A systematic assessment of city-level climate change mitigation and air quality improvement in China

The comprehensive impact of thermal-PM2.5 interaction on subjective evaluation of urban outdoor space: A pilot study in a cold region of China

Urban outdoor space has a very important impact on the quality of people's outdoor activities, which has influenced people's health and moods. Its influence is the result of the combined action of various factors. Thermal and air quality environment are important factors affecting the overall comfort of the urban outdoor space. At present, there are few research on interaction with thermal and air quality environment. Therefore, a meteorological measurement and questionnaire survey have been conducted in a representative open space in a campus in Xi'an, China. The following are the research results:(1) Mean physiological equivalent temperature (MPET) is a significant factor affecting thermal sensation vote (TSV) and thermal comfort vote (TCV). PM2.5 has no significant effect on thermal comfort vote (TCV), but it is a considerable factor affecting thermal sensation vote (TSV) when 10.2°C ≤ MPET<21°C (P = 0.023 *). (2) PM2.5 is a significant factor affecting air quality vote (AQV) and breathing comfort vote (BCV).Mean physiological equivalent temperature (MPET) has no significant impact on air quality vote (AQV), but it is a considerable factor affecting breathing comfort vote (BCV) when 10.2°C ≤ MPET<21°C (P = 0.01 **). (3) Mean physiological equivalent temperature (MPET) is a significant factor affecting overall comfort vote (OCV), but PM2.5 is not. In general, When 10.2°C ≤ MPET<21°C (-0.5 < -0.37 ≤ TCV ≤ 0.12 <0.5), the interaction between thermal and PM2.5 environment is significant on thermal sensation vote (TSV) and breathing comfort vote (BCV). This study can provide experimental support for the field of multi-factor interaction, which has shown that improving the thermal environment can better breathing comfort, while reducing PM2.5 concentration can promote thermal comfort. And can also provide reference for the study of human subjective comfort in urban outdoor space in the same latitude of the world.

The 2022 report of synergetic roadmap on carbon neutrality and clean air for China: Accelerating transition in key sectors

China is now confronting the intertwined challenges of air pollution and climate change. Given the high synergies between air pollution abatement and climate change mitigation, the Chinese government is actively promoting synergetic control of these two issues. The Synergetic Roadmap project was launched in 2021 to track and analyze the progress of synergetic control in China by developing and monitoring key indicators. The Synergetic Roadmap 2022 report is the first annual update, featuring 20 indicators across five aspects: synergetic governance system and practices, progress in structural transition, air pollution and associated weather-climate interactions, sources, sinks, and mitigation pathway of atmospheric composition, and health impacts and benefits of coordinated control. Compared to the comprehensive review presented in the 2021 report, the Synergetic Roadmap 2022 report places particular emphasis on progress in 2021 with highlights on actions in key sectors and the relevant milestones. These milestones include the proportion of non-fossil power generation capacity surpassing coal-fired capacity for the first time, a decline in the production of crude steel and cement after years of growth, and the surging penetration of electric vehicles. Additionally, in 2022, China issued the first national policy that synergizes abatements of pollution and carbon emissions, marking a new era for China's pollution-carbon co-control. These changes highlight China's efforts to reshape its energy, economic, and transportation structures to meet the demand for synergetic control and sustainable development. Consequently, the country has witnessed a slowdown in carbon emission growth, improved air quality, and increased health benefits in recent years.

Multi-scenario reduction pathways and decoupling analysis of China's sectoral carbon emissions

To achieve its goal of carbon emissions peak and neutrality, China requires synergistic efforts across all sectors. In this study, three scenarios-baseline, policy, and green low-carbon-were developed to explore the pathways for China's emissions reduction across sectors from 2020 to 2060, and the timing of decoupling economic growth from CO2. The results showed that, under these scenarios, China's carbon emissions peak in 2030, 2026, and 2025, with strong decoupling time, lagged one year behind peak attainment. The agriculture, forestry, livestock, and fishing (AFH) and mining and quarrying (MQ) sectors would be the first to achieve a carbon peak. Under all three scenarios, all of the other sectors-with the exception of electricity, gas, and water production and supply (EGW)-will achieve a carbon peak by 2030. Therefore, policymakers should set carbon peak goals based on sector characteristics and ensure energy security in the process of achieving carbon neutrality.

Energy and air? The impact of energy efficiency improvement on air quality in China

The global economic growth is hindered by resources shortage, energy demand, air pollution and climate. Energy efficiency can reduce some pollutants while potentially increase others. This study refers to sulfur dioxide (SO2), nitrogen oxides (NOx), and dust and smoke (DS) as primary pollutants to distinguish it from secondary ones. The influence of energy efficiency, socioeconomic, and natural climatic factors on air quality is analyzed under the theory of STIRPAT. It is highly coupled between energy efficiency and the spatial distribution of air quality. Increased energy efficiency can improve air quality by reducing SO2 and NOx, but the impact on DS is insignificant. Air pollutants decrease by about 0.531% for every 1% increase in temperature and 0.105% for every 1% increase in precipitation. Consumption will reduce air pollution, and there is an inverted U-shaped relationship between population density, economic scale, urbanization, technology innovation, and air pollution. It is worth mentioning that this work adds temperature and precipitation to the STIRPAT as natural climatic factors, analyzing the impact of energy efficiency on air pollution under the two-factor restrictions of socioeconomic and natural climatic factors. Finally, management suggestions are made to improve air quality.

Synergistic assessment of air pollution and carbon emissions from the economic perspective in China

The synergistic evaluation integrating air quality, human health, climate impact, and socioeconomic development is significant for green and low-carbon transition. Here, we quantified the contribution of pollutant emissions in 30 provinces (source) to PM_2.5 concentration and related premature mortality in each 20 km grid (receptor) of China in 2020 by an integrated model for the first time. Further, we established a cross-province contribution matrix of health impact intensity (HII, PM_2.5-related deaths per GDP). According to HII and CEI (carbon emission intensity, defined as CO₂ emission per GDP) levels, 30 provinces were divided into 4 regions including LL, HL, LH and HH. In order to assess the synergy in air pollution and carbon emission, we established an index system consisting of ISEC-AC (index for synergistic assessment) and its two sub index: IHI (index for HII assessment), and ICE (index for CEI assessment). Results showed that the ISEC-AC was more easily influenced by IHI as the variance of IHI was much higher than that of ICE. Influenced by various factors, e.g., economic structure, population density, pollution transport, ISEC-AC exhibited substantial spatial heterogeneity. In general, the ISEC-AC of southeast provinces was higher than that of central and western, indicating the environmental and climate impact per GDP was relatively lower in southeast China. For provinces, ISEC-AC of SH and GD were ~ 16 times higher than NX. For regions, due to low carbon emission intensity and health impact intensity, ISEC-AC of LL was the highest with 176; followed by HL (128), LH (126) and HH (77). Further, we figured out the main control problems and then put forward targeted synergetic control suggestions for air pollution and carbon emission from the perspective of energy structure, industry structure and industry layout, which can provide insights into future green and low-carbon policy making in China and other countries.