Cool Climate Collective
Cool Climate Collective is a Sacramento-based climate-tech venture syndicate that backs pre-seed and seed startups across energy, materials, and water. Founded in 2021, it treats water as one pillar of a broader climate thesis: as of 2026, (don't) Waste Water tracks two water-related bets, in waste-to-resource recovery and rice-husk filtration.
Compiled by Antoine Walter, (don't) Waste Water, from official filings and direct intelligence in Leviathan.
The take
Cool Climate Collective began in 2021 not as a fund but as a friendship: Mehrad Yaghmai and Tristan Pollock met at the Terra Climate Fellowship, built a community of climate operators, and turned it into an AngelList syndicate before formalizing the Cool Climate Fund. Tristan Pollock had spent years directing accelerators at 500 Startups; Mehrad Yaghmai runs the fund day to day as managing partner.
Cool Climate Collective sorts the climate problem into three buckets it calls electrons, atoms, and flows: clean energy generation and storage, advanced materials and manufacturing, and the movement of water and waste. Water lives inside that third bucket, flows, rather than as a standalone thesis. The syndicate writes small catalytic checks, roughly $100k to $350k, at the pre-seed and seed stage, and leans on its operator network for go-to-market, hiring, and policy help rather than leading rounds.
Cool Climate Collective's water footprint is small and sits at the circular, waste-to-resource edge rather than in pipes or treatment plants. (don't) Waste Water can place two water-related companies in its portfolio: Wasted, a Vermont public-benefit company recovering nutrients from human waste, and Glanris, which turns rice husks into carbon-negative filtration media. Both are about pulling value out of a waste stream, not building utility infrastructure.
Cool Climate Collective is best read as a climate generalist that will follow a strong technical team into a water-shaped problem, not as a dedicated water investor. For a water founder its draw is a fast early cheque and a deep bench of climate operators, not water-specific domain expertise. That is why (don't) Waste Water rates its water commitment Occasional rather than core.
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 · 2 water companies
Invests alongside
Highlighted = profiled on (don't) Waste Water.
Frequently asked
- What does Cool Climate Collective invest in?
- Cool Climate Collective backs pre-seed and seed climate-tech startups across three areas it calls electrons, atoms, and flows: clean energy, advanced materials and manufacturing, and water and waste. It writes small catalytic checks and supports founders through its operator network rather than leading rounds.
- Is Cool Climate Collective a water fund?
- No. Cool Climate Collective is a generalist climate-tech syndicate, not a water-focused fund; water is one part of its flows pillar. (don't) Waste Water rates its water commitment Occasional: of its tracked portfolio, just two companies are water-related, in waste-to-resource recovery and filtration media.
- Which water companies has Cool Climate Collective backed?
- Cool Climate Collective has backed two water-related companies that (don't) Waste Water tracks: Wasted, a Vermont public-benefit company recovering nutrients from human waste, and Glanris, which makes carbon-negative water-filtration media from rice husks. Both sit at the circular, waste-to-resource edge of water.
- Who founded and runs Cool Climate Collective?
- Cool Climate Collective was founded in 2021 by Mehrad Yaghmai and Tristan Pollock, who met at the Terra Climate Fellowship. Mehrad Yaghmai is Founding and Managing Partner; Tristan Pollock, a former 500 Startups accelerator director, is Co-Founder and Venture Partner. Teddy Hennes serves as Platform Partner.
- Is Cool Climate Collective the same as Climate Collective?
- No. Cool Climate Collective is a Sacramento-based climate-tech venture syndicate, founded in 2021 by Mehrad Yaghmai and Tristan Pollock. It is separate from Climate Collective, a climate network, and from UC Berkeley's CoolClimate Network. Cool Climate Collective is the early-stage investor (don't) Waste Water tracks.