Corrosive Ocean

Pacific Coast Turning More Acidic Corvallis OR (SPX) May 28, 2008 - An international team of scientists surveying the waters of the continental shelf off the West Coast of North America has discovered for the first time high levels of acidified ocean water within 20 miles of the shoreline, raising concern for marine ecosystems from Canada to Mexico. Researchers aboard the Wecoma, an Oregon State University research vessel, also discovered that this corrosi ... more

This article has popped up in a number of places; it's fun to see a dateline with my hometown.

I'm unsure how much importance to attach to this. Probably the most important thing to take away from this is the level of uncertainty associated with making claims for understanding any complex system. The general idea is that as CO2 in the atmosphere increases, more dissolves in the ocean. When CO2 dissolves in water, it creates carbonic acid (this is why club soda tastes sour or tart). Now obviously, the amount dissolved in the ocean is far less than in soda, but there's been a measurable increase in acidity, or in other words, decrease of pH.

Many organisms have calcium carbonate shells- think clams, other mollusks, and coral. In addition to these somewhat familiar large critters, there are many, many less familiar microorganisms that also use calcium carbonate to create an external skeleton. Calcium carbonate comes in two common forms: calcite and aragonite. These two minerals have the same composition, but are organized differently. Calcite is somewhat more stable in normal earth surface conditions, aragonite somewhat less. The concern is that increasing acidity could corrode the shells of argonite secreting organisms. These animals form much of the basis of the oceanic food web.

But again, we don't really know.

Living on this planet sometimes makes me feel like a five-year-old who has found the keys to an Indy race car. We really have no idea of the consequences of our behavior.