As the largest staple food crop, rice plays a pivotal role in China’s stable and safe supply system of grain and important agricultural products. It can be seen that low-carbon rice production is not only related to the promotion of the national dual-carbon strategy, but also of great significance for the improvement of the national grain self-sufficiency rate, the improvement of national dietary nutrition and the implementation of climate diplomacy. This paper systematically discusses the realization path of low-carbon sustainable rice production system from the aspects of China’s rice field methane emission status, emission reduction technology and low-carbon production strategy. In recent years, although the rice planting area in China has fluctuated, the yield per unit area of rice has continued to increase. In 2021, the average yield per mu (1 mu≈667 m2) reached 474.2 kg, a record high in history. At the same time, rice fields are also the main source of methane (CH4) emissions in China (187 Mt CO2e), accounting for 40.1% of the total methane emissions from agricultural activities in China. Therefore, facing the multiple challenges of sustainable rice production, adverse impacts of climate change in the future, and climate diplomacy, CH4 emission reduction in paddy fields must fully consider the comprehensive planning of water, fertilizers, varieties, tillage, and inoculum products. It is necessary to establish a technical system based on human-enhanced measures supplemented by Nature-based Solutions, for inhibiting growth, improving production and increasing efficiency based on near-natural regulation and artificial enhancement, which is applicable to the main rice-producing areas. On this regarding, the implementation of cover crop planting, no-tillage rotation, high-yield and low-emission variety breeding, mulching and moisture conservation, bacterial agent synergistic products, intelligent machinery, reasonable dense planting, decoupling of tillers, alternating wet and dry, and aerobic farming, etc., to ensure the effective supply of rice, reduce emissions and increase carbon, and achieve sustainable, green and high-quality development of rice.
Based on the inventory method, the agricultural CH4 emissions in China from 1981 to 2060 were calculated, and the agricultural CH4 emission reduction effects of five healthy dietary patterns were analyzed based on scenario design. Results show that CH4 emissions from agriculture in China increased from 18.46 Mt to 22.23 Mt from 1981 to 2021, with enteric fermentation, rice cultivation and freshwater aquaculture being the main sources of CH4 emissions. Under the baseline scenario, China’s agricultural CH4 emissions will reach a peak of 24.91 Mt in 2036, and the cumulative emissions from 2022 to 2060 are 940.40 Mt. The five healthy dietary scenarios will promote the early peak of CH4 in China before 2030 (2021-2027), and the cumulative emission reduction potential from 2022 to 2060 is 170.22-343.31 Mt (18%-37%) CH4. Among them, the healthy dietary scenario with relatively less consumption of animal sources food has greater CH4 emission reduction potential.
Methane emission control and reduction is considered as one of the important measures for effectively mitigating global warming effect, which has attracted widespread attention both domestically and internationally. In this paper, based on the EDGAR database, the decoupling index and Logarithmic Mean Divisia Index (LMDI) decomposition method were used to quantitatively analyze the relationship between methane emissions from solid waste treatment and economic development in G7 countries. It is found that methane emissions from solid waste treatment in G7 countries have already peaked, with the per capita GDP of the US, Canada, France, Germany, the UK and Japan being concentrated in the range of 30000-40000 US dollars when reaching the peak, and Italy’s per capita GDP just exceeded 20000 US dollars. No country has achieved absolute decoupling between emissions and economic development. As for the structural decomposition results driven by population, per capita GDP, solid waste generation intensity, and methane emission coefficient, the growth of population and per capita GDP sustainably drives the increase in methane emissions from solid waste treatment in G7 countries, but the driving force significantly weakens as the development speed slows down. The reduction of methane emission coefficient is the most important factor in achieving methane control, and the decrease in solid waste generation intensity can also suppress the increase in methane emissions in most periods. By continuously strengthening solid waste classification and recycling and promoting methane collection and utilization in landfills, methane emission coefficient is expected to continue to decline. Combining with the main methane control policies and actions taken by G7 countries, some suggestions are proposed to help China achieve methane control in the field of solid waste treatment, including formulating emission reduction strategies, controlling the intensity of solid waste generation, reducing organic matter entering landfills, and strongly promoting landfill gas recovery and utilization or disposal.
In order to systematically understand the characteristics and management status of methane (CH4) emissions in Guangdong’s municipal waste disposal sector, the CH4 emissions of solid waste landfill disposal, domestic sewage treatment and industrial wastewater treatment in 2010-2020 in Guangdong province were calculated, and the implementation of control policies in Guangdong was analyzed based on the emission results. Results indicated that from 2010 to 2020, CH4 emissions accounted for more than 70% in the field of municipal waste disposal in Guangdong, mainly from solid waste landfill disposal. Although CH4 emissions from wastewater treatment still showed an upward trend, the increase in CH4 emissions from solid waste landfill treatment in Guangdong has been initially reversed, and the emissions in 2020 were reduced by about 381 and 13 kt respectively compared with 2018 and 2010. The growth trend of CH4 emissions in the field of waste treatment was reversed during the “13th Five-Year Plan” period, denoting that Guangdong’s waste treatment CH4 emission management work has achieved certain results. In addition, in order to deepen the national and provincial CH4 emission reduction action under the goal of carbon peak and carbon neutrality, measures such as issuing an integrated CH4 emission reduction plan, refining the CH4 emission reduction management mechanism of municipal waste disposal and continuously improving the operation and management level of waste treatment facilities were also strongly recommended to the governments.
Under the background of global warming, the tracks of tropical cyclones (TCs) have changed significantly in the Northwest Pacific and the South China Sea. As a result of rapid socio-economic development in China, the exposure to disaster has increased, leading to the new characteristics of TC disasters in China. By utilizing data on provincial-level TC disaster losses from 2001 to 2020, a comparative analysis was conducted to examine the changes of TC disasters in China, with a specific emphasis on monthly variations. The findings reveal that TC disasters losses in China from July to September accounted for more than 84% of the annual total. Most of the 22 provinces (regions, municipalities) experienced the peak of TC disaster losses in August, while Guangxi witnessed the peak in July, and Hainan, Inner Mongolia, and Heilongjiang documented their highest losses in September. Among the disastrous TCs (DTCs) that caused losses to China, approximately 15% did not make landfall. Frequency of non-landfalling DTCs was the highest in Hainan, while TC disaster losses induced by non-landfalling DTCs was the heaviest in Heilongjiang. The annual frequency of DTCs and non-landfalling DTCs during 2011-2020 in China was greater than those during 2001-2010. However, the frequency of landfalling DTCs during 2011-2020 was less than that during 2001-2010. Nonetheless, both landfalling and non-landfalling DTCs demonstrated an augmented frequency in August. Influenced by the changes in TC tracks in the Northwest Pacific and the South China Sea, the prominence of TC disaster losses in August has intensified over the past decade in China. The influence of non-landfalling DTCs have aggravated, and the affected areas by DTCs have expanded northward. These changes pose more challenges for TC disaster forecasting, early warning, and disaster risk reduction efforts in China.
With rapid urbanization in China, urban heat island effect is becoming increasingly severe, and the harm to the ecological environment and human health is also gradually strengthened. Taking 84 major cities in China as an example, the differences between the atmospheric and surface urban heat island effect were compared and analyzed by using meteorological observation and remote sensing data from 2007 to 2017. The main results are as follows. The average atmospheric heat island intensity during the day and night from 2007 to 2017 is 0.37℃ and 1.15℃ respectively, and the change trend was -0.10℃/(10 a) and -0.15℃/(10 a) respectively. The average surface heat island intensity reached 1.08℃ and 1.32℃ respectively, and the change trend was -0.03℃/(10 a) and 0.13℃/(10 a) respectively. There were obvious differences between atmospheric and surface urban heat island effect in intensity, spatial distribution, diurnal variation, seasonal variation and interannual variation trend. In addition, it was found that the existing national meteorological station observation data have the risk of underestimating the urban heat island effect. The results of this paper confirm the great temporal and spatial heterogeneity of atmospheric urban heat island effect in China and its difference from surface urban heat island effect in the temporal and spatial pattern, and emphasize the importance of carrying out multi- method integration research on a large scale, so as to comprehensively grasp the evolution law of urban heat island effect. In the future, it is necessary to strengthen the research on the high-density observation and driving mechanism of atmospheric urban heat island effect.
Low carbon energy transition is essential to achieving carbon peak and carbon neutrality, and is related to economic and social development of China. Based on the LEAP energy system model, and with the electric power industry as the key emission reduction sector, the medium- and long-term pathway was explored for China to achieve carbon peak and carbon neutrality, energy demand, energy supply, CO2 emissions and costs were simulated in multiple scenarios, and the ecological and economic impacts of energy allocation were analyzed. It can be concluded that energy consumption shows a trend of reducing coal, stabilizing oil, increasing gas, and accelerating electricity substitution. Final energy consumptions could reach the peak before 2040 and CO2 emissions from final energy consumptions could reach the peak before 2030. The carbon capture, utilization and storage (CCUS) technology is crucial to achieving CO2 emission targets, while maintaining a certain amount of thermal power capacity to ensure the stability and safety of the power grid, and will gradually have the technical advantage in the future. At last, this paper proposes policy recommendations for achieving the dual carbon goals in terms of promoting controls of total carbon emissions and intensity, accelerating the low-carbon transformation of the power system by CCUS and other technologies innovations, and improving the construction of the national carbon market to promote carbon emissions trading.
The different effects of renewable energy development, carbon tax, and technological progress on the low-carbon transition of power sector were simulated by building a dynamic computable general equilibrium (CGE) model, and the pathways of carbon peak and carbon neutrality in the power sector were discussed. It is found that the clean power sector is the key to achieving carbon neutral. Under the scenario of vigorously developing renewable energy, the power sector will be close to achieving the carbon neutral by 2060. Technological progress is an important support for the low-carbon transition of the power sector. Under the scenario of renewable energy development and strong technological progress, the power sector can achieve carbon neutral after 2058. Carbon tax contributes to emission reduction but damages economic growth. With the optimization of energy structure and technological progress, China can achieve both carbon neutral and economic growth. Finally, it is proposed that while vigorously developing renewable energy and devoting to energy technology innovation, the channels should broaden to promote the high-quality development of low-carbon transition in the power sector.
From the relevant mechanism of quota allocation in the carbon trading market, we can see that China currently mainly uses the benchmark method to allocate quotas. How to set the benchmark value of the industry is the key problem in adopting this method. However, there is only limited research on the problem of setting benchmark value, which mainly focuses on the analysis of single industry. With the increasing number of carbon emissions control industries in China, setting the benchmark of each industry separately will ignore the impact of cost changes in different industries on the whole industry economy. Therefore, this paper proposes to set the benchmark under the research framework of “whole-industry+single-industry”, which compensates for the neglect of the economic impact of the present single industry benchmark and maintains the advantages of the present single industry benchmark. The results show that the price changes in the basic industries have a great impact on the whole industry, so that it is usually necessary to set higher benchmark values for these industries.
The current global financial system fails to effectively drive financial resources to support climate action, as evidenced by the order of magnitude gap between the scale of global climate finance and the financing needs aligned with the temperature rise goals under the Paris Agreement. For many years the climate finance negotiations under the United Nations Framework Convention on Climate Change (hereinafter referred to as “the Convention”) have revolved around developed countries’ funding for developing countries, yet at the 27th Conference of the Parties (COP27) to the Convention in 2022, in addition to the three “funding” issues of long-term climate finance, new collective quantified goal, and funding for loss and damage, all of which resulted in standalone decisions, the Conference also opened a window for discussion on Article 2.1 (c) of the Paris Agreement, echoing the reform of the global financial system. This marks an expansion of the connotation of climate finance under the Convention to climate finance in a broad sense and systemic solutions, i.e., how to mobilize more climate finance globally to respond to the urgent needs of poor and climate-vulnerable countries, as well as the broader financing needs aligned with the Paris Agreement. As it stands, this shift threatens to both blur the focus of negotiations on finance issues under the Convention and the principle of common but differentiated responsibilities, and to further generalize the content of negotiations on finance issues beyond the Convention, closely linked to issues such as debt relief for developing countries and reform of the global financial system. In response to the ongoing changes, China should actively prepare for the negotiations on the issues relating to Article 2.1 (c) of the Paris Agreement, seize the significant opportunity of the transformation of the global financial system, and actively participate in the discussion of the new financial mechanism and the formulation of international standards and rules.
