An ocean sequestration method to dispose of a large amount Of CO2 gas has been developed to mitigate global warming. This system is called the gas lift advanced dissolution (GLAD) system. This system works by dissolving CO2 gas into seawater at a depth of 200-300. The CO2-rich seawater is then transported to a depth greater than 1000 m. This system is composed of short riser pipes for gas-lift and CO2 dissolution, a tank for separating indissoluble gas ingredients from seawater, and long down-comers for transporting CO2-rich seawater to great depths. For the system to function optimally, the riser pipe needs lobe long and wide enough to dissolve CO2 thoroughly. Also the down-comer has to be long enough to transport the CO2-rich seawater to great depths and sufficiently large in diameter to enable transportation of large quantities of seawater. The most important aspect for disposal Of CO2 into the ocean is minimizing the environmental impact, especially its influence on marine life. The CO2 concentration of seawater, therefore, must be limited below a certain value in order to minimize the environmental impact. This paper describes a mathematical model of GLAD's internal flow, which was derived to optimize the system specifications, and the correlations among the design factors of GLAD system derived by using this mathematical model. (c) 2004 Elsevier Ltd. All rights reserved.