Tacit Knowledge

Renaissance Philanthropy

AI is creating a new type of abundance, which raises the question: in a world with AI what stays valuable? We think one answer is ambitious people figuring out what problems to solve, how to solve them, and getting the work done. Every other Friday, Renaissance Philanthropy’s Kumar Garg sits down with someone doing hard, important work. We get their story, challenges, and lessons. From cleaning the air in kids’ classrooms, to stabilizing the Arctic, or pulling hydrogen out of the ground, you’ll meet people driving real breakthroughs. Across the season, you’ll hear from Renaissance Philanthropy’s network: fund leaders on the problems they’re addressing, fellows on the big ideas they’re scoping, and funders on what they’re backing and why. This season, you’ll learn what makes the best problem solvers so good at it. That’s the tacit knowledge: the hidden playbook. Join us.

Episodes

  1. 2h ago

    You Can Be The Adult In The Room

    In this episode, host Kumar talks to David Carel, Director of the Inspired Air Fund at Renaissance Philanthropy. David has spent a decade working on the most pressing problems in health and education, and his latest project aims to boost student health and learning outcomes by improving air quality in classrooms. David discusses the transformative potential of improving the air we breathe indoors, where we spend about 90% of our time, and the surprising things we’re learning about airborne illness. He also shares how he stays motivated in his work to sustainably improve conditions in the classroom, even when the going gets tough. David talks about the mentors throughout his career who have taught him to be the adult in the room when no one else is tackling an issue, and the power of using emotional intelligence to push through the self-doubt that affects all founders. Tacit Knowledge Hosted by Kumar Garg Presented by Renaissance Philanthropy Subscribe to our Substack Produced by All Together Now Follow David https://x.com/davidcarel https://www.instagram.com/davidcarel/ https://bsky.app/profile/davidcarel.bsky.social https://www.linkedin.com/in/david-carel-b433251b3/ KEY QUESTIONS AND TAKEAWAYS What is the Inspired Air Fund (formerly the Clean Air for Schools Fund)? A new fund at Renaissance Philanthropy, led by David Carel, focused on improving indoor air quality in schools — both to reduce airborne disease transmission and to improve learning outcomes. It sits at the intersection of health, education, and biosecurity policy. Why does indoor air quality matter more than most people assume? People spend roughly 90% of their time indoors, so indoor air quality — not just outdoor pollution — determines most of a person's actual exposure. Wildfire smoke advisories that tell people to "go inside" miss this: outdoor air gets drawn inside buildings too, and indoor spaces also generate their own pollution, from manufactured furniture, engineered wood, and even human aerosols from people who are sick. What's the evidence that clean air improves learning, not just health? Air filtration has been shown to cut school absenteeism by 10–20%, and lower carbon dioxide and VOC levels have been linked to measurably better cognitive performance. JPMorgan Chase's new $3 billion Park Avenue headquarters doubled its ventilation rate above code specifically because Harvard research found doing so yields a return worth thousands of dollars per employee per year in productivity. Why has indoor air quality remained a blind spot despite living through a pandemic? David argues it falls into a structural gap: philanthropy and policy are organized into verticals like health, education, and environment, and indoor air quality doesn't fully belong to any one of them, so it rarely becomes anyone's top priority even when it would meet the bar for impact in each vertical individually. Why did public health take so long to accept that diseases could spread through the air? For most of the 20th century, airborne transmission was accepted only for tuberculosis and measles; other respiratory illnesses were assumed to spread via large droplets or surfaces. The WHO initially stated early in the Covid-19 pandemic that the virus was not airborne. Science journalist Carl Zimmer's book Air-Borne traces this history and argues it left the world underprepared for Covid. What historical precedent does David point to for solving this at scale? The late-19th-century clean water movement, which built modern water infrastructure and dramatically cut typhoid rates within a generation. David frames indoor air as a comparable infrastructure opportunity: a relatively low-cost, low-administrative-burden intervention that could address multiple problems — disease transmission, pandemic preparedness, and cognitive development — at once. What is the Fund currently building? A cities competition focused on clean air in schools, designed to learn from the successes and failures of past municipal competitions and challenges. David's ask is for input from people with experience designing these kinds of competitions, and from people with insight into how to coordinate across the health departments, environmental agencies, school systems, and mayor's offices a program like this would need to touch. On agency, uncertainty, and following the thread David traces part of his drive back to working as an undergraduate with Gregg Gonsalves, then a nontraditional student and HIV/AIDS activist, which he says taught him that you don't have to wait for "the adults in the room" to act on something you believe matters. His path ran from co-founding Panorama Education (school data analytics) to running early literacy programs in South Africa to pandemic prevention work at Blueprint Biosecurity before arriving at indoor air — each step following a thread rather than a plan. A formative moment: at 19, volunteering on a tuberculosis study in Tugela Ferry, South Africa — where extensively drug-resistant TB (XDR-TB) was first identified — he learned that TB is airborne, meaning a person could be infected by someone who had left the room hours earlier. His tacit knowledge: recognizing the specific emotional pattern of fear, uncertainty, and doubt that entrepreneurs experience, and not trying to think your way out of it — instead noticing it, holding it lightly, and finding ways to re-engage rather than letting a bad week become a decision to quit. He credits community, specifically joining Renaissance Philanthropy rather than building in isolation, as a concrete tool for getting through those low moments. Kumar's framing, echoing Lindsey Graham's widely circulated remark that "there is no they" — you are the ones in the room — as a model for the mindset this kind of work requires. Special Guest: David Carel.

    You Can Be The Adult In The Room
  2. Oct 2

    Chase Every Idea with Joshua Elliott

    In this episode, host Kumar speaks with Joshua Elliott, Chief Scientist at Renaissance Philanthropy and a former prolific DARPA program officer. Joshua brings deep personal passion to climate work and is a constant source of ideas who also sharpens others’ program designs. Joshua discusses the Advance Research for Climate Emergencies (ARC) Initiative at Renaissance Philanthropy, through which the team identifies experts and ideas, incubates them from small seed grants into fully staffed build-grant programs, and launches them. Joshua traces his ambitious, technically rigorous approach to his years at DARPA, which gave him permission to chase ideas others called impossible. Widely sought out for mentorship, he talks about the Climate Emergency Forum and issues an appeal to scientists and nonprofit leaders. *Tacit Knowledge * Hosted by Kumar Garg Presented by Renaissance Philanthropy Subscribe to our Substack Produced by All Together Now FOLLOW JOSHUA LinkedIn: https://www.linkedin.com/in/joshuawrightelliott/ Substack (The ARC): https://arcinit.substack.com/ KEY QUESTIONS & TAKEAWAYS What is the "Sulfur Tracking Program" trying to figure out? An in-development ARC initiative (still under a stealth name) aimed at launching small satellites and balloon-based sensors to resolve one of climate science's biggest open questions: how much of the Earth's declining reflectivity is due to falling aerosol pollution versus a warming-driven feedback loop that's itself reducing cloud cover. Why might Earth's declining reflectivity be as big a driver of warming as greenhouse gases? NASA's CERES satellite data suggests the planet has lost enough reflectivity since 2000 to contribute roughly 2.7 W/m² of climate forcing — a number comparable to the instantaneous forcing from all greenhouse gases emitted since the Industrial Revolution. That comparison is still being finalized in peer review, but it points to a second, under-discussed pillar of climate change alongside emissions. Why has industrial pollution been masking warming, and what happens as it's cleaned up? Burning fossil fuels releases sulfur dioxide and other aerosols that seed brighter, more reflective clouds. That pollution layer is estimated to be offsetting about half a degree of global warming — meaning, as Joshua puts it, we're already living in a "near two-degree world" that's been masked by the dirtiest possible form of accidental geoengineering. As pollution controls reduce aerosol emissions, that masking effect declines too. What's driving the rest of the loss in Arctic ice and cloud cover? About 30% of lost reflectivity comes from vanishing ice and snow cover (largely Arctic sea ice, mountain glaciers). The remaining majority comes from changes in cloud cover — and current observational and modeling capabilities can't yet disentangle how much of that is falling aerosol pollution versus a self-reinforcing, warming-induced feedback loop. Why do the most accurate climate models predict more warming, not less? A recent study comparing the ~40 global climate models in the CMIP archive found that the models which most accurately reproduce observed changes in reflectivity and Earth's energy imbalance also tend to show 1.5–2x higher climate sensitivity than the model average. If those more accurate models are right, a projected 2.5–3°C future could actually be closer to 4.5–5°C. What is the Heilmeier Catechism, and how does Joshua use it? A set of pressure-testing questions developed by former DARPA director George Heilmeier to evaluate research proposals. Joshua distills it into four core questions he uses as a first-pass filter for any ambitious idea: what are you trying to do, who's doing it now and what's wrong with that, what's your big insight, and who cares. What are the ARC Initiative and BiTS? ARC (Advanced Research for Climate Emergencies) is Renaissance Philanthropy's "nonprofit venture studio" model for finding experts and ideas and building them into fundable climate programs, incubating efforts like the Arctic Stabilization Initiative. BiTS (Big if True Science Accelerator) is a related program Joshua co-designed to teach scientists and engineers how to turn ambitious ideas into coordinated, fundable research programs — modeled on the DARPA program-manager playbook. On program design and ambition Joshua credits his time at DARPA with giving him "permission" to think in 20–40 year horizons and pursue ideas most people call impossible — his rule of thumb is that if fewer than 30% of the people you talk to say your idea is impossible, you're not being ambitious enough. His approach to building expertise quickly is deliberately social: talking to 20 to 100 people in a dense stretch of time, using each conversation to get referred to others, rather than relying only on published research. His most recent program-design insight is about timing: bringing in a wide group of field experts (a "PI meeting" or workshop) only once there's a strong-enough shared mental model to make the conversation productive — citing the "forming, storming, norming, performing" framework for how new groups become effective, and the goal of minimizing time spent "storming."

    Chase Every Idea with Joshua Elliott
  3. Oct 2

    The Tri-Sector Athlete with Cara Eckholm

    In this episode, host Kumar speaks with Cara Eckholm, the founder of Pilot City and a Fellow at Renaissance Philanthropy. An urbanist at heart, Cara has thought deeply about how to build relationships between local governments and their constituent researchers and technologists. Describing herself as a "tri-sector athlete" who has moved between government, academia, and the private sector, Cara talks about growing Pitch Fest, which pairs city government agencies with academics and civic technologists willing to help solve specific, openly shared problems, from 100 attendees and a few agencies in its first year to 40 participating agencies and 104 pitches, with 100 of those pitches drawing at least one interested expert. Cara talks about collaborations, cold-emailing, and the power of connection. *Tacit Knowledge * Hosted by Kumar Garg Presented by Renaissance Philanthropy Subscribe to our Substack Produced by All Together Now FOLLOW LinkedIn https://www.linkedin.com/in/cara-eckholm-506b2236/ KEY QUESTIONS AND TAKEAWAYS What is Pilot City A matchmaking program, started by Cara Eckholm in New York, where city agencies pitch specific problems they need help with and local researchers or technologists apply to work with them — flipping the usual model where academics pitch ideas in search of a government partner. How does the matchmaking process actually work? City agencies present problem statements in short, informal pitches (originally modeled on how Stanford classes help students find startup co-founders). Interested researchers and technologists then apply to work with a specific agency, and the agency chooses who they want to work with from the applicant pool. Why build a "buyer-first" model instead of starting with researchers' ideas? Eckholm observed that both sides were siloed: academics and civic technologists had ideas for improving cities but no government partner, while city agencies had unmet needs but no channel to reach outside talent. Starting with the agency's stated problem — the "buyer" — rather than a researcher's proposal solved the matching problem directly. What makes a city a good candidate for a Pitchfest program? A metro population of at least a million, a government champion willing to publicly share unsolved problems (which runs against how most agencies communicate), and either a research university or an active civic tech community — most U.S. cities already have the latter. What's a real-world example of this kind of collaboration paying off? Economist Al Roth was approached by an NYC Department of Education official who had read his work on medical residency matching and asked him to help redesign the city's high school placement process. The redesign was later adopted in Boston, and Roth went on to win a Nobel Prize for that work and related market-design research, including kidney-exchange matching. How much traction has the program gotten? In its most recent year, 40 agencies submitted 104 pitches, and 100 of those pitches drew at least one interested researcher — some drew as many as 20. The program is now expanding beyond New York to Boston, Hennepin County (Minneapolis), Los Angeles (water district), and Philadelphia (regional transit). What's holding academia back from more of this kind of applied work? Tenure and promotion structures reward publication in a narrow set of journals, not applied public-sector collaboration — to the point that one professor Eckholm spoke with left his work as a city and White House housing policy adviser off his tenure application, worried it would make him look like an activist rather than a scholar. On career and confidence Eckholm's own path into this work began with a cold email — she reached out to her boss's boss, former NYC Deputy Mayor Dan Doctoroff, offering to help with a post-pandemic economic recovery commission, with no idea if he'd respond. That opportunity ended up shaping the next several years of her career. Her tacit-knowledge takeaway is what she calls "delusional confidence" — treating open calls for applications ("apply even if you're underqualified") literally, and being willing to send many speculative emails knowing only a fraction will land. She distinguishes this from overconfidence: the goal isn't to claim expertise you don't have, but to clearly articulate what value you could add and let curiosity — not credentials — carry the pitch.

    The Tri-Sector Athlete with Cara Eckholm
  4. Oct 1

    Go Where the Problem Is with Charlotte DeWald

    In this episode, host Kumar talks to Charlotte DeWald, Director of the Arctic Stabilization Initiative (ASI) at Renaissance Philanthropy. Charlotte is a deep researcher who has spent her career studying runaway climate risks and figuring out what needs to be done to stop them. Charlotte discusses what drove her to assemble ASI's team and create a roadmap around that end goal from the start, and the advice and mindset that led her to make a deliberate departure from how she'd seen other organizations in the field start out. Charlotte talks about the role her delivery focus has played in her own career shift, growing impatient with research that wasn't translating into action fast enough, and what pushed her to build something explicitly designed to produce usable, actionable outputs. Charlotte’s fascinating story sheds light on how to find problems worth working on. *Tacit Knowledge * Hosted by Kumar Garg Presented by Renaissance Philanthropy Subscribe to our Substack Produced by All Together Now FOLLOW CHARLOTTE LinkedIn: linkedin.com/in/charlottebeall KEY QUESTIONS AND TAKEAWAYS What is the Arctic Stabilization Initiative? Housed at Renaissance Philanthropy and directed by Charlotte DeWald, ASI is stage-gated research designed to give governments and multilateral organizations the safety, efficacy, and feasibility data they'd need to evaluate Arctic-targeted climate interventions — not to deploy interventions itself. Why isn't decarbonization enough to stop Arctic tipping points? Climate action has three points of attack rather than two. Decarbonization and adaptation get the most attention, but neither addresses near-term "tipping point" risk already locked in by processes like sea ice loss and permafrost thaw. ASI focuses on the third arm: regional climate stabilization in the Arctic. What are Arctic tipping points? Once certain climate thresholds are crossed, DeWald explains, the resulting state change is irreversible on human timescales — and the Arctic is where several of the most imminent thresholds converge, making it a first test case for humanity's tipping-point response. What types of Arctic climate intervention exist? There are three broad categories: increasing atmospheric reflectivity, structurally reinforcing ice sheets and sea ice, and increasing atmospheric emissivity — helping trapped heat escape. DeWald's research focuses on the third and least-understood category. Why do mixed-phase clouds warm the Arctic instead of cooling it? Mixed-phase clouds cover roughly 60% of the Arctic and trend net-warming, not cooling. Because they sit low to the surface and much of the Arctic year has little sunlight to reflect, these clouds act more like a "hat" trapping heat than a shield blocking it. What is mixed-phase cloud thinning? The proposed intervention is to nudge clouds into ice formation to help them dissipate. The mechanism relies on ice-nucleating particles — rare naturally occurring particles that trigger ice formation at temperatures far above freezing — a topic DeWald spent roughly a decade researching via shipboard instrumentation and national-lab modeling collaborations. Is Arctic cloud seeding a new or untested technology? The approach is neglected, not infeasible. Cloud seeding and cloud shaping are established techniques; what's missing is the applied research connecting them specifically to Arctic stabilization. DeWald built the initiative largely by cold-calling experts across disciplines to pressure-test whether a five-year research agenda was viable. Beyond the science DeWald's path to ASI came from friction with the pace of climate science. After a decade studying aerosol-cloud interactions — widely regarded as one of climate science's most persistent uncertainties — she concluded that incremental scientific understanding wasn't translating into commensurate action, which pushed her toward field-building instead of continued lab research. Defining the "end user" early shaped ASI's structure. A conversation with a former U.S. diplomat (ex-UN envoy for East Africa, USAID) helped DeWald realize the initiative needed a diplomacy function from the outset — since the research is only useful if there's a clear pathway to the governments and multilateral bodies who'd act on it. DeWald's tacit-knowledge takeaway: talk to people, not just papers. Her throughline across the episode is that expertise compounds through networked conversation — knowing who to call, and being willing to call them — as much as through individual technical depth. Open asks from the episode: DeWald is looking to connect with people in conservation (for perspective on intervention risk/tradeoffs), scientists developing Arctic sampling platforms or sensors, and anyone who can "think programmatically" about field-building. She's reachable via Substack and LinkedIn.

    Go Where the Problem Is with Charlotte DeWald

About

AI is creating a new type of abundance, which raises the question: in a world with AI what stays valuable? We think one answer is ambitious people figuring out what problems to solve, how to solve them, and getting the work done. Every other Friday, Renaissance Philanthropy’s Kumar Garg sits down with someone doing hard, important work. We get their story, challenges, and lessons. From cleaning the air in kids’ classrooms, to stabilizing the Arctic, or pulling hydrogen out of the ground, you’ll meet people driving real breakthroughs. Across the season, you’ll hear from Renaissance Philanthropy’s network: fund leaders on the problems they’re addressing, fellows on the big ideas they’re scoping, and funders on what they’re backing and why. This season, you’ll learn what makes the best problem solvers so good at it. That’s the tacit knowledge: the hidden playbook. Join us.

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