Lewis Pugh has swum across seas and in between melting sea ice, but the hardest part of his work is what comes after – contributing to negotiations to protect those same bodies from development. And he’s been successful: In 2016 he got the Russians to sign a pact to create a marine protected area in the Ross Sea – one of the few healthy seas left, and the size of Britain, France, Germany, Italy put together. A negotiation should be an exploration, not a battle, he tells Akshat Rathi. Pugh also talks about how he got his start, the swim that made him into an environmental advocate and what he wants to come out of COP27. Akshat speaks with Salma El Wardany, a Bloomberg News energy and commodities reporter based in Cairo, and Zero producer Oscar Boyd, about their experiences of COP27.

Read a transcript of this episode, here.

Zero is a production of Bloomberg Green. Our producer is Oscar Boyd and our senior producer is Christine Driscoll. Special thanks to Kira Bindrim and Stacey Wong. Thoughts or suggestions? Email us at zeropod@bloomberg.net. For more coverage of climate change and solutions, visit https://www.bloomberg.com/green