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Natural wetlands are among the most important sources of methane; thus, these areas are important for better understanding long-term temporal variations in atmospheric methane concentration. During the last 60 years, wetlands have experienced extensive conversion and global impacts from climate warming, which makes the estimation of methane emission from wetlands highly uncertain. In this paper, we present a modeling framework, integrating CH4MODWETLAND, TOPMODEL and TEM models, to analyze the temporal and spatial variations in CH4 emissions from natural wetlands (including inland wetlands, coastal wetlands, lakes and rivers) in China. Our analysis revealed an increase of 25.5 %, averaging 0.52g m-2 per decade, in national CH4 fluxes from 1950 to 2010, which was mainly induced by climate warming. Higher rates of increasing CH4 fluxes occurred in northeastern, northern and northwestern China, associated with large temperature increases. However, decreases in precipitation due to climate warming o_set the increase in CH4 fluxes in these regions. The CH4 fluxes from the wetland on the Qinghai Tibetan Plateau exhibited a lower rate of increase, which was approximately 25% of that simulated in northeastern China. Although climate warming has accelerated CH4 fluxes, the total amount of national CH4 emissions decreased by approximately 2.35 Tg (1.91-2.81 Tg), i.e., from 4.50 Tg in the early 1950s to 2.15 Tg in the late 2000s, due to a large wetland loss of 17.0 million ha. Of this reduction, 0.26 Tg 0.24-0.28 Tg) was derived from lakes and rivers, 0.16 Tg (0.13-0.20 Tg) from coastal wetlands, and 1.92 Tg (1.54-2.33 Tg) from inland wetlands. Northeastern China had the largest contribution to this reduction, with a loss of 1.68 Tg. The CH4 emissions were reduced by more than half in most regions in China except for the Qinghai Tibetan Plateau, where only a 23.3% decrease in CH4 was observed. [ABSTRACT FROM AUTHOR]

Climate change is the dominant factor affecting the hydrological process, it is of great significance to simulate and predict its influence on water resources management, socio-economic activities, and sustainable development in the future. In this paper, the Xiying River Basin was taken as the study area, China Atmospheric Assimilation Driven Data Set (CMADS) and observation data from the Jiutiaoling station were used to simulate runoff of the SWAT model and calibrate and verify model parameters. On this basis, runoff change of the basin under the future climate scenario of CMIP6 was predicted. Our research shows that: (1) The contribution rates of climate change and human activities to runoff increase of the Xiying River are 89.17% and 10.83%, respectively. Climate change is the most important factor affecting runoff change of the Xiying River. (2) In these three different emission scenarios of SSP1-2.6, SSP2-4.5 and SSP5-8.5 in CMIP6 climate model, the average temperature increased by 0.61, 1.09 and 1.74 °C, respectively, in the Xiying River Basin from 2017 to 2050. Average precipitation increased by 14.36, 66.88, and 142.73 mm, respectively, and runoff increased by 15, 24, and 35 million m³, respectively. The effect of climate change on runoff will continue to deepen in the future. [ABSTRACT FROM AUTHOR]

Wetland loss and climate change are known to alter regional and global methane (CH4) budgets. Over the last six decades, an extensive area of marshland has been converted to cropland on the Sanjiang Plain in Northeast China, and a significant increase in air temperature has also been observed there, while the impacts on regional CH4 budgets remain uncertain. Through model simulation, we estimated the changes in CH4 emissions associated with the conversion of marshland to cropland and climate change in this area. Model simulations indicated a significant reduction of 1.1 Tgyr-1 from the 1950s to the 2000s in regional CH4 emissions. The cumulative reduction of CH4 from 1960 to 2009 was estimated to be ~ 36Tg relative to the 1950s, and marshland conversion and the climate contributed 86% and 14% of this change, respectively. Interannual variation in precipitation (linear trend with P > 0.2) contributed to yearly fluctuations in CH4 emissions, but the relatively lower amount of precipitation over the period 1960-2009 (47 mmyr-1 lower on average than in the 1950s) contributed ~91% of the reduction in the area-weighted CH4 flux. Global warming at a rate of 0.3 °C per decade (P < 0.001) has increased CH4 emissions significantly since the 1990s. Relative to the mean of the 1950s, the warming-induced increase in the CH4 flux has averaged 19 kg ha-1 yr-1 over the last two decades. For the RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5 scenarios of the fifth IPCC assessment report (AR5), the CH4 flux is predicted to increase by 36 %, 52 %, 78% and 95 %, respectively, by the 2080s compared to 1961-1990 in response to climate warming and wetting. [ABSTRACT FROM AUTHOR]

Increased temperature and carbon dioxide concentration caused by climate change will aggravate the creep shrinkage and structural durability of concrete bridges. Overloading also has a great impact on the time-dependent reliability of existing bridges. This research paper analyses the time-dependent reliability of bridges based on climate change and overload. By improving the concrete carbonation model and referring to the B4 model of concrete creep, the effects of ambient temperature and humidity on concrete under different emission-reduction scenarios were considered. At the same time, given the serious problems of vehicle overload in China, combining different overload scenarios with climate change led to the establishment of a time-dependent reliability model for precast-concrete bridges. The results showed that as the overload rate increased, the time-dependent reliability degradation rate of a case study bridge accelerated. Under the scenario considering both high greenhouse gas emissions and the maximum overload rate, the service life of the case study bridge decreased to 50% of its design life. [ABSTRACT FROM AUTHOR]

The excessive carbon emissions not only intensify the global climate change, but also seriously restrict the sustainable development of social economy. However, improving industrial carbon emissions efficiency is the most directly effective way to reduce emissions. Therefore, accurate measurement and analysis of carbon emissions efficiency and evolution characteristics of China's industrial system is the basis for China to improve carbon emissions efficiency. Based on this, we adopted energy consumption method and input-output method to calculate and analyze the industrial carbon emissions efficiency and evolution characteristics of China from 2002 to 2015. The results show that (1) If carbon emissions from cement production are ignored and only energy-related carbon emissions are considered, the calculation results of carbon emissions efficiency of heavy industry will be overestimated about 30%. (2) Compared with 2002, China's industrial carbon emissions efficiency increased by about twice in 2015. Specifically, the optimization of carbon emissions efficiency in agriculture, construction, light industry and service industry is very obvious, which has increased by 5.65, 5.00, 4.69 and 4.68 times respectively; The optimization of carbon emissions efficiency in power sector, heavy industry, transportation and chemical industry was obvious, which increased by 2.55, 2.01, 1.86 and 1.47 times respectively; The carbon emissions efficiency of the fossil energy sector has decreased by 0.36 times. (3) The carbon emissions efficiency of various industries has significant differences. Among them, agriculture, service industry, light industry and construction industry are generally industries with higher carbon emissions efficiency, while power sector, fossil energy sector, transportation industry, chemical industry and heavy industry are generally industries with lower carbon emissions efficiency, especially power and fossil energy sectors. Based on these, this paper provides policy implications and scientific evidence for accurately improving carbon emissions efficiency from the perspective of carbon emissions efficiency. [ABSTRACT FROM AUTHOR]

This paper examines China's policy and position in relation to the evolving climate change negotiations in order to explain how China is dealing with the dilemma of meeting its growing development needs while reducing GHG emissions. It argues that global climate governance requires steering and leadership to deal with the interlocked political process; that the developing countries (DCS) right to develop is challenged by the need for ecosystemic standards especially as climate change is seen as a zero-sum game as the more one country emits the less another one can. This is especially problematic as Industrialized countries (ICS) appear to be both unwilling and unable to increase growth without increasing emissions. This explains China's policy of insisting on its right to develop, of demanding that ics reduce their emissions and that they fulfil their obligations under the FCCC, while expressing its willingness to take on a voluntary target. The paper argues that China's state-led transition has eight unique characteristics that may allow it to lead as it moves beyond a no-regrets policy to a circular and green economy, cooperating with other DCS and mobilizing conscious green values in citizens. The question remains--will the initial success and scale of state-led transition lead the global green transition to a sustainable world? [ABSTRACT FROM AUTHOR]

The current nationally determined contributions, pledged by the countries under the Paris Agreement, are far from limiting climate change to below 2 ∘C temperature increase by the end of the century. The necessary ratcheting up of climate policy is projected to come with a wide array of additional benefits, in particular a reduction of today's 4.5 million annual premature deaths due to poor air quality. This paper therefore addresses the question how climate policy and air pollution–related health impacts interplay until 2050 by developing a comprehensive global modeling framework along the cause and effect chain of air pollution–induced social costs. We find that ratcheting up climate policy to a 2 ∘ compliant pathway results in welfare benefits through reduced air pollution that are larger than mitigation costs, even with avoided climate change damages neglected. The regional analysis demonstrates that the 2 ∘C pathway is therefore, from a social cost perspective, a "no-regret option" in the global aggregate, but in particular for China and India due to high air quality benefits, and also for developed regions due to net negative mitigation costs. Energy and resource exporting regions, on the other hand, face higher mitigation cost than benefits. Our analysis further shows that the result of higher health benefits than mitigation costs is robust across various air pollution control scenarios. However, although climate mitigation results in substantial air pollution emission reductions overall, we find significant remaining emissions in the transport and industry sectors even in a 2 ∘C world. We therefore call for further research in how to optimally exploit climate policy and air pollution control, deriving climate change mitigation pathways that maximize co-benefits. [ABSTRACT FROM AUTHOR]

Purpose – This paper proposes discussing the growing supply chain pressures, both legal and commercial, the background to them and their implications for countries with large consumer markets, such as the UK and for countries, such as the Republic of China, which are suppliers, but themselves increasingly important as consumer markets. Design/methodology/approach – Having regard to the multi disciplinary nature of the readership the paper does not focus too narrowly on legal regulation: nevertheless the legal perspective is important in at least one respect. The imposition of law and penalties provides a powerful incentive to behavioural change, and is very effective in focussing attention. Findings – The paper reveals that plainly it will be a challenge for supplier countries, as it will be for industry in the West, to meet new regulatory standards, particularly those which aim to force technology, like the vehicle emission standards referred to above, or standards relating to supply chain management, which will intervene in the established contractual arrangements between suppliers and their customers. It will also be a challenge to meet consumer demand for "greener" products as education of consumers in sustainability issues improves. Originality – This paper contributes towards green supply chain management that is emerging to be an important approach for enterprises to improve performance. Managerial implications are also identified. [ABSTRACT FROM AUTHOR]

Greenhouse gas emissions in China and India have been increasing rapidly over the last decade. Scenario studies can provide insight into expected future trends and the emission reduction potential in these regions. The scenarios show that growing population, gross domestic product, and energy demand are likely to lead to a further increase in emissions. At the same time, a decreasing emission intensity would still allow to create decarbonization scenarios in line with the requirements for reaching a maximal warming of 2 °C. There is, however, a wide range of assumptions across these studies. Based on the literature review, this paper observes that key assumptions in scenarios developed by national institutes in China and India differ from those presented by international studies or modeling teams. We explore how this-and other factors like data availability-may influence the interpretation of the scenarios and how international and national modeling groups could learn from each other. Our main recommendation is for more extensive collaboration between national and international research groups, so that national and international scenario studies can be compared in more detail in order to support international negotiations. [ABSTRACT FROM AUTHOR]

Climate change is considered one of the major systemic risks facing the world in the 21st century. To address climate change, China has adopted a series of climate policies, but the uncertainty brought about by frequent climate policy issuance has increased pressure on enterprises, which may not be conducive to enterprises reducing emissions. This paper uses data on 1211 listed companies on the A-share market in China from 2012 to 2022 to study the impact of climate policy uncertainty on enterprise pollutant emissions. The research findings show that climate policy uncertainty increases corporate pollution emissions; climate policy uncertainty mainly generates negative impacts on enterprise environmental regulation, social responsibility, and R&D investment, thereby negatively affecting enterprise emissions reduction. Further heterogeneity analysis shows that climate policy uncertainty in China has a more significant impact on non-state-owned enterprises, technology-intensive enterprises, lightly polluting enterprises, and enterprises in western regions. These findings emphasize the importance of enterprise social responsibility, environmental regulation, and R&D investment in enterprise emissions reduction and provide policy implications for Chinese enterprises to optimize their energy-saving and emission reduction strategies in the face of climate policy uncertainty. • We investigate the correlation between uncertainty in climate policy and the corporate pollution emissions. • We utilized an extensive dataset comprising publicly listed Chinese firms spanning the period from 2012 to 2022. • Climate policy uncertainty negatively impacts corporate environmental regulation, social responsibility, and R&D investment. [ABSTRACT FROM AUTHOR]

This paper analyses Chinese sub-national governments' implementation strategies to meet national energy efficiency targets in the 11th Five-Year Plan (2006-2010). Previous research has focused on the ways governance practices and decision-making structures shape implementation outcomes, yet very little attention has been given to what strategies local leaders actually employ to bridge national priorities with local interests. To illustrate how local leaders work politically, this paper highlights specific implementation methods officials use to strengthen formal incentives and create effective informal incentives to comply with energy efficiency mandates. The analysis is drawn from 53 interviews conducted in June and July of 2010 in Shanxi, a major coal-producing and energy-intensive province. Findings suggest that local government leaders conform to national directives by "bundling" the energy efficiency policy with policies of more pressing local importance or by "bundling" their energy efficiency objectives with the interests of groups with significant political influence. Ultimately, sub-national government officials frame policies in ways that give them legitimacy at the local level. [ABSTRACT FROM AUTHOR]

Preparatory talks to the next round of negotiations seem to indicate that a comprehensive agreement to mitigate climate change will not be easily attainable, despite the intentions of the US administration and the high expectations surrounding the Copenhagen meeting. One key reason is to what extent fast growing economies, and especially China, should take actions to reduce their growth of emissions. This paper argues that a turning point for international negotiations on climate change could be achieved if China were to agree on carbon obligations in the future. Results from modelling work suggest that the optimal investment behaviour is to anticipate the implementation of a climate policy by roughly 10 years, and that thus future commitments—if credible—could lead to significantly earlier steps towards carbon mitigation. If fast growing economies, and foremost China, believe in the long term objective of global stabilization of carbon concentrations, it might be economically rationale to sign on future targets, provided developed countries take on immediate action. Such a provision could be beneficial for both the developing and developed world. [ABSTRACT FROM AUTHOR]

China has a large economic and demographic exposure to extreme events that is increasing rapidly due to its fast development, and climate change may further aggravate the situation. This paper investigates China's socioeconomic risk from extreme events under climate change over the next few decades with a focus on sub-national heterogeneity. The empirical relationships between socioeconomic damages and their determinants are identified using a hierarchical Bayesian approach, and are used to estimate future damages as well as associated uncertainty bounds given specified climate and development scenarios. Considering projected changes in exposure, we find that the southwest and central regions and Hainan Island of China are likely to have a larger percentage of population at risk, while most of the southwest and central regions could generally have higher economic losses. Finally, the analysis suggests that increasing income can significantly decrease the number of people affected by extremes. [ABSTRACT FROM AUTHOR]

This paper assesses how the Paris Agreement on climate change affects China and India. Taking a TWAIL (third-world approaches to international law) approach, it argues that patterns of exploitation are repeated in different fields. The UNFCCC required developed countries to reduce their emissions before developing countries would be required to do so. While some developed countries are keeping to their side of the bargain, others are failing to do so. Nevertheless, China and India have accepted an agreement with targets for all countries which requires considerable sacrifices in the energy field but possible gains in the water field. While both countries have agreed to reduce the rate of growth of their emissions, they have high expectations of climate finance, which are unlikely to be fulfilled. Their commitments require major changes to national policy, scarcely the sort of tinkering that the no-regrets policy in India has achieved. [ABSTRACT FROM AUTHOR]

The majority of the total greenhouse gas (GHG) emissions in China are energy-related. Thus, full understanding of energy-related GHG emissions is crucial for local governments to establish a baseline for tracking emission trends and developing mitigation strategies. In this paper, we present a survey-based GHG emission accounting method for sectoral energy consumption and apply it in Xiaolan, a typical town of Zhongshan. The method combines scope and sectoral analyses on the basis of local statistical approach, and pays more attention to data collection process. Scenarios of core findings in the study are list as below: (1) The energy-related GHG emissions of Xiaolan in 2010 was 2,072,444 tons of carbon dioxide equivalents (CO 2 e). Of this, 31.83% was Scope 1 emissions (direct emissions) and 68.17% was Scope 2 emissions (indirect emissions); (2) Emissions from “manufacturing”, “residents”, and “power, gas & water production and supply” made up 90.27%, among which, “manufacturing” represents the biggest emitting sector as 69.09%; (3) In 2010, the per capita GHG emissions was lower than that in most of the other Chinese cities, but higher than several Asian cities including Amman and Tokyo. Some strategic approaches to reduce GHG emissions were proposed: (1) save energy and improve energy efficiency; (2) optimize energy structure and develop low-carbon energy; (3) update manufacturing structure; (4) improve GHG emission management for the resident sector. Finally, we identified a number of key research issues to advance the town level GHG emission method for future research needs. This paper provides a useful method to understand and profile GHG emissions for towns. [ABSTRACT FROM AUTHOR]

Transportation industry accounts for the majority of air pollutant emission, which is one of the leading factors of climate change. Many vehicle emission models have been proposed focusing on emission factors to study the pollutant emission issue. However, little research has been done in China on emission models, though China is a major air pollutant-emitting country. This paper first introduces two emission models- MOBILE model and MOVES model, then proposes model selection methods including AIC (Akaike information criterion) and BIC (Bayesian information criterion) to compare and select the better model which could be applied in China. Experimental results show that the value of AIC and BIC for MOVES model is significantly lower than MOBILE model, which implies that MOVES model has better performance on real data fitness and prediction. Our experimental findings may be useful for future research on air pollutant emission modelling in China. [ABSTRACT FROM AUTHOR]

Abstract: The unprecedented resources and energy needed to support the high growth of urbanization with the emerging issues of environmental degradation and GHG emissions is increasingly dramatic in China. A series of national and local policies have been implemented for achieving the co-benefits of reducing emissions of greenhouse gas (GHG) and air pollution for China's sustainable development. In this paper, the achievement of climate change mitigation and air pollution reduction in different sectors through implementing policies is reviewed. This paper reports on the types of policy measures that have been introduced in two cases (i.e. Tiexi District of Shenyang and Baoshan District of Shanghai) to affect air quality and energy efficiency improvements, which are then collectively examined in terms of their impacts on GHG and air pollutant emissions. Recommendations are made for achieving co-benefits effectively through the integrated approach by comprehensively concentrating on the short and long-term environmental protection and energy conservation at local and national levels based on the analysis made in the paper. The limited coordination and lack of capacity in different government bodies may be the main barriers to the implementation of a co-benefits approach. Enhancing the cooperation and capacity building could overcome these obstacles. [Copyright &y& Elsevier]

The transition from autocracy to democracy may lead a country to break-up. The break-ups of the USSR and Yugoslavia led to sharp falls in the level of emissions (while pre- and post-crisis trends are similar). If something like that would happen in China, an event with an unknown but small probability, projected emissions would fall by 50 % or more. The effect of a break-up on emissions in 2050 is larger than the difference between the SRES scenarios. [ABSTRACT FROM AUTHOR]

ABSTRACT The Clean Development Mechanism (CDM) is a flexible market mechanism intended to reduce greenhouse emissions and promote sustainable development. China hosts a third of all registered CDM projects, and generates two-thirds of all certified emissions reductions. Understanding the political economy of the CDM in China is therefore of critical importance in determining whether the CDM is an effective instrument to promote sustainable development and mitigate climate change. This paper discusses the nature and dynamics of CDM project development in China by analysing the 579 registered CDM projects operating in China as of 1 July 2009. The predominant activities are hydroelectric and wind power projects, with foreign involvement largely by European firms specializing in emerging carbon markets. The sustainability outcomes of projects in China are primarily economic, with environmental benefits largely restricted to cleaner production. The results suggest that the CDM is largely being employed as an ancillary device to attract foreign investment and further China's existing development agenda. We argue that the these results indicate the need for further reform of the CDM to achieve desired outcomes, and that China's approach to the design of integrated policy portfolios might be an example of how to achieve this. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment. [ABSTRACT FROM AUTHOR]

This study aims to assess CO2 levels in China, based on the dry air column-averaged mixing ratios of CO2 measured by the Scanning Imaging Absorption spectrometer for Atmospheric CartograpHY (SCIAMACHY) instrument on board ENVISAT and emission inventories. A land cover and statistical data set, the Regional emission inventory in Asia (REAS), was also used in this study. The results show that the spatial variations of the CO2 concentration in the whole of China are obvious, and with clear seasonal fluctuation during 2003-2005. The monthly averaged variability of CO2 over China fluctuates, with the peak occurring in April to May and the trough occurring in August to October. The largest peak-to-trough amplitude was about 16 ppm in this period. The spatial and temporal variations of CO2 had a strong correlation with anthropogenic CO2 emissions and regional terrestrial ecosystem, as well as local meteorological conditions. This paper illustrates that satellite data are promising for obtaining a comprehensive understanding of the variations of atmospheric CO2 concentrations and of CO2 emissions to the atmosphere. [ABSTRACT FROM AUTHOR]

Methane (CH4) is the most important greenhouse gas and reactive trace gas in the atmosphere. Recently, it has been reported that terrestrial plants can emit CH4 under aerobic conditions, which may call for reevaluation of the inventory of CH4 emissions in China. In this paper, those emissions over China and their effects on CH4 concentrations in lower troposphere were investigated. Firstly, based on the work of Keppler et al., the aerobic plant CH4 emission model (PLANTCH4) for China was established. And by using the database of normalized difference vegetation index (NDVI) derived from NOAN AVHRR, the distribution of net primary productivity (NPP) over China was simulated, and thereby, for the first time, the amount and distribution of the newly identified source in China were estimated. Secondly, with the aid of the three-dimensional atmospheric chemistry model system (MM5-CALGRID), the effects of the emissions were studied. The results show that the annual aerobic plant CH4 emissions over China amount to 11.83 Tg, i.e. nearly 24% of Chinese total CH4 emissions. And the major fraction (about 43%) comes from forests. When those emissions are considered in modeling, computed countrywide mean surface concentration of CH4 is 29.9% higher than without them, with a maximum increase of 69.61 μg · m-3 in the south of Yunnan Province. In conclusion, to study CH4 emissions from terrestrial plants over China may have important implications for correctly estimating the contribution of China to global CH4 budget, and may call for a reconsideration of the role of CH4 in global and regional environment and climate change. [ABSTRACT FROM AUTHOR]

As a extra-large city in China, Beijing faces a serious problem with air pollution. In 1998, a package of air pollution control measures was announced by local government. However in order to reach environment target, further policy options have to be explored. Based on previous studies on technology choices for urban transport in Beijing, this paper presents a policy assessment to examine these options. A methodology framework using criteria for policy evaluation was used in the assessment. Here diesel-car, Compressed Natural Gas (CNG) vehicle and Mass Railway based Transport (MRT) were selected, and barriers to their diffusion were identified. For each barrier, a group of policy options to remove the barrier was evaluated by five criteria. A ranking of these policy options is given in this paper. [ABSTRACT FROM AUTHOR]

Alleviating global climate change requires the development and adoption of green innovation. This study compares the impact of cooperative and independent green innovation on carbon reduction based on the panel data covering 252 cities in China from 2003 to 2019. We examine the heterogeneous impacts of cooperative green innovation across units, and explain the transmission mechanism. The two-way fixed effects model and interaction model are adopted. Results show that: (1) Cooperative green innovation can reduce carbon emissions more effectively than independent green innovation. A 1% increase in cooperative green patents (inventions) will reduce carbon emissions by 0.023% (0.037%), while independent green patents or inventions play a weak role. (2) For research and development (R&D) partners, firms' cooperative green innovation has a stronger positive effect on carbon reduction than research organizations. The carbon reduction effect of cooperative green innovation is better for listed firms and universities. (3) Mechanism analysis shows cooperative green innovation can reduce carbon emissions by improving the industrial structure and decreasing energy intensity. These effects are stronger when cities have more talent, funds and higher marketability. (4) We also find that listed firms' cooperative green inventions with a ten-year lag can still reduce carbon emissions effectively. Cooperative green innovation is conducive to carbon reduction among eastern and central cities of China. [Display omitted] • This paper explores the impact of green innovation on carbon reduction from the new perspective of cooperation. • Cooperative green innovation is more effective than independent green innovation in carbon reduction. • Cooperative green innovation of listed firms and universities is more conducive to carbon reduction. • Cooperative green innovation can optimize the industrial structure and decrease energy intensity for better carbon reduction. • Cooperative green innovation with more talent, funds and market has better carbon reduction effect. [ABSTRACT FROM AUTHOR]

The issue of climate change has become an increasing concern for the international community. At the same time, climate change and, particularly, global warming affects the amount of energy required in China and the structure of this demand, thereby influencing the amount of CO 2 (carbon dioxide) emissions produced. To investigate the possible influence of climate change on China's CO 2 emissions, this paper utilizes the degree-day method to calculate the heating degree days (HDD) and cooling degree days (CDD) in 29 provinces in China from 1995 to 2011. A series of appropriate econometric models are subsequently estimated to measure the impact of climate change on CO 2 emissions per capita. To enhance the explanatory power of the estimation results, several indicators, such as income per capita, industry structure, urbanization rate and population density, are incorporated in the estimation equations as control variables. The estimation results indicate that the feedback effect of climate change on China's carbon emissions is statistically significant but not large in magnitude. During the sample period between 1995 and 2011, approximately 1.687% of China's increased total CO 2 emissions could be attributed to climate change. Moreover, the impacts of climate change on different regions of China are notably different. For example, the influence of HDD on CO 2 emissions per capita are most significant in the middle and southern regions, while the impacts of CDD are most significant in the eastern and northern regions. However, there is no obvious evidence that climate change has affected CO 2 emissions in the western region. [ABSTRACT FROM AUTHOR]

At the Conference of the Parties held in Copenhagen in 2009 (COP15), the Chinese government announced its 2020 commitment to reduce the carbon intensity of the Chinese economy to 40–45% of its 2005 level. A number of analysts have criticised this target, indicating that these reductions can be achieved without the implementation of any active climate change policy. In this paper, we test this argument using a combined input–output based econometric projection approach and the World Input–Output Database (WIOD). Our results show that the projected carbon intensity for 2020 is likely to be 50% lower than the carbon intensity of 2005, without additional active climate change policy measures performed by the Chinese government. On top of it, our study indicates that the total volume of CO 2 emissions would be by 2020 seven times the volume of the year 2005. [ABSTRACT FROM AUTHOR]

China's climate has been warming since the 1950s, with surface air temperature increasing at a rate higher than the global average. Changes in climate have exerted substantial impacts on water resources, agriculture, ecosystems and human health. Attributing past changes to causes provides a scientific foundation for national and international climate policies. Here, we review recent progress in attributing the observed climate changes over past decades in China. Anthropogenic forcings, dominated by greenhouse gas emissions, are the main drivers for observed increases in mean and extreme temperatures. Evidence of the effect of anthropogenic forcings on precipitation is emerging. Human influence has increased the probability of extreme heat events, and has likely changed the occurrence probabilities for some heavy precipitation events. The way a specific attribution question is posed and the conditions under which the question is addressed present persistent challenges for appropriately communicating attribution results to non-specialists. [ABSTRACT FROM AUTHOR]

Abstract: In recent years, heavy metal pollution accidents were reported frequently in China. The atmospheric heavy metal pollution is drawing all aspects of attention. This paper summarizes the recent research results from our studies and previous studies in recent years in China. The level, temporal variation, seasonal variation and size distribution of the heavy metals of atmospheric Lead(Pb), Vanadium(V), Manganese(Mn), Nickel(Ni), Chromium(Cr), Cadmium(Cd), Copper(Cu), Zinc(Zn) and Arsenic(As) were characterized in China. The emission characteristics and sources of atmospheric heavy metals and As in China were reviewed. Coal burning, iron and steel industry and vehicle emission are important sources in China. Control policies and effects in China were reviewed including emission standards, ambient air quality standards, phase out of leaded gasoline and so on, and further works for atmospheric heavy metals control were suggested. The comprehensive heavy metals pollution control measures and suggestions were put forward based on the summarization of the development and experience of the atmospheric heavy metal pollution control abroad. [Copyright &y& Elsevier]

Abstract: The effects of black carbon (BC) aerosol on climate warming have been the study focus in the recent decade, and the reduction of BC is now expected to have significant near-term climate change mitigation. Large uncertainties of BC optical properties, however, still exist and seriously restrict the ability to quantify BC''s climate effects. In this study, advanced instrumentation (a three-wavelength photoacoustic soot spectrometer (PASS-3) and a single particle soot photometer (SP2)) were used to measure black carbon aerosol and analyze its optical properties in a mega-city in South China, Shenzhen, during the summer of 2011. The results indicated that the average BC mass concentration was 4.0 ± 3.1 μg m−3 during the campaign, accounting for ∼11% of the total PM2.5 mass concentration. The PM2.5 light absorption at 405, 532 and 781 nm was 37.1 ± 28.1, 25.4 ± 19.0 and 17.6 ± 12.9 Mm−1, respectively. The average absorption Angstrom exponent of PM2.5 in visual spectrum (AAE405–781 nm) was 1.1 ± 0.1 during the campaign, indicating that the light absorbing carbon mainly came from vehicular emissions, with little contributions from biomass burning emissions. The mass absorption efficiency (MAE) of BC at 532 nm ranged from 5.0 to 8.5 m2 g−1 during the campaign, with an average of 6.5 ± 0.5 m2 g−1, and showed an obvious diurnal pattern with high values in the daytime. The average percentage of internally mixed BC was 24.3 ± 7.9% during the campaign, showing significant positive correlation relationship with the MAE of BC. More quantitative data analysis indicated that the internally mixed BC would amplify MAE by about 7% during the campaign, which stands in accordance with the new finding of a very recent Science magazine paper (Cappa et al., 2012) that the BC absorption enhancement due to internal mixing in the real atmosphere is relatively low, in apparent contrast to theoretical model predictions. [Copyright &y& Elsevier]

Abstract: China is a large developing country with high carbon intensity. It is likely that China will have to face the challenge of CBTA (carbon motivated border tax adjustments) in future. Meanwhile, CBTA would create price gap between CBTA users and target countries, and change the competitiveness of different producers. Under such circumstances, this paper seeks to contribute to the debate on CBTA by focusing on the potential impacts of CBTA on different regions of China from a perspective of competitiveness. We adopt two geographical divides in China (eastern–central–western zones, high-trade-openness to low-trade-openness regions), and simulate the potential impacts across regions through a general equilibrium model. Our simulation results show that CBTA would affect competitiveness of different producers, their comparative advantages, relative trade shares, outputs and emissions. CBTA would induce structure change of the economy, and result in a shift of industrial output toward non-industrial output. There are significant differences in the effects of CBTA among different regions in China. CBTA would result in a relocation of outputs across regions in China. Therefore, CBTA would also have impact on China’s regional development policy. [Copyright &y& Elsevier]

Abstract: Urban building system assumes significant environmental and ecological implications in terms of a contribution of emissions of CO2 and other greenhouse gases. In order to understand the roles of urban building system in the global and regional climate changes, we set up an integrated model to analyze the carbon emissions of urban building system during its life cycle in this paper, which is called LCCE Model. The further analysis is made to examine the sources of CO2 emissions and the life cycle characteristics of typical architectural structures as masonry-concrete and steel-concrete. We first identified four major sources of CO2 emissions during the whole life cycle of urban building system, which are industrial process emissions, energy consumption emissions, fugitive emissions and land footprint emissions. Given an assumption of a building life cycle of 50years, we took urban residential buildings as an example and calculated CO2 emissions in the main five phases of an overall life cycle of a residential building system, including constructive materials preparation, building construction and reformation, building operation, building demolition as well as wastes treatment and recycling. A comparison was made to examine the differences of CO2 emissions among buildings with two typical architectural structures as masonry-concrete and steel-concrete. The results show that the latter produces less CO2 emission than the former per unit area. Specifically, the amount of CO2 emission is 329.61t for masonry-concrete buildings and 315.79t for steel-concrete buildings per 100m2. Most emissions come from energy consumption and land footprint, accounting for 78–83% and 13–20% of the total emissions respectively. According to our LCCE model, there is a great potential of reducing carbon emissions in urban building system. The key to reduce carbon emissions during the life cycle of urban buildings is directed to building wastes recycling, improvement of consumption patterns of energy and materials, preferential use of buildings with a moderate floor area ratio and effective utilization of natural energy and ecologically friendly building materials according to the characteristics of local urban development. [Copyright &y& Elsevier]

Abstract: As an important renewable energy, wind power has been paid more and more attentions in China recent years, in order to weaken the influence of climate change. We should know exactly the benefits wind power can produce, before government formulates relevant policies to accelerate its deployment. In this paper, we calculate the quantity of fossil energy saving and pollutant abatement in its life cycle, comparing with the baseline technology, i.e. 600MW coal-fired thermal power. Considering the damage cost of the pollutants, we can assess the benefits of development of wind power. By our model, we know that wind power can save 0.3839 kgce and avoid 0.203 yuan environmental cost when it generates 1 kWh electric quantity, comparing with coal-fired thermal power. [Copyright &y& Elsevier]

Abstract: Release of CO2 has caused significant climate change, and agricultural land use consitutes an important carbon source as well as principal carbon sinks. This paper, by examining carbon functions of main agricultural land in China, shows that in 2000-2008 the annual growth rate of carbon emission for arable land amounted to 2.47 percent, the average annual growth of carbon sinks for forest reached 3.19 percent, and the diminishing rate of carbon sink for grassland turned to be small but quite distinct. For arable land, higher carbon emissions are mainly located in its central provinces and major agricultural provinces, while higher carbon intensity in its eastern coastal provinces. Agricultural land of 9 provinces in China was found with net carbon emissions, primarily in the agricultural provinces and ecologically fragile urban areas, whereas the other 22 provinces with net carbon sinks. The EKC tests between carbon intensity of agricultural land and agricultural output per capita illustrate a significant inverted Ucurve relationship; as for agricultural output per capita, the inflection point of 9,615 RMB yuan was surpassed by 11 provinces, mainly in eastern China, developed cities and the northeast region. Finally, policy recommendations are proposed to reduce carbon emissions of agricultural land use across China. [Copyright &y& Elsevier]

Abstract: Climate change poses huge challenges to the sustainable development of human society. As a major CO2 emission source, decarbonization of power sector is fundamental for CO2 emission abatement. Therefore, considering the “carbon lock-in” effects, it’s critical to formulate an appropriate roadmap for low-carbon generation technologies. In this paper, key low-carbon technology solutions are firstly identified according to their developing prospects and the fundamental realities of China’s power sector. Then, costs, reduction effects and potentials for the key technology options are evaluated. On this basis, typical scenarios are selected and a scenario set is established which identifies and incorporates the key low carbon factors, and a multi-scenario analysis is implemented to China’s power sector based on a comprehensive power mix planning model. Then, contributions of CO2 reduction among the key technology solutions are revealed. Prospect for CO2 emission reduction is discussed, which informs the possible emission trajectories towards 2030. Finally, low-carbon technology roadmaps under specific scenarios are elaborated, which implies corresponding optimal evolution of power generation mix. [Copyright &y& Elsevier]

Abstract: This paper reports findings of a recent field study that characterized the on-road emissions of individual diesel vehicles in and around Beijing, China during November and December of 2009. We successfully sampled 230 individual trucks on 4 major expressways around the city as well as 57 individual buses in the city using refined mobile chasing techniques and fast response instruments. Emission factors (EF) for carbon monoxide (CO), black carbon (BC) and particulate matter with diameters less than 0.5 μm (PM0.5) are derived from the measurements, which are consistent with the results from laboratory dynamometer tests. The PM0.5 number emission factor distributions demonstrate consistent bimodal modes with peaks around 10 nm and 80 nm, while the mass emission factor distributions demonstrate a unimodal maximum around 110 nm for a majority of the trucks. The BC emissions are shown to be highly correlated with the mass emission of particles with 100–250 nm diameters, which are in good agreement with the results from previous studies. A number of important policy implications are discussed based on the results from this study. First, we identified “heavy emitters” in the on-road fleet we encountered, finding that 5% of diesel trucks in this sample are responsible for 50% of total BC emissions, and 20% of the trucks are responsible for 50% CO and PM0.5 number emissions, 60% PM0.5 mass emissions and over 70% of BC emissions. This suggests that emissions control programs should include identifying and removing heavy emitters from the road or improving their emissions. Second, the BC and PM0.5 number emission factors of trucks registered in regions outside Beijing are significantly higher than those of Beijing-registered trucks, suggesting that improving engine and fuel standards in Beijing alone is not sufficient in reducing the traffic-related air pollution in Beijing. Third, the significantly lower emissions from Euro IV and CNG buses compared to the Euro II and Euro III buses support that introducing clean-burning buses is an effective way to reduce the overall vehicle emissions for the pollutants studied. Fourth, our refined chasing method demonstrates a cost-effective approach to characterize the emissions from a large number of on-road diesel vehicles. Further studies with large sample sizes are critical to constructing more accurate mobile emission inventories to represent the on-road vehicle population. [Copyright &y& Elsevier]

Abstract: The automobile industry in China has rapidly developed in recent years which resulted in an increase in gasoline usage and greenhouse gas (GHG) emissions. Focus on climate change has also accelerated to grow pressure on reducing vehicle weight and improving fuel efficiency. Aluminum (Al) as a light metal has demonstrated a great potential for weight savings in applications such as engine blocks, cylinder heads, wheels, hoods, tailgates etc. However, primary Al production requires intensive energy and the cost of Al is more than traditional steel, which may affect the total benefits realized from using Al in automobiles. Therefore, it is very essential to conduct a study to quantify the life cycle GHG emissions and energy consumption if the plan is to achieve fleet-wide Al intensive vehicles. This paper describes a life cycle assessment (LCA) methodology and the general modeling assumptions used to evaluate the impact of Al intensive vehicle on GHG emissions and energy consumption. The results indicated that the reductions in life cycle GHG emissions and energy consumption were not significant when the maximum Al content in an automobile is 145 kg, which is the average level of Al usage in automobiles in North America. A neural network methodology was used to forecast the vehicle stock in China from 2010 to 2020 and a vehicle fleet model was established to track GHG emissions and energy consumption of the vehicle fleet. A material availability factor was also introduced into the LCA methodology to further assist decision makers in providing rational proposals for a widespread implementation of Al in automobiles. A sensitivity analysis was also conducted to study the impact of the Al content in a vehicle on the final outcomes. The GHG emissions and energy consumption could be further reduced when the Al content in an automobile increases. [ABSTRACT FROM AUTHOR]

Abstract: This paper uses multivariate co-integration Granger causality tests to investigate the correlations between carbon dioxide emissions, energy consumption and economic growth in China. Some researchers have argued that the adoption of a reduction in carbon dioxide emissions and energy consumption as a long term policy goal will result in a closed-form relationship, to the detriment of the economy. Therefore, a perspective that can make allowances for the fact that the exclusive pursuit of economic growth will increase energy consumption and CO2 emissions is required; to the extent that such growth will have adverse effects with regard to global climate change. [ABSTRACT FROM AUTHOR]

Abstract: Monthly nitrogen isotopes of ammonium and nitrate in wet deposition in the city of Guangzhou, and the causes of their variability, are reported in this paper. Nitrate δ15N showed nearly constant values around zero in the dry season (October to April), but oscillating values from negative to positive in the rainy season (May to September). By contrast, ammonium δ15N displayed lower values during the rainy season than in the dry season. The rural area north of the city was considered as the prominent source of ammonium and nitrate in spring and early summer (May and June), as suggested by their concurrent negative isotopic trends and higher NH4 +/NO3 − ratios. From July to September, different dominating sources from the city, i.e., fossil fuel combustion for nitrate, and sewage and waste emission for ammonium, caused disparate δ15N trends of the two species, showing positive nitrate δ15N, but still negative ammonium δ15N. During the cool dry season, the high values of ammonium δ15N and concurrently low NH4 +/NO3 − ratios suggested the decrease in NH3 volatilization and relatively important thermogenic origin of ammonium, but the intermediate nitrate δ15N values around zero may be a result of a balanced emission of NOx from the city and the rural areas. The isotopic effects of chemical conversion of NOx to nitrate and washout of nitrate were ruled out as significant causes of nitrate δ15N variability, but ammonium washout, during which 15N is assumed to be preferentially removed, may partly contribute to the ammonium δ15N variability. [Copyright &y& Elsevier]

In this paper, we report the results and analysis of a recent field campaign in August 2007 investigating the impacts of emissions from transportation on air quality and community concentrations in Beijing, China. We conducted measurements in three different environments, on-road, roadside and ambient. The carbon monoxide, black carbon and ultrafine particle number emission factors for on-road light-duty vehicles are derived to be 95gkg−1-fuel, 0.3gkg−1-fuel and 1.8×1015 particleskg−1-fuel, respectively. The emission factors for on-road heavy-duty vehicles are 50gkg−1-fuel, 1.3gkg−1-fuel and 1.1×1016 particleskg−1-fuel, respectively. The carbon monoxide emission factors from this study agree with those derived from remote sensing and on-board vehicle emission testing systems in China. The on-road black carbon and particle number emission factors for Chinese vehicles are reported for the first time in the literature. Strong traffic impacts can be observed from the concentrations measured in these different environments. Most clear is a reflection of diesel truck traffic activity in black carbon concentrations. The comparison of the particle size distributions measured at the three environments suggests that the traffic is a major source of ultrafine particles. A four-day traffic control experiment conducted by the Beijing Government as a pilot to test the effectiveness of proposed controls was found to be effective in reducing extreme concentrations that occurred at both on-road and ambient environments. [Copyright &y& Elsevier]

Emissions reduction in industrial processes, i.e. clean production, is an essential requirement for sustainable development. Fossil fuel combustion is the main emission source for gas pollutants, such as NOX, SO2 and CO2, and coal is now a primary energy source used worldwide with coal combustion being the greatest atmospheric pollution source in China. This paper analyzes flue gas cleaning by ammonia scrubbing (FGCAS) for power plants to remove gaseous pollutants, such as NOX, SO2 and CO2, and presents the conceptual zero emission design for power plants. The byproducts from the FGCAS process can be used in agriculture or for gas recovery. Experimental results presented for SO2 removal from the simulated flue gas in a continuous flow experiment, which was similar to an actual flue gas system, showed that the effectiveness of the ammonia injection or scrubbing depends on the temperature. The FGCAS process can effectively remove SO2, but the process temperature should be below 60 °C or above 80 °C for SO2 reduction by NH3 scrubbing. [Copyright &y& Elsevier]

In recent years, air pollution has caused more than 1 million deaths per year in China, making it a major focus of public health efforts. However, future climate change may exacerbate such human health impacts by increasing the frequency and duration of weather conditions that enhance air pollution exposure. Here, we use a combination of climate, air quality, and epidemiological models to assess future air pollution deaths in a changing climate under Representative Concentration Pathway 4.5 (RCP4.5). We find that, assuming pollution emissions and population are held constant at current levels, climate change would adversely affect future air quality for >85% of China's population (~55% of land area) by the middle of the century, and would increase by 3% and 4% the population-weighted average concentrations of fine particulate matter (PM2.5) and ozone, respectively. As a result, we estimate an additional 12,100 and 8,900 Chinese (95% confidence interval: 10,300 to 13,800 and 2,300 to 14,700, respectively) will die per year from PM2.5 and ozone exposure, respectively. The important underlying climate mechanisms are changes in extreme conditions such as atmospheric stagnation and heat waves (contributing 39% and 6%, respectively, to the increase in mortality). Additionally, greater vulnerability of China's aging population will further increase the estimated deaths from PM2.5 and ozone in 2050 by factors of 1 and 3, respectively. Our results indicate that climate change and more intense extremes are likely to increase the risk of severe pollution events in China. Managing air quality in China in a changing climate will thus become more challenging. [ABSTRACT FROM AUTHOR]

The development of low‐carbon transportation is growing rapidly, which plays an increasingly important functional role in economic growth and dealing with climate change. The transport carbon emissions in China between 1995 and 2014 using the Intergovernmental Panel on Climate Change emission‐factor approach are estimated in this research. This article analyzes the decoupling relationship between transport carbon emissions and economic growth in China and puts forward a decoupling volatility index to evaluate the stability of decoupling by applying Tapio's decoupling model which is composed of structure, technology, and scale decoupling elasticity. From the results, the relationships between transport carbon emissions and Gross Domestic Product (GDP), and transport carbon emission and its added value, appear to be complex characteristics of the stages and experience a process of weak decoupling. The relationship between added value of transportation and energy consumption intensity is relatively simple and experience a process of strong negative decoupling, while energy consumption intensity and GDP show a strong decoupling relationship. The four elastic decoupling fluctuation indices are large, which illustrate that the state of decoupling is not stable. Policies are made available to facilitate a better understanding of transportation structure, fuel type, and energy efficiency. Future research will focus on aspects of spatial analysis, formation mechanism, and driver factor analysis. © 2018 American Institute of Chemical Engineers Environ Prog, 37: 1696–1704, 2018 [ABSTRACT FROM AUTHOR]

To investigate the influences of different factors on spatial heterogeneity of regional carbon emissions, we firstly studied the spatial-temporal dynamics of regional energy-related carbon emissions using global Moran’s I and Getis-Ord Gi and applied geographical detector model to explain the spatial heterogeneity of regional carbon emissions. Some conclusions were drawn. Regional carbon emissions showed significant global and local spatial autocorrelation. The carbon emissions were greater in eastern and northern regions than in western and southern regions. Fixed assets investment and economic output had been the main contributing factors over the study period, and economic output had been decreasing its influence. Industrial structure’s influence showed a decrease trend and became smaller in 2015. The results of the interaction detections in 2015 can be divided into two types: enhance and nonlinear, and enhance and bivariate. The interactive influences between technological level and fixed assets investment, economic output and technological level, population size and technological level, and economic output and economic development were greater than others. Some policy recommendations were proposed. [ABSTRACT FROM AUTHOR]

Objective: Bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae (Psa) is a major threat to the kiwifruit industry throughout the world and accounts for substantial economic losses in China. The aim of the present study was to test and explore the possibility of using MaxEnt (maximum entropy models) to predict and analyze the future large-scale distribution of Psa in China. Method: Based on the current environmental factors, three future climate scenarios, which were suggested by the fifth IPCC report, and the current distribution sites of Psa, MaxEnt combined with ArcGIS was applied to predict the potential suitable areas and the changing trend of Psa in China. The jackknife test and correlation analysis were used to choose dominant climatic factors. The receiver operating characteristic curve (ROC) drawn by MaxEnt was used to evaluate the accuracy of the simulation. Result: The results showed that under current climatic conditions, the area from latitude 25° to 36°N and from longitude 101° to 122°E is the primary potential suitable area of Psa in China. The highly suitable area (with suitability between 66 and 100) was mainly concentrated in Northeast Sichuan, South Shaanxi, most of Chongqing, West Hubei and Southwest Gansu and occupied 4.94% of land in China. Under different future emission scenarios, both the areas and the centers of the suitable areas all showed differences compared with the current situation. Four climatic variables, i.e., maximum April temperature (19%), mean temperature of the coldest quarter (14%), precipitation in May (11.5%) and minimum temperature in October (10.8%), had the largest impact on the distribution of Psa. Conclusion: The MaxEnt model is potentially useful for forecasting the future adaptive distribution of Psa under climate change, and it provides important guidance for comprehensive management. [ABSTRACT FROM AUTHOR]

Climate change has gained widespread attention, and the rapid growth of the economy in China has generated a considerable amount of carbon emissions. Zhejiang Province was selected as a study area. First, the energy-related carbon emissions from 2000 to 2014 were accounted for, and then the Logarithmic Mean Divisia Index (LMDI) decomposition model was applied to analyse the driving factors underlying the carbon emissions. Finally, three scenarios (inertia, comparative decoupling and absolute decoupling) for 2020 and 2030 were simulated based on the low-carbon city and Human Impact Population Affluence Technology (IPAT) models. The results showed (1) carbon emissions increased by 1.66 times from 2000 to 2014, and trends of carbon emissions were used to divide the study period into three phases (rapid, medium growth and slow decrease phases, with annual growth rates of 12.60%, 4.77% and -1.24%, respectively); (2) the energy intensity effect from 2000-2011 inhibited carbon emissions but was exceeded by the economic output effect, which increased emissions, whereas the energy intensity effect from 2011-2014 outweighed the economic output effect; (3) the scenario analyses revealed that both the comparative and absolute decoupling scenarios would remain consistent with the carbon emissions boundaries in 2020 and 2030, but the comparative decoupling scenario was more reasonable for sustainable development. In addition, appropriate design of emission trading scheme could help to achieve the comparative decoupling by financial incentives. [ABSTRACT FROM AUTHOR]

The winter haze is a growing problem in North China, but the causes are not well understood. The chemistry version of theWeather Research and Forecasting model (WRF-Chem) was applied in North China to examine how PM2.5 concentrations change in response to changes in emissions (sulfur dioxide (SO2), black carbon (BC), organic carbon (OC), ammonia (NH3), and nitrogen oxides (NOx)), as well as meteorology (temperature, relative humidity (RH), and wind speeds) changes in winter. From 1960 to 2010, the dramatic changes in emissions lead to +260% increases in sulfate, +320% increases in nitrate, +300% increases in ammonium, +160% increases in BC, and +50% increases in OC. The responses of PM2.5 to individual emission species indicate that the simultaneous increases in SO2, NH3, and NOx emissions dominated the increases in PM2.5 concentrations. PM2.5 shows more notable increases in response to changes in SO2 and NH3 as compared to increases in response to changes in NOx emissions. In addition, OC also accounts for a large fraction in PM2.5 changes. These results provide some implications for haze pollution control. The responses of PM2.5 concentrations to temperature increases are dominated by changes in wind fields and mixing heights. PM2.5 shows relatively smaller changes in response to temperature increases and RH decreases compared to changes in response to changes in wind speed and aerosol feedbacks. From 1960 to 2010, aerosol feedbacks have been significantly enhanced due to higher aerosol loadings. The discussions in this study indicate that dramatic changes in emissions are the main cause of increasing haze events in North China, and long-term trends in atmospheric circulations may be another important cause since PM2.5 is shown to be substantially affected by wind speed and aerosol feedbacks. More studies are necessary to get a better understanding of the aerosol-circulation interactions. [ABSTRACT FROM AUTHOR]

Tropospheric ozone (O3) is a trace gas playing important roles in atmospheric chemistry, air quality and climate change. In contrast to North America and Europe, long-term measurements of surface O3 are very limited in China. We compile available O3 observations at Mt. Tai - the highest mountain over the North China Plain - during 2003-2015 and analyze the decadal change of O3 and its sources. A linear regression analysis shows that summertime O3 measured at Mt. Tai has increased significantly by 1.7 ppbv yr-1 for June and 2.1 ppbv yr-1 for the July-August average. The observed increase is supported by a global chemistry-climate model hindcast (GFDL-AM3) with O3 precursor emissions varying from year to year over 1980-2014. Analysis of satellite data indicates that the O3 increase was mainly due to the increased emissions of O3 precursors, in particular volatile organic compounds (VOCs). An important finding is that the emissions of nitrogen oxides (NOx) have diminished since 2011, but the increase of VOCs appears to have enhanced the ozone production efficiency and contributed to the observed O3 increase in central eastern China. We present evidence that controlling NOx alone, in the absence of VOC controls, is not sufficient to reduce regional O3 levels in North China in a short period. [ABSTRACT FROM AUTHOR]

Against a background of climate change, Macau is very exposed to sea level rise (SLR) because of its low elevation, small size, and ongoing land reclamation. Therefore, we evaluate sea level changes in Macau, both historical and, especially, possible future scenarios, aiming to provide knowledge and a framework to help accommodate and protect against future SLR. Sea level in Macau is now rising at an accelerated rate: 1.35 mm yr over 1925-2010 and jumping to 4.2 mm yr over 1970-2010, which outpaces the rise in global mean sea level. In addition, vertical land movement in Macau contributes little to local sea level change. In the future, the rate of SLR in Macau will be about 20% higher than the global average, as a consequence of a greater local warming tendency and strengthened northward winds. Specifically, the sea level is projected to rise 8-12, 22-51 and 35-118 cm by 2020, 2060 and 2100, respectively, depending on the emissions scenario and climate sensitivity. Under the +8.5 W m Representative Concentration Pathway (RCP8.5) scenario the increase in sea level by 2100 will reach 65-118 cm-double that under RCP2.6. Moreover, the SLR will accelerate under RCP6.0 and RCP8.5, while remaining at a moderate and steady rate under RCP4.5 and RCP2.6. The key source of uncertainty stems from the emissions scenario and climate sensitivity, among which the discrepancies in SLR are small during the first half of the 21st century but begin to diverge thereafter. [ABSTRACT FROM AUTHOR]

Six global climate models (GCMs) from Coupled Model Intercomparison Project Phase 5 under three Respectively Concentration Pathways (RCP2.6, RCP4.5 and RCP8.5) were used to assess the impact of climate change on streamflow for the Huangnizhuang catchment (HNZ) in China. Change factor method was used for bias correction between GCM outputs and observations and the SWAT model was used to simulate the hydrological processes. The results indicated that the SWAT model performed well in the study catchment with a monthly Nash-Sutcliffe efficiency (NS) of 0.93 and 0.91 and daily NS of 0.63 and 0.68 for calibration and validation periods respectively. Their corresponding relative errors were −2.2 and 8.9, and −2.6 and 8.5 % respectively. The ensemble of multi-GCMs projected an increase of precipitation in the middle and end of twenty-first century over the HNZ, ranging from −2.4 to 9 %. However, streamflow is likely to decline in the future, ranging −6.9 to 0.8 %, mainly due to an increase of evapotranspiration in a warming world, as air temperature shows steadily increases for all the GCMs and RCPs. Average monthly streamflow from six GCMs are likely to increase in August and September but decline from October to June. The associated uncertainties of the reported results were also discussed. It includes, but is not limit to, different GCMs, emissions scenarios, downscaling techniques as well as hydrological simulations. The results of this study can inform planning of long-term basin water management strategies taking into account global change scenarios. [ABSTRACT FROM AUTHOR]

Since the late 1970s, the Chinese government has implemented massive afforestation projects to address grievous environmental disasters, protect human health and provide long-term environmental security. Having a better understanding of the total carbon sink from the afforestation projects is fundamental to assess its global carbon benefit. Here, the sequestered carbon stock based on Chinese national forest inventory data is calculated by using three comparable volume-derived biomass models. Results show that the carbon sink contribution from these Chinese afforestation projects was 1.02 Pg C by the end of 2008 and 0.79 Pg C on average from 1981 to 2008 with a cumulative rate of 0.028 Pg C/a, which corresponds to 2 % of the total industrial carbon emissions from China during the same period. The financial value of carbon sequestration from these projects can be estimated by its value in carbon taxes of Finland and is potentially 190 billion RMB from 1981 to 2008, which is 43.4 % of the original investment. Hence although China's afforestation projects make only modest contributions to offsetting industrial growth in carbon, the carbon sequestered, if valued according to some markets, is a significant fraction of the total project costs. [ABSTRACT FROM AUTHOR]

Historical temperature variability over China during the twentieth century and projected changes under three emission scenarios for the twenty-first century are evaluated on the basis of a multimodel ensemble of 20 GCMs from phase 5 of the Coupled Model Intercomparison Project (CMIP5) and two observational datasets. Changes relative to phase 3 of the Coupled Model Intercomparison Project (CMIP3) are assessed, and the performance of individual GCMs is also quantified. Compared with observations, GCMs have substantial cold biases over the Tibetan Plateau, especially in the cold season. The timing and location of these biases also correspond to the greatest disagreement among the individual models, indicating GCMs' limitations in reproducing climatic features in this complex terrain. The CMIP5 multimodel ensemble shows better agreement with observations than CMIP3 in terms of the temperature biases. Both CMIP3 and CMIP5 capture the climatic warming over the twentieth century. However, the magnitude of the annual mean temperature trends is underestimated. There is also limited agreement in the spatial and seasonal patterns of temperature trends over China. Based on six statistical measures, four individual models-the Max Planck Institute Earth System Model, low resolution (MPI-ESM-LR), Second Generation Canadian Earth System Model (CanESM2), Model for Interdisciplinary Research on Climate, Earth System Model (MIROC-ESM), and Community Climate System Model, version 4 (CCSM4)-best represent surface air temperature variability over China. The future temperature projections indicate that the representative concentration pathway (RCP) 8.5 and RCP 4.5 scenarios exhibit a gradual increase in annual temperature during the twenty-first century at a rate of 0.60° and 0.27°C (10 yr)−1, respectively. As the lowest-emission mitigation scenario, RCP 2.6 projects the lowest rate of temperature increase [0.10°C (10 yr)−1]. By the end of the twenty-first century, temperature is projected to increase by 1.7°-5.7°C, with larger warming over northern China and the Tibetan Plateau. [ABSTRACT FROM AUTHOR]