@article{wang_levis_barlaz_2021, title={Development of Streamlined Life-Cycle Assessment for the Solid Waste Management System}, volume={55}, ISSN={0013-936X 1520-5851}, url={http://dx.doi.org/10.1021/acs.est.0c07461}, DOI={10.1021/acs.est.0c07461}, abstractNote={Life-cycle assessments (LCAs) of municipal solid waste management (MSWM) systems are time- and data-intensive. Reducing the data requirements for inventory and impact assessments will facilitate the wider use of LCAs during early system planning and design. Therefore, the objective of this study is to develop a systematic framework for streamlining LCAs by identifying the most critical impacts, life-cycle inventory emissions, and inputs based on their contributions to the total impacts and their effect on the rankings of 18 alternative MSWM scenarios. The scenarios are composed of six treatment processes: landfills, waste-to-energy combustion, single-stream recycling, mixed waste recycling, anaerobic digestion, and composting. The full LCA uses 1752 flows of resources and emissions, 10 impact categories, 3 normalization references, and 7 weighting schemes, and these were reduced using the streamlined LCA approach proposed in this study. Human health cancer, ecotoxicity, eutrophication, and fossil fuel depletion contribute 75-83% to the total impacts across all scenarios. It was found that 3.3% of the inventory flows contribute ≥95% of the overall environmental impact. The highest-ranked strategies are consistent between the streamlined and full LCAs. The results provide guidance on which impacts, flows, and inputs to prioritize during early strategy design.}, number={8}, journal={Environmental Science & Technology}, publisher={American Chemical Society (ACS)}, author={Wang, Yixuan and Levis, James W. and Barlaz, Morton A.}, year={2021}, month={Mar}, pages={5475–5484} }
 @article{wang_levis_barlaz_2021, title={Life-Cycle Assessment of a Regulatory Compliant US Municipal Solid Waste Landfill}, volume={55}, ISSN={["1520-5851"]}, url={https://doi.org/10.1021/acs.est.1c02526}, DOI={10.1021/acs.est.1c02526}, abstractNote={Landfills receive over half of all U.S. municipal solid waste (MSW) and are the third largest source of anthropogenic methane emissions. Life-cycle assessment (LCA) of landfills is complicated by the long duration of waste disposal, gas generation and control, and the time over which the engineered infrastructure must perform. The objective of this study is to develop an LCA model for a representative U.S. MSW landfill that is responsive to landfill size, regulatory thresholds for landfill gas (LFG) collection and control, practices for LFG management (i.e., passive venting, flare, combustion for energy recovery), and four alternative schedules for LFG collection well installation. Material production required for construction and operation contributes 68-75% to toxicity impacts, while LFG emissions contribute 50-99% to global warming, ozone depletion, and smog impacts. The current non-methane organic compound regulatory threshold (34 Mg yr-1) reduces methane emissions by <7% relative to the former threshold (50 Mg yr-1). Requiring landfills to continue collecting LFG until the flow rate is <10 m3 min-1 reduces emissions by 20-52%, depending on the waste decay rate. In general, for landfills already required to collect gas, collecting gas longer is more important than collecting gas earlier to reduce methane emissions.}, number={20}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, publisher={American Chemical Society (ACS)}, author={Wang, Yixuan and Levis, James W. and Barlaz, Morton A.}, year={2021}, month={Oct}, pages={13583–13592} }
 @article{wang_levis_barlaz_2020, title={An Assessment of the Dynamic Global Warming Impact Associated with Long-Term Emissions from Landfills}, volume={54}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.9b04066}, abstractNote={Landfills are a major contributor of anthropogenic CH4 emissions. Since the greenhouse gas (GHG) emissions associated with landfilling waste can occur over decades to centuries, the standard static approach to estimating global warming impacts may not accurately represent the global warming impacts of landfills. The objective of this study is to assess the implications of using 100-yr and 20-yr static and dynamic global warming potential (GWP) approaches to estimate the global warming impacts from municipal solid waste landfills. A life-cycle model was developed to estimate GHG emissions for three gas treatment cases (passive venting, flare, CH4 conversion to electricity) and four decay rates. For the 100-yr GWP, other model uncertainties (e.g., static GWP values, decay rate, moisture content, or gas collection efficiency) generally had a larger effect on the estimated global warming impact than the choice of static versus dynamic GWP methods. This shows that when comparing single-point GWP values, the choice of static versus dynamic is relatively unimportant for most landfills. While dynamic GWPs consider temporal variance and provide useful estimates for the warming over a set time horizon, for most comparative analyses, static values provide reasonable bounds for the actual 100-yr warming impact.}, number={3}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Wang, Yixuan and Levis, James W. and Barlaz, Morton A.}, year={2020}, month={Feb}, pages={1304–1313} }
 @article{zhang_ma_wang_song_li_yuan_zhang_2020, title={The increasing district heating energy consumption of the building sector in China: Decomposition and decoupling analysis}, volume={271}, ISSN={["1879-1786"]}, DOI={10.1016/j.jclepro.2020.122696}, abstractNote={The district heating system accounts for 40% energy consumption of the building sector in China and still has tremendous growth potential due to the urbanisation. However, few studies have conducted explicit quantification on the drivers and the sustainable development of the district heating energy consumption of the building sector (DHEB) in China, although previous aggregation analysis on whole building energy service could convey implications on the district heating systems. This study investigates the driving factors of the DHEB in China between 2004 and 2016 using a decomposition analysis that incorporates effects of energy mix, heat production technology structure, energy intensity, heating area, and population. The decoupling status between the DHEB and gross domestic product (GDP) in China is then analyzed based on the Tapio decoupling index, along with the contributions of each driving factor to the decoupling. The results show that the effects of district heating area and population dominate the increase in the DHEB, while the heating energy intensity is the strongest factor reducing the DHEB. In addition, the shares of coal and heating boilers positively contribute to the increase in 2004–2008, and have a negative effect in 2008–2016. The complete reverse trend is found in the shares of gas and combined heat and power (CHP) during the same period. These results are largely associated with the implementation of “coal to gas” and the “elimination of old boilers” pushed by the Chinese government. Furthermore, a weak decoupling effect is mainly found between China’s DHEB and GDP from 2004 to 2016. The heating energy intensity is the strongest factor promoting the decoupling, while the growth of the district heating area and population leads to a weak decoupling.}, journal={JOURNAL OF CLEANER PRODUCTION}, author={Zhang, Linghui and Ma, Xin and Wang, Yixuan and Song, Rui and Li, Jiaojiao and Yuan, Weichang and Zhang, Shushen}, year={2020}, month={Oct} }
 @article{song_gao_fullana-i-palmer_lv_zhu_wang_bayer_2019, title={Shift from feeding to sustainably nourishing urban China: A crossing-disciplinary methodology for global environment-food-health nexus}, volume={647}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2018.08.040}, abstractNote={Dietary change is a win-win opportunity to address the nexus of health and the environment. To prevent city dwellers from developing non-communicable diseases, in 2013, China updated the 2000 version of nutrition-based dietary reference intake (DRI) guidelines. However, whether the DRI guidelines have a positive effect on the environment is not well understood. Here, we explored the systematic effects of urbanization on China's health and environmental nexus based on survey data. Then, we optimized the diets of 18 age-gender groups to reduce carbon emissions, water consumption, and land use while meeting the healthy nutrition goals of both DRI guidelines. The results showed that the optimal diets based on the DRI 2013 outperformed these on DRI 2000 in improving China's environmental sustainability, although these diets did not always perform better at an individual scale. Our findings suggest that dietary changes can reduce carbon, water, and ecological footprints by 24%, 15%, and 22% in 2050, respectively; however, the differences in age-specific and gender-specific health goals cannot be neglected.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Song, Guobao and Gao, Xiaobing and Fullana-i-Palmer, Pere and Lv, Daqi and Zhu, Zaichun and Wang, Yixuan and Bayer, Laura Bathe}, year={2019}, month={Jan}, pages={716–724} }