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Wang T, Berrill P, Zimmerman JB, Hertwich EG. Correction to "Copper Recycling Flow Model for the United States Economy: Impact of Scrap Quality on Potential Energy Benefit". Environ Sci Technol 2023; 57:7644. [PMID: 37128934 DOI: 10.1021/acs.est.3c02164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
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Wang T, Berrill P, Zimmerman JB, Rao ND, Min J, Hertwich EG. Improved Copper Circularity as a Result of Increased Material Efficiency in the U.S. Housing Stock. Environ Sci Technol 2022; 56:4565-4577. [PMID: 35302366 PMCID: PMC8988293 DOI: 10.1021/acs.est.1c06474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
Material efficiency (ME) can support rapid climate change mitigation and circular economy. Here, we comprehensively assess the circularity of ME strategies for copper use in the U.S. housing services (including residential buildings and major household appliances) by integrating use-phase material and energy demand. Although the ME strategies of more intensive floor space use and extended lifetime of appliances and buildings reduce the primary copper demand, employing these strategies increases the commonly neglected use-phase share of total copper requirements during the century from 23-28 to 22-42%. Use-phase copper requirements for home improvements have remained larger than the demand gap (copper demand minus scrap availability) for much of the century, limiting copper circularity in the U.S. housing services. Further, use-phase energy consumption can negate the benefits of ME strategies. For instance, the lifetime extension of lower-efficiency refrigerators increases the copper use and net environmental impact by increased electricity use despite reductions from less production. This suggests a need for more attention to the use phase when assessing circularity, especially for products that are material and energy intensive during use. To avoid burden shifting, policymakers should consider the entire life cycle of products supporting services when pursuing circular economy goals.
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Affiliation(s)
- Tong Wang
- Department
of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States
- Center
for Industrial Ecology, Yale University, New Haven, Connecticut 06520, United States
- International
Institute for Applied Systems Analysis (IIASA), Schlossplatz 1, A-2361 Laxenburg, Austria
| | - Peter Berrill
- Center
for Industrial Ecology, Yale University, New Haven, Connecticut 06520, United States
- Yale
School of the Environment, Yale University, New Haven, Connecticut 06520, United States
| | - Julie Beth Zimmerman
- Department
of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States
- Yale
School of the Environment, Yale University, New Haven, Connecticut 06520, United States
| | - Narasimha D. Rao
- International
Institute for Applied Systems Analysis (IIASA), Schlossplatz 1, A-2361 Laxenburg, Austria
- Yale
School of the Environment, Yale University, New Haven, Connecticut 06520, United States
| | - Jihoon Min
- International
Institute for Applied Systems Analysis (IIASA), Schlossplatz 1, A-2361 Laxenburg, Austria
| | - Edgar G. Hertwich
- Industrial
Ecology Programme, Department of Energy and Process Engineering, Norwegian University of Science and Technology (NTNU), 7495 Trondheim, Norway
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Pauliuk S, Heeren N, Berrill P, Fishman T, Nistad A, Tu Q, Wolfram P, Hertwich EG. Global scenarios of resource and emission savings from material efficiency in residential buildings and cars. Nat Commun 2021; 12:5097. [PMID: 34429412 PMCID: PMC8385048 DOI: 10.1038/s41467-021-25300-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 07/16/2021] [Indexed: 11/25/2022] Open
Abstract
Material production accounts for a quarter of global greenhouse gas (GHG) emissions. Resource-efficiency and circular-economy strategies, both industry and demand-focused, promise emission reductions through reducing material use, but detailed assessments of their GHG reduction potential are lacking. We present a global-scale analysis of material efficiency for passenger vehicles and residential buildings. We estimate future changes in material flows and energy use due to increased yields, light design, material substitution, extended service life, and increased service efficiency, reuse, and recycling. Together, these strategies can reduce cumulative global GHG emissions until 2050 by 20–52 Gt CO2-eq (residential buildings) and 13–26 Gt CO2e-eq (passenger vehicles), depending on policy assumptions. Next to energy efficiency and low-carbon energy supply, material efficiency is the third pillar of deep decarbonization for these sectors. For residential buildings, wood construction and reduced floorspace show the highest potential. For passenger vehicles, it is ride sharing and car sharing. Material production accounts for a quarter of global greenhouse gas emissions. Here, the authors show that resource efficiency and circular-economy strategies can allow for cumulative emission reductions of 20–52 Gt CO2-eq from residential buildings and 13–26 Gt CO2e-eq from cars by 2050.
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Affiliation(s)
- Stefan Pauliuk
- Industrial Ecology Group, Faculty of Environment and Natural Resources, University of Freiburg, Freiburg, Germany.
| | - Niko Heeren
- Center for Industrial Ecology, School of the Environment, Yale University, New Haven, CT, USA.,Industrial Ecology Program, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Peter Berrill
- Center for Industrial Ecology, School of the Environment, Yale University, New Haven, CT, USA
| | - Tomer Fishman
- School of Sustainability, Interdisciplinary Center (IDC) Herzliya, Herzliya, Israel
| | - Andrea Nistad
- Industrial Ecology Program, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Qingshi Tu
- Center for Industrial Ecology, School of the Environment, Yale University, New Haven, CT, USA.,Department of Wood Science, University of British Columbia, Vancouver, Canada
| | - Paul Wolfram
- Center for Industrial Ecology, School of the Environment, Yale University, New Haven, CT, USA
| | - Edgar G Hertwich
- Center for Industrial Ecology, School of the Environment, Yale University, New Haven, CT, USA. .,Industrial Ecology Program, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
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Wang T, Berrill P, Zimmerman JB, Hertwich EG. Copper Recycling Flow Model for the United States Economy: Impact of Scrap Quality on Potential Energy Benefit. Environ Sci Technol 2021; 55:5485-5495. [PMID: 33783185 PMCID: PMC8154355 DOI: 10.1021/acs.est.0c08227] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Is recycling a means for meeting the increasing copper demand in the face of declining ore grades? To date, research to address this question has generally focused on the quantity, not the quality of copper scrap. Here, the waste input-output impact assessment (WIO-IA) model integrates information on United States (US) economy-wide material flow, various recycling indicators, and the impact of material production from diverse sources to represent the quantity and quality of copper flows throughout the lifecycle. This approach enables assessment of recycling performance against environmental impact indicators. If all potentially recyclable copper scrap was recycled, energy consumption associated with copper production would decrease by 15% with alloy scrap as the largest contributor. Further energy benefits from increased recycling are limited by the lower quality of the scrap yet to be recycled. Improving the yield ratio of final products and the grade of diverse consumer product scrap could help increase copper circularity and decrease energy consumption. Policy makers should address the importance of a portfolio of material efficiency strategies like improved utilization of copper products and lifetime extension in addition to encouraging the demand for recycled copper.
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Affiliation(s)
- Tong Wang
- Department
of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States
- Center
for Industrial Ecology, Yale University, New Haven, Connecticut 06520, United States
| | - Peter Berrill
- Center
for Industrial Ecology, Yale University, New Haven, Connecticut 06520, United States
- Yale
School of the Environment, Yale University, New Haven, Connecticut 06520, United States
| | - Julie B. Zimmerman
- Department
of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States
- Yale
School of the Environment, Yale University, New Haven, Connecticut 06520, United States
| | - Edgar G. Hertwich
- Industrial
Ecology Programme, Department of Energy and Process Engineering, Norwegian University of Science and Technology (NTNU), 7495 Trondheim, Norway
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Berrill P, Gillingham KT, Hertwich EG. Linking Housing Policy, Housing Typology, and Residential Energy Demand in the United States. Environ Sci Technol 2021; 55:2224-2233. [PMID: 33508933 DOI: 10.1021/acs.est.0c05696] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Residential energy demand can be greatly influenced by the types of housing structures that households live in, but few studies have assessed changes in the composition of housing stocks as a strategy for reducing residential energy demand or greenhouse gas (GHG) emissions. In this paper we examine the effects of three sequenced federal policies on the share of new housing construction by type in the U.S., and estimate the cumulative influence of those policies on the composition of the 2015 housing stock. In a counterfactual 2015 housing stock without the policy effects, 14 million housing units exist as multifamily rather than single-family, equal to 14.1% of urban housing. Accompanied by floor area reductions of 0-50%, the switch from single- to multifamily housing reduces energy demand by 27-47% per household, and total urban residential energy by 4.6-8.3%. This paper is the first to link federal policies to housing outcomes by type and estimate associated effects on residential energy and GHG emissions. Removing policy barriers and disincentives to multifamily housing can unlock a large potential for reducing residential energy demand and GHG emissions in the coming decades.
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Affiliation(s)
- Peter Berrill
- Yale University, School of the Environment, New Haven, Connecticut 06511, United States
| | - Kenneth T Gillingham
- Yale University, School of the Environment, New Haven, Connecticut 06511, United States
| | - Edgar G Hertwich
- Norwegian University of Science and Technology, Department of Energy and Process Engineering, Trondheim NO-7491, Norway
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