Carlisle, S., Waldman, B., DeRousseau, M., Miller, L., Ciavola, B., Lewis, M., and Simonen, K. (2022). Buy Clean California Limits: A Proposed Methodology for Setting Industry-Average GWP Limits for Steel, Mineral Wool, and Flat Glass. Carbon Leadership Forum, University of Washington. Seattle, WA. https://hdl.handle.net/1773/48600
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Abstract
The Buy Clean California Act requires the California Department of General Services (DGS), in consultation with the California Air Resources Board, to establish maximum acceptable global warming potential (GWP) limits at industry-average for structural steel (hot-rolled sections, hollow structural sections, and plate), concrete reinforcing steel, flat glass, and mineral wool board insulation (heavy and light). DGS is directed to set these limits at the industry average using data from facility-specific environmental product declarations (EPDs) or industry-wide EPDs based on domestic production data.
In order for GWP limits to be effective they must be scientifically derived, transparent in their underlying methodology, and clear in scope and definition. Calculating industry-average values using EPDs, as required by the BCCA, is challenging: the quality and quantity of data available for calculating GWP limits varies by product type and is continually growing.
Benke, B., Lewis, M., Carlisle, S., Huang, M., and Simonen, K. (2022). Developing an Embodied Carbon Policy Reduction Calculator. Carbon Leadership Forum, University of Washington. Seattle, WA. https://hdl.handle.net/1773/48566
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Abstract
A growing number of cities are committed to tackling the urgent challenge of their built environment carbon footprint through their policies and programs. 110 cities took the Cities Race to Zero Clean Construction pledges to reduce embodied emissions in their policies and programmes in 2021, and 40 leading cities are participating in the C40 Clean Construction programme and mayors are setting the direction of travel by signing the Clean Construction Declaration, which requires collective action to halve embodied emissions by 2030.
However, embodied carbon is a new policy area for many cities and the lack of city-level data on embodied carbon is a significant barrier for policymakers to gain political support and make informed decisions. The goal of developing an embodied carbon policy reduction calculator is to address these challenges by:
-Modeling the potential embodied carbon reduction of a selected number of policies to give cities the values they need to make informed decisions;
-Allowing for comparison of emissions reduction policies for embodied carbon by key target dates (2030 and 2050) to assess the largest opportunities for impact;
-Evaluating which policies may be required to meet embodied carbon reduction targets, such as those set by city or regional climate action plans; and
-Ultimately enabling cities to make the case for and adopt policies to reduce embodied carbon.
Huang, M., Lewis, M., Escarcega, P., Escarcega, E., Torres, M., Waterstrat, H., Kinder-Pyle, I., Simonen, K. (2022). Buy Clean Buy Fair Washington Project: Final Report. Carbon Leadership Forum and Washington State Department of Commerce.
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Abstract
The Buy Clean Buy Fair (BCBF) Washington Project was a pilot study commissioned by the Washington State Legislature in 2021. This project was funded by two budget provisos that required the University of Washington (UW) College of Built Environments’ Carbon Leadership Forum (CLF) to:
-Develop a reporting database to collect environmental and labor information from state construction projects. For this project, the database is a prototype, meant for testing and demonstration purposes only.
-Conduct a case study using pilot projects. Five projects were enlisted to test out and provide feedback on the data reporting process.
Kalsman, M., Lewis, M., Simonen, K. (2023). Pacific Coast Collaborative: Embodied Carbon Policy Case Studies. Carbon Leadership Forum, University of Washington. Seattle, WA. https://hdl.handle.net/1773/49771.
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Abstract
The PCC Low Carbon Construction Task Force, launched at COP26 in November 2021, is a regional initiative between California, Oregon, Washington, British Columbia, San Francisco, Seattle, Los Angeles, Oakland, Portland, and Vancouver to advance low-carbon materials and methods in building and construction projects. The Task Force aims to create a shared regional strategy with the goal of accelerating innovation, investment, and market development for low carbon materials by leveraging the scale of the Pacific Coast regional economy. The CLF began supporting the taskforce as a technical resource in 2022.
These case studies showcase the region’s policy leadership on low-carbon construction and provide insights to inform other jurisdictions pursuing legislation and other policies within the Pacific Coast region and beyond.
Waldman, B., Hyatt, A., Carlisle, S., Palmeri, J., and Simonen, K. (2023). 2023 Carbon Leadership Forum North American Material Baselines (version 2). Carbon Leadership Forum, University of Washington. Seattle, WA. August 2023. http://hdl.handle.net/1773/49965
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Abstract
The CLF Baseline values represent an estimate of industry-average GHG emissions for construction materials manufactured in North America. An overwhelming majority of the CLF Baselines published in this report are based on a North American industry-wide EPD if one was available at the time of publication. As such, it is appropriate to use this number as a rough estimate of a product type’s embodied carbon before a specific product has been selected or as a reference value against which product-level comparisons can be made.
Each material category has a detailed appendix that includes a description of the embodied carbon impacts, the available EPDs, and summary statistics. The Appendices in this report allow users to better understand the availability of existing industry-wide and product EPDs, and the variability of product types across a category. The snapshot of available EPDs summarized in each Appendix was assembled using the EC3 database in Fall 2022.
Lewis, M., Waldman, B., Carlisle, S., Benke, B., and Simonen, K. (2023). Advancing the LCA Ecosystem: A Policy-Focused Roadmap for Reducing Embodied Carbon. Carbon Leadership Forum, University of Washington. Seattle, WA.
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Abstract
Policy action on embodied carbon is growing quickly. 2021-2023 has seen an unprecedented number of introduced and passed policies targeting embodied carbon reductions in the building and infrastructure sectors in the US, Canada, and internationally. Policies aimed at reducing the embodied carbon of building and infrastructure projects and construction materials typically leverage life cycle assessment (LCA) as a methodology to measure the impacts of a product or project and compare them against a percentage reduction target or embodied carbon performance standard (i.e., global warming potential (GWP) limit).
The effectiveness of policies in reducing embodied carbon relies on the health of the underlying LCA ecosystem – the standards, guidelines, data sources, tools, and actors/organizations that constitute the interdependent building blocks of LCA – to create consistent, reliable estimates of embodied carbon to report and benchmark products and projects.
Ashtiani, M, Lewis, M., Waldman, B., Simonen, K. (2024) Embodied Carbon Toolkit for Roadway Infrastructure. Carbon Leadership Forum.
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Abstract
The CLF Embodied Carbon Toolkit for Roadway Infrastructure is one of several CLF’s Toolkit series that serve as abstract references for practitioners, researchers, and policymakers that are collectively targeted at understanding, estimating, and reducing embodied carbon within the context of buildings and infrastructure. This Toolkit, with a focus on the embodied carbon from building the roadway infrastructure, presents an overview of embodied carbon concepts and accounting mechanisms and provides a summary of critical steps to be taken for reducing climate change impacts of roadways. The Toolkit, in three parts, is intended to guide transportation agencies and other related stakeholders into a decarbonized future by:
-Introducing embodied carbon and its major sources within the context of roadway infrastructure construction.
-Highlighting the significant role of the transportation infrastructure in contributing to climate change impacts.
-Providing a summary of standard methodologies in accounting for embodied carbon through life cycle assessment (LCA).
-Summarizing available tools to conduct LCA for roadway infrastructure as a whole and its constituent components.
-Proposing the most impactful current and future strategies in reducing embodied carbon from the roadway infrastructure.
Kalsman, M., Lambert, M., Lewis, M., & Simonen, K. (2024). Northeast U.S. & Canada Embodied Carbon Policy Case Studies. Carbon Leadership Forum. https://doi.org/10.6069/Q8K9-ED23.
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Abstract
Policy is an essential step towards creating the scale of action required to rapidly reduce embodied carbon in construction. We have historically seen embodied carbon reporting primarily be of a voluntary nature. However, in the coming years we expect these policies to cover more projects, more materials and to become mandatory.
These nine policy case studies highlight only a small portion of embodied carbon policy action in the Northeast region of the U.S. and Canada. Looking forward, we expect to see the rapid proposal and adoption of policies across North America.
Ashtiani, M., Palmeri, J., and Simonen, K. (2024). End of Life Modeling and Data in North American Whole Building Life Cycle Assessment Tools. Carbon Leadership Forum, University of Washington. Seattle, WA.
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Abstract
This document summarizes the Carbon Leadership Forum (CLF) research on end-of-life (EOL) modeling for a selection of building materials in whole building life cycle assessment (WBLCA) tools conducted as part of a larger project in collaboration with the National Renewable Energy Lab (NREL), Building Transparency (BT), and Skidmore, Owings & Merrill (SOM). The overarching goals of the project are to:
Improve EOL modeling in WBLCA tools by exploring data gaps and current tool capabilities.
Explore opportunities for developing and testing an open-access EOL database. This can potentially enable WBLCA tools to draw from this database and better harmonize the modeling of EOL impacts.
The recommendations, limitations, and future research ideas are based on: 1) a review of EOL data and modeling functions for three North American WBLCA tools, 2) direct interviews with North American WBLCA tool providers, and 3) a survey and an online workshop with experienced WBLCA tool users.
Ashtiani, M. Z., Huang, M., Lewis, M. C., Palmeri, J., & Simonen, K. (2024). Greenhouse Gas Emissions Inventory from Roadway Construction: Case Study for the Washington State Department of Transportation. Transportation Research Record, 0(0). https://doi.org/10.1177/03611981241233278
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Abstract
Recent emphasis on actions to reduce greenhouse gas (GHG) emissions has pushed many state departments of transportation (DOTs) to develop carbon accounting practices compatible with their current standard data collection and storage guidelines. Once accurate and reliable accounting of GHG emissions is established, strategies can be formed that could help mitigate the adverse environmental impacts of materials used by state DOTs. To date, the Washington State Department of Transportation (WSDOT) has not conducted comprehensive research on the embodied carbon within its construction material usage (i.e., upstream Scope 3 emissions inventory of procured materials) with most previous carbon accounting practices being focused on Scope 1 and Scope 2 emissions (i.e., the carbon footprint of direct and indirect energy usage). This paper summarizes the results of a life cycle assessment on the agency-wide material procurements and construction operations that emit GHGs at WSDOT as a case study. This study uses several data sources from WSDOT in conjunction with publicly available life cycle emissions factor data to estimate GHG emissions attributed to the materials used to build and maintain roadways under WSDOT’s jurisdiction. Results indicate that upstream Scope 3 emissions for WSDOT as an agency is a significant contributor to its overall GHG emissions inventory. Specifically, between 2017 and 2022, this paper estimates an average annual upstream Scope 3 emissions of 310,000 metric tons of CO2 equivalents, which translates to 56% of the total annual GHG emissions including Scope 1 and 2 emissions.