Friday, January 1, 2010
Does Algae Reduce the Ice Core CO2?
Above is Beck's compilation of historical atmospheric CO2 measurement. A friend said to look at Realclimate.org to see their objections. That is always a good idea to find the objections. After looking over the criticisms of Beck's atmospheric CO2 measurements at Realclimate.org,(Beck's short paper and RC and my previous post on Beck's work) and listening to their defense of the CO2 in the glacial ice. I decided to ask some questions about glacial ice and CO2.
Could there be anything that eats the CO2 lowering it in the glacial ice and making the 'pre-industrial level' not be read correctly? There is a reason for asking this. Many of Beck's sources were German chemists and in the late part of the 19th century continuing into the 20th century, they were, in general, the best chemists on earth at that time. So why the discrepancy between Beck's literature search and the ice cores?
The IPCC relies on Etheridge et al. 1996 in which paper Etheridge et al ignorantly say:
"A record of atmospheric CO2 mixing ratios from 1006 A.D. to 1978 A.D. has been produced by analysing the air enclosed in three ice cores from Law Dome, Antarctica. The enclosed air has unparalleled age resolution and extends into recent decades, because of the high rate of snow accumulation at the ice core sites. The CO2 data overlap with the record from direct atmospheric measurements for up to 20 years."Etheridge, D., L. Steele, R. Langenfelds, R. Francey, J.‐M. Barnola, and V. Morgan (1996), Natural and anthropogenic changes in atmospheric CO2 over the last 1000 years from air in Antarctic ice and firn, J. Geophys. Res., 101(D2), 4115-4128
1978 minus 20 is 1958. These guys are acting like Keeling, whose curve starts in 1958, was the very first person on earth to measure atmospheric CO2 content. Clearly this is wrong. And just as clearly, their derived CO2 profile differs markedly from that of the historical atmospheric measurements turned up by Beck. Look at how the ice core measurements above have no correlation with the historical atmospheric measurements. This strongly implies that something is happening down in the ice cores to change the CO2 content. So, let's look at this issue.
I first looked at inorganic processes that might lower the CO2 in the cores but there appears to be nothing in inorganic chemistry which can do it. But…there is always algae and other microbial life.
When I was in Antarctica there were some pinkish/brownish areas of the snow which was caused by algae living just below the frozen surface. These algae live down to -10 deg C. But I was near the coast. See below.
Did they live at Vostok where the cores were taken? Yes, they did.
"Finally, in terms of understanding microbes within the lake, the overlying Vostok ice core contains a diverse range of microbes including algae, diatoms, bacteria, fungi, yeasts and actiomycetes (Ellis-Evans and Wynn-Williams, 1996). These organisms have been demonstrated to be viable to depths as deep as 2400 m (Abyzov, 1993). " Robin E. Bell " Lake Vostok: Background Information" in Robin E. Bell, David M. Karl," LAKE VOSTOK WORKSHOP" National Science Foundation, Washington D.C. November 7 & 8, 1998, p. 11 source
While deep down, photosynthesis can't happen, up shallow it can. But Vostok surface temperatures never get above -25 deg C. That presented a problem for seeing in them a way to photosynthesize the CO2, except in the veins between ice crystals (see below). Would that be enough? I don't know, but there are other mechanisms for giving the algae a proper habitat.
Looking into issues of the past history of temperatures on the mainland of Antarctica, I ran into a 2009 Ph. D. dissertation on UV absorption in the Antarctic ice cap. Kai Rasmus measured albedos and absorptions of UV light. He was trying to see what the increased UV because of the ozone hole might do to the Antarctic Ice shelf. What he found was that the ice could melt because of the increased UV radiation absorbed by the glacial ice and the slow thermal conductivity of the ice. It would melt small areas of the subsurface ice. He says:
"The melt water pool was 1 m thick after a 50-year integration. This increased to 1.5m when the trend in air temperature was applied. For a typical atmospheric warming scenario of 1.5°C in 50 years subsurface changes were found. It seems that these subsurface changes may be unnoticed at the surface, which remains frozen and largely unchanged during the 50 year integration. The ice did not disintegrate even after a 50-year integration." Kai Rasmus " OPTICAL STUDIES OF THE ANTARCTIC GLACIO-OCEANIC SYSTEM " REPORT SERIES IN GEOPHYSICS No 62 (2009) UNIVERSITY OF HELSINKI DEPARTMENT OF PHYSICS p.58
If parts of the ice melted, then the algae would live, and would photosynthesize what they could in the dim light. That would reduce the CO2 content of the bubbles inside the ice. It would also mean that the impermeable lock-in zone would move shallower (that is the depth at which no air can diffuse further below). So, we have a mechanism to melt subterranean ice in Antarctica caused by the present ozone hole, caused by man's past CFC production. But of course that can’t affect past CO2 levels. The ozone hole is a present problem, right? Wrong.
In 1859 the most massive solar flare ever seen, hit the earth. Scientists believe that it cut the ozone hole by over 30%.
1859 solar flare, ozone depletion studied
March 22, 2007
U.S. scientists believe an 1859 solar flare destroyed more of the Earth's ozone than did a 1989 solar flare -- the strongest ever monitored by satellite.
Researchers led by Brian Charles Thomas of Washburn University used data on nitrate enhancements from Greenland ice cores to determine the September 1859 solar proton event released 6.5 times more energy than did the 1989 event.
Models using that energy release showed 3.5 times more ozone was destroyed during the 1859 episode than in 1989. And since ozone regulates the amount of harmful ultraviolet radiation reaching Earth, the researchers said understanding intense solar proton events will be important in predicting potential damage to the biosphere.
The study by Thomas, Charles Jackbon of the Goddard Space Flight Center, and Adrian Melott of the University of Kansas appears in the current issue of the journal Geophysical Research Letters.
For comparison with the CFC depletion consider this:
"CHLORINE-catalysed depletion of the stratospheric ozone layer has commanded considerable attention since 1985, when Farman et al. 1 observed a decrease of 50% in the total column ozone over Antarctica in the austral spring. Here we examine the depletion of stratospheric ozone caused by the reaction of ozone with nitric oxide generated by energetic solar protons, associated with solar flares. During large solar flares in March 1989, satellite observations indicated that total column ozone was depleted by ˜9% over ˜20% of the total area between the South Pole and latitude 70° S. Chlorine-catalysed ozone depletion takes place over a much larger area, but our results indicate that the influence of solar protons on atmospheric ozone concentrations should not be ignored." JUDY A. E. STEPHENSON & MALCOLM W. J. SCOURFIELD Importance of energetic solar protons in ozone depletion Nature 352, 137 - 139 (11 July 1991);
Apparently this means that the 1859 event did about over 30% damage—almost what CFCs did. If such natural events happen every couple of hundred years (our current observation period), then every couple of hundred years, we could get pockets of meltwater below the Antarctican surface, which would revive the algae, which would then easily reduce the CO2 in the recovered ice cores. And if this is a possibility, then the IPCC may be using cores depleted in CO2.
Some may say that the melting of the ice occurs above the lock in depth, where ice impermeabilty prevents diffusion with the present atmosphere and thus Rasmus' work is irrelevant. If that is so, then there is even a worse problem for the IPCC who uses ice cores for the past 200 years as a measure of CO2 levels in the atmosphere. Studies at Vostok suggest that the age of the lock-in is 6000 years ago, yet IPCC is using ice core data for the past 200 years. That seems flimsy to say the least, especially when they ignore 150 years of atmospheric measurements.
"One reason for this uncertainty is that the relative timing of temperature and CO2 changes is not accurately known.The temporal relation between these two quantities is difficult to discern because air is trapped in ice at the base of the firn layer (7), where, at low accumulation sites such as Vostok, ice may be 6000 years old." Nicolas Caillon, et al " Timing of Atmospheric CO2 and Antarctic Temperature Changes Across Termination III" Science 299(2003), p. 1728
So, the IPCC and AGW supporters are presented with a problem. If they say that Rasmus's melt mechanism doesn't count because it is shallow before the ice permeability locks in the atmospheric content, then they can't claim that using 200 year old ice cores can possibly give a correct value. If they say that 200 year old ice can represent the atmospheric composition correctly, then they have to explain why algae can't lower the CO2 content of the air in shallow ice cores making their values lower than the historical CO2 measurements, and thus irrelevant to the CO2 content of the world for the past 200 years. The horns of a dilemma are tough.
I would also point people to the picture I took in Antarctica a year ago. In the foreground you can see a tilted layer of snow and ice that have dark blue horizontal streaks just below the surface. The dark blue is solid ice--meaning it is an impermeable layer. Notice how close to the surface it is. That layer may be one of the melt layers spoken of by Rasmus. Such layers would lock in and separate the air from above from the air from below. Here is observational data that supports Rasmus's view.
But beyond all this, shallow metabolism is not the end of microbial life. Price describes a habitat for psychrophiles (beings that love cold) in the water that exists between the ice grains. Ice, when it freezes expels most impurities, so some water exists in the form of either highly salty or acidic waters in the veins in between the grains. Microbes can live in such circumstances.
"In the accretion ice, with an age of a few 10^4 years and a temperature a few degrees below freezing, the carbon and energy sources in the veins can maintain significant numbers of cells per cubic centimeter that are metabolizing but not multiplying. In the 4 x 10^5-year-old colder glacial ice, at least 1 cell per cm^3 in acid veins can be maintained. With fluorescence microscopy tuned to detect NADH in live organisms, motile bacteria could be detected by direct scanning of the veins in ice samples. P. Buford Price, " A habitat for psychrophiles in deep Antarctic ice" PNAS, 97(2000), p. 1247
When melted the viable Vostok microbes engaged in more acetate metabolism than anything else.
"Acetate was respired 800 times more rapidly than was glucose." D. M. Karl et al, "Microorganisms in the Accreted Ice of Lake Vostok, Antarctica" Science 286(1999):2145
This was anaerobic metabolism. The big question is are they metabolizing down below? That is something that is unknown at the present time. Price says they might be.
What do we know about that kind of metabolism from similar microbes living in oxygen free places?
"Acetate was metabolized primarily to methane in the sediments and water immediately above the sediment. Sulfide inhibition studies and temperature activity profiles demonstrated that acetate metabolism was performed by several microbial populations. Sulfide additions (less than 5 μg/ml) to water from 21.5 m stimulated methanogenesis from acetate, but inhibited CO2 production."M. R. Winfrey and J. G. Zeikus "Microbial Methanogenesis and Acetate Metabolism in a Meromictic Lake" Appl Environ Microbiol. 1979 February; 37(2): 213–221.
And there are sulfides in ice cores that could inhibit CO2 formation
"The average COS mixing ratio of the SPRESSO data set is (331±18) ppt (parts per trillion in mol/mol, ±1[sigma], n=100), excluding 6 outliers. These data confirm earlier firn air and ice core measurements indicating that the late 20th century COS levels of 500 ppt are greatly increased over preindustrial levels and represent the highest atmospheric levels over the past 2000 years. The data also provide evidence of climate-related variability on centennial time-scales, with relative maxima at the peaks of Medieval Climate Anomaly and Little Ice Age. There is evidence
for a long-term increasing trend in COS of 1.8 ppt per 100 years. Further ice core studies will be needed to determine whether this trend reflects secular variability in atmospheric COS, or a slow post-depositional chemical loss of COS in the ice core." M. Aydin et al, " Carbonyl sulfide in air extracted from a South Pole ice core: a 2000 year record" Atmos. Chem. Phys., 8, 7533–7542, 2008
The fact that the sulfide increases with time may be indicative that microbes are using it up which would mess up the air chemistry derived from ice cores.
All of these issues are poorly understood yet the IPCC chooses to ignore the historical measurments of CO2 in the atmosphere in favor of what might be more of a chemical brew below in the ice cores than they want to beleive.
And if this is the case, then Beck's measurements may be the better of the two, meaning that the atmospheric levels of CO2 may have been as high as 450 ppm within the past 200 years and all the scare-mongering may not be anything but, well, scare-mongering for political purposes.
I think it is time for the climate scare mongers to explain why they rely solely on ice core CO2 when there is clearly the possibility that UV radiation melted small pools allowing the algae to reduce the ice core CO2. Again, at the top of this post is the chart of the historic atmospheric measurements of CO2 put together by Beck and ignored by the IPCC.