I have problems with the conclusions been drawn here in this item anddo not trust them at all. I would like to have data that likely doesnot even exist yet. However, it at least draws attention to amechanism.
Beyond that the global atmospheric CO2 content has continued to climband has reached and passed the ten percent mark over the past fortyyears. This is obviously significant and remains troublesome. Thevery good news is that geological carbon consumption is ready toflatten out and enter a long decline as superior energy sources areput into play.
Yet human production certainly is responsible for CO2 rise. On apositive note, this fresh introduction of CO2 has modestly recoveredthe levels experienced in geological times. We will be needing hugeamounts for Terraforming Terra anyway simply to manufacture soils. Ieven see the possibility that in the future we will deliberately burnmassive amounts of geological carbon merely to restore the decliningCO2 level although the huge oceanic reserves make that unlikely.
Ocean acidification affecting live marine creatures in theSouthern Ocean
by Staff Writers
London, UK (SPX)Nov 28, 2012
The shells of marinesnails - known as pteropods - living in the seas around Antarcticaare being dissolved by ocean acidification according to a new studypublished this week in the journal Nature Geoscience. These tinyanimals are a valuable food source for fish and birds and play animportant role in the oceanic carbon cycle.
During a sciencecruise in 2008, researchers from British Antarctic Survey (BAS) andthe University of East Anglia (UEA), in collaboration with colleaguesfrom the US Woods Hole Oceanographic Institution and the NationalOceanic and Atmospheric Administration (NOAA), discovered severedissolution of the shells of living pteropods in Southern Oceanwaters.
The team examined anarea of upwelling, where winds cause cold water to be pushed upwardsfrom the deep to the surface of the ocean. Upwelled water is usuallymore corrosive to a particular type of calcium carbonate (aragonite)that pteropods use to build their shells. The team found that as aresult of the additional influence of ocean acidification, thiscorrosive water severely dissolved the shells of pteropods.
Ocean acidification iscaused by the uptake of carbon dioxide from the atmosphere emitted asa result of fossil fuel burning. A number of laboratory experimentshave demonstrated the potential effect of ocean acidification onmarine organisms.
However, to date,there has been little evidence of such impacts occurring to livespecimens in their natural environment. The finding supportspredictions that the impact of ocean acidification on marineecosystems and food webs may be significant.
Lead author, Dr NinaBednarsek, formerly of BAS and UEA, and now of the National Oceanicand Atmospheric Administration (NOAA) says: "We know that theseawater becomes more corrosive to aragonite shells below a certaindepth - called the 'saturation horizon' - which occurs at around1000m depth.
"However, at oneof our sampling sites, we discovered that this point was reached at200m depth, through a combination of natural upwelling and oceanacidification. Marine snails - pteropods - live in this top layer ofthe ocean.
"The corrosiveproperties of the water caused shells of live animals to be severelydissolved and this demonstrates how vulnerable pteropods are. Oceanacidification, resulting from the addition of human-induced carbondioxide, contributed to this dissolution. "
Co-author and sciencecruise leader, Dr Geraint Tarling from BAS, says: "Although theupwelling sites are natural phenomena that occur throughout theSouthern Ocean, instances where they bring the 'saturation horizon'above 200m will become more frequent as ocean acidificationintensifies in the coming years.
"As one of only afew oceanic creatures that build their shells out of aragonite in thepolar regions, pteropods are an important food source for fish andbirds as well as a good indicator of ecosystem health.
"The tiny snailsdo not necessarily die as a result of their shells dissolving,however it may increase their vulnerability to predation andinfection consequently having an impact to other parts of the foodweb."
Co-author, Dr DorotheeBakker from the University of East Anglia, says: "Climate modelsproject a continued intensification in Southern Ocean windsthroughout the 21st century if atmospheric carbon dioxide continuesto increase.
"In turn, thiswill increase wind-driven upwelling and potentially make instances ofdeep water - which is under-saturated in aragonite - penetrating intothe upper ocean more frequent.
"Currentpredictions are for the 'saturation horizon' for aragonite to reachthe upper surface layers of the Southern Ocean by 2050 in winter andby 2100 year round. "
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