Can Seaweed and Methane Replace Plastic? (SF Climate Week)

As plastic pollution accelerates alongside climate change, innovators are racing to replace petroleum-based materials with scalable, climate-positive alternatives. In this live episode from the 2026 San Francisco Climate Week, Dylan Garrett speaks with Julia Marsh, CEO and co-founder of Sway, Molly Morse, CEO at Mango Materials, and Ryan Starling, Design Director at frog Design, about how seaweed-based polymers and methane-derived bioplastics could transform the future of packaging and consumer products. They explore why sustainable materials must work within existing manufacturing infrastructure, how rigorous life cycle analysis helps win over brands and buyers, and why nature’s own materials often outperform engineered alternatives. The conversation also examines supply chain resistance, composting policy barriers, and the importance of designing climate solutions that align environmental impact with economic incentives and real-world adoption. What you will learn: Why reduction alone won't solve the plastic crisis How seaweed becomes a viable plastic replacement The methane-to-plastic pathway that actually sequesters carbon How to overcome supply chain resistance through proof and brand alignment. The compostability policy trap that kills promising alternatives Why LCA comparisons are incomplete without context Julia Marsh is CEO and cofounder of Sway, a biomaterials company revolutionizing packaging through seaweed-based plastic alternatives. With a background in design and packaging innovation, Julia recognized the environmental impact of traditional plastics and pivoted her career toward creating sustainable materials that perform as well as conventional plastics while being fully compostable. Molly Morse is cofounder and CEO of Mango Materials, a biotechnology company transforming waste methane emissions into biodegradable PHA (polyhydroxyalkanoate) plastics. Holding a PhD in biodegradable materials and biocomposites, Molly combines deep technical expertise with entrepreneurial vision to address both the production and end-of-life challenges of conventional plastics. Ryan Starling is the Design Director at frog Design, specializing in sustainable product and packaging innovation. With expertise in industrial design and life cycle assessment, Ryan bridges the gap between material science and real-world product adoption by helping corporations navigate the complex trade-offs between performance, cost, and environmental impact. Hardware to Save a Planet is brought to you by Synapse. We are a global product development and engineering firm that partners with visionary companies to design, develop, and realize breakthrough hardware and AI-powered innovations that advance climate technologies. To learn more about Synapse and potential business partnerships we offer outside of the podcast, please visit: https://www.synapse.com/contact/ to get in touch! Chapters: 00:00 Intro: Hardware to Save a Planet 04:46 From Beautiful Trash to Seaweed Solutions 06:21 Methane to Plastic: PHA and Carbon Sequestration 10:26 Design's Role in Sustainable Material Adoption 13:47 Impact on Both Sides: Production and End of Life 19:05 Why Reduction Alone Isn't Enough 22:28 Designing for Reality, Not Ideology 22:44 Commercial Applications: Fashion, Beauty, and Beyond 25:01 Customer Motivations: Performance, Price, and Planet 28:25 Stacking Value Propositions for Adoption 30:42 Scaling Challenges: Supply, Demand, and Confusion 32:56 The Compostability Policy Trap 35:23 Storytelling the Complex Polymer Problem 36:28 Health, Fertility, and Microplastics 38:15 Formulations and Hidden Toxic Additives 41:37 Ecological Effects of Biodegradable Polymers 43:29 Engaging Stakeholders to Overcome Resistance 45:14 Case Studies: From Skepticism to Sales Growth 46:27 Key Takeaways & The Future of Plastic Alternatives Episode Resources: Julia Marsh on LinkedIn -   / julia-marsh   Sway Website - https://swaythefuture.com/ Molly Morse on LinkedIn -   / greenmolly   Mango Materials - https://www.mangomaterials.com/ Ryan Starling -   / ryancstarling   frod Design Website - https://www.frog.co/ Dylan Garrett on LinkedIn -   / dylangarrett   Synapse Website - https://www.synapse.com/ Synapse Podcast Website - https://www.synapse.com/podcast/ Listen and Subscribe on: Apple Podcasts - https://bit.ly/3WXWMk5 Spotify - https://bit.ly/4hRsE1v Fame Host - https://hardwaretosaveaplanet.com