SEQUESTERING ATMOSPHERIC CARBON-DIOXIDE BY INCREASING OCEAN ALKALINITY

We present a preliminary analysis of a geoengineering option based on the intentional increase of ocean alkalinity to enhance marine storage of atmospheric CO2. Like all geoengineering techniques to limit clima te change, with today's limited understanding of the climate system, t his approach must be regarded as a potential strategic option that req uires ongoing assessment to establish its potential benefits and side effects. CO2 would be absorbed from the atmosphere by the oceans at an increased rate if ocean alkalinity were raised. Ocean alkalinity migh t be raised by introducing the dissolution products of alkaline minera ls into the oceans. The limited deposits of naturally occurring soda a sh (Na2CO3) are readily soluble and easily mined. Limestone (CaCO3) is abundant in the Earth's crust but is not readily soluble. This analys is explores the potential feasibility and limits of such approaches.