According to a report published in 2020, approximately four percent of global manmade greenhouse gas emissions are attributable to the fashion industry.1 The majority of these emissions can be categorized as Scope 3 emissions, encompassing all indirect emissions across the value chain, with the exception of indirect emissions from purchased energy (i.e., Scope 2). Fashion brands and retailers are increasingly focusing on investing in strategies to reduce the carbon impact of their products. Our project team of University of Michigan dual-degree Masters of Environment & Sustainability and Masters of Business Administration candidates worked with Sustainability team members at prAna, an active lifestyle apparel and accessory brand with a history of incorporating responsible social and environmental practices into their operations, to determine how prAna’s 2025 goal to transition 100% of their product fibers to more sustainable options (‘preferred fibers’) could reduce carbon emissions of their products.2 Using a baseline year of 2019, our team analyzed internal product data from prAna with industry-standard fiber emissions factors from the Higg MSI database to estimate the total CO2e reduction expected in 2025 assuming the same portfolio of products were made with only preferred fibers. The findings of this project affirmed that with investment in transitioning prAna’s existing fiber selections to more preferred versions, prAna can significantly reduce their carbon footprint emissions and make progress towards a manufacturing emissions reduction target of 30% by 2030, set by both prAna and its parent company, Columbia Sportswear Company.