America’s fastest-growing new bank doesn’t specialize in AI or crypto-currency or some exotic investment strategy with little real world value. It specializes in environmental sustainability.

Based in St. Petersburg, Florida, Climate First Bank was chartered in 2021 with a mission to finance environmental sustainability. Five years later, it’s already pushing $1.8 billion in assets. The bank — which describes itself as the nation’s first climate-focused bank — nearly doubled in size over the course of 2025 alone.

While Climate First is financing solar arrays of all sizes, including community solar and utility-scale battery storage systems, its rapid growth is powered mainly by the oldest force in banking: relationships.