Monday, August 18, 2014

Physics Today Report Indicates Ocean Acidification Increasing

A report published in the most recent issue of Physics Today (August, p. 20), discloses intense concern about the rising acidification of the oceans. The related article highlights the fact that "the oceans aren't vast enough to absorb growing amounts of carbon dioxide without ill effects to marine life and to the 1 billion people who make their living on the sea."

Other related events that have been documented include: longer heat waves, drought, rising sea levels and more intense storms.  Less well known to many is the acidification of the oceans which is projected to continue as the amount of CO2 in the atmosphere increases. Since 2012 the evidence has been reinforced that not only is the acidity of Earth's oceans the greatest since the dawn of the Industrial revolution, but in the past 300 million years.  Indeed, according to the latest research our oceans may be acidifying faster than at any point during the last 300 million years due to industrial emissions, endangering marine life from oysters and reefs to sea-going salmon. And we won't even mention the phytoplankton which generate so much of the planet's oxygen,

As I noted in previous blog posts, the seas absorb CO2 from the atmosphere forming carbonic acid. The particular chemical reaction is:

H2O + CO2 -> H2 CO3

The lower the pH level in the seas ('7' is neutral pH), the more acidic they are. This is also worrisome because mass extinctions of marine creatures in the past have been linked to instances of ocean acidification. Thus the current incremental change could also threaten important species. This according to Baerbel Hoenisch, the paleoceanographer at Columbia, when her paper first appeared in Science two years ago.

Now, according to Ove Hoegh - Guldberg of the University of Queensland, it appears that marine organisms that require carbonate ions to build their shells won't have time to adapt to the changing pH. According to Hoegh - Guldberg:

"We're taking life outside the conditions it actually evolved for."

Since the Industrial Revolution the acidity of the oceans has jumped 25 % from a pH of 8.2 to 8,.1 according to the U.S> Global Change Research Program;s 2014 National Climate Change assessment. If current trends continue unchecked the acidity will increase 100-150 percent above pre-industrial levels by the end of the century, according to Carol Turley of the Plymouth Marine Laboratory in the UK, cited in the article.

The article also notes that tropical corals are especially vulnerable to the combination of acidification and warming of the oceans, noting:

"Clues to what coral reefs may look like in 2100 with unchecked CO2 emissions are available today near naturally occurring CO2 vents off Papua, New Guinea. Fewer and less diverse communities of corals exist just adjacent to those vents compared to communities just a few meters away."


Although reducing the carbon load in the atmosphere from anthropogenic processes is the only sure way to alleviate the problem, there are some researchers exploring atmospheric geo-engineering solutions. These would have as their prime objective increasing the pH level of the seas. The technique would involve spraying aerosols  over the ocean surface but this would do nothing to address acidification.

As the article observes:

"The scale of effort required to buffer the ocean's acidity is mind boggling. The annual mass of the compounds is about an order of magnitude more than the 2 gigatons of carbon absorbed by the oceans each year."

It seems that in terms of the oceans turning  to carbonic acid, we may have passed the point of new return - possibly altering all ocean ecology permanently. A point made by an ocean specialist on Bill Maher's Real Time two months ago who forecast nearly all fish dying, giving way to billions and billions of.....Jellyfish.

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