The prevailing theory (on Dino extinction) is said to be a comet/meteor strike, evidenced in the KT Iridium layer, found worldwide. This study though suggests that even though CO2 was high during the Cretaceous, it could still turn cold abruptly. Obviously a stronger forcing of some kind operated then.
Image above: more info
From a Plymouth University Press Release
Scientists identify freezing times for Cretaceous dinosaurs
Summary
Further detail
The drop is estimated to have occurred some 137 million years ago during a time when dinosaurs roamed the Earth, and would have seen the islands fall from an average of 13 degrees centigrade (ocean temperature) to as low as four degrees.
The findings, which were published in the journal Geology and featured as a highlight in Nature Geoscience, will further contribute to the debate over climate change as they appear to contradict the common model which links high levels of Carbon Dioxide (CO2) – as recorded in the Cretaceous era – with reduced polar ice caps.
Despite being located in the Arctic Circle, Svalbard was home to numerous species of dinosaur and was typically characterised by warm, shallow seas and swamps.
But the research team, led by Dr Gregory Price of the University of Plymouth, found evidence in fossils and carbonate materials preserved in marine rocks in the region of a transient shift to cooler glacial conditions around 137 million years ago.
Dr Price said: “At certain times in the geological past, the world has been dominated by greenhouse conditions with elevated CO2 levels and warm Polar Regions, and hence, these are seen as analogues of future global climate.
“But this research suggests that for short periods of time the Earth plunged back to colder temperatures, which not only poses interesting questions in terms of how the dinosaurs might have coped, but also over the nature of climate change itself.”
Dr Price, along with Dr Elizabeth Nunn, of Johannes Gutenburg Universitat in Mainz, Germany, first visited Svalbard in 2005 to collect fossils and samples, in an area famed for a number of paleontological discoveries, including giant marine reptiles such as pliosaurs and icthyosaurs.
The samples were analysed back in Plymouth and prompted return trips to the area to gather more evidence.
“The flourishing of the dinosaurs and a range of other data indicates that the Cretaceous period was considerably warmer and boasted a high degree of CO2 in the atmosphere,” said Dr Price.
“But over a period of a few hundred or a few thousand years, ocean temperatures fell from an average of 13 degrees centigrade to between eight and four degrees.
“Although a short episode of cool polar conditions is potentially at odds with a high CO2 world, our data demonstrates the variability of climate over long timescales.”
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I found myself thinking “Desperate attempt to link their research to having relevance to Global Warming in the hopes of getting more attention”.
Unless they are arguing for geo-engineering by going out and lasooing a nice big meteorite to fire off into an ocean. Which I suspect they aren’t.
Every one now knows climate change causes everything, including those things that cause climate change.
But seriously folks, check out how rapidly this study says the climate changed. Also note the complete absence of a run-away greenhouse affect. Where are the positive feedbacks which are supposed to be dominating the system?
There’s only one explanation for this: The authors of this study are in bed with “big oil” How do we know that? Dinosaurs. Oil. You figure it out.
Hmmm, why is a picture showing KT boundary layers used here?
I thought that the KT boundary event was 65MYA, not 137MYA?
REPLY: Because it it another “coping event” for Dinosaurs
I don’t know why, but I’ve always suspected that transitions from warm to cold (including ice ages) occur quickly, in the order of one or two centuries at most. In contrast, the reverse happens over periods of thousands of years. We therefore get very little warning of an ice age, which is also far more dangerous to an advanced (soft) civilization than a warm era.
The Telegraph has a much different take on this. They actually state that high CO2 levels caused melting ice, which caused the cooling.
Hot is cold. Up is down. Left is right.
http://www.telegraph.co.uk/science/dinosaurs/7624014/Dinosaurs-died-from-sudden-temperature-drop-not-comet-strike-scientists-claim.html
A better article than the one in the Telegraph that claimed “the drop in temperature happened when the Earth was in a ”greenhouse” climate, which was very similar to now.” (Emphasis added).
Not that this is exactly new news, the drop in temperature spanning the Jurassic/Cretaceous boundary has been known at least since 2001.
Well shucks! Sounds like we’ve got a few thousand years before Svalbard will have shallow warm seas that could support cold-blooded dinosaurs at the current warming rate. By then we can all just move to some other planet.
“The findings, which were published in the journal Geology and featured as a highlight in Nature Geoscience, will further contribute to the debate over climate change…”
Oh no it won’t. Debate’s over. Debate’s over. Debate’s over. La la la la la la la la. Not listening! Debate’s over! La la la la la…
So the theory goes it waz the cosmic rays that did it???????????????
Man is but a blip in time on our beautiful planet. A time will come when all mankind will disappear from the earth. It will be fast and furious and will come from above. This whole idea of AGW global warming is so proposterous I am surprised it is getting nothing more than a chuckle. Sadly, there is a sucker born every minute, which means there are a lot of suckers out there…..roughly 80% of the population….sadly..
Finally common sense is starting to rear its ugly head, and we see the alarmists for who they really are. Pathetic demented control freaks.
Enjoy life, and live every day like it is your last. There is no coming back once you are gone, so do all you can do , and see all you can in the short microcosmic spec of time you are here.
Ian
No S*** Sherlock…..
Myself and many other Earth Scientists (I still detest this description of geologists) who frequent this site have been immersed in these very rocks the Earth has chosen to capture Her history with far longer than would seem apparant from these press releases.
Rocks that have for years told us of a cyclical environment which has blown hot and cold for millennia and will continue to do long after Homo Sapiens has been wiped clean from the surface. Muchlike our reptilian friends were at the end of the Cretaceous.
This is not breaking news. Might be for a muppet like Ed Milliband, the UK’s Climate Change Minister (you couldn’t make it up)
I’d like to focus on this sentence: “At certain times in the geological past, the world has been dominated by greenhouse conditions with elevated CO2 levels and warm Polar Regions, and hence, these are seen as analogues of future global climate.”
Let’s see, according to idealogues future global warming is a disaster of epic proportion, yet it’s pretty obvious that life was thriving during the “greenhouse conditions”, to the point of being capable of supporting life-forms far larger than any that exist today.
On the other hand global cooling, in particular rapid drops in temperatures like the one that occurred some 137 million years ago, leads to mass extinction events.
And hey, if this means that global warming turns birds back into dinosaurs, how cool would that be? An irreverant point perhaps, but no less plausible than a lot of what we here from AGW doomsayers.
Was there a Gulf Stream 140 million years ago? Where was Svalbard?
Climate change to the earth is analagous to navel gazing to a human–simply no big deal; it comes with the territory.
Like other geologists, I fail to see anything new here. But perhaps emphasizing that there are larger, more drastic climate change agents than CO2 will make a few AGW believers think a bit deeper.
So I guess there’s no connection between the opening of the Atlantic Ocean (remember Iceland? ) around the time of the K-T barrier, iridium found in volcanic ash, and the resulting volcanic winter.
The inference in the PR release statement, “Despite being located in the Arctic Circle, Svalbard was home to numerous species of dinosaur and was typically characterised by warm, shallow seas and swamps” is a bit disingenuous since Svalbard thousands of miles to the south of the Arctic Circle at that time.
It is an interesting point regarding dinosaurs and relatively rapid temperature change. As the Cretaceous period was a time when the huge areas of what we now have as dry land was covered in shallow seas, the dinosaurs were considerably more constrained in where they could move to whilst escaping chillier conditions moving toward the equator from the poles. This must have produced some intense competition as forcibly intermixed species attempted to survive.
I notice one of the other articles on the Telegraph website is headed “Breathing causes heart attacks”
Its probably all that super-heated CO2 in the air.
@ur momisugly L. Nettles, you’re on to something there. Given the dynamics of plate tectonics, where indeed was the region of today’s Svalbard Islands 137 million years ago? Perhaps not anywhere near the Arctic Circle. And was there a Gulf Stream? Or even an Atlantic Ocean? And if this sudden cooling was supposed to have had such a dramatic effect on the dinosaurs, how come they didn’t finally die out for another 70 million years? Besides, I thought the latest speculation was that the dinosaurs were warm-blooded, not cold-blooded. Do these geologists have the interdisciplinary creds to back up their theory? Something is very fishy about this study, if you ask me.
“Although a short episode of cool polar conditions is potentially at odds with a high CO2 world, our data demonstrates the variability of climate over long timescales.”
Amazing. Despite all the evidence pointing to the fact that C02 doesn’t drive climate, that it is in fact a result of climate change, going up some 800 years after temperatures rise, and temperatures being able to drop like a stone, despite those high C02 levels, these “scientists” still don’t get it. They really do seem dumber than a box of hammers.
Has the cult of CO2-warming become so overpowering that “earth scientists” completely ignore an inch-thick iridium-rich marker? Do they just miss it or ascribe some other origin for it?–perhaps they believe that Ir was caused by some forcing agent that turns lead into this most unusual of precious metals–only, of course, in the presence of sufficient concentrations of CO2. Would that I could find the magical formula!
Reptiles were GREEN….
That’s why they were destroyed by an asteroid sent from above!
The Telegraph article is all screwed up. Somehow this 137 million year ago event has been confused with the 65 million year ago event. The dinosaurs did survive the 137 mya event, but not the later one.
http://www.telegraph.co.uk/science/dinosaurs/7624014/Dinosaurs-died-from-sudden-temperature-drop-not-comet-strike-scientists-claim.html
Professional journalism strikes again!
No one knows the number theories there are to explain the extinction of the dinosaurs.
Every “scientist” have at least one. It has been like this for as long as I can remember.
Update: Second formatting issue still there. Text under pic still cut off by right-side menu bar.
Viewed on Iceweasel (Firefox) 3.0.6, OS Debian Linux.
A few points in relation to the posts above:
This has absolutely nothing to do with dinosaur extinction. It happenen 137 million years ago, that means 72 million years before dinosaurs became extinct. That is a much longer time than has passed since dinosaurs actually did become extinct (65 million years). The Telegraph article is just AGW spin. Incidentally the climate then was in no way similar to now. It was vastly warmer, truly a greenhouse climate, in contrast to current icehouse climate.
There was NO major extinction at that time.
There was no Gulf stream then, and Svalbard was nearly as far North as it is now.
The iridium layer at the K/T boundary is cosmogenic, not volcanic as shown by the isotope ratios. And it has nothing to do with Icelandic volcanism, which started well after the K/T boundary. Icelandic volcanism may well have something to do with the PETM warm pulse 55 million years ago, but not with dinosaur extinction 10 million years earlier. Volcanism in Deccan, India which spans the K/T boundary on the other hand may have had an influence on dinosaur extinction.