Nielsen, Chris P.

In Press
Qiang Liu, Fei Teng, Chris P Nielsen, Yuzhong Zhang, and Lixin Wu. In Press. “Large methane mitigation potential through prioritized closure of gas-rich coal mines.” Nature Climate Change.
2023
Xi Lu, Shi Chen, Chris Nielsen, Michael McElroy, Gang He, Shaohui Zhang, Kebin He, Xiu Yang, Fang Zhang, and Jiming Hao. 2023. “Deploying solar photovoltaic energy first in carbon-intensive regions brings gigatons more carbon mitigation by 2060.” Communications Earth & Environment, 4, 369. Publisher's VersionAbstract
The global surge in solar photovoltaic (PV) power has featured spatial specialization from manufacturing to installation along its industrial chain. Yet how to improve PV climate benefits are under-investigated. Here we explore the evolution of net greenhouse gas (GHG) mitigation of PV industry from 2009–2060 with a spatialized-dynamic life-cycle-analysis. Results suggest a net GHG mitigation of 1.29 Gt CO2-equivalent from 2009–2019, achieved by 1.97 Gt of mitigation from installation minus 0.68 Gt of emissions from manufacturing. The highest net GHG mitigation among future manufacturing-installation-scenarios to meet 40% global power demand in 2060 is as high as 204.7 Gt from 2020–2060, featuring manufacturing concentrated in Europe and North America and prioritized PV installations in carbon-intensive nations. This represents 97.5 Gt more net mitigation than the worst-case scenario, equivalent to 1.9 times 2020 global GHG emissions. The results call for strategic international coordination of PV industrial chain to increase GHG net mitigation.
Yu Zhao, Yutong Wang, Yiming Liu, Yueqi Jiang, Bo Zheng, Jia Xing, Yang Liu, Shuai Wang, and Chris Nielsen. 2023. “Sustained emission reductions have restrained the ozone pollution over China.” Nature Geoscience. Publisher's VersionAbstract

Near-surface ozone pollution, associated with complex responses to changing precursor emissions and meteorological conditions, has become one of the biggest challenges in China’s air quality management. Here, we present the spatiotemporal evolution of ozone concentrations from 2010 to 2021 using measurements of the national air quality monitoring network. We evaluate the effectiveness of the national air pollution control programme, including Phase 1 (2013–2017) and Phase 2 (2018–2021), in reducing the ozone level over China, using an optimized machine learning approach, high-resolution emission estimates and an improved air quality model. We find that while emission changes in Phase 1 increased the ozone level over the five highly developed regions, further reductions of nitrogen oxide emissions in Phase 2 have generally constrained the ozone pollution. The changing effect of emission controls on ozone pollution is due to the shift in the prevailing regime for ozone formation and the weakened effects of aerosol declines, as emission reductions continue. We further find that current emission controls have been more effective in rural locales in four of the five regions, and more effective in summer than winter. Therefore, further control of ozone pollution should consider these regional and seasonal variations to identify the most important precursors for the pollution.

Lu Liu, Yu Zhao, Hongyan Zhao, Yifei Wang, and Chris P Nielsen. 2023. “Impacts of Receiving International Industrial Transfer on China’s Air Quality and Health Exceed Those of Export Trade.” Environmental Science & Technology, 2023, Pp. 16989–16998. Publisher's VersionAbstract
Benefiting from international economic cooperation on income, technology diffusion, and employment, China also suffers its environmental and health impacts, from both international trade (IT), as is now widely understood, and international industrial transfer (IIT), which has been largely unrecognized. Here, we develop a comprehensive framework to estimate the impacts of exporting IT and receiving IIT. We find that China’s emissions of CO2 and almost all air pollutants associated with IIT and IT together grew after 1997 but then declined after 2010, with the peak shares of national total emissions ranging 18–31% for different species. These sources further accounted for 3.8% of nationwide PM2.5 concentrations and 94,610 (76,000–112,040) premature deaths in 2012, and the values declined to 2.6% and 67,370 (52,390–81,810), respectively, for 2017. Separated, the contribution of IIT to those impacts was more than twice that of IT. Scenario analyses suggest that improving emission controls in its less-developed regions would effectively reduce the impact of economic globalization, but such a benefit could be largely offset by strengthened international economic cooperation. The outcomes provide a scientific basis for adjusting China’s strategic roles in the international distribution of industrial production and its formulation of relevant environmental policies from a comprehensive perspective.
Jingran Zhang, Yiliang Jiang, Yunjie Wang, Shaojun Zhang, Ye Wu, Shuxiao Wang, Chris P Nielsen, Michael B McElroy, and Jiming Hao. 2023. “Increased Impact of Aviation on Air Quality and Human Health in China.” Environmental Science & Technology, 2023, Pp. 19575–19583. Publisher's VersionAbstract
China’s civil aviation market has rapidly expanded, becoming the world’s second-largest. However, the air quality and health impacts caused by its aircraft emissions have been inadequately assessed. Here, we leverage an updated emission inventory of air pollutants with improved temporal and spatial resolution based on hundreds of thousands of flight trajectories and simulate aviation-attributable contributions to ground-level air pollution in China. We find that in 2017, the annual-average aviation-attributed PM2.5 and O3 concentrations were 0.4–1.5 and 10.6–14.5 μg·m–3, respectively, suggesting that aviation emissions have become an increasingly important source of ambient air pollution. The contributions attributable to high-altitude emissions (climb/cruise/descent) were comparable to those at low altitudes (landing and takeoff). Aviation-attributed ambient PM2.5 and O3 exposures are estimated to have caused about 67,000 deaths in China in 2017, with populous coastal regions in Eastern China suffering the most due to the dense aviation activity. We recommend that industrial and policy stakeholders expedite an agenda of regulating air pollutants harmonized with decarbonization efforts for a more sustainable aviation future.
2022
Xi Yang, Chris P. Nielsen, Shaojie Song, and Michael B. McElroy. 2022. “Breaking the “hard-to-abate” bottleneck in China’s path to carbon neutrality with clean hydrogen.” Nature Energy, 7, Pp. 955–965. Publisher's VersionAbstract
Countries such as China are facing a bottleneck in their paths to carbon neutrality: abating emissions in heavy industries and heavy-duty transport. There are few in-depth studies of the prospective role for clean hydrogen in these ‘hard-to-abate’ (HTA) sectors. Here we carry out an integrated dynamic least-cost modelling analysis. Results show that, first, clean hydrogen can be both a major energy carrier and feedstock that can significantly reduce carbon emissions of heavy industry. It can also fuel up to 50% of China’s heavy-duty truck and bus fleets by 2060 and significant shares of shipping. Second, a realistic clean hydrogen scenario that reaches 65.7 Mt of production in 2060 could avoid US$1.72 trillion of new investment compared with a no-hydrogen scenario. This study provides evidence of the value of clean hydrogen in HTA sectors for China and countries facing similar challenges in reducing emissions to achieve net-zero goals.
Zhichang Cai, Chenghe Guan, An Trinh, Bo Zhang, Zhibin Chen, Sumeeta Srinivasan, and Chris Nielsen. 2022. “Satisfaction on self-perceived health of urban residents in Chengdu, China: Gender, age and the built environment.” Sustainability, 14, 40, Pp. 13389. Publisher's VersionAbstract
Self-perceived health is an important factor for assessing urban residents’ satisfaction and quality of life. However, few have comprehensively investigated the impact of demographics, lifestyle and health awareness, indoor environment characteristics, and neighborhood features on self-perceived health. To fill this gap, we designed a framework using multivariable regressions to derive odd rations and to analyze the determinants of self-rated health, stratified into different sub-groups divided by gender, age, and neighborhood types. The study area is Chengdu, one of the most populous cities in western China. The results show that: (1) female respondents reported worse health, with household income level and marital status significantly affecting self-rated health; (2) elderly people reported the worst health, while unique factors affected only younger people (18–29 years old), such as gender, smoking, and indoor environment characteristics; and (3) different types of neighborhoods influence their residents’ perception of health differently due to historical establishment, current population composition, and housing conditions. Our study provides new observations on neighborhood types, while agreeing with previous studies on the influences of gender and age. We contribute to the field by providing a more complex understanding of the mechanism by which people rate their own health, which is important for understanding the satisfaction of urban residents and the built environment in which they live.
Rong Tang, Jing Zhao, Yifan Liu, Xin Huang, Yanxu Zhang, Derong Zhou, Aijun Ding, Chris Nielsen, and Haikun Wang. 2022. “Air quality and health co-benefits of China's carbon dioxide emissions peaking before 2030.” Nature Communications, 13, 1008. Publisher's VersionAbstract

Recent evidence shows that carbon emissions in China are likely to peak ahead of 2030. However, the social and economic impacts of such an early carbon peak have rarely been assessed. Here we focus on the economic costs and health benefits of different carbon mitigation pathways, considering both possible socio-economic futures and varying ambitions of climate policies. We find that an early peak before 2030 in line with the 1.5  C target could avoid ~118,000 and ~614,000 PM2.5 attributable deaths under the Shared Socioeconomic Pathway 1, in 2030 and 2050, respectively. Under the 2  C target, carbon mitigation costs could be more than offset by health co-benefits in 2050, bringing a net benefit of $393–$3,017 billion (in 2017 USD value). This study not only provides insight into potential health benefits of an early peak in China, but also suggests that similar benefits may result from more ambitious climate targets in other countries.

Zhenyu Zhuo, Ershun Du, Ning Zhang, Chris Nielsen, Xi Lu, Jinyu Xiao, Jiawei Wu, and Chongqing Kang. 2022. “Cost increase in the electricity supply to achieve carbon neutrality in China.” Nature Communications, 13, 3172. Publisher's VersionAbstract
The Chinese government has set long-term carbon neutrality and renewable energy (RE) development goals for the power sector. Despite a precipitous decline in the costs of RE technologies, the external costs of renewable intermittency and the massive investments in new RE capacities would increase electricity costs. Here, we develop a power system expansion model to comprehensively evaluate changes in the electricity supply costs over a 30-year transition to carbon neutrality. RE supply curves, operating security constraints, and the characteristics of various generation units are modelled in detail to assess the cost variations accurately. According to our results, approximately 5.8 TW of wind and solar photovoltaic capacity would be required to achieve carbon neutrality in the power system by 2050. The electricity supply costs would increase by 9.6 CNY¢/kWh. The major cost shift would result from the substantial investments in RE capacities, flexible generation resources, and network expansion.
Yu Zhao, Mengxiao Xi, Qiang Zhang, Zhaoxin Dong, Mingrui Ma, Kaiyue Zhou, Wen Xu, Jia Xing, Bo Zheng, Zhang Wen, Xuejun Liu, Chris P. Nielsen, Yang Liu, Yuepeng Pan, and Lei Zhang. 2022. “Decline in bulk deposition of air pollutants in China lags behind reductions in emissions.” Nature Geoscience, 15, Pp. 190–195. Publisher's VersionAbstract
Swift changes in both industrialization and pollution control in China over the past 15 years have created a complex and evolving relationship between emission sources and the depositional sinks of air pollutants. Here, by combining an emissions inventory, an air quality model and a statistical model to estimate bulk deposition (wet plus a part of dry), we present the changes and driving factors of source–sink relationships of typical pollutants throughout China between 2005 and 2020. We find that the deposition of sulfate and nitrate has declined more slowly than the emissions of their precursors, sulfur dioxide and nitrogen oxides, which we attribute, in part, to increased precipitation. In four developed regions of China, enhanced air pollution transport also plays an important role in the slower decline of deposition compared with that of emissions, as has a changing aerosol chemistry in the case of sulfur compounds. Our analysis shows that reducing deposition is not as simple as merely reducing its precursor emissions and suggests that the design of future policies to reduce associated risks may need to vary by region and species, accounting for their evolving interactions over time.
Faan Chen, Chris P. Nielsen, Jiaorong Wu, and Xiaohong Chen. 2022. “Examining socio-spatial differentiation under housing reform and its implications for mobility in urban China.” Habitat International, 119, January 2022, Pp. 102498. Publisher's VersionAbstract
Housing reform in socialist China has incurred considerable restructuring and transformation of urban space and society. Yet its specific socio-spatial outcomes have not been fully investigated from the perspective of housing type at the meso- and micro-levels. This study attempts to fill the gap by examining the nature and magnitude of the consequences of housing reform and the corresponding effects on mobility. Specifically, based on census data and a mobility survey, this paper combines statistical breakdowns and structural equation modeling to capture the socio-spatial differentiation of urban structure resulting from housing reform and its influences on individual vehicle kilometers traveled (VKT) and transportation walking. The results reveal that: (1) different types of housing tend to feature internally homogeneous populations in terms of socio-economic composition and socio-psychological condition, with pronounced social stratification; (2) residents in different types of housing display dramatically different travel styles, with substantial mobility inequities; (3) social differentiation appears to have spatial determinants; in particular spatial segregation contributes to increasing social exclusion; (4) the effects of spatial and social characteristics on mobility are led by housing type; and (5) individual mobility patterns are shaped by the joint influences of spatial and social dimensions of housing differentiation. The findings contribute to further understanding of socio-spatial differentiation in countries with a transitional housing market, suggesting that the design of land-use policies should recognize their social effects and that urban mobility planning practices should deliver sustainability that serves a diverse population, including in particular disadvantaged groups in public and replacement housing. This study serves as a mirror to observe the urban transition compared to other political economies and adds additional richness and diversity to the theoretical debates on the issue of socio-spatial differentiation and empirical evidence on residential and mobility inequities across global contexts.
Ziwen Ruan, Xi Lu, Shuxiao Wang, Jia Xing, Wei Wang, Dan Chen, Chris P. Nielsen, Yong Luo, Kebin He, and Jiming Hao. 2022. “Impacts of large-scale deployment of mountainous wind farms on wintertime regional air quality in the Beijing-Tian-Hebei area.” Atmospheric Environment, 278, 119074. Publisher's VersionAbstract
The development of wind power plays an essential role in achieving China's carbon neutrality goals and air quality standards. A large number of studies have addressed the benefits of substituting fossil fuels with wind power on climate and air quality (defined as indirect impact) by macro-scale methodology. In recent years, more and more researchers have discussed its impacts on the general atmospheric circulation and air pollution dispersion (defined as direct impact) by parameterizing wind energy extraction in meso-micro scale models. However, the comprehensive investigation (considering both direct and indirect impacts) of the utilization of wind power on atmosphere environmental impacts remains vacant. Our study first evaluated both the direct and indirect impacts of wind power on air quality through an integrated methodological framework by using WRF-CMAQ system. The present analysis took wind farms located in Zhangjiakou to explore their impacts on air quality in winter, particularly over the downwind Beijing municipal area in the North China Plain. Results indicated that the deployment of wind power leads to spatially mixed direct impacts on PM2.5 concentrations in Beijing with a monthly net increase of 0.067 μg/m3 (0.08%) relative to the regional average. Contrarily, the substitution of coal-burning with wind power in rural household heating would result in notable indirect benefits to monthly PM2.5 concentrations in Beijing, specifically, reducing emissions of CO2 and conventional air pollutants by 64% in rural heating sector. The combined impacts of wind power displayed regional differences: in the wintertime (January), Zhangjiakou PM2.5 concentrations increased (+0.147 μg/m3) whereas, decreases are achieved (−5.642 μg/m3) in Beijing. Therefore, to support the large-scale deployment of wind power, future energy policies should take comprehensive account of the diverse environmental impacts, including both the indirect benefits of fossil energy substitution and the potential direct atmospheric effects on regional air quality.
Shi Chen, Xi Lu, Chris P. Nielsen, Guannan Geng, Michael B. McElroy, Shuxiao Wang, and Jiming Hao. 2022. “Improved air quality in China can enhance solar power performance and accelerate carbon neutrality targets.” One Earth, 5, 5, Pp. 550-562. Publisher's VersionAbstract
China forecasts that a 14-fold increase in photovoltaic installations is needed to meet 2060 carbon-neutrality targets. In light of the fact that air pollution impairs photovoltaic performance, pollution control could reduce the installation requirement, but research has not yet taken into account the coeval impact of unfavorable meteorological conditions, which also impair performance. Here, we employ a coupled model to determine the impact of air-pollution control policies on China’s photovoltaic power output in the presence of varying meteorological conditions between 1995 and 2019. We find that the benefits of air-pollution control introduced in 2004 were only partially offset by unfavorable meteorological conditions (primarily in Central and South China) and resulted in solar-power performance improvement of 0.9%/decade from 2008 onward. Further analysis shows that solar-power output in 2020 was 1.7% higher thanks to air-pollution control and that more stringent air-quality targets could reduce the demand for photovoltaic installed capacity needed to meet the 2060 carbon-neutrality target.
Shaodan Huang, Shaojie Song, Chris P. Nielsen, Yuqiang Zhang, Jianyin Xiong, Louise B. Weschler, Shaodong Xie, and Jing Li. 2022. “Residential building materials: An important source of ambient formaldehyde in mainland China.” Environment International, 158, 106909. Publisher's VersionAbstract
This study investigates the contribution of formaldehyde from residential building materials to ambient air in mainland China. Based on 265 indoor field tests in 9 provinces, we estimate that indoor residential sources are responsible for 6.66% of the total anthropogenic formaldehyde in China’s ambient air (range for 31 provinces: 1.88–18.79%). Residential building materials rank 6th among 81 anthropogenic sources (range: 2nd–10th for 31 provinces). Emission intensities show large spatial variability between and within regions due to different residential densities, emission characteristics of building materials, and indoor thermal conditions. Our findings indicate that formaldehyde from the indoor environment is a significant source of ambient formaldehyde, especially in urban areas. This study will help to more accurately evaluate exposure to ambient formaldehyde and its related pollutants, and will assist in formulating policies to protect air quality and public health.
2021
Combined solar power and storage as cost-competitive and grid-compatible supply for China’s future carbon-neutral electricity system
Xi Lu, Shi Chen, Chris P. Nielsen, Chongyu Zhang, Jiacong Li, Xu He, Ye Wu, Shuxiao Wang, Feng Song, Chu Wei, Kebin He, Michael P. McElroy, and Jiming Hao. 2021. “Combined solar power and storage as cost-competitive and grid-compatible supply for China’s future carbon-neutral electricity system.” Proceedings of the National Academy of Sciences, 118, 42, Pp. e2103471118. Publisher's VersionAbstract

As the world’s largest CO2 emitter, China’s ability to decarbonize its energy system strongly affects the prospect of achieving the 1.5 °C limit in global, average surface-temperature rise. Understanding technically feasible, cost-competitive, and grid-compatible solar photovoltaic (PV) power potentials spatiotemporally is critical for China’s future energy pathway. This study develops an integrated model to evaluate the spatiotemporal evolution of the technology-economic-grid PV potentials in China during 2020 to 2060 under the assumption of continued cost degression in line with the trends of the past decade. The model considers the spatialized technical constraints, up-to-date economic parameters, and dynamic hourly interactions with the power grid. In contrast to the PV production of 0.26 PWh in 2020, results suggest that China’s technical potential will increase from 99.2 PWh in 2020 to 146.1 PWh in 2060 along with technical advances, and the national average power price could decrease from 4.9 to 0.4 US cents/kWh during the same period. About 78.6% (79.7 PWh) of China’s technical potential will realize price parity to coal-fired power in 2021, with price parity achieved nationwide by 2023. The cost advantage of solar PV allows for coupling with storage to generate cost-competitive and grid-compatible electricity. The combined systems potentially could supply 7.2 PWh of grid-compatible electricity in 2060 to meet 43.2% of the country’s electricity demand at a price below 2.5 US cents/kWh. The findings highlight a crucial energy transition point, not only for China but for other countries, at which combined solar power and storage systems become a cheaper alternative to coal-fired electricity and a more grid-compatible option.

Lu et al. is the cover article of this October issue of PNAS. Read the Research Brief.
Shaojie Song, Haiyang Lin, Peter Sherman, Xi Yang, Chris P. Nielsen, Xinyu Chen, and Michael B. McElroy. 2021. “Production of hydrogen from offshore wind in China and cost-competitive supply to Japan.” Nature Communications, 12, 6953. Publisher's VersionAbstract
The Japanese government has announced a commitment to net-zero greenhouse gas emissions by 2050. It envisages an important role for hydrogen in the nation’s future energy economy. This paper explores the possibility that a significant source for this hydrogen could be produced by electrolysis fueled by power generated from offshore wind in China. Hydrogen could be delivered to Japan either as liquid, or bound to a chemical carrier such as toluene, or as a component of ammonia. The paper presents an analysis of factors determining the ultimate cost for this hydrogen, including expenses for production, storage, conversion, transport, and treatment at the destination. It concludes that the Chinese source could be delivered at a volume and cost consistent with Japan’s idealized future projections.
Yan Zhang, Yu Zhao, Meng Gao, Xin Bo, and Chris P. Nielsen. 2021. “Air quality and health benefits from ultra-low emission control policy indicated by continuous emission monitoring: a case study in the Yangtze River Delta region, China.” Atmospheric Chemistry and Physics, 21, Pp. 6411–6430. Publisher's VersionAbstract
To evaluate the improved emission estimates from online monitoring, we applied the Models-3/CMAQ (Community Multiscale Air Quality) system to simulate the air quality of the Yangtze River Delta (YRD) region using two emission inventories with and without incorporated data from continuous emission monitoring systems (CEMSs) at coal-fired power plants (cases 1 and 2, respectively). The normalized mean biases (NMBs) between the observed and simulated hourly concentrations of SO2, NO2, O3, and PM2.5 in case 2 were −3.1 %, 56.3 %, −19.5 %, and −1.4 %, all smaller in absolute value than those in case 1 at 8.2 %, 68.9 %, −24.6 %, and 7.6 %, respectively. The results indicate that incorporation of CEMS data in the emission inventory reduced the biases between simulation and observation and could better reflect the actual sources of regional air pollution. Based on the CEMS data, the air quality changes and corresponding health impacts were quantified for different implementation levels of China's recent “ultra-low” emission policy. If the coal-fired power sector met the requirement alone (case 3), the differences in the simulated monthly SO2, NO2, O3, and PM2.5 concentrations compared to those of case 2, our base case for policy comparisons, would be less than 7 % for all pollutants. The result implies a minor benefit of ultra-low emission control if implemented in the power sector alone, which is attributed to its limited contribution to the total emissions in the YRD after years of pollution control (11 %, 7 %, and 2 % of SO2, NOX, and primary particle matter (PM) in case 2, respectively). If the ultra-low emission policy was enacted at both power plants and selected industrial sources including boilers, cement, and iron and steel factories (case 4), the simulated SO2, NO2, and PM2.5concentrations compared to the base case would be 33 %–64 %, 16 %–23 %, and 6 %–22 % lower, respectively, depending on the month (January, April, July, and October 2015). Combining CMAQ and the Integrated Exposure Response (IER) model, we further estimated that 305 deaths and 8744 years of life loss (YLL) attributable to PM2.5 exposure could be avoided with the implementation of the ultra-low emission policy in the power sector in the YRD region. The analogous values would be much higher, at 10 651 deaths and 316 562 YLL avoided, if both power and industrial sectors met the ultra-low emission limits. In order to improve regional air quality and to reduce human health risk effectively, coordinated control of multiple sources should be implemented, and the ultra-low emission policy should be substantially expanded to major emission sources in industries other than the power industry.
Jinzhao Yang, Yu Zhao, Jing Cao, and Chris P. Nielsen. 2021. “Co-benefits of carbon and pollution control policies on air quality and health till 2030 in China.” Environment International, 152, 106482. Publisher's VersionAbstract
Facing the dual challenges of climate change and air pollution, China has made great efforts to explore the co-control strategies for the both. We assessed the benefits of carbon and pollution control policies on air quality and human health, with an integrated framework combining an energy-economic model, an air quality model and a concentration–response model. With a base year 2015, seven combined scenarios were developed for 2030 based on three energy scenarios and three end-of-pipe control ones. Policy-specific benefits were then evaluated, indicated by the reduced emissions, surface concentrations of major pollutants, and premature deaths between scenarios. Compared to the 2030 baseline scenario, the nationwide PM2.5- and O3-related mortality was expected to decline 23% or 289 (95% confidence interval: 220–360) thousand in the most stringent scenario, and three quarters of the avoided deaths were attributed to the end-of-pipe control measures. Provinces in heavily polluted and densely populated regions would benefit more from carbon and pollution control strategies. The population fractions with PM2.5 exposure under the national air quality standard (35 μg/m3) and WHO guideline (10 μg/m3) would be doubled from 2015 to 2030 (the most stringent scenario), while still very few people would live in areas with the WHO guideline achieved for O3 (100 μg/m3). Increased health impact of O3 suggested a great significance of joint control of PM2.5 and O3 in future policy-making.
Faan Chen, Jiaorong Wu, Xiaohong Chen, and Chris Nielsen. 2021. “Disentangling the impacts of the built environment and self-selection on travel behavior: An empirical study in the context of different housing types.” Cities, 116, 103285. Publisher's VersionAbstract
Due to spatial heterogeneity worldwide, results from studies examining the effect of residential self-selection on travel behavior vary substantially. As a result of housing reform, the unique housing allocation system in China is a prime example of a context where the self-selection effect may conflict with international knowledge. Using a sample of 3836 residents, whom are living in Transit-Oriented Development (TOD) and non-TOD neighborhoods in Shanghai, this study untangles the effects that the built environment and residential self-selection have on travel behavior, in the context of diversified housing types in urban China. Specifically, this paper employs propensity score matching (PSM) to quantitate the relative importance of the built environment itself, verses residential self-selection, in influencing travel behavior for each of the housing types. The results show that the residential self-selection effect in the four types of housing (work-unit, commodity, public, and replacement) accounts for 15.2%, 30.7%, 18.5%, and 5.9% of the total impact on vehicle kilometers traveled (VKT), respectively. These findings expand the international database of point estimates in the relative contribution of self-selection toward the impact on travel behavior across global contexts, providing a comprehensive framework for similar studies on self-selection in other parts of the world.
Minghao Zhuang, Xi Lu, Wei Peng, Yanfen Wang, Jianxiao Wang, Chris P. Nielsen, and Michael B. McElroy. 2021. “Opportunities for household energy on the Qinghai-Tibet Plateau in line with United Nations’ Sustainable Development Goals.” Renewable and Sustainable Energy Reviews, 144, 110982. Publisher's VersionAbstract
Approximately seven million population in the Qinghai-Tibet Plateau of China, a global climate sensitive region, still rely primarily on yak dung for household cooking and heating. The treatment and combustion of yak dung result in a variety of negative impacts in terms of local alpine grassland degradation, indoor air pollution, public health risk, as well as global climate change. There is an urgent need to explore alternative pathway for affordable and clean energy as indicated in the United Nations’ Sustainable Development Goals for 2030. This perspective has analyzed the key challenges rooted in yak dung use on the Qinghai-Tibet Plateau region. Based on this, this perspective has further proposed a new complementary energy system to take advantage of locally available, clean and sustainable energy sources of wind and solar power, and have provided economic analyses. Meanwhile, this perspective has pointed out the potential barriers to promoting the new complementary energy system in the Qinghai-Tibet Plateau region due to traditional habits, economic factors and policies. Finally, strategies for transitioning from yak dung to the proposed alternative energy system is discussed at the end. Successful energy transition for the Qinghai-Tibet Plateau region offers an important option to achieving many other sustainable development goals related to climate change, economic development, and environment. The perspective is expected to shed light on the development of sustainable energy in other developing region or countries in the world to address multiple societal goals.

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