Update: PDF of this paper is available, see link below
The fear that global temperature can change very quickly and cause dramatic climate changes that may have a disastrous impact on many countries and populations is great around the world. But what causes climate change and is it possible to predict future climate change? New research from the Niels Bohr Institute at the University of Copenhagen shows that it may be due to an accumulation of different chaotic influences and as a result would be difficult to predict. The results have just been published in Geophysical Research Letters.
For millions of years the Earth’s climate has alternated between about 100,000 years of ice age and approximately 10-15,000 years of a warm climate like we have today. The climate change is controlled by the Earth’s orbit in space, that is to say the Earth’s tilt and distance from the sun. But there are also other climatic shifts in the Earth’s history and what caused those?
Dramatic climate change of the past
By analysing the ice cores that are drilled through the more than three kilometer thick ice sheet in Greenland, scientists can obtain information about the temperature and climate going back around 140,000 years.
The most pronounced climate shifts besides the end of the ice age is a series of climate changes during the ice age where the temperature suddenly rose 10-15 degrees in less than 10 years. The climate change lasted perhaps 1000 years, then – bang – the temperature fell drastically and the climate changed again. This happened several times during the ice age and these climate shifts are called the Dansgaard-Oeschger events after the researchers who discovered and described them. Such a sudden, dramatic shift in climate from one state to another is called a tipping point. However, the cause of the rapid climate change is not known and researchers have been unable to reproduce them in modern climate models.
The climate in the balance
“We have made a theoretical modelling of two different scenarios that might trigger climate change. We wanted to investigate if it could be determined whether there was an external factor which caused the climate change or whether the shift was due to an accumulation of small, chaotic fluctuations”, explains Peter Ditlevsen, a climate researcher at the Niels Bohr Institute.
He explains that in one scenario the climate is like a seesaw that has tipped to one side. If sufficient weight is placed on the other side the seesaw will tip – the climate will change from one state to another. This could be, for example, an increase in the atmospheric content of CO2 triggering a shift in the climate.
In the second scenario the climate is like a ball in a trench, which represents one climate state. The ball will be continuously pushed by chaos-dynamical fluctuations such as storms, heat waves, heavy rainfall and the melting of ice sheets, which affect ocean currents and so on. The turmoil in the climate system may finally push the ball over into the other trench, which represents a different climate state.
Peter Ditlevsen’s research shows that you can actually distinguish between the two scenarios and it was the chaos-dynamical fluctuations that were the triggering cause of the dramatic climate changes during the ice age. This means that they are very difficult to predict.
Warm future climate
But what about today – what can happen to the climate of the future? “Today we have a different situation than during the ice age. The Earth has not had such a high CO2 content in the atmosphere since more than 15 million years ago, when the climate was very warm and alligators lived in England. So we have already started tilting the seesaw and at the same time the ball is perhaps getting kicked more and could jump over into the other trench. This could mean that the climate might not just slowly gets warmer over the next 1000 years, but that major climate changes theoretically could happen within a few decades”, estimates Peter Ditlevsen, but stresses that his research only deals with investigating the climate of the past and not predictions of the future climate.
Contact:
Peter Ditlevsen, climate researcher, PhD. Dr. Scient., Associate professor, Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, +45 3532-0603, +45 2875-0603, pditlev@gfy.ku.dk
Link to article in Geophysical Research Letters: http://www.agu.org/journals/gl/papersinpress.shtml#id2010GL044486
Update: PDF of full paper now available here
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some chaos stuff that is not so chaotic
from walterdnes over at solarcycle24.com
Here’s another idea. It’s so glaringly obvious that I wish I had made the connection. But connecting apparently unconnected stuff is the sign of true genius. A post by gus in the “Katla Watch” thread… http://solarcycle24com.proboards.com/ind….1322&post=54230
I’ve read that it is thought to be the natural decay of radioactive elements inside the Earth that keeps the planet hot enough for volcanic action. http://www.tulane.edu/~sanelson/eens211/earths_interior.htm
Here is new proof that increased solar activity slows the decay rate and that the decay rate is higher with a quiet sun like at the current solar minimum.
http://www.sciencedaily.com/releases/2010/08/100825093253.htm
The increased decay rate due to the current solar minimum should result in more heat created inside the Earth that could result in higher volcanic action and so increased risk for Katla to go BOOM!!!
here’s what I read:
theoretical
modelling
might
if
if
could
may
could
theoretically
could
sounds pretty solid to me.
Savage indictment of the IPCC
http://www.telegraph.co.uk/earth/environment/climatechange/7971780/Climate-change-predictions-must-be-based-on-evidence-report-on-IPCC-says.html
“The Earth has not had such a high CO2 content in the atmosphere since more than 15 million years ago,”
Right, and we had CO2 much higher than now during three periods on the last 200 years. So, this argument is bogus. Discounting and ignoring virtually all direct chemical Co2 bottle data is just too pat a way to create a false conclusion. It begs credibility to assume ice core indirect data to be more accurate than direct chemical bottle data. Making such sweeping unsupportable statements, the authors could be accused of simply flowing a political agenda/party line.
“So we have already started tilting the seesaw . . .”
As there is no evidence that CO2 has a great influence, more likely small or none, on the climate, they really need to stop with the extended imaginings and be more realistic/conservative in their musings. Here, Elvis has surely left the building. They are marching towards fear-mongering.
(Peter Ditlevsen) “stresses that his research only deals with investigating the climate of the past and not predictions of the future climate”
After making these alarming predictions and pointing at CO2 as a possibly facilitator of tipping (in my opinion a very weak idea), he then waffles and retreats, having done the damage. The predictions should never have been made, if they required a disclaimer, particularly as it feeds the alarmist agenda – unless that was the goal, of course.
Sorry–I don’t believe the climate acts like a trenched seesaw harboring a ball that moves from one side to the other. I believe the climate acts more like a single ball-harboring trench, and forcing the ball to one side of the trench or the other forces it above the minimal state, after which it returns to that minimal state after the force is removed.
I suspect that what I get out the article will be different than what a warmer will decipher.
I expect CAGW proponents will focus on the possibility of a quick warming cycle caused by CO2.
I get that:
“a result would be difficult to predict” “due to an accumulation of different chaotic influences ” – in other words, models are sophisticated enough for the science.
That the CO2 is only an example of a quick cycle, while admitting that life did just fine in the former warm periods.
That the bulk of earth’s past has been ice ages.
And Dr. Ditlevesen states that his work is of past cycles, not future predictions
Would climate change be “dramatic” if it was predictable ? And don’t “unpredictable” and “chaotic” go hand in hand ?
Maybe they are discovering what we already know.
It seems reasonable that if earth’s orbit suddenly changes or some asteroid or comet crashes into the earth; that “dramatic” climate changes might occur. It also seems reasonable that events like that might tend to be unpredictable.
But other than that I don’t see how one could plan for some future unpredictable possibly dramatic event; the climatic result of which we cannot at this time forsee.
I’m going to regret asking this , but how does onr drtermine the makeup of the atmosphere from fifteen million years ago ? Accurately , that is .
How do the day dreams of climatologists get published so easily?
Correction:
I get that:
“a result would be difficult to predict” “due to an accumulation of different chaotic influences ” – in other words, models are NOT sophisticated enough for the science.
“”” New research from the Niels Bohr Institute at the University of Copenhagen “””
What new research ? Computer modelling is not research. Computer simulation can be valuable; once the science behind the model is validated by observations. I do computer simulations all day long; but they are based on the mathematics of geometrical optics and physics that has been validated for over 300 years or more. The simulations are done to complete a design based on well understood science; and not to discover any “new” unknown science.
wayne says:
August 30, 2010 at 9:14 am
How do the day dreams of climatologists get published so easily?
Peer review. In the mutual addoration society, they enable each others dreaming.
We don’t want their feeling hurt.
P Walker says:
August 30, 2010 at 9:10 am
I’m going to regret asking this , but how does onr drtermine the makeup of the atmosphere from fifteen million years ago ? Accurately , that is .
You need three ingredients: ice cores, guesswork, and arrogance.
Regarding the “10-15,000 years of a warm climate like we have today” , where are we in this time period today ?
Anymore, whenever I see a new climate study based upon a computer model, I feel like barfing. Computer models can only tell you an answer based upon what you have programmed the computer to perform. Research conducted in front of a computer screen. If you don’t have a sound theory and accurate observations/measurements, what can you prove? Where is the experiment? Where is the theory? Just as Lindzen stated: We have replaced theory and observations with computer models and simulations. The latter ain’t science.
I found the proper GIF download for this paper at:
http://imagebin.ca/view/gq1dgNd.html
Note the current position!
Max
Neither of these two models are correct, imo, as they both misunderstand (or ignore) chaos theory. A system that exhibits chaos behaviour does not remain in a single state but constantly bifurcates, or cycles, through a sequence of states. Bifurcation was used in the article to describe the ‘seesaw’ model, but this is misleading because it implies that once the seesaw tips, it will remain in that state. This is not how a chaotic system behaviours.
I believe that rather than requiring explanations of mysterious ‘forcings’, the earth’s natural climate variations are a near textbook example of chaos in action – the system moves from state to state. The important point is that under chaos theory, not forcings are required to cause these changing states. This may sound counter intuitive, but many lab experiments have shown these state changes taking place in various systems while the driver is held constant. Mandelbrot’s book on chaos is an excellent primer and offers numerous such examples.
However, after all is said, this is an important line of inquiry, one that may eventually lead climate scientists to ‘bifurcate’ into a new state of understanding.
For most of the last 650 million yeras the Earth has been warmer, or much warmer, than it is now. The present conditions are not the norm. The current ice age has been with us for the last couple of million years.
This seems to be lacking a few facts to put it into correct perspective
George E. Smith says: “. . . I don’t see how one could plan for some future unpredictable possibly dramatic event; the climatic result of which we cannot at this time forsee.”
And yet they still pass the collection plate after services. What’s up with that?
David , UK – I get the guesswork and arrogance , but I didn’t realize that there was fifteen million year ice old lying around .
wayne says:
August 30, 2010 at 9:14 am
How do the day dreams of climatologists get published so easily?
I have found recently that the daydreams of biologists are also published easily–if the so-called scientist has imagined a negative consequence of CO2 or global warming, or how something bad MIGHT occur. No evidence needed for these things to publish. Pro-wind-farm articles also publish easily, but thankfully, most other biological matters require actual science.
Vince Causey says:
August 30, 2010 at 9:39 am
“However, after all is said, this is an important line of inquiry, one that may eventually lead climate scientists to ‘bifurcate’ into a new state of understanding.”
Meanwhile, it can be used …
“to keep the populace alarmed, and thus clamorous to be led to safety, by menacing it with an endless series of hobgoblins, all of them imaginary.”
So the deniers have hijacked another journal? They must have a rotten peer-review! We should stop citing or publishing any papers in this journal!
Report on problems at the IPCC
http://www.nytimes.com/2010/08/31/world/31nations.html?_r=1&hp
“””The Earth has not had such a high CO2 content in the atmosphere since more than 15 million years ago, when the climate was very warm and alligators lived in England.”””
Really? And where was England 15 million years ago? Think tectonics.