Since the beginning of Earth’s environment, the water parameter of the ocean such as seawater PH level has been changing. A recent study suggests that the acidity of the ocean actually depends on the amount of carbon dioxide (CO2) in the atmosphere.
A joint team from Weizmann Institute of Science and Stanford University have looked back into the history of seawater acidity and analyzed the seawater PH level. The model they have created denotes that when life started originating then the ocean was acidic later it gradually became alkaline.
In the journal of Science, researchers explained that acidity and alkalinity are dependent on the PH scale of a liquid which is also applicable for oceans. The scale is divided in 0 to 14 according to the level of acidity and alkalinity. Water belongs to the level-7 as it is a neutral liquid, lower than neutral is acidic and the higher is alkaline.
Lead researcher and professor from the Weizmann Institute's Earth and Planetary Sciences Department, Dr. Itay Halevy explained in a statement,“ the early Sun was dimmer, even though we don't have evidence for a much colder climate. We think that this is because the early atmosphere had more of the greenhouse gas CO2 than at present and that as the Sun got brighter, CO2 levels decreased”. However, current seawater PH level is about 8.2 which makes it mildly alkaline, but the rising level of CO2 again decreasing its PH value nowadays.
ScienceDaily reported that when CO2 and water mix together then it produce Carbonic acid. It is one of the main reason why earlier oceans were more acidic. However, the higher level of CO2 also resulted in acid rains that led chemical weathering of Earth's rocky crust. Acidic rainwater reacted with the ions that also helped to neutralize the seawater PH level.
Dr. Aviv Bachan who was also connected with the study explained that PH level of Ocean was controlled by a few simple processes on a very fundamental level. Three to four billion years ago from today, the average seawater PH level was between 6.0 and 7.5 when life emerged in the early oceans. Nowadays, the ocean is getting acidified again due to the rising CO2 levels, so this won't cause any short term problem, but Hundreds of thousands of years from now marine organisms and environments may suffer, he explained.
