Wednesday, August 1, 2012

Ocean Acidification and Climate Change – A Case In Point

It has long been understood that the uptake by the oceans of the increasing levels of carbon dioxide (CO2) in the atmosphere,  produced as a result of human activity, leads to the reduction in the pH – increased acidity – of the water.  This increased acidity has the effect of disturbing the carbonate (CO3) balance in the oceans.  What has not been clearly defined is the extent of these changes.

The index for assessing the degree of this imbalance is the so-called "carbonate saturation state."   The aquatic organisms that are especially susceptible to changes in the carbonate saturation state are those that create part of their structure from available calcium carbonate (CaCO3).

Doctor Nicolas Gruber and his colleagues at the Department of Environmental Physics at the Institute of Biochemistry and Pollutant Dynamics , ETH Zurich, Switzerland and at the Atmospheric and Oceanic Sciences Program at Princeton University, Princeton, NJ have studied the California Current System (California CS) in attempt to quantify these changes.  The California CS is of particular importance in that it represents an essential marine ecosystem.

As a result of their findings, they have projected that by the year 2050 the carbonate saturation state will drop to levels that represent under-saturation of carbonates critical to the marine environment.  They have come to this conclusion using two different scenarios – one projecting high emissions of CO2 and the other low emissions.  According to the authors, "Habitats along the sea floor will become exposed to year-round under-saturation within the next 20 to 30 years.  These projected events have potentially major implications for the rich and diverse ecosystem that characterizes the California CS."

These findings represent yet another example of the perils the global human community faces as a direct consequence of the anthropogenic buildup of greenhouse gases in the atmosphere.  It remains to be seen whether or not the plethora of known global environmental disruptions will provide sufficient motivation for the human community to implement meaningful solutions to this enormous problem.  

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