From the University of Leicester press office: An ancient Earth like ours
Geologists reconstruct the Earth’s climate belts between 460 and 445 million years ago
An international team of scientists including Mark Williams and Jan Zalasiewicz of the Geology Department of the University of Leicester, and led by Dr. Thijs Vandenbroucke, formerly of Leicester and now at the University of Lille 1 (France), has reconstructed the Earth’s climate belts of the late Ordovician Period, between 460 and 445 million years ago.
The findings have been published online in the Proceedings of the National Academy of Sciences of the USA – and show that these ancient climate belts were surprisingly like those of the present.
The researchers state: “The world of the ancient past had been thought by scientists to differ from ours in many respects, including having carbon dioxide levels much higher – over twenty times as high – than those of the present. However, it is very hard to deduce carbon dioxide levels with any accuracy from such ancient rocks, and it was known that there was a paradox, for the late Ordovician was known to include a brief, intense glaciation – something difficult to envisage in a world with high levels of greenhouse gases. “
The team of scientists looked at the global distribution of common, but mysterious fossils called chitinozoans – probably the egg-cases of extinct planktonic animals – before and during this Ordovician glaciation. They found a pattern that revealed the position of ancient climate belts, including such features as the polar front, which separates cold polar waters from more temperate ones at lower latitudes. The position of these climate belts changed as the Earth entered the Ordovician glaciation – but in a pattern very similar to that which happened in oceans much more recently, as they adjusted to the glacial and interglacial phases of our current (and ongoing) Ice Age.
This ‘modern-looking’ pattern suggests that those ancient carbon dioxide levels could not have been as high as previously thought, but were more modest, at about five times current levels (they would have had to be somewhat higher than today’s, because the sun in those far-off times shone less brightly).
“These ancient, but modern-looking oceans emphasise the stability of Earth’s atmosphere and climate through deep time – and show the current man-made rise in greenhouse gas levels to be an even more striking phenomenon than was thought,” the researchers conclude.
Reference: Vandenbroucke, T.R.A., Armstrong, H.A., Williams, M., Paris, F., Zalasiewicz, J.A., Sabbe, K., Nolvak, J., Challands, T.J., Verniers, J. & Servais, T. 2010. Polar front shift and atmospheric CO2 during the glacial maximum of the Early Paleozoic Icehouse. PNAS doi/10.1073/pnas.1003220107.
Contacts: (Mark Williams and Jan Zalasiewicz at the Department of Geology, University of Leicester: Respectively tel. 0116 252 3642 and 0116 2523928, and e-mails mri@le.ac.uk and jaz1@le.ac.uk).
See, according to the super-cool enlightenment principles of the PNAS’s Post Normal Science, if you just keep repeating the hallowed CAGW “tenets” as mantric chants, they become “true”!*
*a.k.a., “The Monkeys know it is true, because they always say it is true.” – Mogli, The Jungle Book movie.
Also in this whole CO2 EPA demonization scheme, it is somehow forgotten that during the past Ice Age Co2 levels plummeted to 180 ppm.
Plants cease production at 150 ppm.
Talk about a mass extinction.
Chris
Norfolk, VA, USA
Robert says:
August 10, 2010 at 9:51 am
The Devil, the proud spirit, cannot endure to be mocked
Tomas More
“These ancient, but modern-looking oceans”
Really? What about this:
http://jan.ucc.nau.edu/~rcb7/mollglobe.html
I think we are all missing the point, clearly man made CO2 has far more affect on the temperature than naturally occurring CO2, so even if historical levels were many times today’s level, it could still be considered an unprecedented rise in modern times due to the man made effect
/sarc
More graphs
http://wattsupwiththat.com/2010/08/10/study-climate-460-mya-was-like-today-but-thought-to-have-co2-levels-20-times-as-high/
ice core temps going back 400,000 years
“intense glaciation – something difficult to envisage in a world with high levels of greenhouse gases.”
Of course, since there is no such thing as a greenhouse gas as our atmosphere is not a greenhouse and CO2 cannot trap heat (just as picket fences cannot hold back water), this is easy to envisage.
Of course, during the late Ordovician, there were no land animals and very few (if any) land-living plants. The continents were in quite different locations as well. None of today’s major mountain ranges existed. The biosphere and the carbon cycle were quite different than today. So it is really rather pointless to compare the Earth 460 million years ago with the Earth today in the context of global warming. (Maybe, though, it is instructive to remember that the Ordovician did actually end with one of the greatest mass extinctions in the history of the Earth.)
It’s not worth $10 to actually be able to read this paper; the abstract is enough to make that decision. They appear to have had the audacity to “model” the temperature decline from 8x to 5x “pre-industrial” level and declare that the drop was proportional to the fall in partial pressure of CO2! Proportional? They need to check their equations. Then they proceed to blame this temperature drop for a mass extinction from the cold! Absolutely incredible.
steveta : I’m sure I could find 180 bottles of beer.
But really, it would be better if you didn’t – think of all the CO2 that might be released!
OK… GeoCarb puts the Ordovician CO2 between 4,000 and 5,000 ppmv. GeoCarb is a model based on weathering rates and other geological process estimates. Pedogenic carbonates indicate a CO2 level of about 5,600 ppmv 447 mya – Right in in the middle of the Ordovician ice age.
So… We just assume that the data are wrong during the Ordovician ice age because the GHG-driven AGW model says CO2 levels had to be down around 1,500 to 2,000 ppmv.
Where have I seen this sort of “fitting-the-data-to-the-theory” before… Can you say Ptolemaic Solar System? I didn’t actually “see” the Copernican-Ptolemaic debate; I just read about it. I’m old, but not than old… 😉
“…and show the current man-made rise in greenhouse gas levels to be an even more striking phenomenon than was thought,”
This statement makes no sense. I’ve looked at it repeatedly. I have guessed at missing words. I’ve tried to rearrange the words. I can’t tell what it says (if anything), nor what they wanted it to say. While “it is 5 o’clock somewhere” I haven’t started drinking yet today.
I just came home and have not read any of the above comments, so I hope that the following is not a repeat.
An Aussie researcher opines that increased CO2 will reduce the nutrition in our food and also increase the content of cyanide. Another one for the list of 3000 problems due to CO2.
http://www.abc.net.au/ra/innovations/stories/s2967862.htm
Ian
21.2 hours per day and 414 days per year
Well you can see just by eye; without any computation necessary that the Earth Temperature exactly matches the logarithm (base 2) of the CO2 level; thereby proving Schneider’s Law which is taught to every climate science student in the very first lecture.
Exactly George. The most important part of the course should be left to the end of the course!
Think back to the average state of a first year student, in any neigh all subjects.
Hungover, i’d guess, and thus totally impervious to logical sensitivity.
I vaguely remember my alcohol level 460’ish million years ago. As to the CO2 environment that I co-existed with, forget it. It was all just a blurr!
Ian L. McQueen says:
August 10, 2010 at 1:29 pm
Just turn around and fart at them!
“…[carbon dioxide levels] would have had to be somewhat higher than today’s, because the sun in those far-off times shone less brightly.”
They had to be, I tell you. They just had to be!
And what would be the implication to the CAGW hypothesis if it were discovered that CO2 levels were not so high? That there are actually a zillion other factors (including negative feedbacks) influencing the temperature maybe? But let’s be fair. In the absence of knowledge, we can’t account for the high temperature (then as now) without the attributing it to CO2. I’m sold.
NOT.
steveta_uk says:
August 10, 2010 at 9:19 am
> latitude says:
> August 10, 2010 at 8:41 am
> You couldn’t even find 0.038% of anything.
My house is approx 250 cubic metres.
Therefore 0.038% of my house of approx 95 litres.
95 Litres is approx 180 bottles of beer.
I’m sure I could find 180 bottles of beer.
0.038% would be .ooo38 x 250 = .095 litres or a little over 3 ounces, not even worth finding!
Ian L. McQueen: August 10, 2010 at 1:29 pm
An Aussie researcher opines that increased CO2 will reduce the nutrition in our food and also increase the content of cyanide. Another one for the list of 3000 problems due to CO2.
Ah, yes — the cassava kerfluffle we had here a couple months back.
I’ll bet the researcher didn’t reveal that the folks who eat a lot of cassava know enough to cook the stuff (which breaks down the cyanide) and they *prefer* the taste of the tubers that normally have higher concentrations of cyanide — it’s *spicier*.
Looks like CO2 levels nowadays are dangerously low, rather than dangerously high.
There is a new paper out today on the continental drift twists and turns that Gondwana took in the Cambrian period just before this glaciation period.
http://geology.gsapubs.org/content/38/8/755.full
The graph doesn’t go with the article does it? It’s been around for years. Someone took graphs from two different studies and C&Ped them together. Ain’t photoshop great?
Where were the (4) continents located in the Ordovician compared to today?
What was solar output in the Ordovician compared to today?
How much volcanism was there during the Ordovician compared to today?
Where are the error bars?
REPLY: Apparently you are unable to read captions, where’s your reading glasses? – Anthony
Your understanding is wrong. The sun’s brightness has been steadily increasing ever since the plant formed and it continues to do so.
It was dimmer 460 Mya, although definitely not at 1/5th the current level.
Correct, continental masses were in a completely different configuration than now.
It is extremely dishonest to claim “See, CO2 was much higher 460Mya, and the climate was similar to now, therefore AGW is BS” (seems to be a pattern in this blog). If someting is BS, it is that argument, not AGW.
CO2 is hardly the only thing influencing the climate, there are many many other factors. The point is that none of those other factors has been changing now other than CO2.
Tom C
Venus barely rotates and has a completely uniform heat distribution.
And perhaps time to read the Shaviv and Veizer paper again;
http://www.phys.huji.ac.il/~shaviv/Ice-ages/GSAToday.pdf