak may indicate that diatoms are more sensitive to local acidified habitats than moss. Peatland development in the northern Greater Khingan Mountains was likely induced by the onset of a cooler and wetter climate starting at approximately 2800 cal yr BP, a scenario supported by regional paleoclimate records. Since 700 cal yr BP, the peatland has been affected by both anthropogenic activities and climatic changes, as a drying climate and intensified human activities around the study area reduced diatom species diversity and peat accumulation. Under the background of future global warming and enhanced human activities, the decreasing species diversity and carbon accumulation rate of peatlands in high-latitude permafrost regions need more attention. • Diatoms can indicate local moisture and acidity in permafrost peatlands. • Diatoms are likely more sensitive to microhabitats than bryophytes. • TQ peatland formed after 2800 cal yr BP caused by the cooler and wetter climate. • Rich-fen shifted to poor-fen which co-influenced by deforestation and dry climate at LIA. [ABSTRACT FROM AUTHOR]

The carbon trading market is an effective way to mitigate the threat of climate warming. In the context of carbon neutrality, what is the carbon emission trading scheme's carbon reduction effect? This paper answers the question by examining the carbon efficiency of China's iron and steel industry. This study first constructs CO 2 emission efficiency by employing the data envelopment approach. It then uses the synthetic control method to identify the impact of the carbon emission trading scheme on the CO 2 efficiency of the iron and steel industry. The results show that CO 2 emission efficiency in pilot provinces increased at a 5% significance level compared with the counterfactual scenario. The carbon trading market plays a vital role in industrial CO 2 emission efficiency improvement in Guangdong, Shanghai, Tianjin, Hubei, and Chongqing. From a dynamic perspective, the policy effect of enhancing CO 2 efficiency becomes more prominent over time. Moreover, the effectiveness degree of the carbon emission trading scheme varies across pilot provinces, caused of regional policy differences. Based on the findings, we put forward targeted suggestions for improving the newly-established national carbon trading market. • The DEA model and the synthetic control method are employed in the study. • Impact of carbon market on CO 2 efficiency of iron and steel industry is verified. • The heterogeneity of carbon market effects is explored from regional perspective. • Carbon market significantly promotes industrial CO 2 efficiency in pilot provinces. • China should develop the national carbon market to achieve carbon neutrality. [ABSTRACT FROM AUTHOR]

Global warming can be solved with carbon trading. When carbon emissions become a commodity, it can be a powerful motivator for companies to optimize production capacity and innovate technologically. The goal of this paper is to examine the way in which China's carbon emissions trading policy (CET) influences firm technological innovation in seven pilot regions, using a sample of firms in eight high-carbon industries. We employ difference-in-difference (DID) as well as DID-based propensity score matching (PSM-DID) models to investigate the influence of China's carbon emission policy on firms' technological innovation by using 4745 observations of 749 A-share listed firms in eight high-carbon industries in mainland China from 2007 to 2021. According to the findings, China's CET policy significantly boosts firms' technological innovation, and this beneficial effect persists even after a series of robustness tests that change the policy's implementation year and the technological innovation measure. Further analysis shows that this positive effect is heterogeneous across high-carbon industries and firms with different ownership. In addition, based on the external governance perspective, we find that CET policy performs better in firms in high-carbon industries with a sizable portion of ownership held by institutional investors. This study suggests the effectiveness of CET policy in promoting firms' technological innovation, confirms empirical evidence for Porter's hypothesis, and provides a basis for Chinese firms to achieve their emission reduction targets by improving technological innovation. [ABSTRACT FROM AUTHOR]

The study of household carbon emissions (HCEs) has become one of the most important topics in sustainability research due to the growing awareness of its significances in responding to global warming. This paper aims to identify the trends and characteristics of HCEs research for the period 1993–2019 through the bibliometric analysis approach. The impacts of most productive journals, countries, institutions and authors are evaluated by citation analysis, while the co-authorship network between various countries, institutions as well as the co-occurrence among different keywords are presented. The results of this paper provide a detailed picture on HCEs-related articles from 1993 to 2019. Both the number of publications on HCEs and the cooperation among countries and institutions have increased during the period. Keyword analysis suggests that the revelation of current status of HCEs and corresponding influencing factors are the main lines of HCEs research, and the prediction of HCEs should become the focus of future research. The valuable results obtained from this study can help the academic professionals keep informed of the latest developments in the HCEs-related field. • We employed bibliometric analysis to examine the evolution in HCEs Research. • HCEs research is at its rapid growth stage of development. • USA and China are the most active countries in HCEs research. • The quantification of HCEs and corresponding influencing factors are the main line. • The evolution trend of HCEs should be the focus of future research. [ABSTRACT FROM AUTHOR]

With increased attention on the global warming phenomenon, greenhouse gas management has become an important issue, especially in textile industry. Therefore, an effective greenhouse gas performance appraisal system is necessary for textile enterprises to assess their sustainability and recognize their weakness in the greenhouse gas management. However, few studies have identified the comprehensive connotation of the enterprise’s greenhouse gas management. And there is no relevant research targeting at analyzing the textile enterprises’ greenhouse gas management performance. This paper aims at providing a better understanding of the greenhouse gas management and establishing an evaluation system for textile enterprises. The system divided the evaluation into four categories, including Greenhouse gas management commitment and policy, Greenhouse gas management target and program, Implementation and operation, and Corrective action and public reporting. Literature review, expert interview and on-site investigation were used to supplement the indicators and the weights were determined by Monte Carlo-Analytic Hierarchy Process method. Case studies were conducted on eight typical Chinese textile manufacturers to verify the effectiveness of the evaluation system. The result shows that the new evaluation system can reflect the actual greenhouse gas emission performance of textile enterprises. And the system not only allows textile enterprises to recognize their weakness in the greenhouse gas management and better improve their management level, but also provides reference and experience for other industries to draw upon in establishing the greenhouse gas evaluation system. [ABSTRACT FROM AUTHOR]

Food production consumes a large amount of water consumption and generates huge amounts of greenhouse gas emissions. Quantitative study of impact food wastage imposing on water and greenhouse gas emissions contributes to public awareness that food wastage will further worsen the resource shortage and climate warming, reducing food wastage accordingly. This paper evaluates the impacts of food wastage in the consumption stage on water resources and the environment in China. The result indicates that in the year 2010, the wastage of major food in China was around 62818 M kg in the consumption link, accounting for 14.5% of the total food production, of which the plant food wastage takes up the majority. The loss of water resources (blue water plus green water) caused by food wastage is 60502 Mm³, more than 10% of the country's total water use. Food wastage has a serious impact on agricultural non-point source pollution and greenhouse gas emissions, resulting in a grey water footprint of 16292 Mm³ and 60.85 M ton of carbon emissions. Taking regional differences of food consumption into consideration, the proportion of water footprints and carbon emissions in the eastern and southern developed areas is relatively higher, while the plant food takes a relatively larger share in water footprints and carbon emissions in the western and central provinces. Reducing food waste is important to remove unnecessary burdens on the environment and natural resources. The optimization of resource utilization in the process of food production is conducive to effectively reduce water footprints and carbon emissions of food; healthy diets shall be popularized among citizens so that the animal food consumption which causes more water footprints and carbon emissions can be decreased, alleviating resource and environmental burdens through reduction of the wastage in food consumption. [ABSTRACT FROM AUTHOR]

Regional precipitation patterns may change in a warmer climate, thereby increasing flood and drought risks. In this paper, annual, annual maximum, intense, heavy, moderate, light, and trace precipitation are employed as indicators to assess changes in precipitation patterns under two scenarios in which the global mean temperature increases by 1.5 °C and 2.0 °C relative to pre-industrial levels using the regional climate model COSMO-CLM (CCLM). The results show that annual precipitation in China will be approximately 2.5% higher under 1.5 °C warming relative to the present-day baseline (1980–2009), although it will decrease by approximately 4.0% under an additional 0.5 °C increase in global mean temperature. This trend is spatially consistent for regions with annual precipitation of 400–800 mm, which has experienced a drying trend during the past half century; thus, limiting global warming to 1.5 °C may mitigate these drying conditions. The annual maximum precipitation continues to increase from present day levels to the 2.0 °C warming scenario. Relative to the baseline period, the frequency of trace and light precipitation days exhibits a negative trend, while that of moderate, heavy, and intense precipitation days has a positive trend under the 1.5 °C warming scenario. For the 2.0 °C warming world, the frequency of days is projected to decrease for all precipitation categories, although the intensity of intense precipitation increases. Spatially, a decrease in the number of precipitation days is expected to continue in central and northern China, where a drying trend has persisted over the past half century. Southeastern China, which already suffers greatly from flooding, is expected to face more heavy and intense precipitation with an additional 0.5 °C increase in global mean temperature. Meanwhile, the intensity of intense precipitation is expected to increase in northern China, and the contribution of light and moderate precipitation to the annual precipitation is expected to decrease in southeastern China. Therefore, flood risk in northern China and drought risk in southern China should draw more attention for a global air temperature increase from 1.5 °C to 2.0 °C. [ABSTRACT FROM AUTHOR]

The surge in energy consumption and CO 2 (carbon dioxide) emissions is exacerbating global warming. The Chinese government has promised to reduce CO 2 emission by 60%–65% per unit of GDP over the 2005 level by around 2030. Analyzing the factors influencing CO 2 emissions is one of the key aspects involved in effectively reducing greenhouse gas emissions. In this paper, we add climatic factors based on socio-economic factors, and adopt the extended STIRPAT model to investigate the mechanism driving emissions by the co-action of natural and socio-economic factors. The results show that the 1995–2014 emissions in China's Zhejiang province had an upward trend with growth rates varying between intermediate periods. The order of the factors' elasticity coefficients is urbanization rate (0.181) > GDP per capita (0.180) > population (0.177) > energy intensity (0.170) > trade openness (0.170) > cooling degree days (0.127) > mean temperature anomaly (0.116). Economic development and urbanization were the main factors promoting CO 2 emissions in 1996–1999, while economic development and foreign trade were the main factors in 2000–2014. Policy makers should pay more attention to keeping a healthy pace of economic development, introducing more low energy consumption and low pollution enterprises and encouraging technological innovation. Improving the quality of urbanization, guiding a sustainable lifestyle, adjusting the structure of foreign trade and curbing energy intensity are also expected to reduce emissions. [ABSTRACT FROM AUTHOR]

China is the country with the most population in the world, and its climate is extremely diverse due to tremendous differences in latitude, longitude, and altitude, ranging from tropical in the far south to subarctic in the far north and alpine in the higher elevations of the Qinghai-Tibetan Plateau. Accurate assessment of its modern climate change is conductive to addressing global warming threat. Along with the development of Past Global Changes (PAGES) research, the focus has changed from paleo-climate reconstructions to using paleo-data for assessing the present and predicting the future. Previous studies have been devoted to climate change assessment using modern climate observations and simulations. This paper presents a new assessment approach based on the mid-Holocene, which provides a naturally oriented warming that can be compared to modern human-made global warming. A variety of climatic data, including modern observations, paleo-climate records, CMIP5 (Coupled Model Intercomparison Project Phase 5) and PMIP3 (Paleoclimate Modelling Intercomparison Project 3) simulations, as well as lake level models, were applied in this synthesis. Numerical climate classification was introduced to evaluate climate change impacts to Chinese climate zones on various time scales. The results show that winter and summer seasons have different response to the naturally oriented mid-Holocene warming but human-made global warming makes the warming trend appear in all seasons. Temperate and continental dry winter climates expand dramatically during the mid-Holocene warm period; however, the future global warming could have few impacts to Chinese climate zones. Furthermore, the East Asian summer monsoon was strengthened obviously by the mid-Holocene warm climate and strong low-latitude insolation. There is no consistent trend both for the winter and summer monsoon on the background of human-made global warming. In this study, a new benchmark was established based on paleo-climate to evaluate the impacts of human-made global warming. [ABSTRACT FROM AUTHOR]

The phenomenon of global warming and urban heat island has raised the attention for the outdoor thermal comfort. Vegetation in the improvement of urban micro-climate has been confirmed by a large number of scholars. The problem of the uncomfortable summer climate in China's Cold region didn't get enough research. In this paper, the summer thermal comfort of the street canyon has been studied. The main research intent is to analyze the relationship between the street tree pattern and the thermal comfort of street canyon. It’s demonstrated that, in north-south street, it is suitable for the arrangement of street tree to be at the centre on one side of the street. The higher the height of the street tree, the more comfortable thermal environment the street gets. However, when the ratio of the street tree height to the street building is greater than 10:18, the improvement effect decreases. In east-west street, planting the street tree clinging to the street buildings can provide a better thermal comfort improvement effect. The result of this study can serve as a guide to the greening design in China B-cold region and other regions with similar climatic conditions. [ABSTRACT FROM AUTHOR]

Under the background of global warming, occurrence of heat waves has increased in most part of Europe, Asia and Australia along with enhanced ozone level. In this paper, observational air temperature and surface ozone in the Yangtze River Delta (YRD) region of China during summer of 2013, and the regional chemistry-climate model (RegCM-CHEM4) were applied to explore the relationship between heat wave and elevated ground-level ozone. Observations indicated that YRD experienced severe heat waves with maximum temperature up to 41.1 °C, 6.1 °C higher than the definition of heat wave in China, and can last for as long as 27 days. Maximum ozone reached 160.5 ppb, exceeding the national air quality standard (secondary level) as 74.7 ppb. Moreover, ozone was found to increase at a rate of 4–5 ppb K − 1 within the temperature range of 28–38 °C, but decrease by a rate of − 1.3 ~ − 1.7 ppb K − 1 under extremely high temperature. A typical heat wave case (HW: 24/7–31/7) and non-heat wave case (NHW: 5/6–12/6) were selected to investigate the mechanism between heavy ozone and heat waves. It was found that chemical reactions play the most important role in ozone formation during HW days, which result in 12 ppb ozone enhancement compared to NHW days. Chemical formation of ozone can be influenced by several factors. During heat waves, a more stagnant condition, controlled by anti-cyclone with sink airflow, led to less water vapor in YRD from south and contributed to less cloud cover, which favored a strong solar radiation environment and ozone significantly increasing. High temperature also slightly promote the effect of vertical turbulence and horizontal advection, which beneficial to ozone remove, but the magnitude is much smaller than chemical effect. Our study suggests that the chemical reaction will potentially lead to substantial elevated ozone in a warmer climate, which should be taken into account in future ozone related issues. [ABSTRACT FROM AUTHOR]

Rapid permafrost thawing triggered by heat release from the buried warm-oil pipeline would result in the instability of the pipeline, posing a potential risk of an oil spill in permafrost regions. Therefore, how to precisely control the ground temperature to mitigate pipeline foundation permafrost from thawing is of significant importance. Thermosyphon is a widely-accepted and extensively-used countermeasure against permafrost thawing in permafrost engineering. This paper presents 3-year (2015–2018) monitored data of ground temperature and geophysical survey results conducted by electrical resistivity tomography in April 2018, to investigate the thermal stabilizing effect of thermosyphons installed nearby the China-Russia crude oil pipeline (CRCOP) and the influencing factors. Furthermore, numerical simulation tests were conducted to evaluate their long-term cooling applicability and to optimize their layout parameters. Field observations show that the thermosyphons can cool down and even freeze the thawed soil layers around the CRCOP, prohibiting the infiltration of water into the thawing front to some extent and effectively mitigating the rapid thawing of permafrost beneath the pipeline. The performance of the thermosyphons is greatly influenced by the method and time of thermosyphon installation, as well as layout parameters including the number and longitudinal spacing. Two pairs of thermosyphons with a shorter spacing are unable to control the thawing of the underlying permafrost due to the non-anticipated higher oil temperature, the thermal erosion of water ponding, and climate warming. The simulated results indicate that thermosyphons perform well in the first 5 years after installation. Thermosyphon lowers the mean annual temperature of soils surrounding it by about 2 and 1.4 times when the evaporator section length is increased by 50% and the longitudinal spacing is decreased by 0.5 m, respectively. The application of thermosyphons has proven its strength for thermally stabilizing the pipeline foundation permafrost along the CRCOP. • 3-year ground temperature data and geophysical survey results are presented. • Thermosyphon can mitigate the rapid thawing of permafrost beneath the pipeline. • Thermosyphons performs most significantly in the first five years. • Lengthening thermosyphon and decreasing spacings are favorable for the better cooling effect. [ABSTRACT FROM AUTHOR]

Since coal will be widely used in the next decades, mainly in the developing countries such as China and India, carbon capture and storage (CCS) technologies will have a key role in the containment of global warming. This paper presents a techno-economic comparison between the most promising power generation technologies for a CO 2 -free power generation in a short-term future. In particular, three different power generation technologies have been considered in their conventional (without CCS) and CO 2 -free configurations: (a) ultra supercritical (USC) pulverized coal combustion, (b) oxy-coal combustion (OCC) and (c) integrated gasification combined cycle (IGCC). Process simulation, based on Aspen Plus and Gate Cycle commercial tools, allows to calculate plant performance, including the energy penalty due to the CCS system (10.9% points for USC and 8.7% points for IGCC). In parallel, a detailed economic assessment shows that, among the commercial-ready technologies, USC could be the most convenient solution for power generation without CCS (presenting a levelized cost of electricity – LCOE – of 38.6 €/MW h, significantly lower than 43.7 €/MW h of IGCC), whereas IGCC becomes competitive for CO 2 -free systems (with a LCOE of 59.6 €/MW h, to be compared with 63.4 €/MW h of USC). Moreover, oxy-coal combustion, which is currently not mature enough for commercial-scale applications, promises to become strongly competitive for CCS applications due to its relatively low levelized cost of electricity (62.8 €/MW h). This kind of analysis typically presents strong uncertainties, due to the variability of several key parameters (e.g. fuel and CCS prices, determined by the fluctuation of the international markets, or an improvement of the technologies). Therefore, a sensitivity analysis has been done to determine the effects of these potential fluctuation or the improvement on the economic performance of the plant. [ABSTRACT FROM AUTHOR]

The Ordovician-Silurian (O S) transition witnessed dramatic tectonic, climatic, marine, and biological coevolution, during which organic-rich black shale was widely deposited and is considered an important source rock. However, the potential links between the differential enrichment pattern of organic matter and climate fluctuations and paleoenvironmental evolution during this period are still unclear. In this paper, the Late Ordovician-early Silurian black shale in a JieLong (JL) section in South China was identified by graptolitic fossils, total organic carbon (TOC) content, X-ray diffraction (XRD), scanning electron microscopy (SEM) and geochemical analysis. The results show that the provenances of sedimentary rocks are all granodiorite-like. According to the variations in the TOC content and geochemical indicators, four layers are delineated. Under warm and humid climatic conditions, sea level rise and unstable seasonal upwelling led to Unit 1 organic matter enrichment controlled by high primary productivity, anoxic conditions and effective smectite production. Unit 2 organic matter burial was controlled by cold, arid and oxic environmental conditions, but primary productivity was still relatively high. After the end of the glacial period, warm and humid climatic conditions and rapid transgression were the main factors affecting the burial of organic matter in Unit 3. Under hot and humid climate conditions, higher terrigenous detrital inputs and unfavourable preservation environments, the dilution of organic matter in Unit 4 was accelerated. The corrected chemical index of alteration (CIA corr) values show that the study area experienced a climate change of alternating cold and warm conditions in response to the climate fluctuation during the glacial-interglacial period. The CIA corr value is negatively correlated with the TOC content, while the generation of available clay minerals (smectite) in warm and humid climates is usually consistent with the enhanced burial flux of organic matter, supporting the important role of climate fluctuations in the accumulation of organic matter. Finally, a comparison of the data from the present study with geochemical data from different profiles in South China reveals the role of climatic fluctuations during the O S transition in controlling paleoenvironmental evolution and organic matter enrichment, while such a heterogeneous factor is usually associated with global or regional geological events. Our study highlights this differential enrichment mechanism as a combined response of multiple factors and provides important implications for glacial-interglacial organic matter enrichment mechanisms. • Rapid changes of weathering indices imply climatic fluctuations during the Late Ordovician-Early Silurian. • Four different patterns were established for organic matter accumulation across the O/S. • Climate fluctuations and the heterogeneity nature of ocean systems explain the regional variations of OM accumulation. [ABSTRACT FROM AUTHOR]

Methane (CH 4 ), the second largest greenhouse gas emitted in China, hasn’t been given enough attention in the country’s policies and actions for addressing climate change. This paper aims to perform a bottom-up estimation and multi-regional input–output analysis for China’s anthropogenic CH 4 emissions from both production-based and consumption-based insights. As the world’s largest CH 4 emitter, China’s total anthropogenic CH 4 emissions in 2010 are estimated at 44.3 Tg and correspond to 1507.9 Mt CO 2 -eq by the lower global warming potential factor of 34. Energy activities as the largest contributor hold about half of the national total emissions, mainly from coal mining. Inherent economic driving factors covering consumption, investment and international exports play an important role in determining regional CH 4 emission inventories. Interregional transfers of embodied emissions via domestic trade are equivalent to half of the national total emissions from domestic production, of which two thirds are energy-related embodied emissions. Most central and western regions as net interregional CH 4 exporters such as Shanxi and Inner Mongolia have higher direct emissions, while the eastern coastal regions as net interregional importers such as Guangdong and Jiangsu always have larger embodied emissions. Since China’s CH 4 emissions have significant contributions to global climate change, a national comprehensive action plan to reduce CH 4 emissions should be designed by considering supply-side and demand-side emission characteristics, mitigation potentials and emission responsibilities. [ABSTRACT FROM AUTHOR]

Recently, comprehensive attention has been attracted to global warming. Meanwhile, China is a country with huge energy consumption and greenhouse gas emission. Therefore, it is urgent for China to reduce the air pollutants embodied in each unit of a good for a less greenhouse gas earth. In this paper, air pollutants embodied in goods consumption as well as import-export trade in China was accounted in 1995–2009. Besides, we checked the structural decomposition analysis of emissions' variation. The results showed: (1) in 1995–2009, air pollutants embodied in goods for consumption and import-export trade in China displayed a rising trend. Emission of carbon dioxide was the largest and methane, carbon monoxide, sulphur oxides, non-methane volatile organic compounds, nitrogen oxides, ammonia, nitrous oxide were in proper sequence based at the average level. (2) Air pollutants embodied in goods exported were larger than those in imported and difference among nations existed. (3) The percentages of carbon dioxide, methane, nitrogen oxides, sulphur oxides, carbon monoxide, non-methane volatile organic compounds embodied in Construction were larger than in other departments on the consumption side, while percentages of carbon dioxide, nitrogen oxides, sulphur oxides, carbon monoxide, non-methane volatile organic compounds embodied in Electrical and Optical Equipment was bigger on the trade side. (4) Emission reduction techniques reduced air pollutants embodied in goods consumption and import and export trade in China. Consequently, China ought to pay attention to emission reduction of carbon dioxide and raise awareness of air pollutants controlling, especially in Construction, Electrical and Optical Equipment and other departments. More importantly, China ought to strengthen cooperation with other nations in emission reduction and developing technologies so as to cut down air pollutants, not only for China but also for the earth. [ABSTRACT FROM AUTHOR]

The reserves and exploitable capacity of the wind power resource in China are both ranked first in the world and could be developed to strengthen China’s energy security and mitigate global warming. Carbon footprint accounting of wind farms is vital for large-scale wind energy exploitation. This paper establishes a systematic accounting framework with life cycle assessment (LCA) and input–output analysis (IOA) for the overall carbon footprint of the life cycle of a typical wind farm. Carbon emissions from the construction, operation, and dismantling phases are considered in the LCA of the wind farm. Then, each expense of the wind farm is treated as a change in exogenous demand for the output of the corresponding economic sectors according to the IOA. In addition, the virtual carbon footprint from peak regulation triggered by the on-grid fluctuation of wind power is incorporated. The results show the total carbon footprint of the studied wind farm is 1.45 × 10 4 tCO 2 over the 21-year lifetime. The construction phase accounts for the largest fraction (76.74%), followed by the operation phase (15.32%) and dismantling phase (7.94%). According to the IOA, the indirect carbon footprint of the wind farm is greater than the direct footprint. The “Smelting and Pressing of Metals” sector that produces the steel and copper used to manufacture the wind turbines dominates the carbon footprint. The virtual carbon footprint of coal-fired power for wind power peak regulation is estimated to be 2.08 × 10 3 tCO 2 , which is close to that of the operation phase. [ABSTRACT FROM AUTHOR]

To cope with global warming, China has promulgated Enhanced actions on climate change : China ’ s intended nationally determined contributions and will start the national carbon emissions trading market in 2017. Carbon emissions are distributed by the form of free quota and paid quota. However, few literatures have focused on how the economy and the environment would be changed by the change of free quota ratio. This paper establishes the 10 scenarios of different free quota ratio of carbon emissions rights and uses a dynamic, recursive computable general equilibrium (CGE) model to simulate the carbon emissions trading market, to explore the relationship between free quota ratio and carbon trading price, and the impact of carbon trading scheme (ETS) on China’s economy and environment. The results show that free quota ratio will not have a direct impact on gross domestic product (GDP) and other economic and environment indicators but carbon trading prices. The prices and the rate of free payment in the current pilot cities in China are still relatively conservative. It is possible to reach emission peak, 8.21 billion ton, in 2025 and accumulative CO 2 reduction from 2017 to 2030 is 20.02 billion tons, or 59.60% of 2010 world’s total CO 2 emission. Cement, minerals, electricity and nonferrous metals under ETS will suffer great losses, so subsidy should be considered. Finally, we suggested that China should reduce the total carbon rights to increase the carbon price in 2017, and gradually reducing the proportion of free quota, from 90% in 2017 to 50% or less in 2030, by which the peak year of CO 2 emission can meet in 2025. We also suggest that ETS is an effective strategy for CO 2 reduction and the ratio should be gradually reduced in ETS to prevent violent fluctuation of carbon price in China. [ABSTRACT FROM AUTHOR]

Droughts resulting from global warming severely hamper the healthy development of terrestrial vegetation ecosystems. This paper defines a terrestrial vegetation ecological drought index, i.e., the Standardized Water Supply–Demand Index (SSDI), based on the water balance method using the same calculation model as the SPEI. The theory of run is used to analyze the spatial and temporal distribution of the drought characteristics in the Yangtze River Basin (YRB). The results show that (1) the drought events monitored by the SSDI were in good agreement with historical drought events, and the correlation coefficient between SSDI and NDVI (0.94) was significantly higher than that between SPEI and NDVI (0.88). (2) About 55.4% of the regions in the YRB experienced more than 13 droughts, and about 41.4% of the regions had an average drought duration of more than 3.1 months. In the northern part of the YRB, droughts tend to develop in a short-term high frequency, while in the southern part of the YRB, there is a long-term low-frequency development trend. Nearly 24.5% of the regions have an average drought intensity of more than 1.4, and most of them are located in the lower reaches of the Yangtze River. (3) Over the last 18 years, about 79.5% of the regions in the YRB showed an increasing trend in SSDI, of which 36.8% showed an increasing trend of more than 0.04/yr. In addition, 40.4% of the regions showed a significant upward trend. Precisely analyzing the spatiotemporal variation of drought characteristics in the YRB is critical for drought risk assessment and sustainable development of water resources and could provide a theoretical basis for effective water resource allocation and drought relief. • A new drought monitoring index, i.e., the Standardized Water Supply–Demand Index (SSDI) was defined. • SSDI can effectively monitor drought events. • SSDI is more suitable for monitoring ecological drought. • Drought of vegetation ecosystem in the Yangtze River Basin was assessed and analyzed with the SSDI. • It provides a theoretical basis for drought management and water allocation in the Yangtze River Basin. [ABSTRACT FROM AUTHOR]

This paper examines the extent and the determinants of global climate change beliefs. In contrast to former studies for the U.S. and other western countries, we focus on China due to its crucial role in international climate policy in conjunction with its vulnerability to global warming. The empirical analysis is based on unique data from a survey among more than 1000 adults in five Chinese cities. In line with former studies, our results reveal that the vast majority of almost 90% of the Chinese respondents believes in the existence of global warming. This seems to be a convenient and necessary basis for the support of costly public adaptation activities in China. Our econometric analysis reveals that already perceived experiences with extreme weather events (and particularly heatwaves) alone are strongly correlated with climate change beliefs and that physical or financial damages due to these events lead to even stronger relationships. Our estimation results additionally suggest females as well as people with a lower education, in medium ages, with higher household incomes, and from Chengdu or Shenyang to be more skeptical toward the existence of climate change. [ABSTRACT FROM AUTHOR]

Fire activity in boreal forests will substantially increase with prolonged growing seasons under a warming climate. This trend poses challenges to managing fires in boreal forest landscapes. A fire environment zone map offers a basis for evaluating these fire-related problems and designing more effective fire management plans to improve the allocation of management resources across a landscape. Toward that goal, we identified three fire environment zones across boreal forest landscapes in northeastern China using analytical methods to identify spatial clustering of the environmental variables of climate, vegetation, topography, and human activity. The three fire environment zones were found to be in strong agreement with the spatial distributions of the historical fire data (occurrence, size, and frequency) for 1966–2005. This paper discusses how the resulting fire environment zone map can be used to guide forest fire management and fire regime prediction. [ABSTRACT FROM AUTHOR]

Environmental protection and climate change have become one of the most important issues of great concern. Consequently, improving energy efficiency and developing renewable energy have also become the fundamental energy policies of all countries around the world. China has put forward the ambitious goal to speed up the construction of the resource conserving and environmentally friendly society. In Copenhagen Global Warming Summit, held in November 2009, China made a solemn commitment: by 2020, the CO 2 emissions per unit of GDP (i.e. carbon intensity) will decrease by 40% to 45% compared with that in 2005. Therefore, increasing energy efficiency, reducing energy consumption and protecting environment will undoubtedly become the urgent task in China, hence energy saving and emission reduction prove to be the developing trend. The Energy Saving Power Generation Dispatching (ESPGD) Measures (trial) printed by National Development and Reform Commission (NDRC) was required to carry out energy saving power generation dispatching, so as to maximize the environmental benefits which the renewable energy and other clean energy create, minimize the energy consumption and pollutant emissions, and promote the secure, efficient and clean electric power system. The implementation of ESPGD is facing enormous challenges both in technology and in regulations. How to realize the balance among energy conservation, environmental protection and economic efficiency under the premise of secure and stable system operation, and how to promote the effective implementation through the policy measures, are the key problems to be resolved urgently for China to thoroughly carry out ESPGD. This paper introduces the concept of ESPGD, elaborates the influences of ESPGD on the entire electric power industry, discusses the situation and comparison of ESPGD in the pilot provinces, and puts forward technical and policy suggestions for the effective implementation of ESPGD. [ABSTRACT FROM AUTHOR]

Since carbon emissions are considered to contribute the lion's share in global warming, extensive studies have been devoted to measuring the carbon emissions abatement cost in various ways. This paper derives the shadow prices of China's aggregate carbon emissions at provincial levels by using directional output distance function and Shephard output distance function. The empirical results indicate that the shadow prices estimated by the directional distance function with directional vector of (1,−1) are significantly higher than those estimated by Shephard distance function, which implies that the green production technology is very expensive for the developing country of China. In addition, the shadow prices of carbon emissions present a rising trend during the sample period, which implies that it is increasingly costly for China to regulate CO 2 emissions. Moreover, the shadow price is positively correlated with regional economic development levels. Generally, the shadow price of the high income regions is significantly bigger than that of low income regions. Therefore, China should promote regional scheme of carbon emissions reduction, such as regional carbon emissions trading scheme, to fulfill its ambitious target of carbon emissions reductions. [ABSTRACT FROM AUTHOR]