Global climate tech investment in 2025 was up 8% compared to the previous year, a turnaround from declines in 2023 and 2024. Total investment hit $40.5 billion, according to a new analysis from Sightline Climate, even though the total number of deals fell 18%, indicating a concentration of investor capital in larger, growth-stage companies . While the biggest single deal was in China — $1.6 billion for a state-backed nuclear fusion startup — the top hub for investment remains the US. And the second-highest number of startups reached an exit, most often an acquisition rather than an IPO. Topping the ranking of companies that are acquiring climate startups: European oil majors, including Shell and BP. — Tim McDonnell