Third Sphere
Third Sphere, formerly Urban Us, is a New York climate-tech venture capital firm backing early-stage founders. It is a climate generalist, not a water specialist: of more than 100 investments, just three are in water, all at the seed stage. As of 2026, (don't) Waste Water rates its water commitment Occasional.
Compiled by Antoine Walter, (don't) Waste Water, from official filings and direct intelligence in Leviathan.
The take
Third Sphere started life in 2013 as Urban Us, an accelerator and fund betting that the dull machinery of cities, water, waste and transport was where climate change would actually be won or lost. Co-founders Stonly Baptiste Blue, a Haiti-born entrepreneur who rolled an earlier cloud-software exit into the firm, and Shaun Abrahamson rebranded it Third Sphere in 2022 to say the quiet part out loud: this is a climate fund, and it writes the first cheques most investors are too nervous to.
What sets Third Sphere apart is where it is willing to go: in before a startup has any paying customers, into hardware, and beyond plain equity into credit and asset-finance, the kind of lending and leasing structures most venture firms refuse to touch. Its bet is that the best climate solutions don't look like climate solutions at all, just cheaper, faster, more resilient versions of the systems we already rely on. Water sits inside that worldview as plumbing, not as a separate crusade.
Third Sphere shows up lightly in my Leviathan database, which logs every water raise I can find: three water companies across three seed deals, none of them led. The pattern is telling. Two of the three, Pallon and Varuna, are digital-water plays that make buried pipes legible, one reading CCTV footage of sewers with computer vision, the other wiring utilities with in-pipe sensors. The third, Wasted, is circular sanitation, turning human waste into fertiliser. For a founder in water, Third Sphere reads as an occasional, software-leaning fellow-traveller rather than a dedicated water backer.
Third Sphere remains a generalist with water as a side-thesis, so anyone hunting a fund that backs only water should look elsewhere. But its instinct, that the unglamorous infrastructure under a city is exactly where climate and water meet, is one of the more honest reads in the market, and worth watching for where it wades in next.
Water Commitment Score
Compiled from official filings, third-party records, and direct intelligence from investors and founders, in Leviathan · recomputed monthly · as of Jun 2026.
How they invest
Portfolio · 3 water companies
Invests alongside
Highlighted = profiled on (don't) Waste Water.
Frequently asked
- What does Third Sphere invest in?
- Third Sphere is an early-stage climate-tech venture capital firm. It backs founders across clean energy, sustainable cities, transport, waste and infrastructure, favouring hardware and pre-customer companies. Water is a small part of that: in the Leviathan database Third Sphere has backed three water companies, all at the seed stage.
- What stage does Third Sphere invest at?
- Third Sphere invests at the earliest stages, pre-seed and seed, often before a company has its first paying customer. It writes a startup's first institutional cheques and pairs them with credit and asset-finance, then follows the strongest companies. It has backed water only at seed, and has led none of those rounds.
- Who runs Third Sphere?
- Third Sphere is led by co-founders and managing partners Shaun Abrahamson and Stonly Baptiste Blue, who started the firm in 2013 as Urban Us and rebranded it Third Sphere in 2022. Shilpi Kumar is a Partner and runs the firm's fellowship for early-stage climate founders.
- How many water companies has Third Sphere backed?
- Third Sphere has backed three water companies, all at the seed stage and none as lead investor: Pallon, which reads CCTV sewer footage with computer vision; Varuna, in-pipe sensors for water utilities; and Wasted, a circular-sanitation company. (don't) Waste Water rates its water commitment Occasional.
- Is Third Sphere the same as Urban Us?
- Yes. Third Sphere is the current name of the firm founded in 2013 as Urban Us, an urban-tech accelerator and fund; it rebranded to Third Sphere in 2022 to reflect a broader climate focus. Unrelated companies share the Third Sphere name, but the climate VC is the former Urban Us.