The world’s marine ecosystems risk being severely damaged by ocean acidification unless there are dramatic cuts in CO2 emissions, warn scientists.
The researchers warn that ocean acidification, which they refer to as “the other CO2 problem”, could make most regions of the ocean inhospitable to coral reefs by 2050, if atmospheric CO2 levels continue to increase.
This does indeed sound alarming, until you consider that corals became common in the oceans during the Ordovician Era – nearly 500 million years ago – when atmospheric CO2 levels were about 10X greater than they are today. (One might also note in the graph below that there was an ice age during the late Ordovician and early Silurian with CO2 levels 10X higher than current levels, and the correlation between CO2 and temperature is essentially nil throughout the Phanerozoic.)
Perhaps corals are not so tough as they used to be? In 1954, the US detonated the world’s largest nuclear weapon at Bikini Island in the South Pacific. The bomb was equivalent to 30 billion pounds of TNT, vapourised three islands, and raised water temperatures to 55,000 degrees. Yet half a century of rising CO2 later, the corals at Bikini are thriving. Another drop in pH of 0.075 will likely have less impact on the corals than a thermonuclear blast. The corals might even survive a rise in ocean temperatures of half a degree, since they flourished at times when the earth’s temperature was 10C higher than the present.
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@ur momisugly Steven Goddard,
Steven, your incapacity to grasp even the basics of carbonate chemistry here is getting very old. You’re wrong again (see below).
“Here is a summary which hopefully end all of the ridiculous claims that have been made on this thread.
Limestone formation – sequesters CO2 and increases the amount of H+ (i.e. increases acidity)
2CO2 + 2H2O -> 2H2CO3
2H2CO3 -> 2HCO3- + 2H+
Ca++ + 2HCO3- -> CaCO3 + CO2 + H2O”
Steven, you produced 2H+ in your second equation and didn’t include them in the third (overall) equation. Have we just demonstrated that matter CAN be created and destroyed? (no, of course not)
The way you’ve written the equation we get the removal of 1 unit of C from solution and no change in alkalinity, which is incorrect. In reality the precipitation of CaCO3 removes 1 unit of C from solution and 2 units of alkalinity.
Recall that TCO2 = CO2* + HCO3- + CO3=
Ac = HCO3- + 2CO3- + OH- – H+
The correctly written equation is:
Ca++ + 2HCO3- = CaCO3 + 2H+ + CO2 + H2O
For a given change in TCO2 and Ac the corresponding concentrations for all DIC species (and pH) are easily calculated. See Stumm and Morgan, 1996, Lewis and Wallace 1998, Millero, 2006, etc. for discussions of how to calculate the entire system from TCO2 and Ac (and other parameters).
As you can readily see in any of these, precipitating CaCO3 from solution results in an INCREASE in dissolved CO2.
Let’s talk in hard numbers. Here are some numbers for you: A solution initially has 1000 umol/kg TCO2 and 1000 ueq/kg Ac (@ur momisugly 25 C, 1 atm). 50 umol/kg worth of CaCO3 precipitates so as to reduce Ac by 100 ueq/kg, and TCO2 by 50 umol/kg. The concentration of dissolved CO2 in the solution goes way, way up:
1000 umol/kg TCO2, 1000 ueq/kg Ac => [CO2] = 11.10 umol/kg, pCO2 = 327 uatm
950 umol/kg TCO2, 900 ueq/kg Ac => [CO2] = 51.99 umol/kg, pCO2 = 1531 uatm
The precipitation of CaCO3 here INCREASES [CO2] by 468%!
These calculations done as per Lewis and Wallace, 1998.
“Limestone dissolution – releases CO2 and reduces the amount of H+ (i.e decreases acidity)
CaCO3 + CO2 + H2O -> Ca++ + 2HCO3-
2HCO3- + 2H+ -> 2H2CO3
2H2CO3 -> 2CO2 + 2H2O”
Wrong again. This is the reverse of the above reactions:
950 umol/kg TCO2, 900 ueq/kg Ac => [CO2] = 51.99 umol/kg, pCO2 = 1531 uatm
1000 umol/kg TCO2, 1000 ueq/kg Ac => [CO2] = 11.10 umol/kg, pCO2 = 327 uatm
The dissolution of CaCO3 here REDUCES the [CO2] by 468%!
“This shows how the ocean pH is buffered. As acidity increases, limestone dissolves, releasing CO2, removing H++, and increasing pH.”
No, this shows that Steven has no understanding of the most basic aspects of carbonate chemistry. Honest to goodness Steven—they teach this stuff to undergraduates. How do you not understand this?
“I tried this out in a beaker last night. I put some pure optical calcite (CaCO3) in vinegar. It released lots of CO2 bubbles, until enough of the H+ was removed to bring the pH up to a point where the dissolution stopped.”
And acetic acid is not the same thing as carbonic acid Steven! When you add acetic acid to CaCO3 the H+ from the acetic acid is neutralized by CO3= to produce HCO3- and CO2, while it’s conjugate base (acetate) accumulates. When you add CO2 to CaCO3 the dissociation of H2CO3 into H+ and HCO3- increases the HCO3- concentration while the H+ is neutralized by CO3= to produce HCO3-. The dissolution of CaCO3 REDUCES the concentration of dissolved CO2 because it consumes CO2 from the solution!
Do the same experiment with some CaCO3 and CO2 in a closed system. Over time the CaCO3 dissolves, consuming CO2, just as above.
“(More CO2, higher pH.) This is why it is extremely difficult to lower the ocean pH, and why you can’t make the oceans chemically absorb a lot more CO2. There are billions of tons of CaCO3 in the ocean which buffer the system.”
Wrong yet again Steven. The timescale necessary for CaCO3 and silicates on land to dissolve and reestablish a similar saturation state and CCD in the ocean is on the order of 100,000 yrs, as you can see here: Archer et al., 1998; Archer, 2005; Andersson et al., 2003; Zachos et al., 2005.
Chris
Ack, I messed the font up in the above post. Can a mod please delete when they have a chance—this post is the same, but (hopefully) fixed.
@ur momisugly Steven Goddard,
Also Steven, if the ocean is well mixed, as you argue, and CaCO3 as calcite and aragonite very quickly dissolve to neutralize the addition of CO2, due explain why the surface ocean is predominately supersaturated with respect to both by a substantial degree (5x+ for calcite in the tropics, 3x+ for aragonite in the tropics) and understaturated in the deep see (calcite satutration horizon ~4500 m in the Atlantic, <700 m in the Pacific; aragonite saturation horizon ~2500 m in the Atlantic, < 500 m in the Pacific).
If what you say is true and the ocean very quickly comes to equilibrium with calcite/aragonite upon perterbation (e.g., addition of CO2) then why is most of the ocean out of equilibrium?
Chris
Chris J,
It continues to astonish me that you come back and push the same nonsensical points over and over again. Perhaps we need to go back to the basics, though it is becoming apparent that you are not interested in thinking this through or coming up with a sensible answer.
Since the early days of the planet’s formation, CO2 and H20 has been released from volcanoes. If not for the process of limestone formation, we would have a very different atmosphere, with a high concentration of CO2. This obvious fact alone should make you realize that you are wrong.
Rainwater is acidic because of this equation.
2CO2 + 2H2O -> 2H2CO3
Acid rainwater dissolves silicate rocks, which moves Ca++ ions into the ocean, where they combine with CO2 to form limestones. That is why earth has a low level of CO2. CO2 is sequestered in limestones. Every geologist and geochemist who has studied this problem for the last 100 years or so has come to the same conclusion. This is not under any dispute. You bury yourself in equations that you misinterpret, and come to nonsensical conclusions.
There is nothing missing from my equations. The Ca++ obviously comes from the dissolved silicate rocks I just described. Do you need to have every detail spelled out for you?
2CO2 + 2H2O -> 2H2CO3
2H2CO3 -> 2HCO3- + 2H+
Ca++ + 2HCO3- -> CaCO3 + CO2 + H2O
Furthermore, when you dissolve limestone you reduce acidity and release CO2. Take a piece of limestone and stick it in acid. The limestone visibly releases CO2 and neutralizes the acid – causing the CO2 bubbling to stop over time. Every primary school science student has seen this in their classroom, or at least used to when children were still being taught science. The fact that anyone claiming to be a scientist would attempt to dispute this, leaves me stunned.
CaCO3 + CO2 + H2O -> Ca++ + 2HCO3-
2HCO3- + 2H+ -> 2H2CO3
2H2CO3 -> 2CO2 + 2H2O
Chris,
Again, it astonishes me that you ask why the tropics are saturated and the deep sea undersaturated. If you had any basic understanding of the topic you would be aware that CO2 and CaCO3 solubility in water is lower at higher temperatures. That is why ice cores show higher atmospheric CO2 following planetary temperature trends. As the oceans warm, they release CO2 and precipitate limestone. When they cool, they absorb CO2 and potentially dissolve limestone. It is also why warm beer bubbles over when you open the bottle.
Calcite exhibits an unusual characteristic called retrograde solubility in which it becomes less soluble in water as the temperature increases.
http://en.wikipedia.org/wiki/Limestone
You are attempting to isolate small equations as part of a “closed system,” ignoring the fact that we are talking about a much larger system which includes the earth and sun. This conversation is helping me understand how there could be so much junk science floating around the world of AGW.
Phil. (20:15:56) :
Going back to the “more acidic” means an acid became more so doesn’t work since seawater isn’t an acid. So, let me substitute with “less alkaline”:
So the seawater gets less alkaline because the decrease in alkalinity
outweighs that of total carbon and [CO2] increases.
Sorry, I can’t get past that first line. You have me thinking H+ and OH- dancing in a circular argument then you shift to a black (or clear) solid and [a gas in brackets]. Good thing I got sucked up by computers before getting serious about my ChemE major. What the significance of those brackets? ChrisJ used that too, also TCO2, is that shorthand for Total CO2?
I don’t care who started it, none of you are getting recess tomorrow!
Chris,
You asked “why is most of the ocean out of equilibrium?”
Now that is a good question. The ocean is constantly out of equilibrium because it is part of a dynamic system. Temperatures keep changing, which change solubilities. Chemicals are constantly introduced to the system through river water influx. There are biological processes affecting the chemistry. Layers of silt and mud cover the CaCO3 deposits, isolating them from sea water. Limestones are mechanically removed from the system by uplift and subduction. If not for these processes, the oceans would equilibrate quickly and limestones would cease to form.
Ocean water is not a test tube which can be analyzed in isolation of the incredibly dynamic geological, astronomical, biological and temporal environment it is contained in.
You have given me an excellent idea for an article – thanks.
@Steven Goddard,
Steven, your bait and switch isn’t working. Several times now I’ve demonstrated that you’re incorrect in reasoning, explained your error, and explained the correct processes to you only to have you change the subject, or pretend we were discussing something other than what we were. Unfortunately for you, you can’t take back what you’ve written, and I’m growing tired of your games.
Which is a completely different process than what we are and have been discussing Steven. You’ve made the claim repeatedly that the precipitation of CaCO3 from solution DECREASES the CO2 concentration of that solution:
You further claim that the dissolution of CaCO3 INCREASES the CO2 concentration of that solution:
As I’ve shown above (Chris J (22:51:06) : ) the precipitation of CaCO3 INCREASES dissolved CO2 in solution while the dissolution of CaCO3 REDUCES dissolved CO2 in solution. Your claims to the contrary are simply wrong, as I’ve demonstrated above.
Agreed, but that was never a point of contention.
Agreed on the source of Ca++ to the ocean, but that point is completely irrelevant since the sources of Ca++ to the ocean were never a point of contention. Calcium combines with CO3= in the ocean to form CaCO3, not with CO2.
Which is not the argument you made above, and is not the point of contention between us! You claimed that CaCO3 precipitation REDUCES solution [CO2] and CaCO3 dissolution INCREASES solution [CO2].
Here you point out that the reaction of CaO with CO2 in silicate minerals consumes CO2, which is absolutely true, but was NEVER the point we were discussing. What we’ve been discussing is the effect of CaCO3 precipitation and dissolution on dissolved CO2 in solution.
You can’t simply switch to a different topic and claim that’s what you were talking about, at least not when your claims have been documented. Well, I suppose you actually can do that, but I will point it out for everyone to see, as I’m now doing. Your attempted bait and switch is noted, and a failure.
<
Once again Steven, the source of Ca++ was NEVER a part of our discussion nor a point of contention, and for one very important reason: it is completely irrelevant. It doesn’t matter if Ca++ is derived from CaO in silicate minerals, from CaSO4, from CaCl2, or any other source. The source of Ca++ to the ocean is absolutely irrelevant to any aspect of our discussion, though your attempt at yet another bait and switch is noted.
Previously you also said in response to me:
You are now claiming what I say in my quote, that the chemical weather of carbonates and silicates consumes atmospheric CO2, but in the above passage you said that the reactions have an effect on CO2 that is “quite the opposite” of the claim I made (which you make above) and that the interaction of CO2 with carbonates releases CO2. Hence, you’ve previously claimed that the dissolution of CaCO3 with CO2 INCREASES dissolved CO2, but now that I’ve demolished that nonsensical position you’ve switched over to accepting that the weathering of silicates and carbonates with CO2 REDUCES dissolved CO2.
You’ve tried to have it both ways here. I’m sorry Steven, but you can’t have it both ways, and everyone that might be reading this can easily see through the double-speak you’ve attempted.
And at the very least Steven, learn to balance chemical equations.
The equilibrium you have here is (combining equations 1 and 3—2 is intermediate to the overall rxn):
2CO2 + 2H2O + Ca++ = CaCO3 + CO2 + H2O
1 Ca++ on both sides (good so far)
2 C on both sides (no worries)
6 O on both sides (great)
4 H on the right side, but only 2 H on the left (uh-oh!)
The balanced equation is:
2CO2 + 2H2O + Ca++ = CaCO3 + 2H+ + CO2 + H2O
While you are entitled to your own opinions, you are not entitled to your own facts, and you certainly aren’t entitled to ignore the law of conservation of matter in your argument on chemistry (or anything else, one would suppose).
Chris
@ur momisugly Steven Goddard,
As I’ve said repeatedly Steven, that only works when you use an acid OTHER than carbonic acid since the conjugate base of the acid is allowed to build up. If you dissolve CaCO3 with CO2 you consume the CO2 in the process, resulting in reduced [CO2]. If you disagree, perform the calculation for the dissolution of CaCO3 with CO2. I want the concentrations. I’ve already provided you with them, the least you can do is the same. Either put up or…well, stop talking nonsense.
Do the experiment: drop some CaCO3 into a beaker and bubble in CO2. Do you get bubbles of rising CO2? (I’ll kill the suspense: no, you don’t)
Steven, you just created matter! Where do the 2H+ in equation 2 come from?
You can’t just create and destroy protons when it suits you.
Further, these are equilibrium equations Steven. Simply because you can write an equation tells you nothing about which direction the reaction proceeds. For that you need to perform the calculation. I’ve already done so above, and sure enough [CO2] decreases when CaCO3 dissolves. If you disagree, give me (and all of us) some hard numbers.
Chris
Chris,
I can see why you are not understanding what I am talking about. I am talking about the earth/atmosphere system as a whole, and you think we are talking about an isolated system in a test tube with no boundary conditions.
CO2 is continuously introduced and removed to/from your test tube through a variety of geological and biological processes. That is what is confusing you about conservation of mass.
You make absurd claims like “you’ve previously claimed that the dissolution of CaCO3 with CO2 INCREASES dissolved CO2” I never said anything like that. What I said is that dissolution of CaCO3 by acids releases CO2. Every science student in the world knows this.
Twisting my words and ignoring the big picture is not going to change the science nor make the oceans acidic. What do you hope to accomplish through this bizarre, disconnected academic exercise you are engaged in?
@ur momisugly Steven Goddard,
That’s precisely the point Steven! You claim that the ocean comes to equilibrium very quickly with respect to calcite/aragonite given changes in [CO2], therefore the ocean will be buffered against the increase in [CO2] during this century. You also observe that the shallow ocean is substantially supersaturated with calcite and aragonite while the deep sea is undersaturated.
So on the one hand, you’re claiming that CaCO3 will fall in equilibrium with an increase in [CO2] THIS CENTURY, yet the ocean hasn’t come to equilibrium with the increase in [CO2] that occurred between the last glacial maximum and the beginning of the Holocene.
So, the ocean doesn’t come to equilibrium in terms of calcite/aragonite saturation with a 100 uatm increase in CO2 that occurs over ~8,000 yrs, but it will come to equilibrium with a 100 (optimistically) to 500 uatm increase that occurs by the end of the century. Interesting. Please do explain your reasoning here.
Ha, yes Steven, I know. The decrease in CO2 solubility actually has little impact since the decrease in pKw with temperature essentially overwhelms that effect. The more important effects are on K2 for carbonic acid and the free energy.
The Earth, for all practical purposes, is a closed system with regard to materials (not radiation) Steven. The C, Ca, H2O, etc. that we have here is not wafting off into space, nor being received from space, at any significant rate.
Chris
Chris,
Since you obviously have no training in Geology, let’s start with a simple case that you might be able to understand.
Imagine a lake with a thin layer of limestone at the bottom. If nothing else was going on, the lake would achieve chemical equilibrium internally and with the atmosphere above it.
However, that isn’t how things work in the real world. Sediment washes into the lake, which buries the limestone. (This is a classic limestone/shale interleaved sequence.) The sediment isolates the limestone from the lake water, and disrupts the chemical equilibrium. More limestone forms at the bottom, and more CO2 is absorbed from the atmosphere. It is this process which has allowed huge amounts of CO2 to be removed from the atmosphere and sequestered in limestones over the past few hundreds of millions of years.
If you don’t understand geology, you shouldn’t get involved in a geological discussion. There is a big world outside of your test tube, which does follow conservation of mass, but on a large scale.
Ack, screwed up the text again. If a mod can delete the above screwed-up-text post and leave this non-screwed-up-text post it’d be appreciated!
@ur momisugly Steven Goddard,
Now this is one of the first reasonable things I’ve seen you say. You are exactly correct that most of the ocean is out of equilibrium with respect to calcite/aragonite because of biological and geochemical processes. Were the ocean very rapidly mixed, it would eventually come to equilibrium with respect to calcite, especially in the absence of these processes and CaCO3 precipitation and dissolution would no longer take place—there would be a fixed quantity of accumulated CaCO3.
Of course, CaCO3 has been accumulating in the ocean for hundreds of millions of years and began before biomineralizing organisms evolved (all abiotic and/or biologically induced, like in stomatolites).
The ocean, top to bottom, has been out of equilibrium with respect to calcite for at least this period of time. The only way this is possible is if the processes that set the ocean out of equilibrium (all geochemical/physical in the early ocean—biological and geochemical/physical today) operate significantly FASTER than the rate of mixing. If they did not, the ocean would come and would have come to equilibrium.
I’m glad we’re in agreement here.
Ah, I see. The ocean is too complicated to study. Well, let’s all toss our hands up and go home guys. It turns out we can’t study the ocean (or anything else, presumably) because it’s complicated. Ignore the decades to centuries of data. Ignore the countless verified predictions from countless subdisciplines in marine science and oceanography. No matter how accurately our predictions turn out to be when tested, the ocean is just too complicated to study.
In fact, all of science, technology, medicine, etc. is completely useless because the world is complicated. We can’t put the universe in a test tube, afterall, therefore we can never know anything useful about it.
If you really believe that, well, good luck to you.
>
Ha, glad I could help.
Chris
In above I mean to say that “net CaCO3 precipitation and dissolution would no longer take place”.
Unfortunately this is not the case. It is not only a narrow temperature range but also a narrow range of sunlight quality. The corals being discussed here rely on symbiotic algae, and these only function effectively with adequate sunlight. Once you move away from the tropics the increased angle the sun hits the water means that the quality of sunlight penetrating se water is much reduced.
Unfortunately this is not the case. It is not only a narrow temperature range but also a narrow range of sunlight quality. The corals being discussed here rely on symbiotic algae, and these only function effectively with adequate sunlight. Once you move away from the tropics the increased angle the sun hits the water means that the quality of sunlight penetrating sea water is much reduced.
Chris J (07:11:56) says:
I think I understand those words. Precipitation means that solids come out of the solution. I recall doing that in high school chemistry when we mixed that pretty blue CuSo4 or something with some thing like CaCl, although I can no longer remember what would precipitate. I think I understand words like reduces and increases and dissolution as well.
Then in the same posting you say that:
I am confused, but I must admit to having had only one year of Chemistry in university and it was a long time ago.
However, in the equation you presented above, it would seem that if CaC03 precipitates, it does so by reducing CO2 concentration. It would seem, however, to increase H+.
I just went back and looks again, and you say:
but your balanced equation has us starting with two and ending with one molecule of CO2 (which I can only assume is in solution).
What’s going on? Have I reversed the meanings of increase and reduce all these years? (I cut and pasted from your posting). Is there something else here I am missing?
As a side note, my wife, who is a teacher, came across a teenage male recently who had actually reversed the meanings of ‘true’ and ‘false’. “You are a boy!” Yes, that is false! You are a baby! No, that is true.
maksimovich (13:15:04) :
Bill D (11:38:31)
….
http://www.epa.gov/AthensR/publications/reports/Zepp600R03095UVExposureCoral.pdf
So simply we can assertain that changes in water clarity are the primary mechanism for coral bleaching.
Mak—here is first part of the introduction of the paper that you cited as evidence that UV light causes coral bleaching and that warming is not important. In fact, the authors states in the introduction and discussion that most of the evidence supports warming as the main factor, but my work shows that UV radiation can also be important. Interestingly, the increase in UV radiation is attributed to changes in organic chemicals that block UV light and the author of the paper that you cite attributes the increase in underwater UV light to “climate change.” The author is also very cautious about jumping to conclusions, but supports the hypothesis that climate change is likely responsible for the die offs of corals.
1.1 Coral Bleaching: Impacts of Warming and Light
Photosynthetic coral symbionts, members of the dinoflagellate genus Symbiodinium, provide both color and energy to a wide variety of coral taxa. When these symbionts (zooxanthellae), or their pigments, are expelled or lost from the host coral tissues, the white color of the coral skeleton emerges, leaving a bleached appearance. Bleaching also can involve direct degradation of the pigments in the zooxanthellae. The descriptive term ‘bleaching’ reflects a breakdown of the symbiosis. Records of coral bleaching from 1870 to the present indicate that the severity, locality, and frequency have reached unprecedented levels (D’Elia et al., 1991; Glynn, 1993) Coral bleaching may be the symptom of coral reef degradation that is most closely linked to climate change (Hoegh-Guldberg, 1999). Although bleaching has been correlated with increased temperatures, many studies have concluded that light exposure may also be implicated as a stressor producing additive or synergistic effects (Shick et al. 1996). Research on the effects of solar radiation have examined photosynthetically active radiation (PAR, 400 – 700 nm spectral range) and ultraviolet radiation (UVR). UV-B radiation (280 – 315 nm spectral range) and UV-A radiation (315 – 400 nm spectral range) are two important components of UVR.
maksimovich
I actually read the EPA study that you linked to above. In early posts I mentioned that high temperatures, reduced pH and high intensities of UV light have all be shown to adversely impact corals.
The EPA study that you cite above focused on UV light. In the introduction, the author states that most of the evidence links bleaching to high temperatures but high UV light also seems to be a factor. This study also notes that high UV light is linked to climate change, something that I was not really aware of.
Scientists know that articles need to be read completely and carefully before they are cited. An important role of scientific reviewers is to point out when articles are cited incorrectly and when important citations are left out. In this case, the conclusions of the authors directly conflicts with your conclusions. I don’t know whether this is because you did not read the paper, or you that you read the paper and assumed that no one else has or would read the paper and would notice that it does not support you conclusion.
Steven Goddard,
As Chris J has said above, anyone who’s followed this thread will be able to figure out who has been talking nonsense, so I rather think it pointless for either of you to keep making the claim.
I wonder if you might like to respond to my relatively simple point above? If the oceans are instantaneously/very rapidly chemically mixed by circulation, as you seem to believe, then it follows that they are instantaneously/very rapidly thermally mixed, does it not? I would like to clarify whether or not you do believe in such rapid circulatory mixing, since the implications of such a belief are rather extraordinary.
Simon Evans,
Look at the current map of sea surface temperatures.
http://weather.unisys.com/surface/sst_anom.html
Note the cold area of the equatorial Pacific. This cold water is the result of La Nina, and was pulled up from the deep ocean east along the thermocline along the South American coast – and then blown west by the wind. This process takes several months to years, as evidenced by the frequency of ENSO events.
There is nothing mysterious or controversial about this. How else would cold water make it to the equator?
http://en.wikipedia.org/wiki/El_Ni%C3%B1o-Southern_Oscillation
My question is – Is there any way to have a sane, rational discussion with the AGW groupies?
Bill D (11:07:16)
“Scientists know that articles need to be read completely and carefully before they are cited.”
Indeed we do
3. Conclusions and Management Implications (PAGE 36)
This research has advanced the science of corals as it relates to UV interactions in the following ways:
! It was demonstrated that the UV exposure of coral reefs in the Florida Keys is highly variable and that this variability is linked to climate changes that are occurring over the region. The linkage stems from concurrent changes in physicochemical properties of the waters such as warmer temperatures and increased water clarity.
! We showed that the chromophoric (colored) component of dissolved organic matter (CDOM) in the water over the reefs plays a key role in controlling light exposure. Thus changes in CDOM concentrations caused by climate change and/or land-based human activities can translate into significantly altered UV exposure of coral reefs.
! We identified what may be a major pathway for the large scale impact of El Niño events on mass bleaching of corals. Our results suggest that stratification caused by the prolonged periods of low winds and warm temperatures that accompany El Niño events can result in significant increases in damaging UV radiation over the reefs. We hypothesize that this increased exposure to UV, in concert with warmer waters, places intense stress on the corals that results in extensive bleaching.
! We elucidated possible biological sources of CDOM in waters close to coral reefs. Changes in these biological sources, such as seagrasses and mangroves, caused by climate change and human activities can have long-term detrimental effects on corals by perturbing UV protective substances in the ocean water.
We also understand the textbooks
TOMMY D. DICKEY AND PAUL G. FALKOWSKI The sea 2002
Chapter 10. SOLAR ENERGY AND ITS
BIOLOGICAL–PHYSICAL INTERACTIONS IN THE SEA
Page 402
On ecological time scales, the diel and seasonal cycles determine the number of hours of solar radiation incident on each point on the planet, and thus provide an extrinsic natural clock to which almost all organisms (including humans) have adapted. Earth’s radiative balance, which is absolutely essential to sustaining life, is dictated by the input of solar energy, atmospheric gas composition, and planetary albedo. These processes are inextricably coupled to the ocean by the hydrological cycle through water vapor and ice albedo feedbacks. These physical systems have coevolved and interact with biological systems. Major biogeochemical processes, such as photosynthesis and nitrogen fixation, are also coupled directly to solar radiation. Solar ultraviolet (UV) radiation can lead to alterations in genetic material, which, in turn, affects the tempo of evolution.Finally, migratory patterns and other behavioral responses in the sea are often keyed to diel, lunar, and seasonal changes in radiation.
Page 403
The interaction with and effect of solar radiation on Earth’s energy budget is
strongly dependent on the electromagnetic spectrum. Planetary albedo is only relevant to short-wavelength radiation; hence, all far-red radiation impinging at the top of Earth’s atmosphere will either be absorbed by gases in the atmospheric column or will be transmitted to the surface. Some of the short-wavelength radiation impinging on the top of the atmosphere is scattered and reflected back to space, while the majority penetrates to the surface. Over 70% of Earth’s surface is covered by liquid water that absorbs about 95% of incident solar irradiance. In its upper 3 m the ocean contains the equivalent heat capacity of the entire atmosphere of the planet (Peixoto and Oort, 1992).
Page 405
As in the atmosphere, the direct physical interactions between solar radiation and
the ocean are wavelength dependent. Water itself effectively absorbs all incident
infrared solar radiation (e.g., Morel and Antoine, 1994), and this direct radiative
transfer process provides roughly half of the heat to the ocean surface waters. An
example of potential interactions between solar radiation and physical and biological
processes is depicted in Fig. 10.2, where the following sequence is illustrated:
(1) forcing of the upper ocean physical condition through the input of solar radiation,
including light, heat, and indirectly momentum at the ocean surface; (2) upper
ocean physical responses, including stratification and turbulent mixing that result in
(3) phytoplankton vertical and horizontal motions, which, in turn, lead to (4) feedbacks on distributions of pigments and photosynthetic available radiation (PAR), and
(5) modulation of the upper ocean heating via phytoplankton and their associated
optical properties. The balance between primary production and grazing determine
the concentration of phytoplankton at any moment in time and both processes must
be considered in biological–physical interactions.
The interactions among these processes occur on many time and space scales.
Long-term changes (millennia to millions of years) in ocean circulation are driven
by changes in radiative forcing resulting from orbital variations, albedo feedbacks,
and continental configuration (Fig. 10.3). Short-term changes (seconds to decades)
are driven by atmospheric conditions (e.g., aerosols, cloud cover, albedo, and ozone
concentration) and thermal contrasts between continents and the oceans and from
the equator to the poles. Together, both long- and short-term variations in radiative transfer of broadband, as well as visible solar energy, determine the depth of the upper mixed layer, turbulent kinetic energy, and the vigor of large-scale oceanic circulation,which ultimately determines, on a global scale, the distribution and productivity of phytoplankton.
We can see this in simple changes in say cloud cover eg Snell and Sommerville
We also understand the evolutionary process in changes of radiative spectra ,ontological growth,attenuation and amplification of population of species.eg Hutchinson 1961
Changes to absorption and emission of nutrients are also responsive to changes in both the type and spectra of radiation, these inhibit some populations and enhance others.Indeed what we can see is the ecological communities of microflora, changing rapidly to meet their changing levels of nutrients and energy is a Belousov-Zhabotinsky reaction diffusion mechanism.
And if we use say Phytoplankton as an example Recent work by two theoretical ecologists (Huisman & Weissing, 1999; 2001),has shown that competition for resources by as few as three species can result in long-term oscillations, even in the traditionally convergent models of plankton species growth. For as few as five species, apparently chaotic behavior can emerge. Huisman and Weissing propose these phenomena as one possible new explanation of the paradox of the plankton, in which the number of co-existing plankton species far exceeds the number of limiting resources, in direct contradiction of theoretical predictions. Continuously fluctuating species levels can support more species than a steady, stable equilibrium distribution.
Their results show that external factors are not necessary to maintain non-equilibrium conditions; the inherent complexity of the “simple” model itself can be sufficient.
The publication of dubious ‘catastrophic ‘predictions for the oceans ability to maintain its biological role of atmospheric moderation are simply “creationist wastepaper” the ability of biogenic adaptability is already genetically available “banked for a rainy day so to speak”. Been there done that, got the T-shirt and the DNA! Geologically“ancient”species, which have survived large changes in ocean chemistry, are likely more resilient to predicted acidification ie they retain the evolutionary memory of “past environmental ezperiences”
The high proportion of duplicate genes within plant and algae genomes is indicative of a high rate of retention of duplicate genes (Lynch and Connery, 2000). Gene duplications contribute to the establishment of new gene functions, and may underlie the origin of evolutionary novelty. Duplicate genes can exist stably in a partially redundant state over a protracted evolutionary period (Moore and Purugganan, 2005). A half-life to silencing and loss of a plant gene duplicate is estimated at 23.4 million years such that remnant duplicate genes, which can be reactivated by environmental conditions to encode calcification within coccolithophores under “ancestral” conditions representative 60 Ma, appears reasonable
An indeed the half life of around 25 my is close to the Lyaponov exponent.
eg Raup, D., and Sepkoski, J., 1986, Periodic extinction of families and genera:
Science, v. 231, p. 833–836.
Bottom line changes in PAR and UV and indeed all radiation are significant drivers in changes in ecosystems.
1. So simply we can assertain that changes in water clarity are the primary mechanism for coral bleaching
2. Bottom line changes in PAR and UV and indeed all radiation are significant drivers in changes in ecosystems.
maksimovich (13:04:16) :
Above are the conclusions to two of your recent posts. From my reading of the scientific literature on corals, I would be surprised if any scientists in that field would agree with your first conclusion above. Your second conclusion is much more reasonable and I can say that I agree with it. Certainly for plankton, seasonal changes in light are a big factor. Light is clearly a big issue in comparisons between ecosystems are different latitudes as well.
Interesting that you mention Jeff Huisman, who has done noteworthy experimental and theoretical research on effects of light on phytoplankton communities (as you have noted in your more recent post above). Just this week I read a revised manuscript (in review) where he is one of several co-authors. This study documnts how climate change is affecting plankton communities by altering C:N:P stoichiometry and makes predictions based on theory and data. None of the effects are catastrophic but it is interesting to see climate affecting natural communities in unexpected ways. (I’ve also published a number of articles related to C:N:P stoichiometry, although none that links to climate or eventemperature).
The take home message is that natural systems are complex and showing that one factor is important does not mean another factor is not also important. Indeed, we often see interactive effects, where, for example effects of the negative effects of increased UV light might accentuate the negative effects of warming temperature.
Steven Goddard (12:42:21) :
Simon Evans,
Look at the current map of sea surface temperatures.
http://weather.unisys.com/surface/sst_anom.html
Note the cold area of the equatorial Pacific. This cold water is the result of La Nina, and was pulled up from the deep ocean east along the thermocline along the South American coast – and then blown west by the wind. This process takes several months to years, as evidenced by the frequency of ENSO events.
There is nothing mysterious or controversial about this. How else would cold water make it to the equator?
http://en.wikipedia.org/wiki/El_Ni%C3%B1o-Southern_Oscillation
You have not answered my question. Further up this thread you have presumed that chemical mixing is instantaneous/very rapid throughout the oceans. Now you are saying something about ENSO, which itself affects only a part of the ocean systems (and which does not mix to the ocean bed), taking ‘several months to years’. So which is it? Is the ocean system instantaneously/very rapidly mixed as you previously claimed or is mixing a process which takes a long time? Oceanographers think that complete mixing takes tens of thousands of years, you have asserted otherwise. Now you appear to be engaging in obfuscation.
My question is – Is there any way to have a sane, rational discussion with the AGW groupies?
I see that you resort to an attempted sneer for want of any other means of defending your contradictions. That gives a very clear view of your position, Mr Goddard (if that is your name). i will not make the mistake again of giving any benefit of the doubt in your particular case.
[If my apparently lost comment appears then this will be repetitive – apologies if so]
REPLY: Comments with certain verbiage and links automatically end up in the WordPress spam filter, it happens -Anthony
Steven Goddard (12:42:21) :
Simon Evans,
Look at the current map of sea surface temperatures.
http://weather.unisys.com/surface/sst_anom.html
Note the cold area of the equatorial Pacific. This cold water is the result of La Nina, and was pulled up from the deep ocean east along the thermocline along the South American coast – and then blown west by the wind. This process takes several months to years, as evidenced by the frequency of ENSO events.
There is nothing mysterious or controversial about this. How else would cold water make it to the equator?
http://en.wikipedia.org/wiki/El_Ni%C3%B1o-Southern_Oscillation
As will be entirely obvious to anyone reading this thread, you have avoided answering my question, which was:
“If the oceans are instantaneously/very rapidly chemically mixed by circulation, as you seem to believe, then it follows that they are instantaneously/very rapidly thermally mixed, does it not? I would like to clarify whether or not you do believe in such rapid circulatory mixing, since the implications of such a belief are rather extraordinary.”
You can write as many posts as you wish to avoiding answering the question and the avoidance will continue to speak for itself.
I see that, following your obfuscation, you attempt a personal sneer for want of any other means of diverting from your contradictions, viz.:-
My question is – Is there any way to have a sane, rational discussion with the AGW groupies?
That also speaks for itself, and tells me everything I need to know about you, Mr Goddard (if that is your name).
Mary Hinge (09:21:14) :
I thought of algae while driving to the grocery store. One thing missing from this discussion is the effect on algae and coral’s algae due to an increase in dissolved CO2 and lower pH.
A couple references say more CO2 means declining CaCO3 production, but the science is far from settled. Better references welcome.
From 1999: http://www.thefreelibrary.com/Carbon+dioxide+buildup+harms+coral+reefs-a054419459
From 2008: http://www.physorg.com/news144348139.html and says in part:
“We found that coralline algae, which glue the reef together and help coral larvae settle successfully, were highly sensitive to increased CO2. These may die on reefs such as those in the southern Great Barrier Reef before year 2050,” says Dr Anthony.
On the positive side, some coral species seem able to cope with the levels of ocean acidification expected by the mid-century by enhancing their rates of photosynthesis, says team member Dr David Kline. “This is an important discovery that can buy the reef time while the nations of the world work together to stabilise CO2 emissions,” he says.