Headline Sep 24, 2014/


HUMANS,  being a terrestrial species are pleased to call their home  ''Earth''.

A more honest name might be  ''Sea'' , as more than seven-tenths of the planet's surface is covered with salt water.

Moreover, this water houses algae, bacteria ( known as cyanobacteria) and plants that generate about half the oxygen in the atmosphere. And it also provides seafood  -at least  15% of the protein eaten by 60% of the planet's human population:

An industry worth $218 billion a year. Its well-being is therefore of direct concern even to landlubbers.

That well being, some fear, is under threat from the increasing amount  of carbon dioxide in the atmosphere, a consequence of industrialisation. This concern is separate from anything caused by the role of CO2, as a climate-changing green house gas. 

It is a result of the fact that CO2, when dissolved in water, creates an acid.

That matters, because many creatures which live in the ocean have shells or skeletons made of stuff that dissolves in acid. The more acidic the sea, the harder they have to work to keep their shells and skeletons intact.

On the other hand, oceanic plants, cyanobacteria and algae, which use CO2, for photosynthesis, might rather like world where more of that gas is dissolved in the water they live-in -a gain, rather than a loss, to ocean productivity.

Two reports attempting to summarise the world's rather patchy knowledge about what is going on have recently been published. Both are products of meetings held last year.

One in Monterey, California, looked at the science. The other, in Monaco, looked at possible economic consequences. Together, the documents suggest this is an issue that needs to be taken seriously, though worryingly little is known about it. 

Regular, direct measures of the amount of CO2 in the air date to the 1950s. Those of the oceans' acidity began only in the late  1980s. Since it started, the acidity has risen from  pH 8.11  to pH 8.06 {on the pH scale, lower numbers mean more acid}.

This may not sound much, but pH is a logarithmic scale. A fall of one pH point is this a tenfold rise in acidity, and this fall of  0.05 points in just over three decades in a rise of acidity of  12%.

Patchier data that go back further suggest that there has been a 26% rise in oceanic acidity since since the beginning of the industrial revolution, 250 years ago. Projections made by assuming that:

Carbon-dioxide emissions will continue to increase in line with expected economic growth indicate this figure will be 170%  by 2100.

Worrying about what the world may be like in nine decades might sound unnecessary, given more immediate problems, but another prediction is that once the seas have become more acidic, they will not quickly recover their alkalinity.

Ocean life, in other words, will have to get used to it. So does this actually matter?

The variable people most worry about is called omega. This is a number that describes how threatening  acidification is to seashells and skeletons. Lots of these are made of calcium carbonate, which comes in two crystalline forms: calcite and aragonite.

Many critters, especially reef forming corals and free-swimming molluscs (and most molluscs are free-swimming as larvae),  prefer aragonite for their shells and skeletons. Unfortunately this is more sensitive to acidity than calcite is.

The Honour and Serving of the knowledge continues. Thank you for reading. And see you on the following one.

With respectful and loving dedication to Mariam, Rabo, Dee, Malala, Aneela, Paras, Sorat, Haleema, Anne, Ali, Hussain, Ehsan, Shazaib, Salar, Mustafa, Eman, Ibrahim, Haanyia, Zaeem, Hazeem, Hyder, Aqsa, Muasis, Danyial, Rahym, Armeen, Mayna, Bilal.  See Ya all on !WOW!  -the World Students Society Computers-Internet-Wireless:

''' Omega Point '''

Good Night and God Bless

SAM Daily Times - the Voice of the Voiceless


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