An analysis of seashell calcium carbonate dissolution caused by ocean acidification based on chemistry equilibrium

Abstract

Ocean acidification is a serious marine ecosystem problem caused by the abundant human emission of CO2. It is now a prevalent cognition that the dissolution of CO2 tends to raise the concentration of H+ in the ocean and therefore make it more acidic. Anthropogenic CO2 emission exacerbates the situation. This will then lead to another obvious problem---the dissolution of calcium carbonate shells of certain ocean organisms. This article will present a brief dissolution model, which can provide an analysis of the acidification effects from two perspectives---both the forming and the dissolution of seashells. The model shows an exponential relationship between the dissolved Ca2+ concentration and the pH of seawater. It also presents the anticipation regarding a dissolution turning point in (approximately) 2090 under the RCP8.5 scenario. This turning point indicates an abrupt acceleration of calcium carbonate shells dissolution. The result depicts the drastic but possible change in the seawater solution system and gives a warning signal of a probable deadline for us to control the CO2 emission. Hopefully, it will attract more scholars to pay attention to this topic and figure out methodologies to avoid the possible tragedy.