The environment and climate sectors require digital transformation to keep up with the changing planetary ecosystem and to coordinate urgent and global action in areas including biodiversity loss, disaster displacement and energy grid deficiencies. Blockchain is a powerful tool that can provide breadth and depth to climate mitigation and adaptation efforts by democratizing ownership, improving transparency and integrity, and enabling real-time visibility into emissions reduction and sequestration efforts. But these tools are not without consequence. The impact on people, communities and natural ecosystems already facing climate inaction must be considered when developing both the technology solutions and their implementation. This paper is an output of the Crypto Sustainability Coalition’s Working Group on Web3 Climate Action, exploring the relationship between blockchain innovation and climate action, focusing on real work examples and use cases. It is intended as a primer for those unfamiliar with regenerative finance (ReFi) and a guide to those incorporating blockchain technologies into decarbonization or net-zero commitments. Investigating how blockchain can incentivize a planet-positive economy focused on financing regeneration and climate action at scale, the paper calls for thoughtful coordination, meaningful action, education and regulation to accelerate the adoption and implementation of blockchain across decarbonization sectors.