...sponges, DOC and coral reefs are one just [one] more example of how the oceans and the atmosphere have no difficulty accommodating the ~3% increase in the Earth's carbon budget resulting from human industrial activities.
After some back and forth discussion and analysis of his argument, I offered up my bet summary of his argument in concise bullet form and he made comments to each of my points to clarify.
Unfortunately I don't know enough about this particular topic to find any clear faults in his argument at this time even if it is faulty. My bias is that I suspect his argument is wrong, but I cannot support that.
Here is my summary with The Doctor's comments:
Quote:
Originally Posted by AThousandYoung
[...]So, your claim is: Anthropogenic CO2 emissions help feed the critters that build coral reefs.
Your argument seems to be:
1) Humans have released large amounts of CO2 into the atmosphere.
The answer to that depends on how you define "large amounts." Six billion tons per year is a large number. However it equates to 4 ppmv per year - A tiny number.
Quote:
Originally Posted by AThousandYoung
2) This atmospheric CO2 increases oceanic CO2 concentration.
About 30 to 50 ppmv of the Earth's current atmospheric CO2 concentration (388 ppmv) is probably anthropogenic. But there is no way to segregate the anthropogenic from the natural. At one time it was claimed that Carbon Isotope Excursion (CIE) could be used to find the human fingerprint; but the same CIE occurred early in the Holocene and it occurs whenever CO2 levels rise.Mankind is probably responsible for 8% to 15% of the Earth's current atmospheric CO2.
Quote:
Originally Posted by AThousandYoung
3) This increased oceanic CO2 concentration is used by aquatic organisms in photosynthsis.
It is also used by land organisms in photosynthesis.
Quote:
Originally Posted by AThousandYoung
4) Because of 3), the ocean is not acidifying despite the increase in oceanic CO2 levels.
#3 is part of the buffering process. Rock weathering is another big part of the process.
Quote:
Originally Posted by AThousandYoung
5) Because of 3), there is a greater amount of organic carbon at the surface of the ocean which trickles down in the form of organic carbon detritus.
Most of the Dissolved Organic Carbon (DOC) in the oceans is the result of photosynthesis. Since there is more photosynthesis going on all over the planet because of the slightly elevated atmospheric CO2 and warmer temperatures since the end of the Little Ice Age, DOC and colloidal organic carbon should be slightly elevated along with the rest of the carbon cycle.
Quote:
Originally Posted by AThousandYoung
6) There is a reef organism that feeds on organic carbon detritus that other reef organisms cannot feed on.
7)The organism in 6) does not gain mass despite the great amounts of carbon it ingests. Instead, it excretes the carbon in a form the reef organisms can feed on.
Almost as if these sponges were designed to feed reefs.
Quote:
Originally Posted by AThousandYoung
8) Because of 7), the reefs are getting larger.
Reef calcification rates have trended upwards since the 1700's. This is probably due to increased photosynthesis of the algal symbionts, sponge carbon conversion and warmer temperatures since the end of the Little Ice Age.
Quote:
Originally Posted by AThousandYoung
My best one sentence summary of your position:Because a combination of oceanic organisms including photosynthetic organisms, coral and sponges, processes atmospheric carbon dioxide eventually storing the carbon in the form of coral reefs, human CO2 emissions are not something we should be worrying about.
Carbon sequestration in the limestone built by reefs is one factor. Microbial lime muds are an even larger factor in the sequestration of carbon into limestone.Reefs are only a small, but high profile, part of the process. It has been asserted that anthropogenic CO2 emissions are acidifying the oceans and that this will damage reefs and other carbonate shell building organisms. This assertion is falsified by the empirical demonstrations of coccoliths and otoliths gaining carbonate mass in direct response to elevated CO2 levels, observational evidence that reefs have grown faster in the presence of elevated atmospheric CO2, and the geological record of Earth's oceans responding to far higher CO2 levels by making more limestone.The oceans aren't acidifying because they aren't. Oceanic pH has simply fluctuated within its normal range over the last 200 years. The only clearly documented example of ocean acidification (shoaling of the lysocline) is the Paleocene-Eocene Thermal Maximum (PETM). However, the linkage between the acidification and atmospheric CO2 is tenuous at best.
Quote:
Originally Posted by AThousandYoung
Did I get your argument right? Please carefully look at my summary and let me know if you agree. I don't want to be accused of setting up strawman. I simply want to make sure I know what you're trying to say with this thread and to express it concisely.
The point of this particular thread, is that sponges, DOC and coral reefs are one just more example of how the oceans and the atmosphere have no difficulty accommodating the ~3% increase in the Earth's carbon budget resulting from human industrial activities.
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Later, a global warming skeptic on another forum mentioned Robert Toggweiler, who seems to endorse this idea in a paper he co-wrote:
Marinov, I., A. Gnanadesikan, J. L. Sarmiento, J. R. Toggweiler, M. Follows, and B. K. Mignone (2008), Impact of oceanic circulation on biological carbon storage in the ocean and atmospheric pCO2, Global Biogeochem. Cycles, 22, GB3007, doi:10.1029/2007GB002958.
http://www.agu.org/pubs/crossref/2008/2007GB002958.shtml
At playtheimmortalgame.com, Melanerpes wrote:In past discussions here on global warming (mainly involving MacSwain), the main focus was on the issue that CO2 cannot possibly be an important factor because the great majority of greenhouse gas in the earth's atmosphere is water vapor - with CO2 making up only a very small % of the total. As such, even if you increased CO2 at an extremely rapid rate, it still wouldn't increase the total amount greenhouse gas by anything more than a trivial amount. The argument has been that the global warming alarmists ignore water vapor, and thus make CO2 seem like a much bigger factor than it really is -- therefore, any warming that is occurring is likely due to normal cycles and other natural effects. But I came across this article when doing a Google search on "global warming water vapor" http://www.slate.com/id/2182564/ the article makes the following points: 1. global-warming skeptics argue that water vapor makes up 98% of the atmosphere - which seems to be based on a 1991 article by Richard Lindzen that cited a 1990 IPCC report - but the 1990 report doesn't appear to contain that number. According to both the IPCC and many global climate models, the real number is 60-70%. 2. the amount of water vapor that a given volume of air can hold rises when temperature is higher. So anything that is causing the atmosphere to get warmer, will allow the atmosphere to hold more water vapor. It may well be the case that it's not the CO2 itself that's the main problem - but it's role in allowing the atmosphere to hold a lot more water vapor. 3. a common skeptical argument is that the clouds caused by water vapor actually help to block solar radiation - and this compensates for the greenhouse effect, but a study in the Alps showed that this wasn't the case - despite the increasing clouds over a 7 year period, temperatures still rose steadily.
http://www.playtheimmortalgame.com/board/showthread.php?threadid=122266&page=1#post_2304543
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