Crispin, The term that the scientific community uses is "ocean acidification," and this is a very real environmental problem that most people in the scientific community do not deny.
Many thanks. Paul Olivier On Thu, Aug 8, 2013 at 12:27 PM, Crispin Pemberton-Pigott < [email protected]> wrote: > Dear Friends**** > > ** ** > > I have been catching up on less important correspondence after being in > Asia for a while. There is one thing that still needs to be put down like a > broken-legged horse and that of course is the idea that CO2 ‘acidifies’ > the ocean.**** > > ** ** > > Because this is a high school chemistry level topic and I know some of us > took other things – or as the drummer in my brothers class said, “I don’t > remember Chemistry, I was stoned that year.”**** > > ** ** > > So for those of you who were also stoned that year or can’t remember back > that far, here is a simple review of pH with special reference to the > oceans, CO2 and the false, badly mis-named idea that CO2 ‘increases the > acidity of the oceans’.**** > > ** ** > > The term pH refers to one of three distinct chemical conditions which bear > no relationship to each other. One is called acidity, another is called > alkalinity and third is ‘neutral’. Acidity and alkalinity are so different > that if equal in ‘strength’ they cancel each other completely leaving a > neutral condition. Different pH numbers refer to different conditions.**** > > ** ** > > Acid solutions (it has to be a solution with water in it) have a chemistry > that has Hydrogen atoms stripped of their single electron. They are thus > positively changed and seeking an electron. This they will happily strip > out of anything passing by if they can find it, tearing the molecules to > bits in the process which is why acids ‘eat’ things.**** > > ** ** > > Alkaline solutions (again, involving water) have molecules that have an > extra electron available (but not Hydrogen) and are thus negatively > charged. They will give away an electron happily, often wrecking the object > that receives it which is why they eat things too but by a completely > different process.**** > > ** ** > > Both acidic and alkaline solutions can corrode things like metals and > rocks. One takes electrons and one gives them. Quote opposite. The two > conditions are so incompatible they cannot be present at the same time in a > mixed solution. It is one, the other or ‘neutral’ if neither condition is > present.**** > > ** ** > > If you have an alkaline solution like the ocean (pH 7.8 - 8.4 depending on > where you are, the time of day and a host of other things) and you want to > neutralise it so that all its spare electrons are taken up by various > things, you would have to add something acidic. Adding CO2 by bubbling it > through the seawater will convert some of the CO2 (about 1%) to carbonic > acid which has a deficiency of electrons and that acid will merge with > whichever passing opportunity presents itself. The corresponding alkaline > molecule will be neutralised as its spare electron will be passed to the > carbonic acid molecule (which has an H- in it) and afterwards neither > will have any charge. Both will be neutralised if the charges are balanced. > **** > > ** ** > > Because this happens very quickly, you cannot actually find any carbonic > acid in the ocean. Nor any other acid. The oceans are not acidic at all. > Any ocean has quite a store of available electrons. Anything acidic you > dump into the sea is quickly neutralised and the pH drops slightly because > it is closer to a neutral condition. The oceanic capacity to hand over > electrons to any passing electron gap is very, very large. There are > several processes that would begin to offer electrons but do not because > the ocean is too alkaline to allow them to get started. The ability to do > this is called the ‘buffering’ capacity. You may remember ‘Bufferin’ the > pill that neutralises stomach acid. The pill is alkaline and has a large > buffering capacity so it can hand a lot of electrons over to the acid in > the stomach, thus neutralising it. If you took a whole bottle of Bufferin > pills, your stomach would not become less and less and less acidic. It > would be neutralised and then become alkaline and remains so until the > spare electrons were taken up in a neutralising process. People are, in > general, alkaline and should eat alkaline foods to remain healthy. Excess > acid is a problem.**** > > ** ** > > By the same measure, reducing the availability of spare electrons in the > ocean water does not *at all* make the water acidic because it still has > many more available electrons. It is less alkaline, but it is not acidic at > all – zero in the ‘acidic scale’ (there isn’t one). **** > > ** ** > > In order to make a convenient metric for describing these two conditions > (which can cancel each other out very predictably) the pH scale is used. > Above 7.0 the solution has available electrons and is termed alkaline. > Below 7.0 is has a deficiency of electrons and is called ‘acidic’. The > reason for the use of two different terms is they are chemically dissimilar > and cannot coexist.**** > > ** ** > > Acidity of a solution is often represented by the Hydrogen equivalent [H+] > T which is the total number of Hydrogen electrons that would be needed to > neutralise it.**** > > ** ** > > Alkalinity is often expressed in terms of its equivalence to Calcium > Carbonate CACO3 in mg/Litre.**** > > ** ** > > Q. Can CO2 ‘acidify’ water? **** > > A. Yes, if the water is neutral to begin with, or already > acidic, like rain water. Because rain water is acidic, when it falls into > the ocean it neutralises the drops of seawater where it touches, before > becoming diluted again by the surrounding ocean. Rainwater does not impart > to the ocean any microscopic ability to withdraw electrons. It is quickly > neutralised by some seawater. When it is finished a few seconds later, the > acid has been destroyed.**** > > ** ** > > Q. If one bubbled CO2 through sea water, would it eventually > become acidic?**** > > A. Yes. If you were to first neutralise all the available > electrons by mopping them up, after that it would start to become acidic. > It would not considered be acidic at all until the whole body of the sample > had first been neutralised. These two conditions cannot co-exist.**** > > ** ** > > Q. What about ‘acid rain’. **** > > A. All rain is acidic. It is acidic because fresh water absorbs > CO2 rapidly from the atmosphere, converting about 1% into carbonic acid. > This falls into the oceans and reacts with the available alkaline > molecules. It is easy to acidify rain. It is very difficult to neutralise > the oceans because of the rocks upon which they sit which have a huge, > massive buffering capacity. There are numerous life cycles of creatures > that withdraw CO2, CO3-2 and HCO3- when it is available. Obviously CACO3is > high on the list for uptake by creatures that make shells. > **** > > ** ** > > Q. Which has a larger impact on ocean alkalinity: atmospheric CO > 2 or rain containing CO2?**** > > A. Not clear. Rain has a big effect because oceans actually > have difficulty picking up enough CO2 to drive the level much above 600 > ppm because of the limited surface area compared with the volume and the > huge buffering capacity. Rain is much higher - about 1120 ppm CO2. > Global rainfall totals about half a million cubic kilometers per year and > contains about 600 billion tons of CO2 which is about 20 times > human<http://www.global-greenhouse-warming.com/anthropogenic-climate-change.html>output. > **** > > ** ** > > Q. What is the mass of the oceans?**** > > A. 1.332 billion billion tons.**** > > ** ** > > Q. Do reputable scientific organisations refer to ‘acidifying’ > the oceans even though that is not, chemically, what it happening?**** > > A. Yes. NASA > does<http://www.earthobservatory.nasa.gov/Features/OceanCarbon/>. > “As we burn fossil fuels and atmospheric carbon dioxide levels go up, the > ocean absorbs more carbon dioxide to stay in balance. But this absorption > has a price: these reactions lower the water’s pH, meaning it’s more > acidic.”**** > > ** ** > > Q. But it is less alkaline, not more acidic. Why do they write > that when it is untrue, in fact it is unscientific?**** > > A. I don’t think anyone knows. Perhaps they too missed > Chemistry in high school.**** > > ** ** > > +++++++**** > > Regards > Crispin**** > > ** ** > > ** ** > > ** ** > > *Sent:* Friday, July 26, 2013 3:25 PM > *Subject:* [Stoves] more on ocean acidification**** > > ** ** > > > http://www.scientificamerican.com/article.cfm?id=noaa-scientists-embark-voyage-asses-ocean-acidification > > -- > Paul A. Olivier PhD > 26/5 Phu Dong Thien Vuong > Dalat > Vietnam > > > **** > > _______________________________________________ > Stoves mailing list > > to Send a Message to the list, use the email address > [email protected] > > to UNSUBSCRIBE or Change your List Settings use the web page > > http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org > > for more Biomass Cooking Stoves, News and Information see our web site: > http://stoves.bioenergylists.org/ > > > -- Paul A. Olivier PhD 26/5 Phu Dong Thien Vuong Dalat Vietnam Louisiana telephone: 1-337-447-4124 (rings Vietnam) Mobile: 090-694-1573 (in Vietnam) Skype address: Xpolivier http://www.esrla.com/
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