Tacit Knowledge

*Tacit Knowledge *
Hosted by Kumar Garg
Presented by Renaissance Philanthropy
Subscribe to our Substack
Produced by All Together Now

FOLLOW ISHAN

Twitter: (at)ishan_sharma3
Instagram: (at)ishan_sharma3
LinkedIn: https://www.linkedin.com/in/ishan-kabir-sharma3/

KEY QUESTIONS AND TAKEAWAYS

What is geologic hydrogen, and how is it different from manufactured hydrogen?

Geologic hydrogen (Geo H₂) forms naturally underground, for example when water reacts with iron-rich rock, so it can be found and produced rather than manufactured with expensive, energy-intensive processes. Ishan argues it is zero-emission and potentially a fraction of the cost of today's hydrogen. He cites the estimate that about 2% of the hydrogen thought to be in the ground could meet civilizational needs for centuries.

What is the Chimaera Fund?

The Chimaera Fund is Renaissance Philanthropy's field-building fund, directed by Ishan Sharma, aimed at making geologic hydrogen a credible part of the energy mix in the 2030s. Ishan says the field has already drawn roughly $1 billion in private investment, so the fund isn't trying to compete with startups. It aims to grow the overall pie with open-source testbeds, data sharing, and policy work modeled on what worked in shale and geothermal.

Why does Ishan see geologic hydrogen as essential to decarbonization?

He argues that cheap solar has largely solved the "green electron" half of the emissions problem. The remainder, in food systems and heavy industry like steel and chemicals, needs a cheap green molecule, and he doesn't see manufactured green hydrogen arriving before roughly 2045–2050. Industrial plants are making capital decisions in the next 5–7 years that could lock in emissions for about 40 years. In his view, geologic hydrogen is the only option that could affect that decision window.

What can shale and geothermal teach us about scaling a new energy industry?

Ishan points to a pattern: both industries spent decades in slow, localized progress before inflection points driven by government-backed testbeds and companies sharing subsurface data. Geothermal went from a first well in the 1920s to a Department of Energy testbed in Utah and, now, Fervo Energy's public listing. His conclusion is that opening up solutions and data early is the fastest path to scale, measured in years rather than decades.

How did Chimaera get private companies to share subsurface data?

It started small: one company, a grant of roughly $250K, and an ask for the metadata version of its data rather than the proprietary data itself. Researchers could then propose studies based on what the company actually had. Once that first company signed on and Chimaera announced it at a major geologic hydrogen conference, several dozen other companies asked to do something similar. Early wins then became proof of credibility, including work with the U.S. Air Force and real operating companies.

What is Chimaera working on next?

Ishan previewed a $10M grand-prize challenge with the Japan Cabinet Office to drill the first hydrogen well, and a test bed in East Africa. The East Africa work is framed around reducing smallholder farmers' dependence on imported ammonia, not just emissions. Both were described as upcoming, not yet announced, at the time of recording.

What is the Law of Requisite Variety, and how does Chimaera apply it?

Ishan describes it as the idea that the entity with the most flexibility in a system has the greatest control over its outcome. Chimaera applies it by staying deliberately nimble instead of building headcount. One example he gives is walking away from a donation of about 1,200 acres for test beds to pivot to a faster-moving opportunity.

On careers, credibility, and field-building

• Ishan didn't start in energy. He studied industrial labor relations and economics planning for human rights law, and a paper on surveillance technology led him to defer law school and enter science and tech policy, first at FAS, then the White House, then Renaissance Philanthropy.
• His filter for what to work on is a Venn diagram: a problem that is neglected, where he can see a path to making a difference, and where he has a thesis worth pressure-testing. He says the overlap is small, and once you find it, "why not go hunting?"
• His tacit knowledge: there is enough good work to go around. Approaching a new field with "no pride of place," and wanting to distribute good ideas rather than own them, is what lets an outsider work with deep experts.
• To bring skeptical experts along, he asks whether anyone else has looked at their data and reached a different conclusion, which appeals to their humility instead of forcing a debate. He says credibility comes from early wins and demonstrated taste more than from the size of the funding.
• Kumar's framing: science progresses at the pace of discovery plus persuasion. Good ideas need advocates willing to walk into rooms and answer skeptical questions, one person at a time, like the lone juror in 12 Angry Men.
• Asks and offers: Ishan offers conversations to early-career people weighing an unconventional path. His ask is for anyone excited to work on subsurface activities in sub-Saharan Africa to help build the test bed.

Special Guest: Ishan Sharma.

Links:

• Ishan Sharma — Fellow at Renaissance Philanthropy and director of the Chimaera Fund. Previously principal advisor on industrial innovation at the White House Office of Science and Technology Policy, where he also led geothermal work, and earlier at the Federation of American Scientists.
• Chimaera Fund — Renaissance Philanthropy's fund devoted to responsibly and rapidly scaling geologic hydrogen through open-access field demonstrations and policy advising.
• Renaissance Philanthropy — The organization presenting Tacit Knowledge and housing the Chimaera Fund.
• All Together Now — The content studio and production company that developed and produces the Tacit Knowledge podcast.
• Geologic hydrogen (Geo H₂) — Hydrogen generated naturally in the Earth's subsurface, also called natural, white, or gold hydrogen; the resource at the center of the episode.
• USGS global geologic hydrogen resource estimate (Ellis & Gelman, 2024) — The USGS modeling study behind the widely cited estimate that recovering even a small fraction of Earth's geologic hydrogen could supply projected demand for roughly 200 years.
• Federation of American Scientists (FAS) — The think tank where Ishan worked before joining the White House, and where he first worked with Kumar on ideas for a new administration.
• Fervo Energy — The enhanced geothermal company Ishan and Kumar cite as proof that a once-niche subsurface technology can scale; it listed on the Nasdaq in May 2026.
• Utah FORGE — The Department of Energy's geothermal field laboratory near Milford, Utah, which Ishan cites as the government-backed testbed that helped unlock enhanced geothermal.
• U.S. Air Force geologic hydrogen initiative — A Chimaera-led demonstration with the Department of the Air Force, using partners including HyTerra, Helix Exploration, and Prometheus Hydrogen, to assess whether geologic hydrogen could strengthen energy resilience at bases in Montana and Kansas.
• HyTerra — The ASX-listed geologic hydrogen exploration company whose scientists Ishan cites as partners; it was later selected as a primary performer in the Air Force demonstration.
• ARPA-E — The Department of Energy agency where Doug Wicks and Emily Yedinak advanced its geologic hydrogen portfolio, a program Ishan credits as an early mover in the field.
• Law of Requisite Variety — Cybernetician W. Ross Ashby's principle that a regulator needs enough variety in its responses to match the disturbances it faces.

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.

Links:

• David Carel — Director at Renaissance Philanthropy, leading the Inspired Air Fund (formerly the Clean Air for Schools Fund). Co-founded Panorama Education in 2012; later helped build Funda Wande, a South African early-literacy nonprofit; most recently Managing Director at Blueprint Biosecurity before joining RenPhil.
• Renaissance Philanthropy — The organization producing the Tacit Knowledge podcast and housing the Inspired Air Fund (formerly the Clean Air for Schools Fund).
• Gregg Gonsalves — Epidemiologist and longtime HIV/AIDS activist, now an associate professor at Yale School of Public Health and Yale Law School; a 2018 MacArthur Fellow. David worked closely with him as an undergraduate on global health activism.
• Panorama Education — The Y Combinator-backed school data analytics company David co-founded in 2012, used by public schools across all 50 states.
• Funda Wande — The South African nonprofit David helped create, working with the national government to design and scale early-grade literacy and math interventions.
• Blueprint Biosecurity — A nonprofit focused on ending airborne pandemics, where David served as Managing Director before joining Renaissance Philanthropy.
• Air-Borne: The Hidden History of the Life We Breathe — Science journalist Carl Zimmer's book tracing the history of airborne disease science, including the slow, belated acceptance that Covid-19 spread through the air.
• COGfx Study (Harvard T.H. Chan School of Public Health) — Research led by Joseph Allen's Healthy Buildings Program finding that doubling office ventilation rates significantly improves cognitive performance, at a cost far smaller than the productivity benefit — the study behind the JPMorgan example David cites.
• 270 Park Avenue (JPMorgan Chase headquarters) — JPMorgan Chase's new $3B Manhattan headquarters, built with double the standard ventilation rate specifically in response to Harvard's cognitive-function research.

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."

Links:

• Joshua Elliott — Chief Scientist at Renaissance Philanthropy. Previously a Program Manager at DARPA's Information Innovation Office for six years, where he directed nearly $600M in federal R&D funding; before that, spent almost a decade in academia on computational climate economics and energy systems modeling at the University of Chicago and Argonne National Laboratory.
• Renaissance Philanthropy — The organization producing Tacit Knowledge Podcast, where Joshua leads climate and energy program development.
• ARC Initiative (Advanced Research for Climate Emergencies) — Renaissance Philanthropy's philanthropic fund and "nonprofit venture studio" for translational R&D on catastrophic climate risks — tipping points like ice sheet collapse, Arctic destabilization, and runaway methane emissions — which incubated the Arctic Stabilization Initiative.
• BiTS (Big if True Science Accelerator) — A 15-week accelerator co-designed and co-run by Joshua Elliott and JP Chretien (both former DARPA program managers) that teaches scientists and engineers how to turn ambitious ideas into fundable, coordinated research programs.
• NASA CERES (Clouds and the Earth's Radiant Energy System) — The NASA satellite mission, operating continuously since March 2000, that measures Earth's energy imbalance — the data source behind Joshua's reflectivity-loss figures.
• Heilmeier Catechism — A set of questions developed by former DARPA director George H. Heilmeier to pressure-test research proposals; DARPA's official version lists eight questions, though Joshua describes using a compressed four-question version of his own in practice.

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.

Links:

• Cara Eckholm — Founder of Pilot City; also founder of AKA Urban, an advisory firm for public-sector building projects.
• Pilot City — A program of Renaissance Philanthropy aimed at strengthening state capacity by helping cities, counties, and regions tap into the scientific and technical expertise already present in their communities. Its flagship format is the Pitchfest — a bottom-up matchmaking event where government agency staff pitch problem statements and get paired with regional experts. Pilot City began in New York in 2023 and, with support from the Sloan Foundation and later Coefficient Giving, has since expanded the Pitchfest model to Boston, Hennepin County, and other regions.
• Renaissance Philanthropy — The organization producing Tacit Knowledge Podcast; Cara is a fellow there.
• Cornell Tech's Urban Tech Hub — Where Eckholm did her original fellowship and where Pilot Pitchfest first launched.
• New York City Economic Development Corporation (NYCEDC) — The city agency partner from Eckholm's original fellowship research on agency innovation capabilities.
• Alfred P. Sloan Foundation — Seed funder of the first Pitchfest event.
• Al Roth — Economist (Harvard, then Stanford), 2012 Nobel laureate in Economic Sciences for work on market design — the "knock it out of the park" example Cara cites, where a cold outreach from an NYC public servant led to Roth redesigning the city's high school matching process.
• Mechanism design — The field of economics concerned with designing rules and institutions — like matching markets — to produce a desired outcome; the broader discipline Roth's work belongs to.
• Medical residency match (NRMP) — The National Resident Matching Program, also known as "The Match" — uses the applicant-proposing algorithm that Roth's research built on and that also underlies the NYC high school match and kidney-exchange matching.
• Dan Doctoroff — Former NYC Deputy Mayor for Economic Development (2002–2008), later CEO of Bloomberg L.P. and Sidewalk Labs — the boss's-boss Cara cold-emailed, which opened her path into city work.
• Sidewalk Labs — Alphabet's urban-tech incubator, where Doctoroff later served as CEO and which Cara also applied to.

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: http://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.

Links:

• Charlotte DeWald — Program Director of the Arctic Stabilization Initiative at Renaissance Philanthropy. An atmospheric scientist specializing in ice-nucleating particles — the rare aerosols that trigger cloud ice formation — she holds a Ph.D. in Climate Science from Scripps Institution of Oceanography.
• Arctic Stabilization Initiative (ASI) — A five-year, stage-gated research program producing the evidence governments and multilateral organizations would need to assess whether Arctic-targeted climate interventions are safe, effective, and feasible. Its first focus is Mixed-Phase Cloud Thinning.
• Renaissance Philanthropy — The organization producing this podcast and housing the Arctic Stabilization Initiative.
• Mixed-Phase Cloud Thinning (MCT) — The intervention ASI is evaluating first: seeding Arctic mixed-phase clouds — which cover roughly 60% of the Arctic and trend net-warming — to trigger ice formation and help them thin or dissipate, allowing trapped heat to escape.
• Ice-nucleating particles — Rare naturally occurring particles that trigger ice formation in clouds at unusually warm temperatures — the subject of Charlotte's decade of prior research and the scientific foundation underpinning MCT.
• Aerosol-cloud interactions — The broader, still highly uncertain field of climate science Charlotte spent a decade working in before founding ASI — studying how aerosols shape cloud behavior and, in turn, the Earth's radiative balance.
• Decarbonization and CDR (carbon dioxide removal) — The two dominant strategies in climate action that Charlotte argues are necessary but insufficient on their own to prevent near-term Arctic tipping points, given warming processes already underway.
• Joshua Elliott — Chief Scientist at Renaissance Philanthropy — the person Charlotte ultimately connected with through networked phone calls, whose own climate and RenPhil background helped bring ASI into being.
• Never Split the Difference by Chris Voss — The negotiation book Charlotte references as something she's currently studying. Note: the transcript mishears the author's name as "Chris Fosse" — corrected here to Chris Voss.