From a press release by: National Oceanography Centre, Southampton (NOCS)
Understanding past and future climate
The notion that scientists understand how changes in Earth’s orbit affect climate well enough for estimating long-term natural climate trends that underlie any anthropogenic climate change is challenged by findings published this week. The new research was conducted by a team led by Professor Eelco Rohling of the University of Southampton’s School of Ocean and Earth Science hosted at the National Oceanography Centre, Southampton.
“Understanding how climate has responded to past change should help reveal how human activities may have affected, or will affect, Earth’s climate. One approach for this is to study past interglacials, the warm periods between glacial periods within an ice age,” said Rohling.
He continued: “Note that we have here focused on the long-term natural climate trends that are related to changes in Earth’s orbit around the Sun. Our study is therefore relevant to the long-term climate future, and not so much for the next decades or century.”
The team, which included scientists from the Universities of Tuebingen (Germany) and Bristol, compared the current warm interglacial period with one 400,000 years ago (marine isotope stage 11, or MIS-11).
Many aspects of the Earth-Sun orbital configuration during MIS-11 were similar to those of the current interglacial. For this reason, MIS-11 is often considered as a potential analogue for future climate development in the absence of human influence.
Previous studies had used the analogy to suggest that the current interglacial should have ended 2-2.5 thousand years ago. So why has it remained so warm?
According to the‘anthropogenic hypothesis’, long-term climate impacts of man’s deforestation activities and early methane and carbon dioxide emissions have artificially held us in warm interglacial conditions, which have persisted since the end of the Pleistocene, about 11 400 years ago.
To address this issue, the researchers used a new high-resolution record of sea levels, which reflect ice volume. This record, which is continuous through both interglacials, is based on the ‘Red Sea method’ developed by Rohling.
Water passes between the Red Sea and the open ocean only through the shallow Strait of Bab-el-Mandab, which narrows as sea levels drop, reducing water exchange. Evaporation within the Red Sea increases its salinity, or saltiness, and changes the relative abundance of stable oxygen isotopes.
By analysing oxygen isotope ratios in tiny marine creatures called foraminiferans preserved in sediments that were deposited at the bottom of the Red Sea, the scientists reconstructed past sea levels, which were corroborated by comparison with the fossilised remains of coral reefs.
The researchers found that the current interglacial has indeed lasted some 2.0–2.5 millennia longer than predicted by the currently dominant theory for the way in which orbital changes control the ice-age cycles. This theory is based on the intensity of solar radiation reaching the Earth at latitude 65 degrees North on 21 June, the northern hemisphere Summer solstice.
But the anomaly vanished when the researchers considered a rival theory, which looks at the amount of solar energy reaching the Earth the same latitude during the summer months. Under this theory, sea levels could remain high for another two thousand years or so, even without greenhouse warming.
“Future research should more precisely narrow down the influence of orbital changes on climate,” said Rohling: “This is crucial for a better understanding of underlying natural climate trends over long, millennial timescales. And that is essential for a better understanding of any potential long-term impacts on climate due to man’s activities.”
The study was funded by the United Kingdom’s Natural Environment Council and the German Science Foundation.
Publication:
Rohling, E.J., et al., Comparison between Holocene and Marine Isotope Stage-11 sea-level histories. Earth and Planetary Science Letters (2010). doi:10.1016/j.epsl.2009.12.054
For those of you who were curious, the “rival theory” where the 2 thousand to 2.5 thousand year anomaly vanished is:
Huybers, P., 2006, “Early Pleistocene glacial cycles and the integrated summer insolation forcing”, Science 313, 508–511.
http://www.sciencemag.org/cgi/content/abstract/1125249
Mike Ramsey
Again I would like to give a link to;
“Celestial driver of Phanerozoic climate?”
by
Nir J. Shaviv and Ján Veizer;
http://www.phys.huji.ac.il/~shaviv/Ice-ages/GSAToday.pdf
This will probably put me into the “Flat Earth’ers” camp….
I say keeping the ice age at bay is a GOOD THING.
Possibly being 2,000 yrs overdue for an ice age beginning is very scary stuff indeed. Worrying about warming when the exact opposite is what we most likely face is a very serious crime being foisted upon us by scientists and the media.
I wonder if there are any geoengineering solutions available to counter this. Seriously, this is no laughing matter.
Ack (10:45:51) :
Why do the eco-wackos want the earth covered in ice?
My first line argument with these folks is: “Clearly you think it’s too hot! How cold would you like it?”
This opening points out the essential absurdity of their position.
“Ian L. McQueen (11:28:08) :
[…]
http://www.bbc.co.uk/podcasts/series/oneplanet/
It runs close to 30 minutes.
I couldn’t believe my ears!”
…your own *lying* ears!
@Ian L. McQueen
Wow, you really found a gem there 🙂 I really like how he keep Van Ypersele on the grill. It is especially sweet to my ears, given that the clown is from my country, and from the same university I’ve got my PhD…Not a great flagholder for this uni, I fear…
Philhippos C (10:09:33) : …another excellent item in the Guardian http://www.guardian.co.uk/technology/2010/feb/05/science-climate-emails-code-release – hope you can use it.
The CRU code is in no way special. On the contrary it is of the average mediocre quality that can be found in most academic institutions. In order to fix such codes and develop a high quality reliable software, non-trivial time-consuming and cumbersome professional commercial engineering work is required.
Just completed reading Climategate: The CRUtape Letters. Excellent book! Yes this is:
1. Academic science vs. Commercial engineering.
2. Secrecy vs. Transparancy.
3. Corruption vs. Honesty.
4. Michael Mann and Phil Jones vs. Steve McIntyre and Anthony Watts.
And it’s David vs. Goliath.
One more point. The papers positing that Man is responsible for the 2-2.5 ky delay in the onset of the next ice age are:
Ruddiman, W.F., 2003. The anthropocene greenhouse era began thousands of years
ago. Clim. Change 61, 261–293.
Ruddiman, W.F., 2005. Cold climate during the closest Stage 11 analog to recent
millennia. Quat. Sci. Rev. 24, 1111–1121.
Ruddiman, W.F., 2006. On “The Holocene CO2 rise: anthropogenic or natural”. Eos
Trans. AGU 87 (35), 352–353.
Ruddiman, W.F., 2007. The early anthropogenic hypothesis: challenges and
responses. Rev. Geophys. 45, RG4001, doi:10.1029/2006RG000207.
Hansen, J., Saito, M., Kharecha, P., Beerling, D., Berner, R., Masson-Delmotte, V.,
Pagani, M., Raymo, M., Royer, D.L., Zachos, J.C., 2008. Target atmospheric CO2:
where should humanity aim? Open Atmos. Sci. J. 2, 217–231.
The bottom-line is that the AGW argument for the delay in the onset of the next ice age as calculated by straight application of Milankovitch theory can be dismissed by accepting Huybers’ “Early Pleistocene glacial cycles and the integrated summer insolation forcing” explaination. The fact that the MIS-11 interglacial can be explained by Huybers’ theory with presumably no AGW influences is significant.
Mike Ramsey
Ice Ages maybe a result of Earths position in the Milky Way according to CERN
Call me a simple Mechanical Engineer if you wish, but I fail to see how the Earths orbit can change hugely without a massive increase or reduction of kinetic energy. This could only occur in practice if the Earth was hit by something pretty massive.
I accept that gravitational forces of other bodies can change the shape of the orbital ellipse, but this would not produce a global Ice Age. Rather it would mean that the Earth would exhibit more extreme temperatures (ie it would be hotter and colder) within the cycle.
And none of this accounts for why Ice Ages turn up almost like clockwork – ie they are too regular to be the result of a chance impact.
The only logical answer I have seen for why Ice Ages are so regular was put forward by CERN scientists. They said the frequency coincided precisely with the time it took Earth to travel between the spiral arms in the Milky Way – about 140,000 years. They said was that whilst Earth was in one of the spiral arms, the atomic ray intensity was much, much higher causing a huge increase in cloud seeding. The Earth was blanketed in cloud for thousands of years and temperatures just plummeted. It seemed so logical to me. Especially as the correlation was perfect. It also explains why the ice retreats afterwards and ‘snowball Earth’ doesn’t happen.
I saw a presentation online recently but I am dammed if I can find it again.
Sorry
‘Atomic ray’ should be ‘atomic particles’.
Unfortunately the “Rohling metod” that this study is based on is a can of worms. What it measures is not the sea-level as such, but rather the height of the sea level above the threshold in the Bab el Mandeb strait.
Unfortunately this area is one of the most tectonically active areas on Earth (it is a “Triple Junction”, i e a place where three continental plates are separating from each other). It is incidentally also right next to the “Afar triangle”, the only place on Earth where a sizable piece of oceanic crust is above sealevel.
In this environment the chances of the level of the sill and the profile of the strait remaining unchanged for 400,000 years are very low.
Looking at insolation over the whole season has to make more sense than just at solstice. For several reasons. The integration of the orbital elements is non trivial, and not amenable to simple one date analysis. For example, changes in obliquity will interact with changes in the precession of the equinox and changes in eccentricity of orbit. There will be epochs where solstice NH insolation is high, but tails off more rapidly in the shoulder seasons, and epochs where solstice insolation is lower, but stays at highish levels into the shoulder seasons.
Richard Lawson (12:36:06) :
Jasper Kirkby:
video
http://cdsweb.cern.ch/record/1181073/
PDF
http://indico.cern.ch/getFile.py/access?resId=0&materialId=slides&confId=52576
Chris F (12:18:58) :
(…)
I wonder if there are any geoengineering solutions available to counter this. Seriously, this is no laughing matter.
In a few hundred years we’ll have self-replicating robots on the Moon who can fabricate reflectors and start covering the surface. Aim them at the Earth as needed for the few extra watts to keep the ice at bay. That’s much saner than trying to directly modify the situation down here on the planet.
Still groping in the dark. We´re in need of a new cosmological view. However scientists have to live neither hurting common paradigms nor believers or deniers alike, just “roses, roses”, everybody happy…until the next “gate” opens up.
Richard Lawson (12:36:06)
Link is here: http://cdsweb.cern.ch/record/1181073/
Svalgaard: what is the energy in the cosmic ray flux compared to simple day light?
DirkH (13:13:06)
Thank you.
Look for a link in the sidebar under “Pages”.
[Note: for some browsers the screen size must be expanded in order to see Tips & Notes. On a Mac, hold down the ⌘ (Command) key while hitting the “=” key. Same sequence using the “-” (minus) key reduces the screen size. ~dbs]
“Why do the eco-wackos want the earth covered in ice?”
That’s easy to answer. It would make humans extinct.
The history of the natural climate is and will remain the history of the astronomical orbit and at least E+03 accurately discerned cycles of period E+05 years demonstrate that conclusively, and there is no energy influence to change the Earth’s climate that would not change the Earth’s angular momentum or the topology of the Earth’s orbit in it’s course round the Sun.
Things that were considered foundational to science fifty years ago are ignored today, if nothing else, I suppose this demonstrates the magnitude of the influence of the cult of personality
I find it interesting that a single or primary cause is sought after. There is no reason both theories cannot be effective. In the context of this article, there is also no need for a rival theory, unless one makes the assumption that the galactic arms maintain the same shape and identical spacing over each 400K orbit of the solar system. Another concept of the same ilk has been proffered regarding past climate. The MIS-11 interglacial had CO2 ranging from 4000ppm dropping to current levels over its interval.
Paleo temp/CO2 plot: http://i46.tinypic.com/2582sg6.jpg
crosspatch (11:08:43) I agree with your assessment, I noticed the decline in the peaks of previous warm periods since the Holocene.
“That’s easy to answer. It would make humans extinct.
Excepting for those who could bear the cost of survival. I had a discussion with a Greenpiece advocate who confided that he was aware that the “poor end” would not survive a shift to “green,” progressively fewer able to survive as “carbon” limits were ratcheted down to some 80% of what they are today.
That single discussion put the burning anger in me that is reflected in every single thing that I write
Chris F (12:18:58) :
Possibly being 2,000 yrs overdue for an ice age beginning is very scary stuff indeed. Worrying about warming when the exact opposite is what we most likely face is a very serious crime being foisted upon us by scientists and the media.
I wonder if there are any geoengineering solutions available to counter this. Seriously, this is no laughing matter.
Hmmm, so the next Ice Age is overdue by two millenia. And the reason is a mystery. Now what was it that happened approximately 2000 years ago that promised salvation for all humankind? Hmmm, now what could that be?
No, geoengineering will not save us from the cold, but prayer just might!
(This comment was entirely tongue-in-cheek, but I think my explanation is about as plausible as this attempt to extend blame for AGW back to the ancient world. Darn those Romans and all their civilizing technology!)
Brian G Valentine (14:04:52) :
“That’s easy to answer. It would make humans extinct.
Excepting for those who could bear the cost of survival. I had a discussion with a Greenpiece advocate who confided that he was aware that the “poor end” would not survive a shift to “green,” progressively fewer able to survive as “carbon” limits were ratcheted down to some 80% of what they are today.
That single discussion put the burning anger in me that is reflected in every single thing that I write
———————
Count me in on that one-as one who wouldn’t pass an Aryan test, and seems to into Klowns like your Greenpeece character on a regular basis,a white,
greeines biggest fear is healthy,happy_prosperous_ dark skinned people…