River alkalinity enhancement projects are a carbon-removal project type within the ocean & water segment of the carbon market. They are designed to add alkalinity to river systems to enhance downstream carbon uptake and storage. The carbon benefit comes from enhanced dissolved inorganic carbon formation and downstream storage via river alkalinity addition. Common project configurations include River alkalinity enhancement with mineral inputs under protocol controls.

Rivers offer a potential transport pathway for added alkalinity, but flux measurement and downstream fate are central to credible accounting. Ocean-based pathways are developing quickly and can be scientifically compelling, but they generally require especially careful MRV, strong ecological safeguards, and a clear accounting framework for permanence and reversals. For buyers and program designers, the most important diligence questions are: How is alkalinity transport modeled? Are ecological impacts assessed? How conservative is the air-sea uptake accounting?