Third Sphere invests in early‑stage climate‑focused founders building hardware‑enabled solutions, often complemented by software and AI, that address mitigation, resilience, and adaptation challenges. They target pre‑seed and seed rounds with initial checks of $250 k–$1 M and provide follow‑on capital up to $2 M to help companies scale in the US and global markets. Their thesis emphasizes techno‑economic efficiency, automation, and transformative impact on planetary systems while delivering strong financial returns.