Unlocking Climate Investing to 401(k) Retirement Plans (with Alex Wright-Gladstein of Sphere)

This is CC Pod - the Climate Capital Podcast. You are receiving this because you have subscribed to our Substack; manage.Disclaimer: For full disclosure, Sphere is a portfolio company at Climate Capital, where Sundeep Ahuja is the Founder and General Partner.CC Pod is not investment advice and is intended for informational and entertainment purposes only. You should do your own research and make your own independent decisions when considering any investment decision. But first: Network Fund & Climate Angels→Invest in the Network Fund. Large fund access with micro-fund minimums.→Join Climate Angels. Sessions w/ top investors, discounted carry, community & more.Don’t miss an episode from Climate Capital!Retirement savings represent one of the largest pools of capital in the world, yet they are rarely discussed in the context of climate impact. In this conversation, CC Pod host Sundeep Ahuja speaks with Alex Wright-Gladstein, founder and CEO of Sphere, about how the $45 trillion of retirement savings could become a powerful lever for climate-aligned investing.Sphere helps advisors and employers demonstrate their commitment to fiduciary duty with a high-quality product at reasonable fees while also satisfying a deeply personal desire of clients, without having to choose between the two. Building on this, the company’s flagship strategy, the Sphere 500 Fossil-Free Index, tracks the 500 largest US companies by market capitalization while excluding fossil fuel exposure to reduce stranded asset risk. It also directs shareholder voting toward climate-aligned outcomes rather than maintaining the status quo, embedding climate considerations directly into capital allocation.The conversation traces Alex’s path into building Sphere, which began far outside finance. She previously founded Ayar Labs, an MIT spin-out valued at roughly $3.75–4 billion that uses photonic interconnects to move data between chips using light, significantly improving energy efficiency and performance in AI computing systems. Despite working on frontier hardware innovation, her eventual pivot into retirement investing came from a very personal operational challenge inside her own company.While leading Ayar Labs, Alex attempted to add a climate-aligned option to the company’s 401(k) plan. What initially seemed like a simple internal change turned into a multi-year effort that revealed deeper structural constraints in the retirement industry. Even employees at climate-focused companies were often defaulted into funds with fossil fuel exposure, not because of lack of demand, but due to fiduciary risk frameworks, fee sensitivity, and the absence of compliant index-based climate alternatives.That friction became the foundation for Sphere. The company’s insight was that the barrier to climate-aligned retirement investing was not investor intent, but product structure. Instead of relying on higher-cost, actively managed ESG strategies, Sphere designed passive index funds that mirror standard benchmarks while excluding fossil fuel companies, allowing them to meet fiduciary standards on fees, tracking error, and legal defensibility.Sphere has since focused on embedding its funds directly into major 401(k) platforms, making it possible for employers to add climate-aligned options without switching providers or redesigning their retirement plans. This plug-in model removes operational friction for HR teams and plan advisors, which has historically been one of the biggest blockers to adoption.Beyond product design, Sphere also operates as a systems-change platform. It highlights long-term market data showing that fossil fuel-heavy sectors have underperformed broader indices over time, reframing climate alignment as both a values-driven and financially competitive choice. The company also supports employee-led advocacy, where individuals push HR departments and 401(k) advisors to introduce climate-aligned options, creating change from within large organizations.The episode further explores how Sphere has partnered with broader public awareness efforts, including campaigns led by cultural figures and pension participants, to highlight the scale of fossil fuel exposure in retirement funds. These efforts have helped bring visibility to an issue that most savers are unaware of, despite its significant climate implications.Today, Sphere is expanding its product suite beyond its initial index fund, building a broader range of climate-aligned retirement options designed to replicate standard 401(k) allocations across asset classes. The company’s long-term goal is to make climate-aligned investing a default feature of workplace retirement plans, rather than a niche or optional add-on.To learn more about Sphere, visit https://www.oursphere.org/. Get full access to Climate Capital at climatecap.substack.com/subscribe