Transportation sector is one of the key sources of local air pollutants and GHGs emissions in China. Because of rising scale of transportation, the share of emissions from transportation increased compared with those from industrial and residential sources. This research applies an integrated CGE-CIMS model system to quantify the local air pollutants and CO2 co-control effects of environmental economic policies in China’s transportation sector. Compared with BAU scenario, all environmental economic policy instruments, including environmental tax, carbon tax, fuel oil consumption tax and their policy combinations, will lead to electricity consumption substitution for gasoline, diesel oil and other petroleum products in China’s transportation sector. Even considering the indirect emissions caused by electricity power generation, the comprehensive emission reductions, indicated by Integrated Air Pollutant Co-control Emission Reduction (ICER), are still positive, meaning all environmental economic policies and their policy combinations have co-control effects. This research made policy suggestions for supporting the environmental economic policy implementation in transportation, including focusing on high emission vehicles, applying green transportation subsidies and low carbon electric power development.
An evaluation was conducted on the co-control effect of energy-saving and emission reduction measures in the iron and steel industry. The results could be used to support the co-control planning of local air pollutants and greenhouse gases reductions. The emission factor method was used to calculate the emission reduction of various local air pollutants and greenhouse gases by different measures. Various emission reductions were then converted into Integrated Air Pollutant Co-control Emission Reduction (ICER). Co-control effects coordinate system, co-control cross elasticity, unit pollutant reduction cost and the marginal abatement cost curve were applied to examine the co-control effects for different measures. The results show that, in 2025, the 28 measures in the iron and steel industry can reduce SO2 emission by 518.0 kt, NOx by 713.5 kt, PM10 by 290.7 kt, and CO2 by 664 Mt. Except for end-of-pipe decarbonization and pollution reduction measures that do not have co-control effects, the other 25 measures have good co-control effectiveness. The “High-Temperature/High-Pressure Boiler Technologies for Coke (T3)” has the lowest cost, and the “Ultra-Low Emission Retrofitting (T28)” has the highest cost. Most energy-efficiency improvement measures, raw (fuel) material substitution measures can bring benefits (or reduce costs). Structural adjustment and energy-efficiency improvement measures have the greatest potential for emission reduction. In the future, the co-control technology development and co-control planning in the iron and steel industry should be strengthened to realize the optimization of the co-benefits of local air pollutants and greenhouse gases synergetic reductions.
Cement industry is a key sector for co-control of greenhouse gases and local pollutants. In the past, research on the industry’s co-control evaluations either was targeted at individual companies, or applied top-down and bottom-up simulation models in combination with scenario analysis to evaluate the industry’s co-control benefits. There is rarely research on systematic evaluation of the cement industry’s full range of energy-saving and emission reduction measures’ co-control effects. In the paper, a new index of Integrated Air Pollutant Co-control Emission Reduction (ICER) of 24 different measures is calculated. Co-control effects coordinate system, co-control cross elasticity, unit pollutant reduction cost and the marginal abatement cost curve are applied to examine the co-control effects for different measures. The results show that most energy-saving and emission reduction measures can synergistically reduce pollution; the greatest potential for emission reduction is from structural adjustment measures; the unit cost of energy efficiency improvement and energy-saving measures is relatively low, but the potential for emission reduction is limited. The analysis of the co-control performance of the energy-saving and emission reduction measures can provide a reference for the industry to carry out co-control path planning.
Large amounts of methane (CH4) and nitrous oxide (N2O) are released during the operation of sewage treatment plants, which are important sources of man-made greenhouse gas emissions. Based on 2005-2015 statistical data and IPCC accounting methods, the CH4 and N2O emissions from domestic sewage treatment plants in China from 2005 to 2015 were estimated, characteristics and influencing factors were analyzed. Three emission reduction scenarios (low emission reduction, medium emission reduction and high emission reduction) were set based on the carbon neutral background, and emission trends and temporal and spatial changes from 2020 to 2050 were estimated. The results showed that the greenhouse gas emissions of sewage treatment plants increased steadily from 2005 to 2015. CH4 increased from 11.35 Mt CO2e to 15.01 Mt CO2e, and N2O increased from 26.51 Mt CO2e to 27.87 Mt CO2e, the average annual growth rate was 2.8% and 0.5%, respectively. Under the three emission reduction scenarios, CH4 and N2O emissions from 2020 to 2050 show a trend of increase first and then decrease, and CH4 and N2O emissions under the low emission reduction scenario will peak in 2036 and 2025, respectively, with 24.31 Mt CO2e and 28.19 Mt CO2e; CH4 peaks in the medium and high emission reduction scenarios will occur in 2027 and 2025, respectively, while the peak N2O emissions will both occur in 2025. Compared with the low emission reduction scenario, the respective emission reduction rates of CH4 emissions under the medium and high emission reduction scenarios are about 47% and 94% in 2050. N2O emissions under the low, medium and high emission reduction scenarios in 2050 will be reduced by 12%, 53% and 95% respectively compared with 2015. There are significantly spatial differences in the emissions of CH4 and N2O. East China has the highest emissions and Northwest China has the lowest ones. The overall emission pattern is that the provinces in the southeast are higher than those in the northwest. Among the influencing factors, the level of economic development is closely related to greenhouse gas emissions.
Based on the Regional Climate Model Version 4 (RegCM4) simulations (named CdR, EdR, HdR, and MdR, respectively) dynamically downscaling from four global climate models (GCMs) as well as the observed high-resolution grid dataset CN05.1, the regional rainstorm events that occurred in China during 1981-2005 were identified by using a “tracing” objective method. On this basis, the fidelity of the RegCM4 downscaling in simulating the climate features of regional rainstorm events in China was evaluated. The results show that the four RegCM4 simulations and their ensemble can reasonably capture the observed annual cycles and climate mean values of the frequency, duration, rainfall amount, extent, and comprehensive intensity of regional rainstorm events averaged in China. They can also well reproduce the probability of duration, rainfall amount, extent and comprehensive intensity of regional rainstorm events in different bands and the climatologically spatial distribution of accumulative frequency, duration and rainfall amount of regional rainstorm events in the observation. The spatial correlations of the simulations with the observation are all above 0.9 and the root-mean-square errors are generally below 0.4. However, the simulations slightly underestimate the frequency of regional rainstorm events, mainly due to the underestimation of moderate regional rainstorm events. The average duration and average rainfall amount are slightly overestimated, while the average extent is slightly underestimated. The comprehensive intensity is overestimated by the simulations (especially by MdR) with the exception of HdR. For spatial distribution, the performance of CdR is relatively lower than that of other simulations. The relative errors of the ensemble simulation with reference to the observation are 13%, 2%, -11%, and 3% for the average duration, rainfall amount, extent, and comprehensive intensity of regional rainstorm events, respectively.
There is a special region on the southeast side of Tibetan Plateau. Southerly wind occurs through the whole year, which is closely related with East Asian monsoon and plays an important role in the weather and climate in its downstream region. Under global warming, rapid warming Tibetan Plateau makes this southerly sensitive. In order to estimate its future change under global warming, CMIP5 simulations were analyzed and compared. The results show that, in 13 CMIP5 models, only BCC-CSM1.1, GFDL-CM3 and MIROC5 models can well simulate the southerly region and its “double-peak” evolution feature in seasonal cycle. However, there are significant differences among models in the future change of the southerly. In MIROC5, the southerly will significantly enhance from June to December. But the southerly in BCC-CSM1.1 and GFDL-CM3 simulation will be significantly weakened after the autumn. Further analysis indicates that the difference of the southerly wind change is occasioned by the simulation difference of the thermal contrast between the Tibetan Plateau and East Asian plain. For MIROC5 simulation, the temperature increase over Tibetan Plateau is larger than its surrounding. The induced thermal contrast will further enhance the southerly wind. Therefore, Reasonable simulation of the thermal contrast between the Tibetan Plateau and its surrounding is very important for East Asian climate estimation.
RHtest software and station metadata were used to detect and adjust artificial shifts of the annual average temperature of Guangzhou during 1908-2019. The results showed that there were seven significant abrupt change points in 1912, 1928, 1942, 1988, 1995, 2004 and 2010. The temperature increasing rate was 1.39℃/(100 a), which was higher than the series without homogenization adjustment, with significant quasi-50-year and quasi-3-year periods. DB16 orthogonal wavelet was applied to analyze the multiple time scale changing characteristics. The trend component had the largest variance contribution, followed by quasi-3-year and quasi-6-year periodic components. The trend component began to show a continuous warming trend from the 1940s. The rapid warming from the middle 1980s to the end of the 20th century was the result of superposition of the rising phase of the quasi-50-year period component, quasi-20-year period component and the trend component. The warming hiatus from 1998 to 2014 was caused by the superposition of the cooling phase of the quasi-50-year period component, quasi-20-year period component and the quasi-10-year period component.
Agriculture is one of the most sensitive areas in response to climate change, and future crop yields may be profoundly affected. To quantitatively assess the final economic impact of climate change on crop yields, it is necessary to conduct a chain study on the comprehensive “climate change-crop yield-economic impact”. In this study systematic assessment and Meta regression methods were used to integrate 667 research results from 55 literatures, deriving the quantitative relationship between the main crop yields (rice, corn, wheat) in the seven sub-regions of China and future temperature and precipitation changes in the local area. Subsequently, the crop yields data were input to the improved multi-regional input-output model as the loss of the agricultural sector to evaluate the economic ripple effects (ERE) in and between the seven sub-regions. Results are as follows. (1) The impact of climate change on crop yields was mainly reflected in temperature increases, with an average yield loss of 2.6%-12.7% per℃, and with crop yields being more vulnerable in Northeast China and Northwest China than in other sub-regions. (2) Crop failure caused by climate change is estimated to have a more serious impact on China’s economy, each 1% drop in GDP due to crop failure will have an additional 17.8% ripple effects. (3) At the end of the 21st century, the ERE is -0.1% - 13.6% of GDP (negative values indicate economic gains) without considering CO2 fertilization effect, of which the ERE in the most pessimistic pathway is equivalent to the total agricultural output in China in 2012. (4) Sub-regional-level results show an uneven distribution of economic impact in China, which is related to the regional economic development. Southwest China experiences 2.8-8.5 times more ERE than East China.
This paper is based on 2075 articles on “climate change” “perception” and “adaptation” published in the core database of Web of Science (WOS) from 2007 to 2019, using the network visualization analysis function of CiteSpace software, combined with the relevant statistical tools in the core data set of WOS. This paper studies the literature characteristics and evolution in this field. We hope to clarify the characteristics, the foundation of knowledge and hot spot evolution of historical research in this field, and point out the future research trend, so as to provide reference for development and innovation. The results show that: in addition to climate change, adaptation and perception, vulnerability, impact, risk, management, variability, adaptive capacity, resilience, agriculture, risk perception, policy, drought and farmers are also hot words in the field of climate change perception and adaptive behavior. New words are constantly emerging in research, and more and more attention is paid to coastal areas and smallholder problem. The individual experience of the public has been paid more and more attention, and the climate change sensitive area will be a hot research area in the future. China is still in the initial stage of climate change perception and adaptive behavior research.
Carbon market and power market will jointly play a decisive role in the optimal allocation of resources and bring challenges to the operation and development of the market subject, i.e. the power generation enterprises. Based on the economic impact model of power generation enterprises considering the carbon cost, the impact of different development stages of carbon market on the electricity cost of power generation enterprises was quantitatively analyzed, and the economy of investment income of different energy structure and the impact on clearing order of centralized bidding market was quantitatively evaluated. The results show that as the paid quota allocation proportion and carbon price increase, the proportion of carbon cost in the total cost per kilowatt hour gradually rises. The carbon cost of coal-fired units accounts for 29% of the total cost per kilowatt hour, and the proportion of gas-fired units accounts for 6% of the total cost per kilowatt hour. The carbon market will promote the investment tendency to clean and efficient thermal power units and renewable energy gradually, and affect the clearing order of generating units, so as to further consolidate the high-efficiency and low-emission units competitiveness in the centralized bidding market.
Enhancing international cooperation on climate adaptation is an important part of the enhanced and comprehensive adaptation actions under Paris Agreement. Based on the current situation of global adaptation to climate change, this paper systematically reviews the international cooperation mechanisms of major developed countries and groups and the key practices of international cooperation on global climate adaptation. Considering intergovernmental communication mechanism like high-level dialogue, bilateral and multilateral cooperation, international organization cooperation and South-South cooperation with developing countries in recent years, it is concluded that the lack of funding and cooperation channels, the urgent need to deepen the international cooperation program, and the challenge of “green economy” in post epidemic Era are main problems for China to carry out international cooperation on climate change adaptation. In the post-Pairs times, in order to play an important role as a participant, a contributor and a leader in the construction of global ecological civilization, and to make China’s international cooperation on climate adaptation go further, China will truly focus on deeply participating in the construction of global climate adaptation governance mechanism, deepening cooperation with Global Center on Adaptation, exploring good practices of international cooperation on climate adaptation and developing international cooperation at city level.
