Wars and national defense cause enormous greenhouse gas emissions. But military-related climate pollution is generally excluded from climate change emission totals, including those reported under the UNFCCC (the United Nations Framework Convention on Climate Change).

Obviously, the Trump administration has been pushing US allies to shoulder more of their own security. And many European nations have already been ramping up military spending at least since Russia’s invasion of Ukraine in 2022. But at the same time, the US has also continued to increase its own military spending. And so have other nations around the world, from Russia and China to Pakistan, Mexico, Japan, and others.

My guest today is Ellie Kinney. She’s the Senior Climate Advocacy Officer at a UK-based NGO called the Conflict and Environment Observatory. She and her colleagues advocate for the inclusion of military emissions in national accounting for greenhouse gas pollution. They estimate that the climate costs of military activities is above 5.5% of annual global emissions. That’s nearly half the amount produced by all the world’s cars, and more than all the emissions from aviation.

I sat down with Ellie to learn why military emissions data is so hard to come by. I wanted to know what can be done to improve transparency and how the climate impact of militaries might be reduced. I wanted to better understand what strategies and innovations the Conflict and Environment Observatory and allied organizations are using in their efforts to highlight and alleviate this enormous, growing, and mostly hidden problem.

Additional resources mentioned in this episode:

• The Conflict and Environment Observatory
• https://militaryemissions.org/
• Initiative on Greenhouse Gas Accounting of War
• Benjamin Neimark and Kate Mackintosh: "How wars ravage the environment – and what international law is doing about it"
• Bellingcat

Catastrophe bonds, or cat bonds, have exploded in popularity in recent years. They have emerged as a critical financial tool to foster resilience from hurricanes and other disasters that are made worse or more frequent by climate change. By the end of 2025, more than $60 billion in cat bonds were outstanding.

The world’s leading firm in structuring cat bond transactions is Aon Securities. My guest today is its CEO, Richard Pennay. Over more than two decades, he has helped to pioneer development of this innovative financial instrument.

I sat down with Richard to learn more about how these deals work and what they’re used for. I wanted to better understand their unique role in resilience. And I was curious to know how their use may expand as the effects of climate change worsen, and as states and localities may need to shoulder more of the cost of their own recovery from disasters.

For decades, municipal bonds have made up a vital asset class for savers, retirees, and institutional investors. In the United States, that market is worth more than $4 trillion. At the same time, the revenue from issuing muni bonds pays for nearly 70% of the country’s infrastructure—everything from roads and bridges to water purification and sewage treatment plants. Yet as the effects of climate change are felt more strongly, this crucial system may face serious vulnerabilities.

My guest today is Tom Doe. He’s the founder and was the long-time CEO of a company called Municipal Market Analytics. Since the 1990s, the firm has advised well-heeled and sophisticated clients on all aspects of municipal bonds.

I sat down with Tom to better understand how this kind of climate vulnerability could play out. I wanted to know why, in spite of climate dangers, that the current effects of climate change on the muni market are still so hard to detect. And I was interested to learn how the power and resources of this vast market might be used to foster climate resilience.

Links:

• Municipal Market Analytics, Inc.

Like so many things in Silicon Valley, venture capital investment in climate tech is cyclical. Climate tech first gained attention from venture capitalists starting around 2006, thanks in part to legendary venture investor John Doerr. After initially seeming to fizzle, climate tech VC bouced back. In 2021, at least $49 billion of climate tech VC investments were made, which PWC estimates at 14% of the year’s total. Since then, climate tech VC fell again—along with overall venture capital investing, which was hurt by the spike in interest rates that started in 2022.

Yet climate tech investment has continued to make up 10% or more of total venture funding. Even that significant proportion greatly understates the tremendous attention and optimism that climate VC funding continues to attract. Partly this is because Silicon Valley has an outsized influence on our national economy, culture, and discourse. The valley’s can-do attitude, outside-the-box thinking and record of transforming society have generated justified optimism that tech entrepreneurs can help drive progress on climate.

Yet silicon valley’s monomaniacal pursuit of unimaginable profits have sometimes caused its leaders to betray their vaunted ideals of social progress. And tech firms in recent years have often burdened workers, communities, and the broader society with devastating and persistent side effects of the next big thing.

My guest today is Catherine Bracy, founder and CEO of the nonprofit organization TechEquity. She’s also the author of World Eaters: How Venture Capital is Cannibalizing the Economy.

I sat down with Catherine to talk about her insightful book and related work. Although her work doesn’t focus primarily on climate tech, her perceptive critique of Silicon Valley’s excesses and venture capital’s pathologies provided for me a new way to think about the consequences of VC as a driving force behind climate tech.

Additional resources:

• TechEquity
• World Eaters: How Venture Capital is Cannibalizing the Economy

In the U.S., between 2020 and 2024, the total cost of major weather related disasters averaged about $150 billion per year. That’s more than five times the annual average during the 1980s, even after adjusting for inflation. At the same time as they’ve gotten more costly, major disasters have become more frequent. Inevitably, increasing losses have begun to strain property insurers. In some areas, like parts of California, premiums have gone up drastically. In some markets, insurance is now only offered through last-resort government-sponsored programs.

My guest today is Dr. Carolyn Kousky, an expert on disaster insurance and climate risk management. She has advised numerous communities on these subjects. Her many publications include the 2022 book Understanding Disaster Insurance: New Tools for a More Resilient Future. She’s taught courses on related subjects at the Wharton School of Business at the University of Pennsylvania. More recently she founded a nonprofit organization called Insurance for Good, and she currently serves as Associate Vice President for Economics and Policy at the Environmental Defense Fund.

I sat down with Carolyn to better understand the current and future points of failure in markets for insurance against weather disasters. I was interested to know what the broader consequences may be of a breakdown in those markets. I wanted to hear about what kinds of innovations or policy changes might help in this critical area of climate finance, which has the potential for such profound effects on households and businesses everywhere.

Additional resources:

• Institute for Business & Home Safety (IBHS)
• First Street
• United Policyholders
• Insurance for Good
• Understanding Disaster Insurance: New Tools for a More Resilient Future, by Carolyn Kousky
• Environmental Defense Fund (EDF)

Few people are more closely associated with the climate movement than Bill McKibben. In 1989 he published The End of Nature. It was the first popular book for a broad audience on the climate crisis. Over more than 35 years since then, he’s written about 20 books, and many, many articles in prominent publications. In 2008, he founded a climate advocacy nonprofit called 350.org, which now has about $20 million in annual revenues and is active on six continents. More broadly, he played a critical role in establishing a grassroots activist movement for climate action. He’s been instrumental in a number of climate campaigns, encouraging fossil fuel asset divestment and pushing to block construction of the Keystone XL pipeline, among many other efforts.

With all the things he’s been involved with, you or I may quibble with McKibben about this or that particular strategy or tactic or approach. But it’s undeniable that he has worked more tirelessly and authentically over a longer time period than almost anyone toward progress on the climate crisis.

I sat down with Bill to talk about his latest book, which is called Here Comes the Sun: A Last Chance for the Climate and a Fresh Chance for Civilization. I wanted to learn more about how he sees the current role of the climate movement. And I wanted to hear how and why he thinks solar power may provide a uniquely important path forward for climate progress at this dangerous and critical moment.

Additional resources mentioned in this episode:

• Here Comes the Sun by Bill McKibben
• The Crucial Years
• Third Act
• Sun Day
• 350.org
• Short Circuiting Policy, by Leah Cardamore Stokes
• How Big Things Get Done, by Bent Flyvbjerg and Dan Gardner

Anyone paying even a bit of attention to climate solutions knows that we’ve seen in recent years tremendous development of wind and solar power generation. Most people also understand that that development needs to continue, along with deployment of other carbon-free power sources.

But in order for the clean energy transition to succeed, we also need to make ambitious improvements to America’s transmission grid. The transmission system is a vast, intricate, nationwide machine that most of us take for granted. Most people don’t fully understand all the things it does, why it’s so important, or how is needs to evolve.

My guest today, is Rob Gramlich. He’s the founder and President of a Washington-DC-based consultancy called Grid Strategies. You’d be hard pressed to find someone more knowledgeable than he is about the challenges and opportunities of grid improvement. He frequently testifies before Congress, the Federal energy regulatory commission, and state agencies, and he’s widely respected by key decisionmakers across the political spectrum. Rob has founded a number of important organizations, including Americans for a Clean Energy Grid. Before founding Grid Strategies, he also held important roles at the American Wind Energy Association, the Federal Energy Regulatory Commission (FERC) and elsewhere.

I sat down with Rob to better understand why improvements to the transmission system are essential for the success of the renewable energy transition. I was curious what needs to be improved to make the grid function as it needs to. I wanted to hear what obstacles are impeding these improvements, and where there may be opportunities—even in the current political environment—for meaningful progress on this complex and crucial aspect of the climate problem.

Other resources:

• Grid Strategies, LLC
• Federal Energy Regulatory Commission (FERC)
• Abundance, by Ezra Klein and Derek Thompson

In the last episode of this show, I had the privilege of talking with Elizabeth Burch and Adam Orford, two law professors from University of Georgia. They helped me to better understand many of the types of climate lawsuits that have proliferated in recent years.

But there are so many varieties of climate litigation that there’s a whole other category we barely touched on, which has special relevance to the nexus of climate and finance. I’m talking about shareholder lawsuits brought under corporate or securities law. As before, I wanted to talk with an expert insider, but someone who has more objectivity and a broader perspective than a lawyer immersed in pending cases. 

My guest today is Emily Strauss. She’s a law professor at UC Law San Francisco. That’s the University of California law school that was formerly known as UC Hastings. She’s an expert in corporate law and securities and financial regulation, and some of her recent scholarly research spcifically explores patterns in climate-related shareholder litigation. I sat down with Emily to learn more about how these lawsuits relate to other types of climate-related shareholder advocacy and other types of climate lawsuits. I wanted to know what opportunities shareholder litigation might create to push corporations toward action on climate, and what limitations they may have as a tool for advancing environmental or social goals. 

Additional resources:

• Climate Change and Shareholder Lawsuits (academic paper by Emily Strauss)
• Is Everything Securities Fraud? (academic paper by Emily Strauss)
• Climate Change Litigation Databases (Columbia Law School, Sabin Center for Climate Change Law)