Day by Day

Thursday, June 14, 2012

Ocean "Acidity" Myth

Since Mr. Hunt repeats the same two limited studies of Atlantic sediments and Oregon oysters in each of his letters, I’ll provide information about the science involved.
The oceans have remained alkaline during the last 540 million years.
Rainwater (pH 5.6) reacts with the most common minerals on Earth (feldspars) to produce clays, which consume acids, then alkali is leached into the oceans (making them salty), silica is redeposited in sediments, which consumes acid and is accelerated by temperature. Sea water has a local and regional variation in pH  (7.8 to 8.3, but ranging from 7 to 9 in Chesapeake Bay). Since pH is a log scale, there is not enough CO2 in fossil fuels to create oceanic acidity because most of the planet’s CO2 is locked up in rocks. 
In the Precambrian, reactions rapidly responded to huge changes in climate (-40°F to +122°F), large sea level changes (+1,968’ to -2,100’) and rapid climate shifts from ‘snowball’ or ‘slushball’ Earth to very hot. About 750 million years ago life started to extract huge amounts of CO2 from the oceans, life expanded and diversified, and this process continues (which is why we have low CO2 today).
The history of CO2 and temperature shows no correlation. Compared to now: CO2 was 15 times higher in the Ordovician-Silurian glaciation (ice age). Both methane and CO2 were higher in the Permian glaciation. CO2 was 5 times higher in the Cretaceous-Jurassic glaciation. 
The atmosphere once had at least 25 times the current CO2 content, and now CO2 is the lowest it has been for billions of years.
Algae blooms fed by sewage runoff cause increased alkalinity in less salty areas of bays, and higher acidity closer to the open ocean, so atmospheric CO2 is not a factor. Someone should tell those Oregon oysters.

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