Decline Of Plankton That Gobble Carbon Dioxide Coincided With Ancient Global Cooling

The evolutionary history of diatoms -- abundant oceanic plankton that remove billions of tons of carbon dioxide from the air each year -- needs to be rewritten, according to a new Cornell study. The findings suggest that after a sudden rise in species numbers, diatoms abruptly declined about 33 million years ago -- trends that coincided with severe global cooling.

The research casts doubt on the long-held theory that diatoms' success was tied to an influx of nutrients into the oceans from the rise of grasslands about 18 million years ago. New evidence from a study led by graduate student Dan Rabosky of Cornell's Department of Ecology and Evolutionary Biology and the Cornell Laboratory of Ornithology takes into account a widespread problem in paleontology: that younger fossils are easier to find than older ones.

"We just tried to address the simple fact that the number of available fossils is colossally greater from recent time periods than from earlier time periods," Rabosky said. "It's a pretty standard correction in some fields, but it hasn't been applied to planktonic paleontology up till now."

More than 90 percent of known diatom fossils are younger than 18 million years. So an unadjusted survey of diatom fossils suggests that more diatom species were alive in the recent past than 18 million years ago.

The dearth of early fossils is understandable. Sampling for diatom fossils requires immense drill ships to bore into seafloor sediment. To find an ancient fossil, scientists first have to find ancient sediment -- and that's no easy task because plate tectonics constantly shift the ocean floor, fossils and all. Much of the seafloor is simply too young to sample.

So Rabosky and co-author Ulf Sorhannus of Edinboro University of Pennsylvania controlled for how many samples had been taken from each million-year period of the Earth's history, going back 40 million years. After reanalysis, the long-accepted boom in diatoms over the last 18 million years disappeared. In its place was a slow recent rise, with a much more dramatic increase and decline at the end of the Eocene epoch, about 33 million years ago.

With the new timeline, diatoms achieved their peak diversity at least 10 million years before grasslands became commonplace.

"If there was a truly significant change in diatom diversity at all, it happened 30 million years ago," Rabosky said. "The shallow, gradual increase we see is totally different from the kind of exponential increase you would expect if grasslands were the cause."

As an example of that kind of increase, Rabosky turned to another fossil record: horse teeth. Before grasslands, horses had small teeth suited for chewing soft leaves. But as grasslands appeared, much hardier teeth appeared adapted to a lifetime of chewing tough, silica-studded grass leaves. Diatoms ought to show a similar evolutionary response to the sudden availability of silica, Rabosky said, but they don't.

Although the new results don't explain the current prevalence of diatoms in the ocean, Rabosky said that whatever led to diatoms' rise at the end of the Eocene, the tiny organisms may have contributed to the global cooling that followed.

"Why diatom diversity peaked for 4 to 5 million years and then dropped is a big mystery," Rabosky said. "But it corresponds with a period when the global climate swung from hothouse to icehouse. It's tempting to speculate that these tiny plankton, by taking carbon dioxide out of the air, might have helped trigger the most severe global cooling event in the past 100 million years."

THE ACQUITTAL OF CARBON DIOXIDE
by Jeffrey A. Glassman, PhD

ABSTRACT:

"Carbon dioxide in the atmosphere [historically] is the product of oceanic respiration due to the well-known but under-appreciated solubility pump. Carbon dioxide rises out of warm ocean waters where it is added to the atmosphere. There it is mixed with residual and accidental CO2, and circulated, to be absorbed into the sink of the cold ocean waters. Next the thermohaline circulation carries the CO2-rich sea water deep into the ocean. A millennium later it appears at the surface in warm waters, saturated by lower pressure and higher temperature, to be exhausted back into the atmosphere. Throughout the past 420 millennia, comprising four interglacial periods, the Vostok record of atmospheric carbon dioxide concentration is imprinted with, and fully characterized by, the physics of the solubility of CO2 in water, along with the lag in the deep ocean circulation.

Notwithstanding that carbon dioxide is a greenhouse gas, atmospheric carbon dioxide has neither caused nor amplified global temperature increases. Increased carbon dioxide has been an effect of global warming, not a cause. Technically, carbon dioxide is a lagging proxy for ocean temperatures. When global temperature, and along with it, ocean temperature rises, the physics of solubility causes atmospheric CO2 to increase.

If increases in carbon dioxide, or any other greenhouse gas, could have in turn raised global temperatures, the positive feedback would have been catastrophic. While the conditions for such a catastrophe were present in the Vostok record from natural causes, the runaway event did not occur. Carbon dioxide does not accumulate in the atmosphere."

http://www.rocketscientistsjournal.com/2006/10/co2_acquittal.html

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The graph above represents temperature and CO2 levels over the past 400,000 years. It is the same exact data Al Gore and the rest of the man-made global warmers refer to. The blue line is temps, the red, CO2 levels. The deep valleys represent 4 separate glaciation/ice-age periods. Look carefully at this historical relationship between temps and CO2 levels (the present is on the right hand side of the graph) and keep in mind that Gore claims this data is the 'proof' that CO2 has warmed the earth in the past. But does the data indeed show this? Nope. In fact, rising CO2 levels all throughout this 400,000-year period actually *followed* temperature increases -lagging behind by an average of 800 years! So it couldn't have been CO2 that got Earth out of these past glaciations. Yet Gore continually and dishonestly claims otherwise. Furthermore, the subsequent CO2 level increases due to dissolved CO2 being released from warming oceans, never did lead to additional warming, the so-called "run-away greenhouse effect" that Al Gore and his friends keep warning us about. In short, there is little if any evidence that CO2 had ever led to increased warming, at least not when the levels were within 10-15 times of what they are today. -ETL

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"The above chart shows the range of global temperature through the last 500 million years. There is no statistical correlation between the level of carbon dioxide in the atmosphere through the last 500 million years and the temperature record in this interval. In fact, one of the highest levels of carbon dioxide concentration occurred during a major ice age that occurred about 450 million years ago [Myr]. Carbon dioxide concentrations at that time were about 15 times higher than at present." [also see 180 million years ago, same thing happened]:
http://www.tcsdaily.com/article.aspx?id=010405M

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So, greenhouse [effect] is all about carbon dioxide, right?

Wrong. The most important players on the greenhouse stage are water vapor and clouds [clouds of course aren't gas, but high level ones do act to trap heat from escaping, while low-lying cumulus clouds tend to reflect sunlight and thereby help cool the planet -etl]. Carbon dioxide has been increased to about 0.038% of the atmosphere (possibly from about 0.028% pre-Industrial Revolution) while water in its various forms ranges from 0% to 4% of the atmosphere and its properties vary by what form it is in and even at what altitude it is found in the atmosphere.

In simple terms the bulk of Earth's greenhouse effect is due to water vapor by virtue of its abundance. Water accounts for about 90% of the Earth's greenhouse effect -- perhaps 70% is due to water vapor and about 20% due to clouds (mostly water droplets), some estimates put water as high as 95% of Earth's total tropospheric greenhouse effect (e.g., Freidenreich and Ramaswamy, 'Solar Radiation Absorption by Carbon Dioxide, Overlap with Water, and a Parameterization for General Circulation Models,' Journal of Geophysical Research 98 (1993):7255-7264).

The remaining portion comes from carbon dioxide, nitrous oxide, methane, ozone and miscellaneous other 'minor greenhouse gases.' As an example of the relative importance of water it should be noted that changes in the relative humidity on the order of 1.3-4% are equivalent to the effect of doubling CO2.

http://www.junkscience.com/Greenhouse/

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Water Vapor Rules the Greenhouse System

Water vapor constitutes Earth's most significant greenhouse gas, accounting for about 95% of Earth's greenhouse effect (4). Interestingly, many 'facts and figures' regarding global warming completely ignore the powerful effects of water vapor in the greenhouse system, carelessly (perhaps, deliberately) overstating human impacts as much as 20-fold.

Water vapor is 99.999% of natural origin. Other atmospheric greenhouse gases, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and miscellaneous other gases (CFC's, etc.), are also mostly of natural origin (except for the latter, which is mostly anthropogenic).

Human activities contribute slightly to greenhouse gas concentrations through farming, manufacturing, power generation, and transportation. However, these emissions are so dwarfed in comparison to emissions from natural sources we can do nothing about, that even the most costly efforts to limit human emissions would have a very small-- perhaps undetectable-- effect on global climate.

http://www.geocraft.com/WVFossils/greenhouse_data.html

Carbon Dioxide Rich Atmosphere in an Ancient Ice Age

Research by the University of Birmingham has provided evidence that a warm atmosphere rich in carbon dioxide was present in an ancient ice age. This could only have happened if the planet was nearly all covered in ice and snow.

Scientists from the University's School of Geography, Earth and Environmental Sciences, say that, whereas today, we associate more greenhouse gases with a warm world, in a very severe ice age, even plenty of greenhouse gas cannot stop the world being covered in reflective ice and snow.

This type of glaciation could occur again in the future if the Earth's atmosphere reflected too much solar radiation - this process could be triggered by a nuclear war creating a dusty mantle around the Earth. The same applies if we were not careful with a suggested technological fix for global warming and launched tiny particles (aerosols) of sulphate into the atmosphere. Such aerosols arise both from industrial pollution and from volcanic activity, and even in trace quantities are known to cause cooling. Dr Ian Fairchild, lead investigator, says, `We came up with an independent test of a theory that the Earth, like a baked Alaska pudding, was once hot on the outside, surrounding a cold, icy surface. It happened naturally in the past, but the wrong use of technology could make it happen again'

The breakthrough discovery was made by studying limestones that were deposited around 630 million years ago in salt lakes next to an ice sheet. The scientists measured the relative amounts of heavier and lighter forms of oxygen and sulphur and found anomalies that could only be accounted for by a very unusual composition of the atmosphere at the time. Appropriately, the place where the samples were collected is in Svalbard in the Arctic Ocean and is today covered in ice and snow, but 630 million years ago, nearly the entire planet would have been ice-bound.

Ends

Notes to Editors:

This paper was written with Huiming Bao, Louisiana State University, Peter Wynn, Lancaster University, Christoph Spoetl, University of Innsbruck.

The paper will appear in Science on Friday 2nd January 2009. Please visit:
http://www.gees.bham.ac.uk/staff/fairchildresearchglacial.shtml
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Note from Admin: Looking at the actual paper, unless I read it wrong, it seems that the atmospheric CO2 concentration was around 12,500 to 80,000 ppmv compared to about 380 ppmv today.

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