Search

To motivate public participation in climate change mitigation, both "carrot" policies that create positive incentives for mitigated carbon and "stick" policies that create negative incentives for emitted carbon have been widely applied. Given the joint deployment of these measures, a key question is whether they are compatible with each other. Focusing on the Low-Carbon Reward Scheme (LCRS) and carbon taxes, two prominent proposals on China's climate policy agenda, this study evaluates how one incentive policy affects public support for the other. The results of a large survey experiment with Hangzhou residents indicate a two-way crowding-out effect, wherein introducing the LCRS diminished support for the tax, albeit primarily among LCRS proponents, and introducing the tax reduced support for the LCRS. Aligning with the proposed account, crowding out was driven by a decrease in policy effectiveness and fairness perceptions. These findings reveal a contradictory relationship between carrot and stick policies at the citizen level and illuminate the underlying mechanism. • Both carrot and stick policies are applied to motivate climate mitigation behaviors. • We identify a two-way crowding-out effect between these policies in public opinion. • Introducing a stick (carbon tax) reduces support for a carrot (low-carbon reward). • Introducing a carrot reduces support for a stick among people favoring the carrot. • Crowding out is driven by weakened policy effectiveness and fairness perceptions. [ABSTRACT FROM AUTHOR]

Cities face twin challenges of changing climate and urban heat island (UHI) effect, with the environmental implications of urbanization still unclear. This study employs the Weather Research and Forecasting (WRF) model to examine the impacts of urbanization in the Greater Bay Area (GBA) during warm and cold seasons in past (2000) and near-future (2030) scenarios [i.e., under shared socioeconomic pathways (SSP): SSP1-26, SSP2-45, and SSP5-85]. Datasets from the World Urban Database and Access Portal Tools (WUDAPT) were incorporated into the WRF model to improve the representation of urbanization effects on weather patterns. Our findings indicate that urban expansion significantly increases urban temperatures and decreases wind speed across selected climate change scenarios. The spatially averaged urban temperatures in the fine resolution domain for 2030 could rise by 0.9 °C (warm season) and 2.4 °C (cold season), respectively, and urban wind speed decreases by ∼ 3 m/s under the SSP5-85 scenario. In cold season, the UHI effect could last over 20 h, while urban area may experience cooler nighttime temperatures than rural areas in warm season. Moreover, the future scenario predicts higher daytime O 3 levels due to the warming effects of climate change and urbanization, but lower nighttime levels in warm season, attributed to intensified south-easterly sea breeze and background winds, when compared to the past scenario. This study highlights the importance of incorporating urbanization and climate change in future urban atmospheric environment studies, and underscores that urban climate change adaptation and mitigation should consider extra impacts on built-environment caused by urbanization. • Climate change and urbanization impacts on meteorological and O 3 fields were explored in GBA. • Urbanization and climate change are expected to raised temperatures by 0.9 °C in warm season over the study area. • Urbanization and climate change are expected to raised temperatures by 2.4 °C in cold season over the study area. • Urbanization is expected to reduce wind speed by 3 m/s and intensify sea breeze penetration over the study area. [ABSTRACT FROM AUTHOR]

Carbon neutrality strategies have a significant role in climate mitigation efforts. As global concerns regarding climate change continue to increase, achieving carbon neutrality has emerged as a paramount objective for reducing greenhouse gas emissions and limiting the adverse impacts of anthropogenic activities on the environment. This research investigates a wide range of scholarly works to conduct an in-depth analysis and synthesis of the relevant information about carbon neutrality strategies. The review introduces carbon neutrality principles and terminologies, highlighting their importance in climate mitigation. It then proceeds to explore the wide range of strategies employed across different sectors and industries, investigating their effectiveness, scalability, and potential challenges. A multidimensional analysis contrasts the United States Nationally Determined Contributions pathway 2023, China's Nationally Determined contributions 2023, and the EU Directive 2023/2413, assessing their economic, environmental, political, and social impacts. The study evaluates strategies' effectiveness, scalability, and innovation for transitioning to a sustainable, low-carbon future. It fills a gap by analyzing global approaches across the US, China, and the EU, which account for about 50% of the world's total GHG emissions. It evaluates the novel application of diverse strategies, from renewable energy transitions to innovative policy measures, highlighting their potential to mitigate climate change effectively. By providing a multidimensional analysis of these strategies' impacts, the research not only enhances understanding of effective carbon neutrality tactics but also underscores the importance of international cooperation in realizing a sustainable, low-carbon future. • Identifies and analyzes carbon neutrality strategies, emphasizing the need for diverse US, Chinese, and EU approaches. • Evaluate renewable energy, carbon capture, and policy tools for carbon reduction effectiveness, scalability, and innovation. • Highlights the study's novelty in synthesizing current knowledge on carbon neutrality, addressing a significant research gap. • Concludes with strategic ideas for international collaboration and policy development for low-carbon futures. [ABSTRACT FROM AUTHOR]

China has made substantial investment in agricultural research and development (R&D) to promote technological change (TC). Although the role of TC in enhancing agricultural production and mitigating environmental impacts is widely recognized in separate contexts, knowledge about its' effects on food security and the environment, especially with a focus on China, is still lacking. This study uses an agro-economic optimization model to assess the impact of TC on food security and climate change mitigation. Our results indicate that TC plays an important role in improving agricultural productivity, which, in turn, contributes to a comparative advantage in agricultural trade. It also strengthens food security through lowering food prices. By contrast, a higher TC level increases greenhouse gas (GHG) emissions, albeit marginally, due to higher agricultural production for exports. This indicates a rebound effect of agricultural productivity on GHG emissions. Therefore, additional efforts are required in China to improve food security without compromising GHG mitigation. • Technological change (TC) enhances China's agricultural production and comparative advantage in trade. • A higher level of TC within China's agriculture and land-use (AFOLU) sectors could contribute to lowering food prices in China. • Increase in TC within China's AFOLU sectors can causes trade-offs between food security and climate change mitigation. [ABSTRACT FROM AUTHOR]

[Display omitted] China is playing an increasing role in global climate change mitigation, and local authorities need more city-specific information on the emissions trends and patterns when designing low-carbon policies. This study provides the most comprehensive CO 2 emission inventories of 287 Chinese cities from 2001 to 2019. The emission inventories are compiled for 47 economic sectors and include energy-related emissions for 17 types of fossil fuels and process-related emissions from cement production. We further investigate the state of the emission peak in each city and reveal hidden driving forces. The results show that 38 cities have proactively peaked their emissions for at least five years and another 21 cities also have emission decline, but passively. The 38 proactively peaked cities achieved emission decline mainly by efficiency improvements and structural changes in energy use, while the 21 passively emission declined cities reduced emissions at the cost of economic recession or population loss. We propose that those passively emission declined cities need to face up to the reasons that caused the emission to decline, and fully exploit the opportunities provided by industrial innovation and green investment brought by low-carbon targets to achieve economic recovery and carbon mitigation goals. Proactively peaked cities need to seek strategies to maintain the downward trend in emissions and avoid an emission rebound and thus provide successful models for cities with still growing emissions to achieve an emission peak. [ABSTRACT FROM AUTHOR]

Natural climate solutions (NCS) offer immediate and cost-effective ways to tackle the climate crisis by transforming atmospheric carbon to soil carbon or avoiding greenhouse gas emissions. However, the climate mitigation potential and economic costs of NCS for cropping systems in China remain inconclusive. The major objectives of this study are (i) to estimate the NGHG reduction potential across Chinese main cropping systems caused by NCS, (ii) to quantify the economic costs of adopting optimal management with different abatement potentials. The Denitrification-Decomposition (DNDC) model was used to estimate the NGHG, including SOC sequestration, N 2 O emissions, and CH 4 emissions. After calibration, we ran the DNDC model with derived data at municipality-level. We estimated the NGHG under current management, adopting optimal management individually, and integrated optimal management to project the maximum NGHG reduction potential caused by NCS. We used the marginal abatement cost method to estimate the economic cost. The four natural climate solutions, N fertilization management (NFM), straw returning management (SRM), tillage management (TM), and rice irrigation management (RIM) can reduce national NGHG in main cropping systems by approximately 118.8 Tg CO 2 -eq, 116.3 Tg CO 2 -eq, 35.2 Tg CO 2 -eq, and 74.4 Tg CO 2 -eq, respectively. The integrated optimal management may potentially reduce NGHG by 256.9 Tg CO 2 -eq, equivalent to 90.2% of current NGHG, and 80% of which can be realized at the price of CN¥ 285 (Mg CO 2 -eq)−1. We further identify the priority NCS for different crops and regions and conclude that nitrogen fertilization management should be the priority NCS at the national level. Our findings highlight the great potential of NGHG reduction by adopting NCS precisely and the importance of optimizing agricultural management as a whole, and they will help policy makers to develop smart-agriculture in China. [Display omitted] • Estimating net greenhouse gas emissions (NGHG) reduction potentials of agriculture. • IPCC recommended tier 3 method was applied for seven cropping systems in China. • The integrated optimal management may potentially reduce NGHG by 256.9 Tg CO 2 -eq. • 80% of NGHG mitigation can be realized at the price of CN¥ 285 (Mg CO 2 -eq)−1. • The priority NCS was identified for different crops and regions. [ABSTRACT FROM AUTHOR]

Planning power system (PS) towards renewable energy is crucial for reducing carbon dioxide (CO 2) emission as well as mitigating climate change. However, the inherent uncertainty and hierarchical structure of PS pose intractable challenges to the planning process. This study develops a multi-GCM-based interval bi-level programming (MIBP) method that can balance two-level decision-making conflict between CO 2 -emisison reduction and system cost minimization. MIBP can also deal with uncertainties expressed as interval values in objective functions and constraints. Then, a MIBP-PS model is formulated to plan PS for China (2021–2050), where the upper-level objective is to minimize CO 2 emission and the lower-level objective is to minimize the system cost. The major findings are: (i) the CO 2 emission for PS would reach peak value before 2030 and then reduce by [10.2, 20.4]% in 2050, which is mainly owing to the curtailment of fossil fuel; (ii) compared with the conventional model, CO 2 emission from MIBP-PS model could decrease by [3.1, 4.8]%, which shows the superiority of the developed model; (iii) the fossil-fuel power would be gradually replaced by renewable energy, and the proportion of coal-fired power would decrease by 38.8% by 2050, especially small coal-fired facilities (i.e., below 0.3 GW) should be gradually phased down. [Display omitted] [ABSTRACT FROM AUTHOR]

• Implementation costs are a more relevant constraint to afforestation than opportunity costs. • Financial incentives for afforestation are constrained by market access and market prices. • Carbon-neutral and food multi-oriented land policies need further exploration. • Collaboration among global carbon markets can enhance CO 2 removal efficiency. Afforestation is a promising nature-based climate solution for mitigating climate change, but it is subject to a complex web of biophysical, cost-benefit, market, and policy processes. Although its biophysical feasibility has been established, the cost, market, and policy constraints that affect climate change mitigation through afforestation are still unclear. Here, we estimate such cost, market, and policy constraints on the basis of biophysical feasibility. Our findings reveal that implementation costs are a more relevant constraint than opportunity costs on mitigating climate change through afforestation. The China Certified Emission Reduction market currently provides only a 0.308 % incentive for climate change mitigation through afforestation, due to market access constraints. The current market prices of China Certified Emission Reduction, China Carbon Emissions Trading Exchange, and Nature Based Carbon Offset in Voluntary Carbon Market constrain 88.15 %, 87.95 %, and 85.75 % of CO 2 removal actions through afforestation, compared to the carbon price scenario (US$62.97 tCO 2 -1) of the EU Emissions Trading System. Moreover, land policy under the scenarios of prohibiting conversion of cultivated land to forest and forest restoration in degraded areas exhibit 8.87–29.59 % and 65.16–74.10 % constraints, respectively, on mitigating climate change through afforestation compared to land-use freedom conversion scenarios from 2020 to 2060. Thus, enhancing the incentive price of CO 2 removal, addressing the market access barrier, strengthening cooperation between global carbon markets, and exploring carbon–neutral and food multi-oriented land policies can be valuable sources of mitigation efforts over the next 40 years. [ABSTRACT FROM AUTHOR]

The remarkable economic growth of China over recent decades has been accompanied by significant achievements in poverty reduction. However, this growth has also led to increased resource consumption and greenhouse gas (GHG) emissions. It's now evident that addressing the triple challenges of climate change, biodiversity loss, and pollution hinges in part on China's capacity to curtail its resource use and emissions. Our study utilises an integrated economic modelling framework to assess China's role in the global context. We evaluate ambitious policies in resource efficiency, GHG reduction, and land-use transformation within China. Our findings indicate that, under such ambitious policies, China could likely achieve peak material use and emissions by 2030 and attain net zero emissions by 2050. Moreover, our analysis underscores that China can play a pivotal role in helping achieve global climate goals in collaboration with the rest of the world. Implementing well-designed policies, including the adoption of a circular economy approach, might enable China to meet these environmental targets with minimised economic costs. [Display omitted] [ABSTRACT FROM AUTHOR]

• A CGE model elaborately depicting six CCS technologies was developed. • Impacts of four CCS incentive scenarios on decarbonization pathways were simulated. • CCS can sequester 960 ∼ 1,604 MtCO 2 annually in China by 2060 with policy incentives. • CCS incentives can reduce China's future primary energy demand by 7.7 ∼ 17.4 %. • CCS incentives can increase GDP by 5.64 ∼ 6.59 % compared to no policy scenario. Carbon capture and storage (CCS) technology, considered as a pivotal tool in mitigating climate change within the fossil energy system, particularly in China, has experienced slower development than expected. The exploration of direct incentive policies to facilitate its growth remains relatively underdeveloped. This study developed a hybrid dynamic computable general equilibrium (CGE) model to simulate the substantial impacts of CCS incentive policies on China within the context of carbon neutrality target. Two potential incentive policies, carbon emission trading system (ETS) and 45Q tax credit, were simulated, with different sectoral coverage. The results indicate that CCS technologies can reduce carbon emissions by 960 ∼ 1,604 MtCO 2 annually by 2060 through the strategic implementation of these incentive policies. The 45Q tax credit demonstrates its effectiveness in promoting early-stage research and development (R&D) and demonstration of CCS, while the ETS policy facilitates the commercial development of CCS in the later stage of development. By 2060, the implementation of CCS incentive policies could potentially result in 7.7 ∼ 17.4 % reduction in China's primary energy consumption, 71.2 ∼ 82.7 % decrease in the carbon price of ETS and 5.64 ∼ 6.59 % increase in the GDP compared with the no-policy scenario. In addition, the sectoral output in various sectors and the welfare of urban and rural households also increase. This paper provides an important reference for the realization of China's carbon neutrality goal and the model framework can be applied to other countries. [ABSTRACT FROM AUTHOR]

Carbon emission reduction in China matters to global climate change mitigation. China has been experiencing extensive land changes, which profoundly influence terrestrial ecosystem carbon storage (TECS) and carbon emissions. Scholars have predicted influences of land changes on TECS in China with scenarios obtained from global integrated assessment models (IAMs), which lack national details. Moreover, universally existing variations in land-use intensity have not been considered when estimating influences on TECS. This study simulated changes of land-use intensity of China from 2000 to 2050 using CLUMondo under China-specified policies for sustainable development modeled by a national IAM named Threshold21-China. We proposed a more precise TECS estimation method by distinguishing land-vegetation and land-soil types. Results demonstrated that under scenario with preceding policies, the total TECS can increase by 865.5 Tg C from 2000 to 2050. Through implementing preceding policies, TECS loss by conversions from cultivated land to artificial surfaces can decline by 82 Tg C, and new TECS accumulated by increased and densified forests can increase by 73 Tg C. Mountainous and rapidly urbanizing regions are sensitively influenced and need more restrict land change management policies. This study demonstrates the significance of sustainable development policies for TECS conservation and indicates specific critical regions. • Introducing national IAM into land change simulation. • Considering land-use intensities in land change simulation. • Proposing an improved TECS estimation method. • Estimating influences of land changes on China's TECS. • TECS accumulation could be improved under sustainable policies. [ABSTRACT FROM AUTHOR]

Micro-level concerns about climate change can not only affect individual low-carbon behaviors but also exert intense pressure on carbon emission reduction strategies and policy design. However, whether public concern about climate change can affect per capita carbon emission is still unclear. Based on panel data from 30 provinces in China and 188,943 climate change-related blogs from 2012 to 2019, this research investigates the impact of public concern on per capita carbon emissions. Results show that, in general, public concern about climate change has a significant negative impact on per capita carbon emissions in China, indicating that climate crisis awareness has a supervisory effect on greenhouse gas emissions. Nevertheless, the effects of different public concerns on per capita carbon emissions are different, with the topics of "low-carbon appeal" and "concern for future" have significant positive impacts on per capita carbon emissions, while the topics of "carbon governance performance" and "climate change mitigation strategies" have significant negative impacts on per capita carbon emissions. The findings yield new opportunities to delve into the relationship between the externality of people's will and governmental behaviors and provide in-depth insights for decision-makers to develop tailor-made solutions towards carbon reduction and sustainable development. [Display omitted] [ABSTRACT FROM AUTHOR]

• Forest residues, a renewable energy, have great potential to substitute fossil fuels to reduce enormous pressures of energy shortages in mitigating climate change. However, it is a challenge to quantify forest residues at a fine spatial scale due to large spatial variations of forest species and lacking of suitable research methods. In addition, the natural decomposition of forest residue is often ignored in future greenhouse emission prediction, • We estimated the total forest residues in China reached 152.13 million t in 2018. The forest residues had faster decomposition rate (annual natural decomposition value of carbon from forest residues) in the first ten years, and then gradually decreased. In the first 14 years, the half forest residues was decomposed. The national contribution to climate change (CCC) from forest residues over one-hundred-year reached 49.27 million t CO 2 eq. The peak values of the provincial annual CCC were reached within 15 years and we found that the highest annual CCC occurred in the second year since the natural decomposition. • There are two major contents. First, a method is put forward to downscale the reserve of forest residue to county-level administrative unit. Prior to this, the resolution of the estimations was generally at provincial level. Obviously, more refined data was conducive to encourage the utilization of biomass by providing references for policymakers and investors. Second, a new index was implemented to assess the contribution of the natural decomposition of unused forest residues to climate change. • We estimated that CCC caused by their natural decomposition reaches 4.927 million t CO 2 eq, which was 0.96%−6.5% of other carbon emission sources (i.e. staple crops, inland water) in China. From a global perspective, such carbon emission was 0.015% of global wetland carbon emissions and 1.59% of global peat land carbon emissions. • Our study provides new data to support future climate mitigation, reducing the significant uncertainty in related research, and will make researchers, policymakers, and investors recognize the great potential of forest residues as an energy source and the significant contribution of their natural decomposition to climate change and promote carbon neutrality transition. Under the energy shortage and emerging climate change caused by fossil energy, forest residues were encouraged to be used as an energy resource. However, it is a challenge to quantify the forest residue at the fine spatial scale due to the available data and suitable research methods. We aimed to quantify the available forest residues in China at the county scale and clarify their potential contribution to climate change (CCC). The availability of forest residues reached 152.13 million t in 2018 in China. The CCC accumulated by natural decomposition of forest residues over one-hundred-year had reached 49.27 million tCO 2 eq. The peak values of provincial annual CCC were reached in the first 3 years in the southern region. The top four counties of CCC were all from Yunnan Province. The energy utilization of forest residues is of great significance to the management of forest resources. [Display omitted] [ABSTRACT FROM AUTHOR]

Climate change is related to human well-being and the health of the planet. Education is a critical component of global action to mitigate climate change, and young people are future citizens in the fight against climate change. This article discusses the factors that affect adolescents' willingness to continue participating in climate change governance actions. First, based on an expansion of the Theory of Planned Behavior (TPB), the article conducts partial least square-structural equation modeling (PLS-SEM) analysis on the data collected before adolescents participate in climate change education courses and clarifies the factors that significantly impact adolescents' behavioral willingness to participate in climate change governance actions. The results showed that emotions (EMO, β = 0.323) had the most significant effect on the willingness to engage in social good (SG) behaviors, followed by attitudes toward environmental protection (ATEP, β = 0.198) and pro-natural emotion (PNE, β = 0.123). Secondly, the researchers devised an exploratory climate change education curriculum and validated its efficacy through empirical research. The single group comparison of before and after lessons results shows that the exploratory climate change education curriculum can improve the scores of the nine measured factors. Higher effect sizes for attitudes toward environmental protection, confidence in protecting the environment, and pro-natural emotion. This study provides a reference theoretical framework and curriculum model for developing climate change education courses. Effective climate change education courses are crucial in improving youth climate literacy and guiding them to respond scientifically to climate change. [Display omitted] • Expand TPB and evaluate the factors that affect adolescents' willingness to participate in climate change behaviors. • The regional dimension difference analysis is carried out on Chinese adolescents' perception of climate change. • It has provided an effective educational model for advancing climate change education in developing countries. [ABSTRACT FROM AUTHOR]

• We quantified wood substitution benefits in the furniture sector for China. • Displacement factor is used to assess substitution effects on emission reduction. • The avoided emissions for the products were weighted by consumption statistics. • Each tC in wood used for material substitution reduces 1.46 tC of emissions. Wood and wood-based products have positive effects on climate change mitigation. These products can substitute for energy-intensive products made of conventional materials. The main objective of this study was to quantify substitution benefits of wood furniture for China via national-scale mitigation analyses. We selected a basket of representative furniture and estimated the emission reduction for two functionally equivalent products, which differentiate in wood intensity. The emissions avoided in each type of product were weighted by its share of the furniture market to ensure that the basket can represent the current situation. Then, avoided emissions were estimated for wood commodities contained in the products basket. Results demonstrated that wood materials exerted low environmental impacts. From the less to the more wood intensity products with the equivalent function, the proportion of energy-intensive materials decreased 24% while the proportion of their greenhouse gas (GHG) emissions decreased 34%. The overall displacement factor for the wood material was 2.67 kg CO 2 eq/kg or 1.46 tC/tC. The findings highlight the importance of material selection in mitigating climate change in the furniture sector. It is urgent to use of the existing timber resources efficiently and pursue alternative schemes for emission reduction to achieve the goal of GHG mitigation. [ABSTRACT FROM AUTHOR]

Coastal salt marshes suffering from anthropogenic coastal development and sea level rise have attracted much attention because of their capacity for carbon sequestration and global climate change mitigation. Accurate mapping of coastal salt marshes is always the first step for their protection, management, and restoration. The inherent complexities of vegetation, dynamics of tides, and anthropogenic disturbances pose challenges for remote sensing-based approaches. Existing studies have utilized phenology information and various black-box algorithms to reduce misclassifications. However, the approaches with dual-temporal images containing phenology information have suffered from inefficiency; the misclassifications have been objectively post-processed rather than considered in the method design, and the tacit knowledge of the trained black-box models has not been revealed. To address the above issues, we proposed a new approach with solid improvements in dual-temporal image construction, misclassification processing, and tacit knowledge analysis, including an efficient method to synthesize dual-temporal images based on the common divisor of the green-up season or senescence season resulting from latitudinal gradients in narrow coastal areas of China, a detailed classification scheme by interpretation of iteratively collected samples, and a key decision rule approximating the trained model. We applied the approach to Sentinel-1/2 images and DEM data, thus deriving a 10-m resolution coastal salt marsh map of China with an overall accuracy of 92.5%. A qualitative comparison showed that the map produced in this study was fitted well with actual salt marsh distributions, resulting in improved accuracy when compared to recently generated maps. The most important contribution is that the overall nature of the trained model observed from the training samples was approximated by a four-feature decision rule following the principle of explainable artificial intelligence, i.e., B8 senescence /B4 senescence < 2.06 & B4 green /B8 green < 0.78 & B12 green /B11 green < 0.72 & elevation < 2.13 , and thus established a new potential classification mechanism for dual-temporal black-box algorithms, i.e., the water signal was covered up by flourishing vegetation, but the situation changed when vegetation withered. This study not only generates an accurate coastal salt marsh map at a national scale but also provides a classification mechanism for dual-temporal image-based coastal salt marsh identification and mapping. • Developed an efficient method for constructing senescence and green images. • Established a mechanism for dual-temporal image-based coastal salt marsh mapping. • Provided a coastal salt marsh map with solid improvements on the most recent one. • Explored a case of explainable artificial intelligence (XAI) in the coastal. [ABSTRACT FROM AUTHOR]

• We assessed the climate change impact on wheat production in China. • We employed the FGLS, DOLS, and D–K estimation techniques. • Temperature negatively affected wheat production in the long–run. • Precipitation contributed positively to wheat production in the long-run. • Agro–chemical input (fertilizer use) enhanced wheat production in the long–run. Northern and Southern regions are the two major wheat production belts of China. Agro–climatic resources have changed significantly in recent years, threatening staple food production in these regions. As a result, it is critical to investigate the long–term effect of climate change and agri–inputs on wheat production in China's top six wheat producing provinces (Hebei, Shandong, Henan, Jiangsu, Anhui, and Hubei) from 1995 to 2020. The estimated long-run results from the FGLS, DOLS, and D–K estimators revealed that climatic factors, specifically temperature, had a negative impact on wheat production, while precipitation had a positive impact. The findings also revealed that agrochemical inputs, such as fertilizer, increases wheat production, whereas pesticide use decreases wheat production significantly. The results from the Dumitrescu–Hurlin panel causality test showed a bidirectional causality between rainfall, fertilizer use, and cultivated area with wheat production, while a unidirectional causality association is running from labor force to wheat production. The current study provides several critical policy recommendations for China's sustainable food production through green agricultural practices and robust climate mitigation strategies. [Display omitted] [ABSTRACT FROM AUTHOR]

• Public interest in climate change topics is affected by extreme temperatures. • There is however clear disparity in types of climate knowledge sought by the public. • Due to self-protective reasons, interest is highest for climate adaptation topics. • Extreme temperatures do not induce similar interest on mitigation topics. • Projected climate change will likely cause adaptation to overshadow mitigation. Many earlier studies concluded that exposure to changes in local weather or extreme weather events prompt public interest in climate change, and in turn raise support for mitigation policies. However, these findings do not square with observations of record-breaking temperatures, and decades of failure to reduce greenhouse gas emissions. To address this conundrum, we use Protection Motivation Theory to form hypotheses on the specific type of climate change-related information that individuals seek during periods of extreme local weather. Using daily-level internet search engine data from Chinese cities, we find that residents are purposeful and rational in seeking information on climate change. Specifically, when faced with high or abnormal temperatures, they are much more likely to seek information to appraise their susceptibility to climate change threats, and evaluate coping responses. On the other hand, due to the lack of direct benefits, they do not seek out information on climate mitigation behaviors. In contrast to earlier studies, our findings suggest that it is unlikely that extreme weather events will prompt support for climate mitigation actions. Instead, as worldwide weather becomes more extreme and unpredictable, it is likely that public's attention will shift in the direction of adaptation measures. [ABSTRACT FROM AUTHOR]

Partnerships emerge as part of an environmental governance paradigm shift towards less hierarchical, more collaborative, and non-regulative steering arrangements. This paper examines the prevalence of partnerships in environmental governance on an urban level in a semi-authoritarian setting, by exploring climate initiatives in cities in China. The paper presents exploratory qualitative analysis of governance in urban China through analysis of a database of 150 climate initiatives in 15 cities, which are seen at the forefront of climate protection. The analysis suggests that climate partnerships are used as a governance strategy in China. Moreover, partnerships perform a range of essential governance functions, from rule-setting and provision of public infrastructure and services, to supporting technology development and low carbon demonstration projects. The results indicate that partnerships can facilitate local climate action by creating access to resources, such as information, technology, and funding, as well as contribute to introduction of emission reduction technology and new policy approaches. However, the inclusion of non-state actors in the formulation and delivery of climate mitigation projects redefines the lines of authority over public issues. This draws attention to two key governance challenges in the context of a comparatively state-controlled, top-down political system: skewed participation and lack of deliberative opportunities. [ABSTRACT FROM AUTHOR]

The ambitious goals to limit global warming can only be reached with a broad acceptance and participation of the general public. This paper relies on surveys among citizens in China, Germany and the U.S. and investigates the determinants of the acceptance of national and international adaptation and mitigation efforts. The empirical findings indicate that specific beliefs and environmental awareness are important drivers in all three countries, while political attitudes and socio-economic characteristics are the main sources of cross-country heterogeneity. The study thereby points at important starting points and target groups for raising the acceptance of national and international climate policy. [ABSTRACT FROM AUTHOR]

The grassland ecosystems in Tibetan Plateau (TP) and Inner Mongolia (IM) of China play important roles in climate change mitigation and food and livestock production. These two regions have increasingly experienced higher temperatures and changing precipitation regimes over the past three decades. However, it remains uncertain to what extent rising temperature and varying precipitation regulate the water and carbon fluxes across alpine (TP) and temperate (IM) grasslands. Here, we first optimize a process-based model of carbon and water fluxes using eddy-covariance data (three sites in TP and six sites in IM), and analyze the simulated carbon and water fluxes based upon the optimized model exposed to a range of annual temperature and precipitation anomalies. We found that the changes in net ecosystem-atmosphere carbon exchange (NEE) of TP grassland are relatively small because the ecosystem respiration (R e ) and the gross primary productivity (GPP) increase at comparable rate with warming across multiple sites (R e : 22.1 ± 21.4 g C m −2 year −1 °C −1 , GPP: 22.43 ± 36.41 g C m −2 year −1 °C −1 ), which is due to the possibility that grasslands cannot respire more than the available supply of photosynthesis. The NEE of IM grassland increases (more carbon loss from ecosystem) with warming, which is mainly because GPP decreases faster than R e under warm-induced reduction in moisture availability, and the sensitivity of R e to warming (1.17 ± 3.56 g C m −2 year −1 °C −1 ) is much smaller than that of GPP (15.53 ± 15.91 g C m −2 year −1 °C −1 ). These results indicate that water is the major limiting factor in IM grasslands, but not in TP grasslands. In contrast to warming, we found an asymmetric response of water and carbon fluxes to drying and wetting in TP grasslands (i.e. a large decrease under the drying condition and a small increase under the wetting condition) but almost a linear response in IM grasslands. We therefore highlight that the underlying processes regulating the responses of water and carbon cycles to warming are fundamentally different between TP and IM grasslands, with the moisture being the major limiting factor in IM while grasslands in TP are much more limited by thermal conditions. Our results also imply that warming would significantly stimulate the net ecosystem carbon loss to atmosphere but not significantly enhance ET in IM grasslands, which may provide a positive feedback to accelerate climate change. Inversely, warming could not significantly affect the ecosystem carbon exchange but significantly enhance ET in TP grasslands, which may provide a negative feedback to mitigate climate change in alpine grasslands. [ABSTRACT FROM AUTHOR]

Black carbon mitigation has received increasing attention for its potential contribution to both climate change mitigation and air pollution control. Although different bottom-up models concerned with unit mitigation costs of various technologies allow the assessment of alternative policies for optimized cost-effectiveness, the lack of adequate data often forced many reluctant explicit and implicit assumptions that deviate away from actual situations of rural residential energy consumption in developing countries, where most black carbon emissions occur. To gauge the theory-practice gap in black carbon mitigation – the unit cost differences that lie between what is estimated in the theory and what is practically achieved on the ground – this study conducted an extensive field survey and analysis of nine mitigation technologies in rural China, covering both northern and southern regions with different residential energy consumption patterns. With a special focus on two temporal characteristics of those technologies – lifetimes and annual utilization rates, this study quantitatively measured the unit cost gaps and explain the technical as well as sociopolitical mechanisms behind. Structural and behavioral barriers, which have affected the technologies’ performance, are discussed together with policy implications to narrow those gaps. [ABSTRACT FROM AUTHOR]

Climate change is affecting hydrological variables and consequently is impacting water resources management. Historical strategies are no longer applicable under climate change. Therefore, adaptive management, especially adaptive operating rules for reservoirs, has been developed to mitigate the possible adverse effects of climate change. However, to date, adaptive operating rules are generally based on future projections involving uncertainties under climate change, yet ignoring historical information. To address this, we propose an approach for deriving adaptive operating rules considering both historical information and future projections, namely historical and future operating rules (HAFOR). A robustness index was developed by comparing benefits from HAFOR with benefits from conventional operating rules (COR). For both historical and future streamflow series, maximizations of both average benefits and the robustness index were employed as objectives, and four trade-offs were implemented to solve the multi-objective problem. Based on the integrated objective, the simulation-based optimization method was used to optimize the parameters of HAFOR. Using the Dongwushi Reservoir in China as a case study, HAFOR was demonstrated to be an effective and robust method for developing adaptive operating rules under the uncertain changing environment. Compared with historical or projected future operating rules (HOR or FPOR), HAFOR can reduce the uncertainty and increase the robustness for future projections, especially regarding results of reservoir releases and volumes. HAFOR, therefore, facilitates adaptive management in the context that climate change is difficult to predict accurately. [ABSTRACT FROM AUTHOR]

Understanding future climate change is crucial for securing and managing water supplies necessary for agricultural activities in China, particularly in rainfed agriculture regions. This paper evaluates the projected climate change for nine major agricultural zones in China, using ensembles of regional climate models (RCMs) simulated under the Coordinated Regional Downscaling Experiment-East Asia second phase (CORDEX-EA-II) framework. The simulations were conducted for two climate scenarios (RCP2.6 and RCP8.5) at a 25 km grid spacing, with three RCMs (RegCM4, REMO, and WRF) driven by multiple CMIP5 global climate models (GCMs). The study compares the RCM simulations to the driving CMIP5 and the recent CMIP6 ensembles, focusing on surface temperature, precipitation, and surface relative humidity for the present day (1981–2010), mid-future (2036–2065), and far future (2070–2099) periods. The model evaluations indicate that the GCM and RCM simulations are consistent with observations, with RCMs showing better performance than the driving GCMs. The results show that both GCMs and RCMs project increased temperature and precipitation in most agricultural zones of China in the future, with the CMIP6 ensembles projecting the largest temperature increase and the CORDEX-EA-II ensemble showing the finest spatial details. Relative humidity is projected to decrease over major rice-producing areas of South China in the CORDEX-EA-II, CMIP5, and CMIP6 ensembles. This study provides valuable information to support climate change adaptation and mitigation efforts in China, particularly in the agricultural sectors. • CORDEX-EA-II simulations demonstrate better model performance over China. • Temperature and precipitation are projected to increase in the future. • Relative humidity is projected to decrease over South China. [ABSTRACT FROM AUTHOR]

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

• Urban drainage pressure (UDP) would increase across China from the 2020s to 2090s. • Northern China would see 30% lager UDP since the 2020s under SSP5–8.5 scenario. • Climate mitigation would reduce UDP in more than half of the cities across China. • Low impact development would reduce UDP particularly in northern China. • Pipe enlargement would postpone the occurrence of dangerous UDP in eastern China. High pressure on urban drainage systems caused by extreme precipitation events would lead to an increase risk of urban floods. Across China, future changes in urban drainage pressure (UDP) and its response to global-scale climate mitigation and local adaptation, have seldom been studied. Here, based on climate projections from the Coupled Model Intercomparison Project Phase 6 (CMIP6), we assessed UDP changes from 2020 to 2099 under different scenarios in 285 cities across China. Under the shared socioeconomic pathway (SSP) 5–8.5 scenario, 30% larger increase of UDP relative to the baseline level (1985–2014), would occur in 22.80% and 79.65% cities over 2020–2049 and 2050–2099, respectively. Under climate mitigation (SSP2–4.5 scenario), UDP in northern China would decrease by 10–30% over 2020–2049. On this basis, 10% enhancement of underlying surface retention capacity (LID 10% scenario) would reduce UDP by more than 10% particularly in northern and northeastern China (23.51% cities). Pipe enlargement adaptation (Pipe 10% scenario) would benefit UDP mainly in eastern China (46.31% cities), by postponing the first decade with 30% larger pressure relative to the baseline level by 1-3 decades. [ABSTRACT FROM AUTHOR]

Dietary change presents an opportunity to meet the dual challenges of non-communicable diseases and the effects of climate change in China. Based on a food survey and reviewed data sets, we linked nutrient composition and carbon footprint data by aggregating 1950 types of foods into 28 groups. Nine dietary scenarios for both men and women were modeled based on the current diet and latest National Program for Food and Nutrition. Linear uncertainty optimization was used to produce diets meeting the Chinese Dietary Reference Intakes for adults aged 18–50 years while minimizing carbon footprints. The theoretical optimal diet reduced daily footprints by 46%, but this diet was unrealistic due to limited food diversity. Constrained by acceptability, the optimal diet reduced the daily carbon footprints by 7–28%, from 3495 to 2517–3252 g CO 2 e, for men and by 5–26%, from 3075 to 2280–2917 g CO 2 e, for women. Dietary changes for adults are capable of benefiting China in terms of the considerable footprint reduction of 53–222 Mt. CO 2 e year − 1 , when magnified based on the Chinese population, which is the largest worldwide. Seven of eight scenarios showed that reductions in meat consumption resulted in greater reductions in greenhouse gas emissions. However, dramatic reductions in meat consumption may produce smaller reductions in emissions, as the consumption of other ingredients increases to compensate for the nutrients in meat. A trade-off between poultry and other meats (beef, pork, and lamb) is usually observed, and rice, which is a popular food in China, was the largest contributor to carbon footprint reductions. Our findings suggest that changing diets for climate change mitigation and human health is possible in China, though the per capital mitigation potential is slight lower than that in developed economies of France, Spain, Sweden, and New Zealand. [ABSTRACT FROM AUTHOR]

No-till (NT) has been widely regarded as a potential option to enhance soil organic carbon (SOC) sequestration and thus mitigate climate change. However, recent studies have shown that previous estimates of SOC storage under NT seem to be overestimated due to shallow sampling and improper SOC accounting. In China, the overall trend and magnitude of changes in SOC storage in response to NT adoption remain inconclusive. Here we use a meta-analysis to assess the relative change in SOC storage (profiles ≥20 cm) based on 95 comparisons between NT and conventional tillage (CT) from 57 experimental sites (≥3 years) covering various cropping systems, soil types, and climatic regions of China. The results revealed that compared to CT, adopting NT led to SOC accumulation in the upper 20 cm layer and SOC depletion in the 30–40 cm layer. On average, NT improved SOC stocks over CT by 3.8% [95% confidence interval (CI): 1.4%–6.3%; P = 0.005] and 5.1% (95%CI: 2.5%–7.7%; P < 0.001) as represented by the equivalent soil mass (ESM) and fixed-depth (FD) approaches, respectively. The relative change in SOC storage rate under NT over tilled soil for the top 30 cm layer was therefore significantly higher ( Mean : 0.300 Mg ha −1 yr −1 , 95%CI: 0.054–0.547; P < 0.001) calculated by FD approach than that by ESM ( Mean : 0.141 Mg ha −1 yr −1 , 95%CI: −0.102–0.384; P = 0.100). Further analysis suggested that the effect of NT on SOC storage was significant with residue retained‎, double cropping systems, and in the coarse textured soils. We conclude that although NT was an effective agronomy option for soil conservation in China, the potential for mitigation climate change through increased SOC sequestration by NT should not be amplified. [ABSTRACT FROM AUTHOR]

Macroalgae aquaculture faces grand challenges from extreme temperature events in the context of global warming. For mapping aquaculture areas and assessing potential risks, it is urgent to evaluate the thermal sensitivity of commercially and ecologically important macroalgae. In the present study, thermal tolerance of commercial macroalgae species in China and sea surface temperature (SST) under current conditions and three Shared Socioeconomic Pathways (SSP1–2.6, SSP3–7.0, SSP5–8.5) scenarios in 2050 were collected for calculating thermal safety margin (TSM), an index of thermal sensitivity, for each species in the aquaculture area. Our results indicated that a few species were particularly sensitive to current conditions, and the kelp Saccharina japonica and Ulva pertusa were the most sensitive species to heat and cold stress, respectively. As indicated by the regional thermal sensitivity (RTS) (i.e., the mean of TSMs for all species in each grid cell), the commercial macroalgae located in southern China (20–25°N) were more sensitive to heat stress, while the commercial macroalgae located in the regions of 27–40°N was more sensitive to cold stress. Commercial macroalgae nearby the Yangtze River Estuary (~30°N) were sensitive to both heat and cold stress. Under the three SSP scenarios, macroalgae aquaculture would be more sensitive to heat stress, and the impacts from cold stress would relatively weaken in 2050. Our findings provide crucial information for the management of macroalgae aquaculture and for climate change mitigation and adaptation in China. • Species-specific and region-specific thermal sensitivity of macroalgae aquaculture in China were evaluated. • The impacts of heat stress will increase while cold stress will decrease in the future in the face of climate change. • Macroalgae farming potentially is running out of traditional geographies. • Effective adaptation and mitigation efforts are urgent for the sustainable development of macroalgae aquaculture. [ABSTRACT FROM AUTHOR]

Carbon neutrality objectives affect meteorology and ozone (O 3) concentration in China, both of which would influence crop yields, thus food security. However, the joint impact of these two factors on crop yields in China is not clear. In this study, we investigated future trends in China's maize, rice, soybean, and wheat yields under a carbon-neutral scenario considering both regional emission reduction and global climate change in 2060. By combining a process-based crop model (Agricultural Production Systems sIMulator, APSIM) with O 3 exposure equations, the impacts of regional emission reduction and global climate change were studied. The results suggest that regional emission reduction dominated the increase in yield by reducing the O 3 concentration, whereas global climate change led to yield loss mainly through meteorological factors. The national yield decreases for the four crops ranged from 1.0% to 38.0% owing to meteorological factors, while O 3 reduction resulted in additional yield increases ranging from 2.8% to 7.0%. The combined effect of carbon neutrality, which included both meteorological factors and O 3 concentration, resulted in changes to the yields of maize, rice, soybean, and wheat of +4.3%, -7.3%, -24.0%, and -31.7%, respectively. It seems that crop production loss caused by meteorological factors in 2060 would be mitigated by the O 3 reduction. Given the advantages of declining O 3 concentration, regional emission reduction would likely benefit crop growth. However, global climate change may offset the benefits and threaten food production in China. Therefore, more strict emission reduction policies and global climate change mitigation actions are necessary to ensure food security in China. [Display omitted] • Low carbon emissions would lead to increased crop yields in China. • Crop yield loss is mitigated owing to ozone decreases induced by emission reduction. • Global climate change would cause yield loss mainly through meteorological factors. [ABSTRACT FROM AUTHOR]

China’s commitment to the UNFCCC to peak its emissions by 2030, or sooner, signaled a long anticipated shift in China’s model of development with far reaching consequences. Cities in China, and particularly the residential sector in cities, will be charged with making significant reductions in emissions growth even as rates of urbanization continue to climb. Focusing on Beijing and Shanghai, this paper carries out a measures-based economic analysis of low carbon investment opportunities in the residential sector. Results find significant opportunity: between 2015 and 2030, BAU levels of CO 2 emissions could be reduced by 10.2% in Beijing and 6.8% in Shanghai with the adoption of economically attractive low carbon measures. While these headline results underline the case for low carbon investment in the residential sectors of these megacities in China, a closer analysis provides insights for understanding the economics of decarbonisation in cities more generally. [ABSTRACT FROM AUTHOR]

[Display omitted] • The greening rate increased with time after cascade-dam implementation. • Temperature was the most significant driving force on vegetation growth. • Temperature and sunshine hours positively affected vegetation. • Vegetation was negatively correlated with precipitation and vapor pressure deficit. The eco-environment in ecologically fragile regions has received increasing concern due to its vulnerability to climate changes. Determination of vegetation dynamics is a prerequisite for sustainable management of eco-environment evolution due to its vital role in regulating earth system and ecosystem services. China′s Three Gorges Reservoir area (TGRA), as a typical ecologically fragile region, was selected to explore its vegetation dynamics and response to local climate in different periods (1982–2020) of GZD-TGD (Gezhou Dam-Three Gorges Dam). The 1982–2020 NDVI dataset was obtained by integrating the overlapping period (2001–2015) of GIMMS NDVI and MODIS NDVI. The results demonstrated that TGRA exhibited a generally greening trend in 1982–2020, and the greening rate increased with the implementation of GZD-TGD, particularly in the last 20 years, which greatly promotes the capacity of vegetation carbon sink. At the annual scale, the mitigation of climate warming occurred with GZD-TGD implementation, particularly after the first impoundment of TGD (−0.0114 ℃yr−1). At the seasonal scale, a certain cooling effect in summer and a warming effect in other seasons (especially in winter) induced by this cascade project were observed, which became more pronounced after the water level reached 175 m. Furthermore, temperature had the most significant positive effect on vegetation dynamics, which increased with GZD-TGD implementation. The driving force of precipitation, VPD (vapor pressure deficit) and sunshine hours was relatively less significant but could not be ignored, with negative contributions from precipitation and VPD and positive contribution from sunshine hours. These findings provide further insights into the effect of climate changes mediated by GZD-TGD on vegetation growth and facilitate the dissection of the complex soil–plant-atmosphere feedback interaction. [ABSTRACT FROM AUTHOR]

The Ten-Thousand Enterprises Program is China’s keystone energy conservation and climate change program. The program has effectively created a class of energy-intensive enterprises that are regulated by the government for energy conservation purposes. Through an empirical study conducted in Changchun, this paper shows that the adoption of energy efficiency technologies and practices has been highly uneven in this class of enterprises because of two reasons. First, a de facto two-tier regulatory system has emerged within the framework of the Ten-Thousand Enterprises Program. Central state-owned enterprises are closely regulated by the State-Owned Assets Supervision and Administration Commission (SASAC) which is a central government apparatus, whereas local state-owned enterprises and privately owned enterprises are regulated by the local government, which has fewer resources and incentives to implement the program rigorously. Second, the Ten-Thousand Enterprises Program bundles together different types of enterprises. This approach places smaller enterprises at a disadvantage and limits their ability to conserve energy. [ABSTRACT FROM AUTHOR]

The carbon balance in urban areas has become a major research challenge and a principal policy concern in efforts to address anthropogenic climate change. Rapid urbanization and industrialization in China urge the search for integrated strategies to mitigate and adapt to climate change, which not only limit to traditional infrastructure sectors, but also cover urban green infrastructure, because plants and soils function as carbon sinks through biotic sequestration. This study presents a nationwide study about how urban green infrastructure could contribute to the carbon balance in 35 major Chinese cities. By the end of 2010, the total area of urban green spaces (the dominant components of urban green infrastructure) accounts for 6.38% of the total land area of these cities and represented 51.7% of the total urban green spaces of all 657 cities in China. Based on empirical data from the literature, the total amount of carbon stored in the vegetation of the urban green infrastructure of 35 cities was estimated at 18.7 million tons, with an average carbon density of 21.34 t/ha. In 2010, the amount of carbon sequestration totaled 1.90 million tons with an average carbon sequestration rate of 2.16 t/ha/year. Collectively, only 0.33% of the carbon emissions from fossil fuel combustion can be offset, ranging from 0.01% in Hohhot to 22.45% in Haikou. Nevertheless, the dominance of young vegetation stands in Chinese urban green infrastructure suggests this small carbon sequestration efficiency could become substantial in the near future, given that appropriate policies and management practices are adopted to promote urban green infrastructure for climate change mitigation and adaptation. [ABSTRACT FROM AUTHOR]

Achieving the carbon neutral targets before year 2060 is one of the important commitments for mitigating global climate change by Chinese government. However, the manner in which one would maximize the carbon sequestration of the planted forests is still unclear. Estimating accurately the carbon balance in forestry depends highly on the dynamics of numerous delay-released carbon pools (e.g., harvest residues, wood products), thus the strategies used to account for the carbon emissions of these components may have great influences on the decision-making and profitability associated with planted forests. This study developed a tool that allows forest managers and policy makers to analyze the effects of alternative accounting strategies for recognizing carbon emissions on the optimal rotation lengths and profitability of planted forests. The considered carbon balance not only refers to the within-forest pools, e.g., living biomass, harvest residues, annually generated litters and dead trees, but also refers to the outside-forest pools that include wood products, biofuel, operating process and substitution effect. The obtained results indicated that the lengths of optimal forest rotation decreased significantly with increases in site index, planting density and discount rate, while they increased dramatically with increases of carbon price. The gaps in rotation lengths were as large as 13.5 years, 6.9 years, 27.6 years and 11.0 years, respectively for the ranges of site index (10–18 m), planting density (2500–4444 trees per hectare), discount rate (1%–5%), and carbon prices (0–880 CNY/ton CO 2) assumed. The effects of delay-released carbon pools on the optimal rotation lengths were not significant, when the substitution effects of wood products and biofuels were considered under the current carbon trading markets; however, some exceptions were observed when a very high carbon price (880 CNY/ton CO 2) was assumed. [Display omitted] • A management tool that considers carbon balance and wood production was developed. • The optimal rotations are sensitive to forest- and economic-based variables. • The delayed effects of carbon emissions on optimal rotations were offset by substitution effects. • Pricing CO 2 sequestrated in forests can increase optimal rotations and profitability. [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) emissions from energy consumption have become a major focus all over the world. Cities, especially, are playing an important role in responding to the challenges of global climate change. However, there is still a lack of case studies on the whole life stage (including energy import, production, and consumption) at the city level. This is the first study to systematically estimate the whole lifecycle GHG emissions of urban energy consumption in Macau using the life cycle assessment (LCA) method. It identifies the main contributors, draws the balance framework diagram of energy GHG emissions, and proposes the effective reduction measures through a scenario analysis. The results show that the total GHG emissions of energy consumption in Macau increased from 2.10 × 103 kt CO 2 eq. in 2000 to 5.34 × 103 kt CO 2 eq. in 2018. In 2018, the energy-related GHG emissions in the import phase, production phase, and consumption phase were 3.37 × 103, 4.08 × 102 and 5.34 × 103 kt CO 2 eq., respectively. Since the return of Macau from Portugal to China (December 20, 1999), its GHG emissions from energy import have come to depend more on Mainland China, increasing from 71% in 2000 to 98% in 2018. For the consumption phase, indirect GHG emissions are more important, accounting for 75.3% of total GHG emissions in Macau. From the final consumption perspective, the gambling industry results in the largest GHG emissions (38.07% in 2018), followed by the transportation industry; while for the final energy consumption types, electricity consumption has become the predominant source. The scenario analysis shows that under an ideal scenario, the GHG emissions can be slowed down and will peak in 2033. [Display omitted] • It firstly estimates the whole lifecycle GHG emissions from Macau urban energy consumption. • The GHG emission dependence on the mainland China increases from 71% to 98% since 2000. • It draws the balance framework diagram of energy GHG emissions. • Gambling industry results in the largest GHG emissions in Macau. • Under ideal scenario, the GHG emissions will peak in 2033. [ABSTRACT FROM AUTHOR]

Abstract: Climate change was not on the policy agenda in Hong Kong before 2007. In 2010, a consultation document, Hong Kong’s Climate Change Strategy and Action Agenda, was published proposing a voluntary carbon intensity reduction target of 50–60% by 2020 (from the 2005 level). This review attempts to understand why there was a sudden shift to climate issues and whether the proposed strategy, actions and targets are appropriate to the climate change challenges faced by the city. Through synthesizing existing literature on climate change at the city level, a framework outlining possible actions at the strategic, knowledge accumulation and implementation phases is developed to position Hong Kong’s experience. It is found that Hong Kong’s move towards climate change is strongly affected by China’s efforts. The city is facing some real climate change threats. However, while the carbon intensity reduction target looks impressive, it is actually too modest for the city’s developed economy. The city needs to reflect critically on its economics-first strategy and undertake more refined vulnerability studies and risk assessments to identify spatially and sectorally-specific adaptation measures. To be a responsible global citizen and to pursue sustainable development, Hong Kong needs more concerted and comprehensive efforts to combat climate change. [Copyright &y& Elsevier]

Abstract: The National 12th Five-Year-Plan for Social and Economic Development (2011–2015) (national development policy) in China requires knowledge of ecological complexity to better guide policy development for adaptation strategies and mitigation to complex climate change. The thinking of human–environment interactions supplements climate change related policies in supporting sustainability through adaptation and mitigation. Based on a review of the climate change contents of the National 10th and 11th Five-Year-Plan in China, the paper illustrates the complexity of climate changes that have affected China''s environmental sustainability now and offers policy viewpoints for the in-preparing 12th Five-Year Plan, with five core areas for the implementation of climate change policy: (A) development of the transition to a low carbon economy, (B) prevention and treatment of urban environmental negative effects caused by climate change, (C) adaptation to sea level rises in coastal zones, (D) maintaining the resilience of natural ecosystems affected by climate change, and (E) prevention and control of climate disaster and environmental risk. [Copyright &y& Elsevier]

Abstract: Characterizing the carbon footprint (CF) of agricultural production offers key information for pursuing low carbon agriculture and food consumption. While China has long strived for increasing food production capacity for its large and still growing population, the high emissions cost, especially from the over use of agro-chemicals, has been widely debated for the last decade. However, the CF of China''s crop production has not yet been assessed. This paper reports a basic estimate of CF of crop production using national statistical data available for the period of 1993–2007. The dataset includes the amount of individual agricultural inputs (fertilizer, pesticide, diesel, plastic film, etc.), cultivation area and total of production whole crops. Using the emission factors estimated for China''s agricultural features and available abroad, the mean overall CF of China''s crop production was estimated to be 0.78±0.08tCEha−1 yr−1 and 0.11±0.01tCEt−1 yr−1, for land use and bulk production respectively. For the duration the data covered, the carbon intensity under cultivation land use was seen to increase since 1993. Among the total, fertilizer induced emissions exerted the largest contribution of ∼60%, being 0.45±0.04tCE per ha and 0.07±0.01tCE per ton of production, on average. Compared to the UK, the estimated overall CF of China''s crop production was higher in terms of cultivation land use. While there was a significant positive correlation of carbon intensity with total production, carbon efficiency was shown in a decreasing trend during 2003-2007. Therefore, low carbon agriculture should be pursued, and the priority should be given to reducing fertilizer application in agriculture of China. However, for developing best management practices for climate change mitigation in crop production of China, further studies of crop and regional specific CFs and the variation with climate conditions and agricultural managements are needed. [Copyright &y& Elsevier]

Abstract: Future trends of cooling load due to heat gain through the building envelopes in the residential sector in subtropical Hong Kong under different emissions scenarios in the 21st century were investigated. Predicted monthly weather data from five general circulation models were gathered and analysed. An increasing trend of building envelope cooling load was observed. The average annual cooling load during the 2009–2100 period would be 6.1% and 9.8% more than that during 1979–2008 for low and medium forcing, respectively. If only the last 30 years (2071–2100) were considered, the percentage increase would be much larger at 12.3% and 21.6%. Four mitigation or energy conservation measures – raising the indoor temperature, thermal insulation, double glazing and tinted glass – were considered. Among them, raising the indoor temperature has the best mitigation potential because there is a growing awareness and recognition of adaptive thermal comfort and it can be readily applied to both existing and new buildings at no extra cost. [ABSTRACT FROM AUTHOR]

Abstract: Soil C sequestration in cropland could play an important role in mitigating the rapidly increasing CO2 emissions in China. Many efforts had been dedicated to estimating the potential for C sequestration in croplands. Potential increases in SOC in China''s croplands had been recently evaluated using inventory-up-scaling simulation and crop-soil C process-based modeling. In this study, data of SOC change at monitoring sites from croplands across mainland China were collected from publications available from 1985 to 2006 to perform a statistical analysis. The data set comprises 1081 observations (404 from rice paddies, RPs and 677 from dry croplands, DCs). Frequency analysis indicates that over 70% of observations show an increase in SOC, which is higher among RPs than DCs. To quantify SOC dynamics, a Relative Annual Change Index in gkg−1 year−1 (RAC, gkg−1 year−1) is defined and calculated using the initial and final SOC values for the duration of monitored observations. RAC values ranged from −0.806 to 0.963gkg−1 year−1 for DCs and from −0.597 to 0.959gkg−1 year−1 for RPs, respectively. From this data, the average is estimated to be 0.056±0.200gkg−1 year−1 for DCs, and 0.110±0.244gkg−1 year−1 for RPs, with an overall estimate for China''s croplands, with RPs and DCs combined, of 0.076±0.219gkg−1 year−1. A mean increase in topsoil C (0–20cm) stock of China''s croplands was estimated to be 25.5TgCyear−1 (8TgCyear−1 in RPs and 17.5TgCyear−1 in DCs) between 1985 and 2006, with a total topsoil C stock increase of 0.64 Pg C over the whole period. The annual stock increase may offset ∼20%, on average, of the total CO2 emissions of China for 1994. This study suggests an important role of China''s croplands, especially rice paddies, for C sequestration to mitigate climate change. [Copyright &y& Elsevier]

The reduction of agricultural greenhouse gas emissions relies on farmers' active involvement in mitigation actions. However, little is known about farmers' capability of engaging with climate change mitigation. This study addresses the gap by delineating an actor-centered, capability-based, and multi-dimensional framework of farmers' carbon capability to elucidate how and to what extent farmers are equipped to engage in climate change mitigation. A structural equation model and farm-level data collected from China are used to explore the structural relationships between the carbon capability constructs. The results show that farmers' intrapsychic constructs are pro-environmental, and their cognitive knowledge about pro-climate farming practices is moderate. However, the performance of pro-climate farming is largely not under farmers' behavioral control. Farmers generally have a weak tendency to perform stable pro-climate farming behaviors, while they are slightly more inclined to behave pro-environmentally in social interactions. In addition, farmers' behavioral control capability emerges as the strongest predictor of the behavioral capability of farming, which, in turn, is an essential prerequisite for both the behavioral capability of socializing and influence capability. The findings of this study have important strategic implications for policymakers seeking to reduce agricultural greenhouse gas emissions. • A conceptual framework of farmers' carbon capability is proposed and tested. • Analyses elucidate the aspects in and extent to which farmers are equipped to engage in climate change mitigation. • Pro-climate farming is largely not under farmers' behavioral control. • Farmers' control over pro-climate farming matters to their own behaviors but also to peers' responses. [ABSTRACT FROM AUTHOR]

Promoting technology development co-operation is particularly relevant while addressing global climate change or regional pollution. Investors may contribute to increasing environmental-related patents, which may help to improve the quality of the environment as long as supported by proper regulations and policies. In the quest towards a cleaner environment via the mitigation of climate change, this study investigates the relationship between technological innovation, income level, renewable energy and carbon emissions in both the United States and China. Applying the dynamic auto-regressive distributive lag (DARDL) simulation method revealed varying impacts of regressors on CO 2 emissions in the short-run and long-run. Accordingly, this study empirically confirms that (i) technological innovation reduces carbon emissions in the United States but it is not statistically significant in China. (ii) Renewable energy reduces carbon emissions in both countries. (iii) The impact of income level on emissions decreases from short-run to long-run in both countries. Decision-makers in China should stimulate more effective environmental-related innovations to decrease CO 2 emissions and should permit easy access to environmental-related patents together with reducing its cost of registration. • Investigates the role of green technological innovation in decreasing CO 2 emissions. • Applies the novel Dynamic ARDL simulation. • Green technological innovation reduces CO 2 emissions in the U.S. Only. • Confirms that renewable energy mitigates CO 2 emissions both in the U.S. and China. [ABSTRACT FROM AUTHOR]

• Halocarbon emissions in the building sector is increasing. • Non-Annex parties become bigger emitter instead of Annex parties. • Building sector accounts for more than half of global HFCs emissions. • Data sufficiency is key barrier for policy making. • Building cooling demand increase will push further halocarbon emissions. Estimates of the non-CO 2 greenhouse gas (GHG) emissions contributed by the buildings sector are necessary to evaluate this sector's potential for climate change mitigation. As data is lacking on fluorinated gases (F-gases) and hydrofluorocarbon (HFC) emissions from the buildings sector, this study aimed to estimate these emissions. First, the share of total global GHG emissions represented by buildings-sector emissions was estimated. Then, the HFC emissions of the buildings sectors in several countries (USA, EU, Japan, and China) are compiled. Next, based on necessary assumptions, global buildings-sector HFC emissions were estimated. Finally, this paper discusses implications for policy-makers. [ABSTRACT FROM AUTHOR]

As bioenergy produces neutral or even negative carbon emissions, the assessment of biomass resources and associated emissions mitigation is a key step toward a low carbon future. However, relevant comprehensive estimates lack in China. Here, we measure the energy potential of China's domestic biomass resources (including crop residues, forest residues, animal manure, municipal solid waste and sewage sludge) from 2000 to 2016 and draw the spatial-temporal variation trajectories at provincial resolution. Scenario analysis and life cycle assessment are also applied to discuss the greenhouse gas mitigation potentials. Results show that the collectable potential of domestic biomass resources increased from 18.31 EJ in 2000 to 22.67 EJ in 2016 with overall uncertainties fluctuating between (−26.6%, 39.7%) and (−27.6%, 39.5%). Taking energy crops into account, the total potential in 2016 (32.69 EJ) was equivalent to 27.6% of China's energy consumption. If this potential can be realized in a planned way to displace fossil fuels during the period 2020–2050, cumulative greenhouse gas emissions mitigation would be in the range of 1652.73–5859.56 Mt CO 2 -equivalent, in which the negative greenhouse gas emissions due to the introduction of bioenergy with carbon capture and storage would account for 923.78–1344.13 Mt CO 2 -equivalent. Contrary to increasing bioenergy potentials in most provinces, there are declining trends in Tibet, Beijing, Shanghai and Zhejiang. In addition, Yunnan, Sichuan and Inner Mongolia would have the highest associated greenhouse gas mitigation potentials. This study can provide valuable guidance on the exploitation of China's untapped biomass resources for the mitigation of global climate change. • China's bioenergy potential in 2016 accounted for 27.6% of its energy consumption. • The bioenergy potential in Tibet, Beijing, Shanghai and Zhejiang was declining. • GHG mitigation potentials of China's bioenergy would be 1653–5860 Mt CO 2 e by 2050. • China's bioenergy can contribute 6–21% to a global carbon mitigation goal in 2050. [ABSTRACT FROM AUTHOR]

Risk perception understanding is fundamental for risk management. The effects of catastrophic events on public risk perception of projects such as nuclear plants have become a critical concern, however, there is still few studies concentrate on public risk perception of extreme weather brought by climate change. In this study, the proposed statistical methods were applied to evaluate the impacts of Typhoon Meranti on climate change risk perception of undergraduates from Xiamen University, China. It is found that both the evaluation on personal efforts and domestic community efforts on climate change mitigation were significantly affected by the Typhoon Meranti, while the public risk perception structure of climate change did not change significantly after the typhoon. Meanwhile, disciplinary background, teaching contents and the location of hometown are main influential factors on interviewees' risk perception of climate change. The results indicated that the transformation of public risk perception is a long-term process, education can be an effective approach to promote public's concern and comprehension on climate change. The proposed framework explores a quantitative method to measure the impacts of an extreme weather event on public risk perception and its policy implications on public risk. Image 1 • Public risk perception changes after an extreme event are quantitatively studied. • Evaluation on personal and domestic community level efforts affected significantly. • The structure of public risk perception of climate change remained post-typhoon. • Education can be effective to promote public's concern and comprehension on climate. [ABSTRACT FROM AUTHOR]

• Baseline scenarios are essential and important in forward-looking studies. • Carbon tax policy impacts are found to be highly diverse across baseline scenarios. • Output levels can change dramatically (e.g. −19% to −64% for power output in India). • Real GDP can also change significantly (e.g. −0.66% to 1.54% in China). • Baselines with honed renewable projections facilitates fewer economic trade-offs. As a result of statistical contingencies, research frequently employs aged databases to examine the impacts of energy and climate change policies in contemporary situations, or in forward timeframes out to 2050 or even 2100. These forward-looking studies require a base case scenario in order to assess the impacts of a policy. In this article, we hypothesise how a baseline is 'rolled forward', and specifically, how this process can materially alter the apparent performance of an energy or climate change policy. In the literature, we find a variety of methods are used to update databases and project forward base case scenarios, some which scale an entire economy to a general trend of growth, whereas others account for sectoral differences. We extend a global electricity-detailed model (GTAP-E-Power) to examine our hypothesis. We evaluate impacts of a world-wide carbon tax policy ($50/t of carbon dioxide equivalent) using three different baselines, with varying levels of specificity relating to macroeconomic projections and sectoral developments and constraints. Results show the impact on sectors and the overall economy in all countries are highly diverse when different baselines are used. For example, fossil-based power output in the United States declines between 36.7 and 65.5% while Real GDP in China declines between −0.66 and −1.54% for an identical policy, depending on which baseline methodology is used. Above all, we find that stronger development of renewable energy and technology in the baselines results in lower costs of a climate change mitigation policy. [ABSTRACT FROM AUTHOR]

The Paris Agreement on climate change has calls for urgent, radical, and transformative actions in mitigation and adaptation, particularly in terms of reducing greenhouse gas (GHG) emission. There are many terms used to describe the process of reducing GHGs, including decarbonization, low carbon development (LCD) or low carbon transition (LCT). The conceptualization of these terms remains puzzling and there has not been any consensus to explain the meaning and their interrelationship. Clearer definition and conceptual boundaries are necessary to improve the coherence of overarching practices to cut CO 2 emission. The paper aims to review key concepts related to climate change mitigation related to the reduction of CO 2 and efforts toward net-zero emission in the academic literature, by (1) examining progress of the literature over time, (2) identifying geographical locus and sectoral focus of the literature, (3) determining the interrelationships between the key concepts. We use a Systematic Literature Review (SLR) method for data collection by selecting peer-reviewed literature from Scopus and analyzing the data with content analysis and bibliometric analysis. The findings are, firstly, the publications of the literature are influenced by global and national climate change policies and the interest of scholars affiliated to institutions from major emitter countries. Therefore, the literature is mostly originating from countries that emit the most CO 2 while also implement mitigations to reduce CO 2 emission. Secondly, China is the country where studies are mostly focused and also where the authors are affiliated/located. However, publications from the United Kingdom are cited the most. Thirdly, there are three clusters of literature found, namely that LCD and LCT are the terms used to identify visions for climate mitigation, while decarbonization is the actions and processes to achieve either LCD or LCT (as the visions). • The dynamic of climate change policies influence the literature trend. • The literature is mostly originating from major CO 2 emitter. • Low carbon development and low carbon transition are visional terms. • Decarbonization indicates the processes of decoupling CO 2 to achieve the visions. [ABSTRACT FROM AUTHOR]

• Abnormal correlation was verified between the actual evaporation (AE) and evaporation demands (ED) in the humid region. • Penman and Budyko equations were combined to assess the integrated response chain from a changing environment to AE. • The compensation function of afforestation was highlighted for the decrease in AE against the impact of decreasing ED. • Transformation mechanism of the Penman into Bouchet hypotheses is investigated in the regional water-energy balance. Generally, atmospheric evaporation demand (AED) shows a positive correlation with actual evaporation (AE) in the Yangtze River basin. In order to explore whether and why abnormal correlation exits in its five sub-basins, the temporal changes between AED and AE were compared, and then the impacts of climate change and human activities on abnormal correlations were assessed using the sensitivity method of Penman equation and the decomposition method of Budyko equation. The results indicated: (1) Pan evaporation and potential evaporation (indicators of AED) decreased at rates of up to -0.04 and -0.06 mm d−1 decade−1, respectively. In contrast, the water budget-derived evaporation (an indicator of AE) increased at the rate of 0.09 mm d−1 decade−1 in the Fuhe River basin and remained stable in other basins. Abnormal correlations (nonpositive correlations) were observed. (2) Decreasing net radiation and wind speed were major climate factors resulting in simultaneous temporal decreases in AED and AE. In contrast, afforestation was a major human factor leading to an increase in annual AE of 78 mm, but had no effect on AED. Afforestation was the primary driving force of the abnormal correlation. These results could provide water-energy guidance for urban climate change mitigation and flood/drought disaster management. [ABSTRACT FROM AUTHOR]

Forest-steppe ecotones are generally regarded as very sensitive to climate change. However, it is still unclear whether they can be used to track past climate changes due to the combined effects of climate forcing and topographic factors. We first explored shifts of the whole forest-steppe ecotone in northern China during the Holocene by collecting 383 topsoil pollen samples to establish discriminant functions representative of forest, forest-steppe ecotone, and temperate steppe. The discriminant functions were applied to 39 fossil pollen sites to reconstruct the range of the forest-steppe ecotone during the Holocene. Our results showed that the shift of the forest-steppe ecotone exhibited a generally consistent trend with the intensity of the EASM, which was characterized by southward retreat during the early Holocene from 12,000 to 8000 cal. yr BP, northward expansion during the middle Holocene from 8000 to 4000 cal. yr BP, and southward retreat during the late Holocene from 4000 to 0 cal. yr BP, suggesting a dominant role of precipitation provided by the EASM. However, some sites in mountainous regions still indicated forest group membership within the ecotone, implying possible vertical forest migration. We stress that EASM and topography co-determine the shift of the forest-steppe ecotone in northern China, and mountainous terrain differences also benefit the vertical forest migrations when threatened by the dry climate. Our study implies that future climate change may cause three-dimensional changes in vegetation, which should be considered in climate change mitigation. • East Asian summer monsoon and topography co-determine the shift of the forest-steppe ecotone in northern China. • Mountainous terrain differences also benefit the vertical forest migrations when threatened by the dry climate. • The climate indication of the forest-steppe ecotone needs to be considered from three dimensions. [ABSTRACT FROM AUTHOR]