Potential of CO2 sequestration through accelerated weathering of limestone on ships

Abstract

Calcium carbonate dissolution is the dominant negative feedback in the ocean for neutralizing the acidity from rising atmospheric carbon dioxide. Mimicking this natural process, the accelerated weathering of limestone (AWL) can store carbon as bicarbonate in the ocean for tens of thousands of years. Here, we evaluate the potential of AWL on ships as a carbon sequestration approach. We show a successful prediction of laboratory measurements using a model that includes the most recent calcite dissolution kinetics in seawater. When simulated along a Pacific shipping lane in the Estimating the Circulation and Climate of the Ocean–Darwin ocean–general circulation model, surface alkalinity and dissolved inorganic carbon increase by <1.4% after 10 years of continuous operation, leaving a small pH and partial pressure of carbon dioxide impact to the ocean while reducing 50% carbon dioxide emission in maritime transportation.