Title: Evaluating enhanced weathering as a promising carbon dioxide removal strategy using intermediate complexity Earth system model cGENIE 

Abstract: Enhanced weathering (EW) is a promising carbon dioxide removal (CDR) strategy that could contribute to meeting the Paris Agreement goal of limiting global warming to well below 2°C above pre-industrial levels. EW involves the application of crushed silicate or carbonate rocks to terrestrial or marine environments to accelerate naturally slow weathering processes through increasing reactive surface area. During weathering, atmospheric CO₂ reacts with minerals and water to form dissolved bicarbonate and cations, which are ultimately transported to the ocean for storage on timescales of millennia. However, several challenges and uncertainties lingers and raises concerns around deploying EW at large scales. These include feedstock availability, the fate of weathering-derived carbon during riverine transport, and uncertainties in ocean biogeochemical feedbacks that may alter long-term carbon storage. This dissertation employs Earth system model of intermediate complexity cGENIE as a main tool to address these challenges through three complementary studies. First, it demonstrates that industrial by-products, including steel slag and cement waste, can serve as alternative EW feedstocks, with a cumulative carbon removal potential of ~ 400 Gt CO₂ by 2100. Second, it shows that riverine carbon loss through carbonate-system re-equilibration of different river/stream systems has a negligible impact on long-term carbon removal efficiency, because ocean uptake largely compensates for riverine carbon loss when alkalinity is retained and delivered to the ocean. Third, it evaluates the sensitivity of EW performance to uncertainties in ocean circulation and biogeochemistry, identifying key physical and biogeochemical controls on carbon removal efficiency and climate response.

Date, time, and location: 24 June 2026, 9:30am., L1114 and  https://gatech.zoom.us/j/9267172570?omn=94533274204

Committee members: Dr. Christopher Reinhard (advisor), Dr. Shuang Zhang (external), Dr. Takamitsu Ito, Dr. Martial Taillefert, Dr. Yuanzhi Tang.