Ocean Acidification: Chicken Little of the Sea Strikes Again

Reef exihbit on ocean acidification. — Image by Tom Clifton via Flickr

Guest Post by David Middleton

Introduction

As global warming morphs into climate change and global climate disruption and anthropogenic CO2 emissions give way to stochastic variability, clouds, the Sun, cosmic rays and our oceans as the primary drivers of climate change, environmental extremists are raising a new CO2-driven ecological disaster scenario to hysterical levels: Ocean acidification. Claims have been made that oceanic pH levels have declined from ~8.2 to ~8.1 since the mid-1700’s. This pH decline (acidification) has been attributed to anthropogenic CO2 emissions – This should come as no surprise because the pH estimates are largely derived from atmospheric CO2 concentrations (Orr et al., 2005). It has also been postulated that anthropogenic CO2 emissions will force an additional 0.7 unit decline in oceanic pH by the year 2100 (Caldeira et al., 2003).

Alarmist organizations like the National Resources Defense Council are hard at work extrapolating these oceanic pH model predictions into ecological nightmares…

Scientists predict the Arctic will become corrosive to some shelled organisms within a few decades, and the Antarctic by mid-century. This is pure chemistry; the vagaries of climate do not apply to this forecast.

OA is expected to impact commercial fisheries worldwide, threatening a food source for hundreds of millions of people as well as a multi-billion dollar industry. In the United States alone, ocean-related tourism, recreation and fishing are responsible for more than 2 million jobs.

Shellfish will be affected directly, thus impacting finfish who feed on them. For example, pteropods—tiny marine snails that are particularly sensitive to rises in acidity— comprise 60 percent of the diet for Alaska’s juvenile pink salmon. And this affects diets farther up the food chain, as a diminished salmon population would lead to less fish on our tables.

Coral reefs will be especially hard hit by ocean acidification. As ocean acidity rises, corals will begin to erode faster than they can grow, and reef structures will be lost worldwide. Scientists predict that by the time atmospheric CO2 reaches 560 parts per million (a level which could happen which could happen by mid-century; we are currently nearing 400 ppm), coral reefs will cease to grow and even begin to dissolve. Areas that depend on healthy coral reefs for food, shoreline protection, and lucrative tourism industries will be profoundly impacted by their loss.

This sounds like a serious threat… As have all of the other alarmist clarion calls to halt capitalism in the name of the most recent environmental cause célèbre. Just to be fair, before pitching Ocean Acidification into the dustbin of junk science along with Anthropogenic Global Warming, let’s look at the science.

The answers to the following questions will tell us whether or not CO2-driven ocean acidification is a genuine scientific concern:

Is atmospheric CO2 acidifying the oceans?
Is there any evidence that reefs and other marine calcifers have been damaged by CO2-driven ocean acidification and/or global warming?
Does the geological record support the oceanic acidification hypothesis?

Is atmospheric CO2 acidifying the oceans?

Before we can answer this question, we have to understand a bit about how the oceans make limestone and other carbonate rocks. The Carbonate Compensation Depth (CCD or Lysocline) is the depth at which carbonate shells dissolve faster than they accumulate. That depth is primarily determined by several factors…

-Water temperature

-Depth (pressure)

-CO2 concentration

-pH (high pH values aid in carbonate preservation)

-Amount of carbonate sediment supply

-Amount of terrigenous sediment supply

Calcium carbonate solubility increases with increasing carbon dioxide content, lower temperatures, and increasing pressure.

SOURCE

What evidence do we have that the lysocline or CCD has been becoming shallower or that the oceans have been acidifying over the last 250 years? The answer is: Almost none.

Pelejero et al., 2005 found a cyclical correlation between pH and the PDO…

Fig1) Pelejero et al., 2005, “Fig. 2. Record of Flinders Reef coral 11B, reconstructed oceanic pH, aragonite saturation state, PDO and IPO indices, and coral calcification parameters. (A) Flinders Reef coral 11B as a proxy for surface-ocean pH (24); 11B measurements for all 5-year intervals are available in table S1. (B) Indices of the PDO (28, 39) and the IPO (27) averaged over the same 5-year intervals as the coral pH data. Gray curves in panels (A) and (B) are the outputs of Gaussian filtering of coral pH and IPO values, respectively, at a frequency of 0.02 ± 0.01 year–1, which represent the 1/50-year component of the pH variation (fig. S2). (C) Comparison of high-resolution coral Sr/Ca (plotted to identify the seasonal cycle of SST) (32), 11B-derived pH, and wind speed recorded at the Willis Island meteorological station (data from the Australian Bureau of Meteorology) (40). Note the covariation of wind speed and seawater pH; strong winds generally occur at times of high pH, and weak winds generally occur at times of low pH. All high-resolution 11B measurements are available in table S2. (D) Aragonite saturation state, , where is the stoichiometric solubility product of aragonite, calculated from our reconstructed pH assuming constant alkalinity (24). (E) Coral extension and calcification rates obtained from coral density measured by gamma ray densitometry (38).”

Is there any evidence that reefs and other marine calcifers have been damaged by CO2-driven ocean acidification and/or global warming?

Using the data from Pelejero et al., 2005, I found no correlation between pH and reef calcification rates…

Comparison of pH to Flinders Reef calcification rate (Pelejer0 et al., 2005) — Fig. 2) Flinders Reef: Calcification Rate vs. pH (Pelejero et al., 2005)

Fig. 3) Fliners Reef pH (Pelejero et al., 2005) vs atmospheric CO2

Fig. 4. Average mass of CaCO3 per coccolith in core RAPID 21-12-B and atmospheric CO2. The average mass of CaCO3 per coccolith in core RAPID 21-12-B (open circles) increased from 1.08 x 10–11 to 1.55 x 10–11 g between 1780 and the modern day, with an accelerated increase over recent decades. The increase in average coccolith mass correlates with rising atmospheric PCO2, as recorded in the Siple ice core (gray circles) (26) and instrumentally at Mauna Loa (black circles) (38), every 10th and 5th data point shown, respectively. Error bars represent 1 SD as calculated from replicate analyses. Samples with a standard deviation greater than 0.05 were discarded. The smoothed curve for the average coccolith mass was calculated using a 20% locally weighted least-squares error method. — Fig. 4) Iglesias-Rodriguez et al., 2008, “Fig. 4. Average mass of CaCO3 per coccolith in core RAPID 21-12-B and atmospheric CO2. The average mass of CaCO3 per coccolith in core RAPID 21-12-B (open circles) increased from 1.08 x 10–11 to 1.55 x 10–11 g between 1780 and the modern day, with an accelerated increase over recent decades. The increase in average pre=”average “>coccolith mass correlates with rising atmospheric PCO2, as recorded in the Siple ice core (gray circles) (26) and instrumentally at Mauna Loa (black circles) (38), every 10th and 5th data point shown, respectively. Error bars represent 1 SD as calculated from replicate analyses. Samples with a standard deviation greater than 0.05 were discarded. The smoothed curve for the average coccolith mass was calculated using a 20% locally weighted least-squares error method.”

And when sudden increases of atmospheric CO2 have been tested under laboratory conditions, “otoliths (aragonite ear bones) of young fish grown under high CO2 (low pH) conditions are larger than normal, contrary to expectation” (Checkley et al., 2009).

A recent paper in Geology (Ries et al., 2009) found an unexpected relationship between CO2 and marine calcifers. 18 benthic species were selected to represent a wide variety of taxa: “crustacea, cnidaria, echinoidea, rhodophyta, chlorophyta, gastropoda, bivalvia, annelida.” They were tested under four CO2/Ωaragonite scenarios:

409 ppm (Modern day)

606 ppm (2x Pre-industrial)

903 ppm (3x Pre-industrial)

2856 ppm (10x Pre-industrial)

7/18 were not adversely affected by 10x pre-industrial CO2: Calcification rates relative to modern levels were higher or flat at 2856 ppm for blue crab, shrimp, lobster, limpet, purple urchin, coralline red algae, and blue mussel.

6/18 were not adversely affected by 3x pre-industrial CO2: Calcification rates relative to modern levels were higher or flat at 903 ppm for halimeda, temperate coral, pencil urchin, conch, bay scallop and whelk.

3/18 were not adversely affected by 2x pre-industrial CO2: Calcification rates relative to modern levels were higher or flat at 903 ppm for hard clam, serpulid worm and periwinkle.

2/18 had very slight declines in calcification at 2x pre-industrial: Oyster and soft clam.

The effects on calcification rates for all 18 species were either negligible or positive up to 606 ppm CO2. Corals, in particular seemed to like more CO2 in their diets…

Fig. 5) Coralline red algae calcification response to increased atmospheric CO2 (modified after Ries eta la., 2009)

Fig. 6) Temperate coral calcification response to increased atmospheric CO2 (modified after Ries et al., 2009).

Neither coral species experienced negative effects to calcification rates at CO2 levels below 1,000 to 2,000 ppmv. The study reared the various species in experimental sea water using 4 different CO2 and aragonite saturation scenarios.

It appears that in addition to being plant food… CO2 is also reef food.

More CO2 in the atmosphere leads to something called “CO2 fertilization.” In an enriched CO2 environment, most plants end to grow more. The fatal flaw of the infamous “Hockey Stick” chart was in Mann’s misinterpretation of Bristlecone Pine tree ring chronologies as a proxy for temperature; when in fact the tree ring growth was actually indicating CO2 fertilization as in this example from Greek fir trees…

Fig. 7) Example of CO2 fertilization in Greek fir trees (Koutavas, 2008 from CO2 Science)

Coral reefs can only grow in the photic zone of the oceans because zooxanthellae algae use sunlight, CO2, calcium and/or magnesium to make limestone.

The calcification rate of Flinders Reef has increased along with atmospheric CO2 concentrations since 1700…

Fig. 8) Flinders Reef calcification rate plotted with atmospheric CO2.

As the atmospheric CO2 concentration has grown since the 1700’s coral reef extension rates have also trended upwards. This is contrary to the theory that increased atmospheric CO2 should reduce the calcium carbonate saturation in the oceans, thus reducing reef calcification. It’s a similar enigma to the calcification rates of coccoliths and otoliths.

In all three cases, the theory or model says that increasing atmospheric CO2 will make the oceans less basic by increasing the concentration of H+ ions and reducing calcium carbonate saturation. This is supposed to reduce the calcification rates of carbonate shell-building organisms. When, in fact, the opposite is occurring in nature with reefs and coccoliths – Calcification rates are generally increasing. And in empirical experiments under laboratory conditions, otoliths grew (rather than shrank) when subjected to high levels of simulated atmospheric CO2.

In the cases of reefs and coccoliths, one answer is that the relatively minor increase in atmospheric CO2 over the last couple of hundred years has enhanced photosynthesis more than it has hampered marine carbonate geochemistry. However, the otoliths (fish ear bones) shouldn’t really benefit from enhanced photo-respiration. The fact that otoliths grew rather than shrank when subjected to high CO2 levels is a pretty good indication that the primary theory of ocean acidification has been tested and falsified.

Some may say, “Hey! That’s just one reef! Flinders reef is an outlier!” Fair point. So let’s look at a larger data set.

The January 2, 2009 issue of Science featured a paper, Declining Coral Calcification on the Great Barrier Reef, by Glenn De’ath, Janice M. Lough, Katharina E. Fabricius. This is from the abstract:

Reef-building corals are under increasing physiological stress from a changing climate and ocean absorption of increasing atmospheric carbon dioxide. We investigated 328 colonies of massive Porites corals from 69 reefs of the Great Barrier Reef (GBR) in Australia. Their skeletal records show that throughout the GBR, calcification has declined by 14.2% since 1990, predominantly because extension (linear growth) has declined by 13.3%. The data suggest that such a severe and sudden decline in calcification is unprecedented in at least the past 400 years.

I have not purchased the article and my free membership to the AAAS does not grant access to it; but I did find the database that appears to go with De’ath et al., 2009 in the NOAA Paleoclimatology library: LINK

Well… I downloaded the data to Excel and I calculated an annual average calcification rate for the 59 cores that are represented in the data set. This is what I came up with…

Fig. 9) Great Barrier Reef Calcification Rate (after De’ath et al., 2009)

It is “cherry-picking” of the highest order, if that last data point really is the basis of this claim: “Their skeletal records show that throughout the GBR, calcification has declined by 14.2% since 1990, predominantly because extension (linear growth) has declined by 13.3%. The data suggest that such a severe and sudden decline in calcification is unprecedented in at least the past 400 years.”

Over the last 400+ years the Earth’s climate has warmed ~0.6°, mean sea level has risen by about 9 inches and the atmosphere has become about 100 ppmv more enriched with CO2; and the Great Barrier Reef has responded by steadily growing faster.

1. Rising Temperature: The Great Barrier Reef likes the warm-up since the depths of the Little Ice Age…

Fig. 10) GBR calcification rate and temperature.

2. Rising Sea Level: The Great Barrier Reef likes the slight sea level rise since the depths of the Little Ice Age…

Fig. 11) GBR calcification rate and sea level.

3. Rising Atmospheric CO2 Concentrations: The Great Barrier Reef likes the increase in CO2 levels since the depths of the Little Ice Age…

Fig. 12a) GBR calcification rate and atmsopheric CO2.

Fig. 12b) GBR calcification rate and atmospheric CO2 cross plot.

Does the geological record support the oceanic acidification hypothesis?

Average annual pH reconstructions and measurements from various Pacific Ocean locations:

60 million to 40 million years ago: 7.42 to 8.04 (Pearson et al., 2000)

23 million to 85,000 years ago: 8.04 to 8.31 (Pearson et al., 2000)

6,000 years ago to present: 7.91 to 8.28 (Liu et al., 2009)

1708 AD to 1988 AD: 7.91 to 8.17 (Pelejero et al., 2005)

2000 AD to 2007 AD: 8.10 to 8.40 (Wootton et al., 2008)

The low pH levels from 60 mya to 40 mya include the infamous Paleocene-Eocene Thermal Maximum (PETM). E ven then, the oceans did not actually “acidify;” the lowest pH was 7.42 (still basic).

The Paleocene-Eocene Thermal Maximum (PETM) was a period of significant global warming approximately 55 million years ago and has often been cited as a geological analogy for the modern threat of ocean acidification. There is solid evidence that the Lysocline “shoaled” or became shallower for a brief period of time during the PETM. Several cores obtained from the Walvis Ridge area in the South Atlantic during Ocean Drilling Program (ODP) Leg 208 contained a layer of red clay at the P-E boundary in the middle of an extensive carbonate ooze section (Zachos et al., 2005). This certainly indicates a disruption of the lysocline during the PETM; but it doesn’t prove that it was ocean acidification.

The PETM was a period of extensive submarine and subaerial volcanic activity (Storey et al., 2007) and pedogenic carbonate reconstructions do support the possibility that seafloor methane hydrates released by that volcanic activity may have sharply increased oceanic CO2 saturation.

But… The terrigenous paleobotanical evidence does not support elevated atmospheric CO2 levels during the PETM (Royer et al., 2001). The SI data indicate CO2 levels in North America to have been between 300 and 400 ppmv during the PETM.

So, the PETM may have been an example of ocean acidification… But there is NO evidence that it was caused by a sharp increase in atmospheric CO2 levels.

The range of oceanic pH variation over the last 200 years is well within the natural variation range over the last 7,000 years.

Fig. 13) 7,000 years of pH and atmospheric CO2

Some have asserted that there is no geological precedent; claiming atmospheric CO2 concentrations have risen faster in the last 150 years than at any time in recent geological history. Ice core-derived CO2 data certainly do indicate that CO2 has not risen above ~310 ppmv at any point in the last 600,000 years and that it varies little at the decade or century scale. However, there are other methods for estimating past atmospheric CO2 concentrations.

Plants “breathe” CO2 through microscopic epidermal pores called stomata. The density of plant stomata varies inversely with the atmospheric partial pressure of CO2. Several recent studies of plant stomata from living, herbarium and fossil samples of plant tissue have shown that atmospheric CO2 fluctuations comparable to that seen in the industrial era have been fairly common throughout the Holocene and Recent times.

Plant stomata measurements reveal large variations in atmospheric CO2 concentrations over the tast 2,000 years that are not apparent in ice core data (Kouwenberg, 2004)…

Fig. 14) Kouwenberg (2004) Figure 5.4: Reconstruction of paleo-atmospheric CO2 levels when stomatal frequency of fossil needles is converted to CO2 mixing ratios using the relation between CO2 and TSDL as quantified in the training set. Black line represents a 3 point running average based on 3–5 needles per depth. Grey area indicates the RMSE in the calibration. White diamonds are data measured in the Taylor Dome ice core (Indermühle et al., 1999); white squares CO2 measurements from the Law Dome ice-core (Etheridge et al., 1996). Inset: Training set of TSDL response of Tsuga heterophylla needles from the Pacific Northwest region to CO2 changes over the past century (Chapter 4).

Century-scale fluctuations in atmospheric CO2 concentrations have also been demonstrated in the early Holocene (Wagner et al., 1999)…

(Wagner et al., 1999)Fig. 1. (A) Mean SI values (±1 ) for B. pendula and B. pubescens from the early Holocene part of the Borchert section (Netherlands; 52.23°N, 7.00°E) and reconstructed CO2 concentrations. The scale of the section is in centimeters. Three lithological (Lith.) units can be recognized (18): a basal gyttja (=), succeeded by Drepanocladus peat (//), which is subsequently overlain by Sphagnum peat ( ). Six conventional 14C dates (in years before the present) are available (indicated by circled numbers): 1, 10,070 ± 90; 2, 9930 ± 45; 3, 9685 ± 90; 4, 9770 ± 90; 5, 9730 ± 50; and 6, 9380 ± 80. Summary pollen diagram includes arboreal pollen (white area) with Pinus ( ) and with Betula ( ) and nonarboreal pollen with Gramineae ( ) and with Cyperaceae, upland herbs, and Ericales ( ). Regional climatic phases after (18): YD, Younger Dryas; Fr., Friesland phase; Ra., Rammelbeek phase; and LP, Late Preboreal. For analytical method, see (13). Quantification of CO2 concentrations according to the rate of historical CO2 responsiveness of European tree birches (Fig. 2). P indicates the reconstructed position of the Preboreal Oscillation. — Fig. 15) (Wagner et al., 1999) Fig. 1. (A) Mean SI values (±1 ) for B. pendula and B. pubescens from the early Holocene part of the Borchert section (Netherlands; 52.23°N, 7.00°E) and reconstructed CO2 concentrations. The scale of the section is in centimeters. Three lithological (Lith.) units can be recognized (18): a basal gyttja (=), succeeded by Drepanocladus peat (//), which is subsequently overlain by Sphagnum peat ( ). Six conventional 14C dates (in years before the present) are available (indicated by circled numbers): 1, 10,070 ± 90; 2, 9930 ± 45; 3, 9685 ± 90; 4, 9770 ± 90; 5, 9730 ± 50; and 6, 9380 ± 80. Summary pollen diagram includes arboreal pollen (white area) with Pinus ( ) and with Betula ( ) and nonarboreal pollen with Gramineae ( ) and with Cyperaceae, upland herbs, and Ericales ( ). Regional climatic phases after (18): YD, Younger Dryas; Fr., Friesland phase; Ra., Rammelbeek phase; and LP, Late Preboreal. For analytical method, see (13). Quantification of CO2 concentrations according to the rate of historical CO2 responsiveness of European tree birches (Fig. 2). P indicates the reconstructed position of the Preboreal Oscillation.

If the plant stomata data are correct, the increase in atmospheric CO2 that has occurred over the last 150 years is not anomalous. Past CO2 increases of similar magnitude and rate have not caused ocean acidification. In fact, marine calcifers would probably take 3,000 ppmv CO2 in stride, just by making more limestone… Kind of like they did during the Cretaceous…

Fig. 16) East Texas Stratigraphic Column and Creatceous CO2

Once again, we have an environmental catastrophe that is entirely supported by predictive computer models and totally unsupported by correlative and empirical scientific data. We can safely pitch ocean acidification into the dustbin of junk science.

References

Reef data from:

De’ath, G., J.M. Lough, and K.E. Fabricius. 2009. Declining coral calcification on the Great Barrier Reef. Science, Vol. 323, pp. 116 – 119, 2 January 2009.

Lough, J.M. and D.J. Barnes, 2000. Environmental controls on growth of the massive coral Porites. Journal of Experimental Marine Biology and Ecology, 245: 225-243.

Lough, J.M. and D.J. Barnes, 1997. Several centuries of variation in skeletal extension, density and calcification in massive Porites colonies from the Great Barrier Reef: a proxy for seawater temperature and a background of variability against which to identify unnatural change. Journal of Experimental Marine Biology and Ecology, 211: 29-67.

Chalker, B.E. and D.J. Barnes, 1990.

Gamma densitometry for the measurement of coral skeletal density. Coral Reefs, 4: 95-100.

Temperature data from:

Moberg, A., D.M. Sonechkin, K. Holmgren, N.M. Datsenko and W. Karlén. 2005. Highly variable Northern Hemisphere temperatures reconstructed from low-and high-resolution proxy data. Nature, Vol. 433, No. 7026, pp. 613-617, 10 February 2005.

University of Alabama, Hunstville

Sea Level data from:

“Recent global sea level acceleration started over 200 years ago?”, Jevrejeva, S., J. C. Moore, A. Grinsted, and P. L. Woodworth (2008), Geophys. Res. Lett., 35, L08715, doi:10.1029/2008GL033611.

CO2 data from:

D.M. Etheridge, L.P. Steele, R.L. Langenfelds, R.J. Francey, J.-M. Barnola and V.I. Morgan. 1998. Historical CO2 records from the Law Dome DE08, DE08-2, and DSS ice cores. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A.

Dr. Pieter Tans, NOAA/ESRL (www.esrl.noaa.gov/gmd/ccgg/trends)

Other references:

Royer, et al., 2001. Paleobotanical Evidence for Near Present-Day Levels of Atmospheric CO2 During Part of the Tertiary. Science 22 June 2001: 2310-2313. DOI:10.112

Caldeira, K. and Wickett, M.E. 2003. Anthropogenic carbon and ocean pH. Nature 425: 365.

Orr, J.C., et al., 2005. Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature 437, 681-686 (29 September 2005) | doi:10.1038

Pelejero, C., Calvo, E., McCulloch, M.T., Marshall, J.F., Gagan, M.K., Lough, J.M. and Opdyke, B.N. 2005.

Preindustrial to modern interdecadal variability in coral reef pH. Science 309: 2204-2207.

Zachos, et al., 2005. Rapid Acidification of the Ocean During the Paleocene-Eocene Thermal Maximum . Science 10 June 2005: 1611-1615. DOI:10.1126

Storey, et al., 2007. Paleocene-Eocene Thermal Maximum and the Opening of the Northeast Atlantic. Science 27 April 2007: 587-589. DOI:10.1126

Late 20th-Century Acceleration in the Growth of Greek Fir Trees. Volume 11, Number 49: 3 December 2008, CO2 Science

Iglesias-Rodriguez, et al., 2008. Phytoplankton Calcification in a High-CO2 World. Science 18 April 2008: 336-340 DOI:10.1126

Koutavas, A. 2008. Late 20th century growth acceleration in greek firs (Aibes cephalonica) from Cephalonia Island, Greece: A CO2 fertilization effect? Dendrochronologia 26: 13-19.

The Ocean Acidification Fiction. Volume 12, Number 22: 3 June 2009, CO2 Science

Checkley, et al., 2009. Elevated CO2 Enhances Otolith Growth in Young Fish. Science 26 June 2009: 1683. DOI:10.1126

Liu, Y., Liu, W., Peng, Z., Xiao, Y., Wei, G., Sun, W., He, J. Liu, G. and Chou, C.-L. 2009. Instability of seawater pH in the South China Sea during the mid-late Holocene: Evidence from boron isotopic composition of corals. Geochimica et Cosmochimica Acta 73: 1264-1272.

Ries, J.B., A.L. Cohen, D.C. McCorkle. Marine calcifiers exhibit mixed responses to CO2-induced ocean acidification. Geology 2009 37: 1131-1134.

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David Middleton

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January 14, 2011 2:55 pm

There seems to be a great deal of confusion as to what the data presented in Ries et al., 2009 demonstrate.
The calcification rates of 16/18 species did not drop below the low end of the control range until the simulated CO2 level exceeded 3X pre-industrial levels. The calcification rates of soft clams and oysters dropped below the control range at ~500 ppm and 600 ppm respectively. The “control range” simulated current conditions.
Ries Fig 1 w/ Ranges
None of the species experienced dissolution below 1,000 ppm CO2.
Ries Fig 1 w/Dissolution Thresholds

kadaka (KD Knoebel)

January 14, 2011 3:19 pm

rushmike said on January 14, 2011 at 12:09 pm:

Kadaka,
like so many on here you counter a discussion with emotive fear mongering with no sources to back up your points.
Please try and counter scientific points with…err…science?
Thankyou.

Because, at least superficially, the scientific part of the discussion has delved far deeper than I can reach. Others more well versed than I are handling that part quite ably. Not that it matters much, “From Peru” appears resistant to scientific research that counters the (C)AGW teachings he has absorbed. I said “superficially” as it has become less of a discussion and more of an “intellectual” food fight with the throwing of figures and papers, the “science” as “From Peru” is presenting it just pretties it up.
But the “emotive fear mongering” that has been raised, dressed up (although it has been denied) in moral justification as the rectifying of a current injustice, which is somehow even more just as a partial redress of past unresolved grievances, is something I can address. Even under the cloak of scientific discussion, this is clearly the core of the matter.
Pardon me for not noticing where I have engaged in “emotive fear mongering.” To my reckoning I have been pointing out what I stated before, this is moot. Throw up as much evidence as you can dig up about The Terrible Tragic Catastrophes To Come if we don’t soon reduce carbon (dioxide) emissions. The stated problem is Global Warming. The stated solution is a reduction in Global CO2 emissions. This will need a Global binding agreement.
The solution must come soon, since as “From Peru” has stated we are already tripping over tipping points. The “developed nations” cannot reduce their emissions enough to offset the coming increases from “developing nations” including China and India, even a complete immediate shutdown would be only a temporary respite. Check out this list from the Union of Concerned Scientists with 2008 figures. China and India, the #1 and #4 emitters, release 8,029 million metric tons of CO2 combined. The US and Russia, #2 and #3, release a total of only 7,562 million metric tons. Look at the per capita figures. Those “developing countries” are making up the difference with CO2-emitting energy sources as they are relatively cheap and easy to obtain. Crank the numbers, the emissions will skyrocket just to get up to the per capita rate of France, which famously is awash in zero-emission nuclear power-generated electricity.
Everyone must act, all countries need to join together. There can be no exceptions, no further emission increases. Already the global emissions are too high. New Peer-Reviewed Published Research says we are already committed to many centuries of warming from the emissions already released, even with zero new emissions, which agrees with info I had previously gleaned about the IPCC reports. There has to be an immediate global cap on total emissions, followed by a global lowering of total emissions.
As it stands, we cannot get global agreement on even that much. Thus further discussions about who should be allowed to develop and emit more while someone else must emit less, are meaningless. “From Peru” is arguing that the “developed” nations should basically buy a low-emission economy for the “developing” nations. Well, they don’t have that much wealth on hand, and even if they did it’d take too long to install such infrastructure with everything else needed for it (infrastructure improvements like road paving, etc). We don’t have the equipment and materials needed just lying around in warehouses either. It’ll take several decades to make them, with tremendous additional releases of CO2 involved in the manufacture and deployment. Meanwhile the (C)AGW proponents keep shouting how we must act now.
Given the timeframe, we can’t get there from here.
Climate Science™ says the solution must come soon. Climate Science™ says it may already be too late. I have noted, given the current economic and political climates, that the solution will not come in time. I have engaged in no more fear mongering than a doctor who informs a patient his cancer is terminal without the prompt discovery of a cure, and none are expected let alone soon enough.

From Peru

January 14, 2011 4:20 pm

Smokey says:
January 14, 2011 at 1:51 pm
“The planet itself falsifies the CAGW conjecture by not cooperating with climate model predictions. Natural climate variability – the null hypothesis – fully explains observations. There is no need to summon a “carbon” demon to explain natural climate fluctuations”
In what planet do you live, or to better say, in from what parallel universe do you come from?
In this universe, basic physical chemistry shows that CO2 is a greenhouse gas.
Contrary to what you say, observations of past and present climate only make sense if we consider the effect of Greenhouse gases, mainly CO2 and CH4.
If you want to exclude CO2 and CH4 as an explanation for climate, I have a series of questions to you:
What caused the Paleocene-Eocene Thermal Maximum (PETM), if not a massive liberation of CO2 and CH4?
Why in periods of Earth History with high CO2 the planet was ice-free (like the Cretaceous and the Paleocene-Eocene), while in periods with low CO2 (like the Quaternary Period- the last 2 million years) we have a series of ice ages?
What caused the global glaciations (the so-called “snowball earth” periods, when ice reached the equator) if not severe drop in CO2 and CH4, and what ended them if not the accumulation of volcanic CO2 in the millions of years that lasted the global glaciations?
Why CO2 and temperature are so intimately correlated across the glacial-interglacial stages of the Quaternary Period, as shown in the ice cores?
“What Mr Peru doesn’t get is the scientific method, which states that those proposing a hypothesis such as CO2=CAGW have the burden of showing that their alternate hypothesis explains observations better than the long-accepted null hypothesis.”
That burden is provided by the thousands of studies showing the deep correlation between CO2 and warming. Your non-CO2 climate variability “null hipothesis” completely fails to explain the climate of the entire history of Earth (some 4500 million years)
“The null hypothesis has never been falsified, and Occam’s Razor says that we don’t need to add an extraneous variable like CO2 to explain natural variability; the simplest explanation is the best.”
If your “null hypothesis” is so good, and most climate scientists, geologists, physicists, are wrong, then explain without using greenhouse gases the warming and cooling episodes of Earth. For example, the episodes I listed above.

From Peru

January 14, 2011 4:45 pm

kadaka (KD Knoebel) says:
“From Peru” is arguing that the “developed” nations should basically buy a low-emission economy for the “developing” nations.”
Let’s make a clarification. With “developing, 3rd world countries” I intend poor nations that are NOT industrial/economic superpowers. That is, most nations in Latin America, Africa and parts of Asia.
China does not precisely fit in this category. It is an emerging industrial superpower, now the biggest polluter on Earth. It has an oppressive regime, and any internal opposition is crushed. Labor conditions for the workers are very poor.
India is a mixed state: parts of it are emerging as a major industrial power, while in others people are starving to death. It is difficult to classify: in part is like China, in part like sub-Saharan Africa. But the industrialized part of India make it to be in a different group than poor nations like mine.
So we have the 1st world, countries like Canada, the USA, Europe, Japan and Russia.
We have the 3rd world, countries in Latin America, Africa and parts of Asia.
And we have something like an intermediate, “2nd World” of emerging industrial superpowers like China and India.
When I talk about aid to developing nations to develop clean and renewable souces of energy, I was talking of the above sensu-stricto 3rd World countries, not the “2nd World” emerging superpowers like China and India, that have more than enough resources to develop the clean energy by themselves.
Now I hope to have clarified my point.
As a final note, INDIA formely one of more active opponents of domestic carbon regulations, HAS NOW ANNOUNCED A CARBON TAX and great improvements on energy efficiency:
http://www.indiaenvironmentportal.org.in/files/India%20Taking%20on%20Climate%20Change.pdf
Quoting the document:
“India has announced a levy – a clean energy cess – on coal, at the rate of Rs. 50 (~USD 1) per ton, which will apply to both domestically produced and imported coal.
• This money will go into a National Clean Energy Fund that will be used for funding research, innovative projects in clean energy technologies, and environmental remedial programmes.
• The expected earnings from this cess is around USD 500 million for the financial year 2010-11.
India’s cabinet approved the National Mission on Enhanced Energy Efficiency (NMEEE) on 24th June, 2010. The Mission includes several new initiatives – the most important being the Perform, Achieve and Trade (PAT) Mechanism, which will cover facilities that account for more than 50% of the fossil fuel used in India, and help reduce CO2 emissions by 25 million tons per year by 2014-15.”
So India, with its own resources has began its climate action. European nations are also implementing carbon taxes in addition to the cap and trade scheme.
When will the United States and China follow?
We in Peru await the decision of the G-2 (USA and China)…

dbstealey

January 14, 2011 6:05 pm

For the edification of our true believer from Peru, I have never stated that CO2 has no effect. My position has always been that the climate’s sensitivity to CO2 is <1°C per doubling from pre-industrial levels, meaning that the resulting warming is inconsequential.
Further, a 1° warmer planet is a net benefit to the biosphere, as is the increased CO2. A warmer world will open up millions of acres to food production at higher latitudes, and added CO2 will result in more ag productivity. Win-win. And as Kadaka notes, nothing can be done to stop it. Demonizing “carbon” is simply a UN-led scam to force people to open their wallets.
Next, the climate null hypothesis refers to the Holocene, and not to the past several billion years as Peru mistakenly assumes. I’ve noted this too many times to count. I suggest once again that Mr Peru should start reading the WUWT archives and comments, and get up to speed on the global warming subject. Linking to papers based on models has little worth. Models are not evidence, they are conjecture. Raw, unadjusted data is a good example of empirical evidence.
All of Peru’s questions are discussed in the archives, and it would be a waste of time trying to provide an explanation to an eco-zealot who believes that during glaciations “ice reached the equator.” It never did.
Prof Richard Lindzen states that there is ample evidence that the equator has remained within ±1°C for more than a billion years. Dr Lindzen also stated: “If one assumes all warming over the past century is due to anthropogenic greenhouse forcing, then the derived sensitivity of the climate to a doubling of CO2 is less than 1°C.” I think I’ll trust Prof Lindzen over climate alarmists.
The null hypothesis compares today’s climate with the temperature parameters during the Holocene, and we are about in the middle of the range, well away from the extreme highs or lows. Nothing unusual is happening, despite the fervent hopes of the Climate Cult of Doom.
Dr Roy Spencer, a well respected climatologist, describes the situation this way: “No one has falsified the hypothesis that the observed temperature changes are a consequence of natural variability.” The burden is on the promoters of the CAGW conjecture to falsify the null hypothesis. They have universally failed to do so. That is why Kevin Trenberth is so desperate to do away with the null hypothesis and the scientific method. They reduce his CAGW conjecture to little more than impotent arm-waving.
Finally, it wouldn’t hurt to review the charts again in David Middleton’s excellent article, which clearly show that CO2 is a harmless and beneficial trace gas – not the evil “carbon” demon that some make it out to be.

kadaka (KD Knoebel)

January 15, 2011 4:15 pm

From ” From Peru” on January 14, 2011 at 4:45 pm :

As a final note, INDIA formely one of more active opponents of domestic carbon regulations, HAS NOW ANNOUNCED A CARBON TAX and great improvements on energy efficiency:
http://www.indiaenvironmentportal.org.in/files/India%20Taking%20on%20Climate%20Change.pdf

Ah dang, and here I was hoping you’d actually learned something about real-world economics and politics.

• This money will go into a National Clean Energy Fund that will be used for funding research, innovative projects in clean energy technologies, and environmental remedial programmes.
• The expected earnings from this cess is around USD 500 million for the financial year 2010-11.

Once government gets their hands on money, they tend to spend it wherever they want. This has been repeatedly noted in governments worldwide throughout history. Plus this invites cronyism, the money will tend to get distributed to the politically-influential rather than to those projects that truly have the best merits. And, “Big Oil” companies like BP have been touting their Green credentials and “clean energy” developments for quite some time, as well as big manufacturers like GE. Therefore if the money is going to research and development of clean energy, very large chunks shall be going to profitable large corporations that can get by without it.
You should have read the Bloomberg Businessweek write-up:

Coal, used to fire more than half of India’s electricity generation…

Thus it targets those without viable alternatives, since electricity is centrally generated.

Chief executive officers including Rex Tillerson of Exxon Mobil Corp. and Paolo Scaroni of Italy’s Eni SpA have advocated a flat tax over carbon-trading systems like the European Union’s, saying a levy allows companies to plan for a simpler, more stable cost of pollution.

Thus the “big polluters” got what they wanted.
And it’s not even a real “carbon tax” as it’s on coal:

The coal tax was announced on Feb. 26 along with a decision to impose duties on crude and oil products that were withdrawn after record oil prices and the global recession.

Thus it’s only on the “low hanging fruit,” easily-demonized cheap and “dirty” coal.
Which leads to the important part (bold added):

India has set a voluntary target to cut its carbon intensity, or the amount of carbon dioxide released per unit of gross domestic product, by as much as 25 percent from 2005 levels by 2020.

It’s not an internationally-binding goal. They can back out of it if they want. They couldn’t even tax oil. If times get tough and opposition rises, that voluntary target and even the coal tax can go away.
Does that sound like a solid commitment to help avert Immediate Impending Global Doom?

So India, with its own resources has began its climate action.

Much more like raising taxes under the cover of this “noble cause” as we expect politicians to do.

European nations are also implementing carbon taxes in addition to the cap and trade scheme.

As noted, “Big Pollution” prefers carbon taxes anyway. And I think you might ultimately be in error. The European ETS scheme is seriously flawed, others want to see it gone, thus “in addition” will likely be transitory as that scheme will get scrapped.
Quoting the write-up from here, about this definitive report from the esteemed Friends of the Earth Europe:

The EU emissions trading system: failing to deliver
The Emissions Trading System (EU-ETS) is Europe’s principal policy mechanism for reducing emissions in the power generation and industrial sectors. Analysis by Friends of the Earth Europe shows that the EU-ETS is not delivering the CO2 cuts required by science, historical responsibility and sound financial practices. Over-reliance on carbon markets is also obstructing the use of other more effective policy measures such as regulation, investments, and taxation.

As the report says (pg 2):

What Friends of the Earth Europe calls for:
• End the reliance on the EU-ETS. Priority should be given to other policy options, such as regulation, taxation and subsidies which are able to deliver the scale and speed of emissions reductions that are necessary to avoid catastrophic climate change.
• The most dangerous loopholes in the EU-ETS must be removed by ending overseas offsets, stopping free permits to polluters, introducing a much tighter cap, and preventing the use of banked permits from earlier phases of the EU-ETS scheme. Auctioning money must not be used to subsidise fossil fuels, such as state aid for new coal power plants, or false solutions such as nuclear power or CCS.
• The EU-ETS must not be expanded by either linking with schemes outside of the EU or instituting sectoral trading with developing countries. Carbon markets cannot be a replacement for mandatory targets under a binding international climate agreement, and adequate and appropriate public funding for climate finance in developing countries.
• The EU-ETS should not be used as an argument to prevent other policies such as setting binding energy efficiency targets or to prevent any other measures at national level such as national climate laws to tackle industry or industry sector emissions.

Fascinating reading.
Thus India has decided to raise some tax money and can back out of their target if they want. The EU-ETS is a disaster. And none of that is anything like the international binding agreement with hard absolute reductions in Global CO2 emissions that will be absolutely required to avert the Immediate Impending Global Doom.
Thus effectively, India and the EU have done basically nothing to solve the problem. And Global CO2 emissions continue to rise.

When will the United States and China follow?

Trust me, they have.

Willis Eschenbach

Editor

January 15, 2011 11:07 pm

Could I ask Kadaka or From Peru, or any of you who keep going on about a mythical thing called a “tipping point”, for a definition of a “tipping point” and also an example of a tipping point showing what tipped and when?
People keep claiming that some action of ours or another is putting us closer to some dread “tipping point”. But since they can’t tell me what the tipping point might be, and they don’t know where it might be, it is equally probable that our action has moved us away from a tipping point.
Me, I always imaging the dread “tipping point” as looking like one of the dragons on those old maps that say “Here There Be Dragons” … and as far as I can tell, tipping points are just as hard to find and photograph as real dragons.
However, tipping points do serve a very real purpose, the same purpose as the dragons on the old maps, to identify the parts of the world that are only imagined.
Because when someone starts warning us about approaching tipping points, the odds are very high that they have wandered off of the map of reality and are dealing with imagination, it’s a reliable sign … and if a “scientific” paper talks about tipping points, you can be pretty sure that they have left the realm of Science entirely.
w.

kadaka (KD Knoebel)

January 16, 2011 1:37 am

From Willis Eschenbach on January 15, 2011 at 11:07 pm:

Could I ask Kadaka or From Peru, or any of you who keep going on about a mythical thing called a “tipping point”, for a definition of a “tipping point” and also an example of a tipping point showing what tipped and when?

Hell if I know, Mr. Eschenbach. These people just keep shoveling this stuff off the back of that wagon they pull around, and I just keep tossing it back on. Confounds them for some reason. Maybe someday it’ll amount to something, but in the meanwhile the smell is… Let’s just say “honey” is one heck of a euphemism for what that wagon’s carrying.
☺

From Peru

January 16, 2011 1:20 pm

Willis Eschenbach says:
January 15, 2011 at 11:07 pm
“Could I ask Kadaka or From Peru, or any of you who keep going on about a mythical thing called a “tipping point”, for a definition of a “tipping point” and also an example of a tipping point showing what tipped and when?”
Tipping point is the point at which an object is displaced from a state of stable equilibrium into a new equilibrium state qualitatively dissimilar from the first
Here is a cartoon:
http://munchweb.com/the-tipping-point
A “tipping point” is an event that characterises certain non-linear systems. Basically the non-linear systems that present tipping points are characterized initially by a linear and gradual, somethimes even small, response to an external influence. This response is a mix of the direct response to the external influence and a (positive) feedback that occurs in the system (for example, Arctic warming melts sea ice, exposing dark, sunlight absorbing seawater that causes more warming and then more melt). The feedback + direct response is stable until the intensity of such external infulence (in climate, this influence is the radiative forcing) reaches a point that the system suffers an abrupt change and/or the process initially caused only by the external influence proceeds, thanks to the feedback, even if the external influence stops.
The are several possible “tipping points” in the climate system:
-The melting of Arctic sea ice: after a certain amount of sea ice has disappeared, the warming caused by the melt (i.e. the ice-albedo feedback) is so big that melt will continue even if no further global warming occurs, until all the ice is gone.
-The melting of Ice sheets: after the ice shelves and glacial terminations of the glaciers has melted more than a treshold, the speed of ice loss (in particular, the speed of ice flow) is so big that (even if warming stops) the melting is unstoppable and will continue until all the ice sheet is gone.
-desertification of rainforests: after continued drought and/or deforestation had reduced the area of forest more than a certain treshold such that the reduction in precipitation as a consecuence of reduced vegetation is big enough, the rainforest system is unstable and will change until a new stable configuration is reached, such as savanna or desert ( this in particular would be a catastrophe for Peru and its neighbours).
About ocean acidification the tipping point is not in the response of the ocean chemistry itself to increasing pCO2 but in the response of marine organisms to reduced calcium carbonate (in particular aragonite): after the CaCO3 saturation state is lower than a certain threshold, the system shift from calcification to dissolution. This can drive organisms that depends on their shells for survival to extinction.
This change had happened ALREADY in the Arctic Ocean for most aragonite calcifiers, because two years ago (in 2008) the aragonite saturation state dropped below unity. See here:
“Aragonite Undersaturation in the Arctic Ocean- Effects of Ocean Acidification and Sea Ice Melt”
http://www.whoi.edu/beaufortgyre/pdfs/yamamoto-kawai_aragonite_science2009.pdf
Now the Arctic is CORROSIVE to any material made from aragonite. Any shell made of aragonite will dissolve. Organisms that have adapted to aragonite oversation for millions of years are now in big trouble. Maybe some organism with exceptionally high calcification rates (rates bigger than the current rate of shell dissolution) can survive, but all other organisms face extinction.

From Peru

January 16, 2011 2:08 pm

kadaka (KD Knoebel) says:
January 15, 2011 at 4:15 pm
“Ah dang, and here I was hoping you’d actually learned something about real-world economics and politics.
(…)
Once government gets their hands on money, they tend to spend it wherever they want.”
In this you are absolutely right. But getting the money from polluters (increasing the cost of dity energy), is a step in the right direction by itself, because it increases the competitiveness of sustainable energy sources.
“And it’s not even a real “carbon tax” as it’s on coal”
Coal is the Nº1 source of carbon dioxide, and unlike petroleum (that will peak in about 10 or 20 years, if it hasn’t already) the reserves of coal are huge, and will not be depleted in centuries. So putting aprice on coal is a core climate regulation. Petroleum prices will skyrocket by themselves (only think that we are just coming out on the worst recesion since the 1930s and oil is already above 90$/barrel).
“Which leads to the important part (bold added):
India has set a voluntary target to cut its carbon intensity, or the amount of carbon dioxide released per unit of gross domestic product, by as much as 25 percent from 2005 levels by 2020.
It’s not an internationally-binding goal. They can back out of it if they want. They couldn’t even tax oil. If times get tough and opposition rises, that voluntary target and even the coal tax can go away.
Does that sound like a solid commitment to help avert Immediate Impending Global Doom?””
It is clearly not an enough strong action. But is a step in the right direction. Remember that the Indian Government trashed a UN report about Soth Asia air pollution (the so-called “Atmosphric Brown Cloud”) just two years ago!
“‘Brown clouds’ stir Asian conspiracy storm”
http://www.atimes.com/atimes/South_Asia/JK25Df01.html
So this action against coal burning pollution is really an U-turn from the blame game againt the developed nations of two years ago. I hope they do not undo this important step in the future. That will be very sad for a nation severely menaced by climate change.
“As noted, “Big Pollution” prefers carbon taxes anyway. And I think you might ultimately be in error. The European ETS scheme is seriously flawed, others want to see it gone, thus “in addition” will likely be transitory as that scheme will get scrapped.”
Yes, the cap and trade shemes probably are serously flawed (I don’t know the economics very well) and the alternative (carbon taxes) will be prefered by “Big Pollution” if they are small and constant.
Any decent carbon tax must grow with time (until the price of dirty energy like coal is bigger than renewable energy), and the money obtained must be invested in clean energy development, that in turn must be accesible to everyone (that is, not restricted by patent rights) and also invested in clean energy subsidies.

kadaka (KD Knoebel)

January 16, 2011 3:26 pm

From ” From Peru” on January 16, 2011 at 1:20 pm:

This change had happened ALREADY in the Arctic Ocean for most aragonite calcifiers, because two years ago (in 2008) the aragonite saturation state dropped below unity. See here:
“Aragonite Undersaturation in the Arctic Ocean- Effects of Ocean Acidification and Sea Ice Melt”
http://www.whoi.edu/beaufortgyre/pdfs/yamamoto-kawai_aragonite_science2009.pdf
Now the Arctic is CORROSIVE to any material made from aragonite. Any shell made of aragonite will dissolve. Organisms that have adapted to aragonite oversation for millions of years are now in big trouble. Maybe some organism with exceptionally high calcification rates (rates bigger than the current rate of shell dissolution) can survive, but all other organisms face extinction.

*sigh*
Aragonite sea (Wikipedia), bold added in third paragraph:

An aragonite sea contains aragonite and high-magnesium calcite as the primary inorganic carbonate precipitates. Therefore, the chemical conditions of the seawater must be notably high in magnesium content for an aragonite sea to form. This is in contrast to a calcite sea in which low-magnesium calcite is the primary inorganic marine calcium carbonate precipitate.
The Early Paleozoic and the Middle to Late Mesozoic oceans were predominantly calcite seas, whereas the Middle Paleozoic through the Early Mesozoic and the Cenozoic (including today) are characterized by aragonite seas.[1][2][3][4][5]
Aragonite seas form due to several factors, the most obvious of these is a high magnesium content. However, the sea level and the temperature of the surrounding system also determine whether an aragonite sea will form.[6] Aragonite is the predominant mineral in warm, shallow marine environments. Calcite on the other hand, is the dominant mineral in cool marine water environments. This trend has been observed by looking at the chemistry of carbonates, dating them and analyzing the conditions under which they were formed. (…)

Citation #6, Adabi 2004, has the abstract available here. To get through the paywall and acquire the full article will take US$34.
Looks to me that the Arctic Ocean “flipping the switch” to favoring calcite is consistent with a cooling Arctic Ocean. Given how cold it is to begin with, that it favored aragonite seems slightly odd, might be related to the magnesium content and inflows from the Atlantic.
A snippet from the Wikipedia Arctic Ocean entry:

The Arctic Ocean’s temperature and salinity vary seasonally as the ice cover melts and freezes;[4] its salinity is the lowest on average of the five major oceans, due to low evaporation, heavy freshwater inflow from rivers and streams, and limited connection and outflow to surrounding oceanic waters with higher salinities.

Thus the Arctic Ocean had low salinity relative to those other oceans thus lower magnesium content, and was cold anyway. Thus the changeover from favoring aragonite to favoring calcite doesn’t look surprising. Before you start blaming “Ocean Acidification!” , research needs to be done as to what the “tipping points” are for the calcite-aragonite switch, and how close the Arctic Ocean has been to them. Data showing the magnesium content over a few decades would be helpful.

From Peru

January 17, 2011 5:31 pm

kadaka (KD Knoebel):
In the reference 6) you linked, I quote from the abstract the following:
“These results are not in agreement with the concept of a “calcite sea” during the Ordovician and the Upper Jurassic periods. Very recently, Westphal and Munnecke (2003) showed that in spite of the tendency of abiotic precipitates (Sandberg 1983) and skeletal mineralogy (Stanley and Hardie 1999) to follow the general trend of calcite seas and aragonite seas, organisms with calcite and aragonite mineralogy coexisted throughout the Phanerozoic.”
Here some organisms calcificate aragonite in “calcite seas” and calcite in “aragonite seas”.
The terms “aragonite sea” and “calcite sea” are a bit misleading. In an “aragonite sea” what precipitates is aragonite + Mg-calcite, while in a “calcite sea” low Mg-calcite dominates, but there is still biological aragonite precipitation . An example is here:
“Aragonite production in calcite seas: effect of seawater Mg/Ca ratio on the calcification and growth of the calcareous alga Penicillus capitatus”
http://www.unc.edu/~jries/PaleobiologyRies.pdf
By Ries, the author of the study quoted by David Middletown. It states that:
“This work complements other experiments by Stanley et al. (2002, in press) and Ries (2004), which demonstrated that calcareous organisms that produce high-Mg calcite in modern ‘‘aragonite seawater’’ (molar Mg/Ca ø5.2), such as coralline algae, echinoids, serpulid worms, crabs, shrimp, and coccolithophores, produced low-Mg calcite and, in the case of the coccolithophores, grew faster in artificial ‘‘calcite seawater’’ (molar Mg/Ca ;1.0).”
Making clear that 1) in the current “aragonite sea” this organisms precipitate Mg-calcite and in a “calcite seawater” they switch to low Mg-calcite. There is still a lot of calcite precipitation in an “aragonite sea”! (indeed coccolithophores, that make their shells of calcite, are the main phytoplanckton calcifiers)
The organism in the study, Penicillus capitatus, when grown in a Mg-poor (Mg/Ca =1) seawater, still precipitates aragonite:
” X-ray diffraction of the powdered specimens revealed that algae grown in the artificial calcite seawater (molar Mg/Ca = 1) produced 22 +/- 3% of their CaCO3 as low-Mg calcite (4 +/-0.4 mole % MgCO3) and 78 +/- 3% as aragonite (Fig. 6), whereas specimens grown in the artificial aragonite seawaters produced their CaCO3 exclusively as aragonite (Table 1)”

From Peru

January 17, 2011 5:39 pm

kadaka (KD Knoebel):
(continuation)
But the link to the study I posted about the Arctic to all this is a much more basic, fundamental chemistry question: kinetics vs. thermodynamics.
The whole calcite/aragonite seas issue is a kinetic one, as should be clear from this paper (I’m sorry that is not free, link to the abstract):
“Calcite and Aragonite Precipitation Under Controlled Instantaneous Supersaturation: Elucidating the Role of CaCO3 Saturation State and Mg/Ca Ratio on Calcium Carbonate Polymorphism”
http://jsedres.geoscienceworld.org/cgi/content/abstract/79/6/363
That makes clear in the abstract:
“The predominance of aragonite at high solution Mg/Ca and low supersaturations is attributed to a relative decrease in calcite growth rates as a result of increasing incorporation of Mg2+ in the calcite lattice at higher solution Mg/Ca ratios. As suggested by abundant experimental work, increasing solution Mg/Ca decreases the growth rate of calcite while aragonite growth rates stay unaffected. Our experiments do demonstrate that despite decreased growth rate the percentage of MgCO3 in calcite increases with increasing solution Mg/Ca ratio. As calcite growth rates decrease, aragonite growth rates stay constant and it becomes the dominant mineral phase in solutions with high Mg/Ca ratio and low supersaturations”
So when the ratio Mg/Ca of seawater goes up, the rate of growth of calcite drops, while the rate of of aragonite growth stays the same. At high Mg/Ca ratios the calcite precipitation is so kinetically suppressed that aragonite precipitation dominates.
To precipitate a significant amount of CaCO3 as calcite, the calcite saturation state must go up:
“The data show that for increasing solution Mg/Ca ratios, progressively higher supersaturation level is required for calcite precipitation.”
What is happening now in the oceans as a consecuence of ocean acidification and global warming is not a change in the kinetics of calcification, but a change in the thermodynamic state (i.e. chemical equilibrium) of the oceans. In particular is happening this:
CO2 +H2O = H2CO3
H2CO3 = H+ + HCO3-
CO3(-2) + H+ = HCO3-
So the concentration of the carbonate ion [CO3(-2)] is dropping as a consecuence of higher pCO2 .
And as a consecuence of this the saturation state of calcium carbonate is dropping also, because it is the product:
CaCO3 saturation state = [Ca(+2)][CO3(-2)]/Kps CaCO3
Where Kps is the solubility product of calcium carbonate.
When CaCO3 saturation state drops below unity, the water becomes corrosive to calcium carbonate materials. Because aragonite is more soluble than calcite, the first CaCO3 species that go undersaturated is aragonite.
And in polar regions, CO2 dissolves more easily because the water is cooler. So they are the first to be severely impacted by ocean acidification. In the Arctic, this already happened since 2008.
You may thought that global warming will offset the acidification by reducing the CO2 solubility in water. But the opposite is true for the Arctic, because there is another big change in addition to water warming: sea ice melting.
As the sea ice melts, this processes happen:
1)The meltwater lowers salinity and alkalinity of seawater, diluting the carbonate, lowering [CO3(-2)]
2)The water over ice-free Arctic is now exposed to air, increasing CO2 dissolution in the seawater
3)The ocean surface is exposed to Arctic winds enhancing deepwater upwelling. The deepwater is carbonate-depleted.
4)The water warms, decreasing CO2 solubility in seawater
Process 1,2,3 overwhelm process 4, producing the observed result : aragonite undersaturation.
This is explained in the paper:
“Aragonite Undersaturation in the Arctic Ocean- Effects of Ocean Acidification and Sea Ice Melt”
http://www.whoi.edu/beaufortgyre/pdfs/yamamoto-kawai_aragonite_science2009.pdf
This process has nothing to do with Mg/Ca ratios, as the meltwater dilutes both Ca and Mg.
And I said before, a change in Mg/Ca ratios change the kinetics of carbonate deposition, not the thermodynamic state of seawater (i.e. the CaCO3 saturation state)
So the very interesting discussion of “aragonite/calcite oceans” is not relevant to this case.
Note: the distinction between Mg/Ca ratios and aragonite/calcite saturation state is not absolute. In geological timescales, higher acidity of the oceans and higher temperatures caused by high CO2 levels increase dissolution of carbonate from the bottom of the sea and from the continents, increasing the saturation state of calcium carbonate because more Ca2+ is dissolved. So the amount of Ca dissolved increase, lowering the Mg/Ca ratio and then leading to “calcite seas”.
This increase of calcium carbonate saturation state is not contradicting the decrease of calcium carbonate saturation state caused by rapid CO2 releases. A big and rapid CO2 release lowers the CaCO3 saturation state by the chemical reactions above in the short term (i.e. decades to centuries) while on the long term (hundred of thousands to millions of years) increases it. Indeed, that is what happened in the Paleocene/Eocene Thermal Maximum (PETM): it took 100 000 years for the ocean to recover from CO2-induced calcium carbonate depletion.

Doug Schnurrenberger

January 27, 2011 10:48 am

Dave – I’m trying to figure out what is going on with ocean acidification and coral reefs. I went to the data link you posted and plotted up the data and they don’t look like the graph you presented – primarily because there are several thousand data points from 60 different cores. I can’t directly compare to the original paper as they don’t show the actual data points but the shape of their curve is very different than the one you posted. I’m wondering what the problem is?
Thanks
Doug