CREJ

40 / BUILDING DIALOGUE / March 2020 ELEMENTS Carbon Elevating Embodied Carbon: Industry Can Choose Materials that Minimize Carbon Emissions During their Production W ith all that is going on in theworld to- day, it would have been easy to miss a few recent critical headlines like the American Institute of Architects Code of eth- ics change, the Intergovernmental Panel on Cli- mate Change’s Special Report, the AIA’s landmark initiative to drive climate action, the Structural Engineers 2050 challenge, and Architect Magazine’s January issue entirely devoted to embodied carbon. When strung together, these stories, along with so manymore, point to anawakeningwithinAEC indus- tryanda shift inpriorities toaddress thebuilt environ- ment’s role in climate change. As documented by the World Resources Institute Ross Center for Sustainable Cities, building production and operations emit 33% of the global energy-related greenhouse gas emissions, making them the single biggest carbon emitter by sector, and emissions are expected to double by 2050. American Society of Heat- ing, Refrigerating and Air-Conditioning Engineers stan- dards, aggressive code changes, and clean-energy grid sourcing are all inmotion andneed to be rampedup to address the carbon emissions associatedwith the oper- ations of our buildings. But another huge part of the carbon equation is the “embodied” carbon associatedwith the industrial prac- tices in the manufacturing of our building materials. Eight percent of CO2 emissions globally come from cement production alone, according to UK-based pub- lic policy think tank Chatham House. Other critical building materials such as steel, aluminum, and glass are alsomajor CO2 contributors, and the impact of pro- ducing these four major buildingmaterials could be as high as 20%of all global emissions. Knowingthatthenext10yearsarecriticalasoutlined in the IPCC’smodels and our buildings have anaverage estimated life of 60 years, thematerials we choose year one may be just as important, if not more so, than the energy reductionof thebuilding’soperation. Sohowdo we start reducing carbon emissions from the produc- tion of thesematerials? First, wherever possible, reuse and reposition exist- ing buildings. Extending the life of existing buildings can save anywhere from 50% to 75% of the embodied Jill Kurtz, AIA Director of Building Sciences, Page