The Stream (with Will & Tom)

Will Sarni & Tom Freyberg

An unscripted conversation with guests who reject the status quo with a bias for action, in the world of water and beyond. Co-hosted by Will Sarni and Tom Freyberg.

  1. Taking on PFAS (forever chemicals) with synthetic biology – Nicole Richards

    10/09/2025

    Taking on PFAS (forever chemicals) with synthetic biology – Nicole Richards

    In this episode, we welcomed Nicole Richards, CEO of US firm Allonnia, a company that promises to enzymes and microbes to degrade environmental contaminants. Now the topic of PFAS, per and polyfluoroalkyl substances, known as forever chemicals, is getting a lot of attention. Known for their unbreakable bonds, they’re used in pretty much everything, from non-stick saucepans through to waterproof jackets, and military firefighting foam applications. Following a regulatory limit introduction by the US Environmental Protection Agency, as well as corporate fines to chemical companies responsible for PFAS pollution, there has been almost a space race of start-ups in this space promising destruction techniques. It was great to get Nicole’s perspective because Allonnia is quite unique. It was launched out of Ginkgo Bioworks Ferment Consortium with a $40 million Series A funding round, which was then boosted by another $15 million funding round from DARPA, the Defense Advanced Projects Agency. Now, $55 million for a start-up is ana extremely rare position to be in! Nicole discusses this, as well as making the leap from almost 30 years in chemical engineering over to the start-up world. There’s a lot of discussions on PFAS, the impact on human health, and how technology innovation will help to solve this problem. Nicole comes at it from an interesting perspective of how synthetic biology will play a role. 🔔 We hope you enjoy the episode and make sure to follow and subscribe to our channels to get alerts on the episodes. We’re delighted you can join us on this voyage of discovery, as we journey down The Stream. Special thanks to this season's sponsor, Raymond James. And our charity partner, Frank Water. And thanks to our knowledge partners: British Water, WWF, Water Alliance, DCU Water Institute, SurplusWater25, Earth and Environmental Science at Berkeley Lab, Water Foundry and Atlantean Media.

    46 min
  2. Galvanizing climate solutions – Ida Hempel on water investments and her time at Tesla

    09/18/2025

    Galvanizing climate solutions – Ida Hempel on water investments and her time at Tesla

    How do you invest $1 billion dollars to accelerate climate and water solutions? 🌍 In this episode of The Stream Podcast, we speak with Ida Hempel from Galvanize Climate Solutions, the investment platform co-founded by Katie Hall and Tom Steyer, former hedge fund manager, climate philanthropist, and 2020 U.S. presidential candidate. In September 2023, Galvanize closed its $1B Innovation & Expansion Fund, one of the largest climate venture funds ever raised. Ida takes us inside the fund’s three strategies, from venture & growth to global equities and real estate, and shares how water infrastructure improvements are being integrated into their decarbonisation playbook. We also dive into Ida’s experience at Tesla, where she witnessed pivotal moments in the company’s history, and explore what large-scale climate investment really looks like in practice. If you’re curious about the future of climate finance, water innovation, and scaling sustainability, this episode is for you. 🔔 We hope you enjoy the episode and make sure to follow and subscribe to our channels to get alerts on the episodes. We’re delighted you can join us on this voyage of discovery, as we journey down The Stream. Special thanks to this season's sponsor, Raymond James. And our charity partner, Frank Water. And thanks to our knowledge partners: British Water, WWF, Water Alliance, DCU Water Institute, SurplusWater25, Earth and Environmental Science at Berkeley Lab, Water Foundry and Atlantean Media.

    41 min
  3. Planting 12.5 million trees and counting – Earthshot winner Florent Kaiser on local water stewardship in Latin America

    08/28/2025

    Planting 12.5 million trees and counting – Earthshot winner Florent Kaiser on local water stewardship in Latin America

    How do you plant 12.5 million trees and mobilise over 40,000 local and Indigenous people across six South American countries? 🌎 In this episode of The Stream, we sit down with Florent Kaiser, Executive Director of Global Forest Generation and co-founder of Acción Andina, a grassroots movement restoring high Andean forests. A past Earthshot Prize winner and recognised by the UN as one of the World Restoration Flagships, Florent shares: Why the next phase of Acción Andina is called “the path of water.” 💧How restoration ties directly to water stewardship, climate resilience, and community livelihoods.New financial models shifting from corporate to local finance.The role of Indigenous leadership in linking global sustainability ambitions with local action.We first met Florent at London Climate Action Week, and his vision left a lasting impression. Tune in to hear how a movement rooted in local action is reshaping global water and nature restoration. 🔔 We hope you enjoy the episode and make sure to follow and subscribe to our channels to get alerts on the episodes. We’re delighted you can join us on this voyage of discovery, as we journey down The Stream. Special thanks to this season's sponsor, Raymond James. And our charity partner, Frank Water. And thanks to our knowledge partners: British Water, WWF, Water Alliance, DCU Water Institute, SurplusWater25, Earth and Environmental Science at Berkeley Lab, Water Foundry and Atlantean Media.

    49 min
  4. Building a stock exchange for nature recovery – Guy Thompson

    08/14/2025

    Building a stock exchange for nature recovery – Guy Thompson

    Season 9 kicks off with a deep dive into nature finance, water, and market innovation, with Guy Thompson, MD at EnTrade. After more than a decade advising the UK government at Natural England, Guy Thompson made a bold leap into the private sector. In this episode, he shares why he had to scratch the itch of building something new, and how that led him to co-found EnTrade, a pioneering platform driving market-based solutions for nature. We unpack how EnTrade evolved from a Wessex Water incubator into an independent company, and how it’s forging unlikely partnerships, from start-up thinkers to giants like Arup, to link farmers, utilities, and developers in innovative new ways. From biodiversity net gain in the UK planning system to bridging the £44 billion nature finance gap, Guy shares use cases from Somerset and beyond, showing how we can harness the power of water markets to deliver outcomes for nature, water quality, and climate. We also reflect on the recently published Cunliffe Review, what’s working (and what’s not) in policy, and why EnTrade is looking to shake things up. 👉 If you're curious about the intersections of biodiversity, policy, water, and finance: this one’s for you. 🔔 We hope you enjoy the episode and make sure to follow and subscribe to our channels to get alerts on the episodes. We’re delighted you can join us on this voyage of discovery, as we journey down The Stream. Special thanks to this season's sponsor, Raymond James. And our charity partner, Frank Water. And thanks to our knowledge partners: British Water, WWF, Water Alliance, DCU Water Institute, SurplusWater25, Earth and Environmental Science at Berkeley Lab, Water Foundry and Atlantean Media.

    46 min
  5. Voices of Regeneration: Founders Driving Innovation

    07/25/2025

    Voices of Regeneration: Founders Driving Innovation

    This special episode of The Stream takes you inside Northumbrian Water’s Innovation Festival 2025, where this year’s theme, Regeneration, inspired bold ideas and brilliant collaborations. Tom sits down with five founders and innovators in water, sustainability, and infrastructure. From 3D-printed concrete and microbial electrolysis cells to citizen-powered AI and leakage detection, these conversations shine a light on the future of the industry, and the minds building it. Featured guests: John Marsden, Origin Tech – Detecting and fixing leakage through satellitesNatalie Wadley, Changemaker3D – Reinventing concrete and enabling 3D printed infrastructure regeneration.Kapil Singhal, Vyntelligence – Using AI and citizen science to streamline water operations.Pavlina Theodosiou, MetZero – Advancing circular wastewater treatment through microbial electrolysis.Sigga Siguroardottir, Veitur – Bringing Icelandic innovation spirit to the UK.We hope you enjoy this special episode of The Stream on the road. Keep an eye out for Season 9 coming soon.  🔔 We hope you enjoy the episode and make sure to follow and subscribe to our channels to get alerts on the episodes. We’re delighted you can join us on this voyage of discovery, as we journey down The Stream. Special thanks to this season's sponsor, Raymond James. And our charity partner, Frank Water. And thanks to our knowledge partners: British Water, WWF, Water Alliance, DCU Water Institute, SurplusWater25, Earth and Environmental Science at Berkeley Lab, Water Foundry and Atlantean Media.

    1h 14m
  6. From FIG to FIGS – Usha Rao-Monari on water economics and the need to make flexible financing work

    04/26/2025

    From FIG to FIGS – Usha Rao-Monari on water economics and the need to make flexible financing work

    Former UN Under-Secretary-General Usha Rao-Monari joins The Stream to explore why blended finance isn’t working for water, lessons from the energy sector, and how her FIGS model can drive change through finance, innovation, governance, and social equity.  In this episode of The Stream podcast, Will and Tom are joined by Usha Rao-Monari — Senior Partner at Wellers Impact and Former Under-Secretary-General at the United Nations. Usha reflects on her 25+ year career across finance, infrastructure, and development, including her time as Associate Administrator of the United Nations Development Programme (UNDP). We dive deep into why blended finance — combining public and private investment, grants, equity, and debt — still isn’t working in the water sector, and what water can learn from energy and renewables when it comes to incentives and investment models. She also shares her updated FIGS framework (Finance, Innovation & Infrastructure, Governance, and Social equity) — a model designed to drive real impact in complex systems. If you've heard Usha speak before, you'll know how clearly she explains big ideas. This episode is packed with insight, inspiration, and practical takeaways for anyone working at the intersection of water, climate, finance, and development. 🧠 Topics include: -The challenges and promise of blended finance -Economic models for scaling water solutions -Parallels between water and energy investment -How to embed social equity into infrastructure strategy -Career reflections from the UN and beyond 🔔 We hope you enjoy the episode and make sure to follow and subscribe to our channels to get alerts on the episodes. We’re delighted you can join us on this voyage of discovery, as we journey down The Stream. Special thanks to this season's sponsor, Raymond James. And our charity partner, Frank Water. And thanks to our knowledge partners: British Water, WWF, Water Alliance, DCU Water Institute, SurplusWater25, Earth and Environmental Science at Berkeley Lab, Water Foundry and Atlantean Media.

    45 min

Ratings & Reviews

5
out of 5
4 Ratings

About

An unscripted conversation with guests who reject the status quo with a bias for action, in the world of water and beyond. Co-hosted by Will Sarni and Tom Freyberg.