As world leaders gathered in Belém, Brazil, for COP30 in November 2025, blockchain-based carbon credits emerged as both a promising innovation and a contested tool in global climate action. Advocates argue the technology could improve transparency, accountability and funding for reforestation and conservation, particularly in the Global South. Critics warn that without stronger regulation, blockchain credits risk enabling greenwashing and delaying meaningful emissions reductions. Hosting the summit in the Amazon placed renewed focus on how emerging technologies could support credible, equitable climate finance.