Climate Rising

Danielle Rapson, HBS alum and Co-founder and COO of Mantel, joins Climate Rising to explain how her company is developing a novel molten-based carbon capture system for hard-to-abate industrial sectors. Danielle shares the story of how Mantel spun out of an MIT lab, what sets its technology apart from existing amine-based carbon capture, and why the economics of steam reuse are critical to its efficiency. She also discusses how Mantel’s early projects in pulp and paper and oil refining are shaping its path to commercialization, and what policy and regulatory incentives—like 45Q and Canada’s carbon tax—mean for scaling carbon removal solutions. This episode is part of our alumni series, which also features Eric Adamson, Robotics Executive at Oishii and co-founder of Tortuga AgTech, and Hui Wen Chan of Crusoe, which uses stranded energy to power AI data centers. Explore the full series at climaterising.org. Resources Mentioned • Mantel – Developing molten material-based carbon capture for industrial emissions • Breakthrough Energy Fellows – A program supporting early-stage climate tech innovators • The Engine – VC firm backing tough tech startups out of MIT • MCJ – "My Climate Journey," a podcast and investor network on climate tech • Kruger– Canadian pulp and paper partner for Mantel’s first demonstration project • 45Q Tax Credit (U.S. IRS) – U.S. tax credit for carbon capture and sequestration • Canada’s Carbon Tax Policy – A national carbon pricing mechanism incentivizing low-carbon tech Host and Guest Host: Mike Toffel, Professor, Harvard Business School (LinkedIn) Guest: Danielle Rapson, Co-founder & COO, Mantel (LinkedIn)

Eric Adamson, Robotics Executive at Oishii and co-founder of Tortuga AgTech, joins Climate Rising to share how automation and AI are transforming fruit farming. Eric explains how his team designed a strawberry-harvesting robot capable of operating in outdoor tunnels and vertical farms, bringing operational efficiency, labor savings, and climate resilience to high-value crops. He discusses why harvest is the hardest—and most impactful—problem in agriculture to automate, what it took to move from lab demo to field-scale deployment, and how they integrated custom robotics and 17 on-device AI models to achieve 97% picking accuracy. Eric also shares his climate thesis on why controlled environments reduce emissions, waste, and chemical use, and how UV-powered robots and environmental buffering help adapt to floods, fungi, and labor volatility. This episode is part of our alumni series, which also features Danielle Colson of Mantel, a carbon-capture climate-tech start-up, and Hui Wen Chan of Crusoe, which uses stranded energy to power AI data centers. Explore the full series at climaterising.org

Microsoft’s Brian Marrs, Senior Director of Energy and Carbon Removal, and Chestnut Carbon CFO Greg Adams share their perspectives as a major buyer and developer of carbon removal credits. Their 2025 deal is one of the largest carbon removal deals in the U.S. and seeks to deliver 7 million tons of nature-based carbon credits over 25 years. Brian explains Microsoft’s carbon negative strategy and targets, and the role of carbon removal credits. He also describes how Microsoft is using its Climate Innovation Fund and procurement efforts to “build missing markets” in decarbonized energy, materials, and transportation. Greg describes how Chestnut Carbon combines afforestation, land ownership, and a private equity-backed project development model to deliver high-integrity carbon credits. He explains how their work is similar to long-term energy infrastructure contracts like power purchase agreements (PPAs), and how they are using proprietary tools to scale. Brian and Greg also share their advice for those looking to learn more and work in the field.

Ashley Fill, Global Director of Sustainability at P&G Home Care joins Climate Rising to discuss how consumer behavior and innovative technologies can reduce household carbon and water footprints. Ashley shares how life cycle assessments reveal that 87% of the emissions in P&G’s Home Care portfolio come from product use, particularly dishwashing. She describes how their products are engineered to deliver superior performance while reducing water and energy. Ashley also discusses P&G’s partnerships with appliance manufacturers, NGOs, and coalitions like the 50L Home Coalition to encourage sustainable home practices. She reflects on regional water use trends, behavior change challenges, and how P&G ensures credible sustainability claims. Ashley also shares career advice for those entering sustainability roles in consumer goods

ClimateAi co-founder and CEO Himanshu Gupta explains how his company uses machine learning to forecast extreme weather and help businesses adapt to climate volatility. Himanshu shares his journey from rural India to co-founding ClimateAi while he was an MBA student. He describes how ClimateAi's "biophysics-driven AI" combines limited weather and crop yield data to inform procurement, logistics, and planting decisions for a quarter of the top 200 food and beverage companies. He also shares examples of government partnerships focused on food security and national supply chain resilience and offers insight on the future of adaptation technologies and enterprise AI. Finally, Himanshu gives advice to those looking to work at the intersection of AI and resilience in the food and agriculture industry. This episode is a part of our series on Climate Resilience, which also features Sarah Russell, Managing Director at Google X; Jacqueline Novogratz, CEO of Acumen; and Alex Berkowitz, CEO of Coastal Protection Services. Visit climaterising.org to explore the entire series!

This episode is another in our series on Climate Resilience featuring Alex Berkowitz, Founder and CEO of Coastal Protection Solutions (CPS), a startup developing nearshore infrastructure that reduces wave energy and enhances climate resilience. Alex shares how her personal experience with Hurricane Sandy in her hometown of Rockaway Beach led to the creation of the Wave Breaker—an innovative floating barrier designed to protect coastal communities from storm surge and erosion. She explains how CPS integrates landscape design, marine engineering, and microgrid energy into its solution, and how it differs from traditional seawalls or breakwaters. Alex also discusses navigating public policy, permitting, and insurance incentives, and finally, Alex shares her career advice for those who are interested in climate resilience. Host and Guest Host: ⁠Mike Toffel⁠, Professor, Harvard Business School (⁠LinkedIn⁠) Guest: ⁠Alex Berkowitz⁠, Founder & CEO, Coastal Protection Solutions (⁠LinkedIn⁠)

In this Climate Rising episode in our series on climate resilience, Jacqueline Novogratz, Founder and CEO of Acumen shares how impact investing is agriculture is helping smallholder farmers build climate resilience. Jacqueline shares insights from two decades of investing in poverty alleviation that includes climate resilience and adaptation social enterprises engaging in agriculture and off-grid solar. She explains how Acumen uses blended capital, including philanthropic first-loss investments and commercial impact funding, to scale business models in underdeveloped markets where traditional investors hesitate. Jacqueline also shares examples of companies solving food insecurity and extreme climate risks for smallholder farmers and discusses how a “post-aid” world demands new tools, structures, and partnerships for impact investing.

This episode, part of the Climate Rising series on climate resilience, features Sarah Russell, General Manager of Project Bellwether at X, The Moonshot Factory at Alphabet (formerly Google X). Sarah shares how geospatial data and artificial intelligence can help communities and businesses anticipate and respond to climate risks. Sarah shares insights from her work building predictive wildfire risk models using satellite imagery, AI, and systems design to enable more targeted insurance underwriting and disaster preparedness. She also explains how Bellwether is creating geospatial AI infrastructure and tools to support natural disaster response by the National Guard. Sarah also shares how emerging foundational geospatial models will transform adaptation, and she offers career advice for those in climate tech and applied AI.

Patrik Frisk, CEO of ReJu, joins Climate Rising to discuss his company’s mission to recycle textile waste and build circular supply chains for apparel made of polyester fabric. Patrik brings his prior experience leading Under Armour and other global brands across the textile and footwear industry for over 35 years. Patrik describes how ReJu turns discarded apparel made of polyester blends into new polyester, and how it tackles the logistical and technical challenges of sorting, processing, and regenerating blended fabrics at scale. Patrik also describes relevant policy trends such as extended producer responsibility and offers advice for those pursuing careers in the circular economy.

James Reinhart, CEO of ThredUp, one of the largest online resale platforms for secondhand clothing. James co-founded the company while he was a Masters’ student at Harvard and has spent the last 15 years scaling a national logistics and digital infrastructure platform for resale. In this episode James describes why the company decided to handle physical goods rather than act as a pure marketplace, how ThredUp helps brands run their own resale channels, and how AI and automation are reshaping their operations. James also describes related public policies like extended producer responsibility (EPR) and provides advice for those pursuing careers in circular economy innovation.

In the latest episode of Climate Rising from Harvard Business School, Karen Pflug, Chief Sustainability Officer of Ingka Group (IKEA), shares how IKEA is embedding circularity throughout its business model. She discusses how IKEA is redesigning iconic products like the Billy bookcase to make them easier to disassemble and repair, how secondhand retail pilot programs at IKEA stores are reaching new customers, and how investments like RetourMatras are developing circular solutions for end-of-life mattresses. Karen also describes how policy, design, and customer nudges can accelerate circularity at global scale—and offers advice for those seeking careers in circular economy innovation.

Lauren Rodriguez, who leads partnerships at Circular Services, a Closed Loop Partners company, joins host Mike Toffel to discuss building the infrastructure and investment models needed to scale the circular economy. Lauren explains how Closed Loop Partners supports the transition from a linear to a circular economy through capital management, innovation initiatives, and operating companies like Circular Services. She shares how their private equity, venture capital, and catalytic credit strategies are helping scale recycling, reuse, and circular supply chains.Lauren also explores the critical role of policy—especially extended producer responsibility(EPR) laws—in driving investment and highlights emerging technologies like AI-powered waste stream analysis and autonomous electronics disassembly that are accelerating progress. She closes with advice and resources for students and professionals interested in careers at the intersection of circular economy, investing, and innovation.

Fabian Barthel, Co-Founder of Vytal, a circular economy packaging-as-a-service startup, joins host Mike Toffel to explore the innovation, behavioral science, and regulations shaping the market for reusable containers for take-out food and beverages. Fabian shares how Vytal is tackling packaging waste by building a reusable container system for restaurants, canteens, and major events. He explains why deposit-based systems often fail, how Vytal’s “borrow and return” model changes consumer behavior, and how data, technology and behavioral science underpin their service design. Fabian also discusses the evolving regulatory landscape, including Germany’s reuse mandates and emerging municipal single-use taxes. He closes by offering advice to circular economy entrepreneurs about how to align impact with profit.

In this bonus episode of Climate Rising, we share an episode from Harvard Business School’s Cold Call podcast, featuring HBS professor Mike Toffel and Duncan van Bergen, Co-Founder of Calyx Global. The discussion focuses on Mike’s recent HBS case study, Calyx Global: Rating Carbon Credits, which explores how the company is helping improve transparency and credibility in the voluntary carbon market. Mike and Duncan join host Brian Kenny to unpack how Calyx Global evaluates carbon credit quality, how the company maintains independence in a space vulnerable to conflicts of interest, and how data and technology—from satellite sensing to AI—are transforming how carbon credits are verified and rated. The conversation also highlights key themes in the voluntary carbon market, including the tension between financial models and credibility, the challenges of measuring impact, and the broader implications for corporate climate action.

Luke Leslie, Co-Founder and CEO of Key Carbon, joins Climate Rising as part of our series on voluntary carbon markets. Luke has spent over 20 years in carbon markets and finance, working in investment banking, private equity, and structured finance. Luke explains how Key Carbon is financing high-integrity carbon projects and how new overlaps between the voluntary and compliance carbon markets are at the center of their investment strategy. He provides a “climate finance 101” introduction and discusses the role of investors in the carbon credit space, how structured finance can scale climate solutions. Luke also describes how investors source and evaluate carbon projects, the risks of over-crediting, and the future role of biodiversity markets. Finally, he offers career advice for those interested in climate finance.

Alexia Kelly, Managing Director of the Carbon Policy and Markets Initiative (CPMI) at theHigh Tide Foundation, joins host Mike Toffel for the fifth episode in our series on voluntarycarbon markets. Alexia has worked for nearly two decades atthe intersection of carbonmarkets, policy, and finance, with roles spanning government, private industry, andnonprofits. In this episode, Alexia discusses how voluntary carbon markets are evolving, the criticalrole of policy in shaping carbon finance,and how standards and governance can improvemarket integrity. She also explores how advances in digital technology, data transparency,and AI-driven monitoring are transforming carbon credit verification and marketconfidence. Additionally, she shares herperspective on the integration of voluntary andcompliance markets, including recent developments in Article 6 of the Paris Agreement.Alexia also offers career advice for those looking to enter the field and shares resources forstaying informed on carbon markets and climate finance.

Amy Merrill, CEO of the Integrity Council for the Voluntary Carbon Market (ICVCM) joins host Mike Toffel in this fourth episode of the Climate Rising series on voluntary carbon markets. Amy has extensive experience in carbon markets, including leading negotiations on Article 6 of the Paris Agreement and advising on global carbon finance. Amy explains how ICVCM uses a multi-stakeholder approach to enhance the integrity of carbon credits, including by developing ten Core Carbon Principles (CCPs) and using them to evaluate and strengthen carbon credit programs and methodologies. She discusses the challenges in ensuring credit quality and how the boundary is evolving between voluntary and compliance markets. Amy also shares her insights into the latest trends in carbon markets and offers advice for those interested in learning more about these topics.

This episode, the third in our series on Voluntary Carbon Markets, features Mark Kenber, Executive Director of the Voluntary Carbon Markets Integrity Initiative (VCMI). Mark has worked in carbon markets and climate finance for nearly three decades, with experience at organizations like WWF, The Climate Group, and Fundación Natura in Ecuador. Mark describes VCMI’s mission to provide guidance for companies and other non-state actors on how to credibly use carbon credits as part of their climate commitments. He discusses the current challenges and opportunities in voluntary carbon markets, the role of businesses and governments in ensuring integrity, and how emerging trends—such as the blurring lines between voluntary and compliance markets—will shape the future. Mark also shares career advice for those interested in working in carbon markets and climate finance.

Our second episode on the voluntary carbon market is a bonus episode of a panel discussion recorded at Harvard Climate Action Week in 2024. Harvard Kennedy School Professor Joe Aldy moderates this discussion with Nat Keohane from the Center for Climate and Energy Solutions, Donna Lee from Calyx Global, UC San Diego Professor David Victor, and Carolyn Weinberg, formerly of Blackrock. Together, they bring perspectives from policy, business, and academia. The conversation explores the role of voluntary carbon markets in mobilizing finance for decarbonization, ensuring the integrity of carbon credits, and scaling high-quality projects. They also discuss emerging standards, innovative financial products, and how companies can leverage VCMs to achieve net-zero goals while addressing climate risks.

Dr. Jennifer Jenkins, Chief Science Officer at Rubicon Carbon, joins our host Mike to talk about the critical role of voluntary carbon markets in achieving net-zero goals. Dr. Jenkins shares insights on how Rubicon Carbon is advancing the integrity and scalability of carbon credit through tools like the Rubicon Carbon Integrity Framework (RCIF). The conversation explores the lifecycle of a carbon credit, the challenges of managing risks like additionality and leakage, and how voluntary carbon markets can incentivize global climate action. Dr. Jenkins also shares her outlook on the future of carbon markets and offers advice for those pursuing careers in sustainability and climate solutions.