Posted on 06/01/2006 1:02:47 PM PDT by Ernest_at_the_Beach
A treasure trove of scientific data is revealing detailed information about conditions of subtropical warmth at the North Pole about 55 million years ago while also providing a window into the future, when greenhouse gases are expected to reach the same levels that caused Earth's ancient heat wave.
Researchers aboard a fleet of icebreakers collected samples by drilling into the floor of the Arctic Ocean during a 2004 expedition, and scientific findings will be published for the first time in several papers to appear Thursday (June 1) in Nature magazine.
"This project was a technological feat, and all of the findings in these papers are especially new and exciting given the fact that nobody's ever taken core samples like this before from the floor of the Arctic Ocean," said Matthew Huber, an assistant professor of earth and atmospheric sciences in Purdue University's College of Science. "As a climate modeler, gaining access to this data is a once-in-a-lifetime opportunity."
The expedition was part of an international research effort called the Integrated Ocean Drilling Program, which explores the Earth's history and structure as recorded in seafloor sediments and rocks.
Huber used new data from the research to compare against results from complex climate-model simulations he performed to study and predict the effects of greenhouse gases. He co-authored two research papers to appear in Nature detailing conditions in the Arctic Ocean 55 to 50 million years ago during a time of unprecedented global warmth.
The cylindrical core samples contained the remains of ancient plant and animal life, which yielded critical new information about the Arctic Ocean during that time. Researchers used a recently developed technique called TEX-86, which enables scientists to measure the temperatures that existed when ancient organisms lived by analyzing the composition of fatty substances called lipids in their cell membranes. Using this technique, the researchers found that sea surface temperatures at the North Pole had soared to 23 degrees Celsius, or around 73 degrees Fahrenheit, during the Paleocene-Eocene Thermal Maximum, or the PETM, about 55 million years ago. Today's mean annual temperature at the North Pole is around minus 20 degrees Celsius, Huber said.
Researchers also discovered the remains of tiny algae called dinoflagellates, belonging to the species Apectodinium, which previously had been restricted to warmer regions of the world.
"The presence of Apectodinium during the Paleocene-Eocene Thermal Maximum provides confirmation that subtropical conditions arrived in the Arctic during this time," Huber said.
Among the most important reported findings was the discovery that 5 million years later, around 50 million years ago, the Arctic Ocean was frequently covered with dense mats of a freshwater fern called Azolla, which flourishes in ponds, said Henk Brinkhuis, a marine palynologist and biogeologist from Utrecht University in the Netherlands and lead author on one of the Nature papers.
"Imagine that the Arctic Ocean was a giant lake, with this vegetation growing in it," Brinkhuis said. "What these findings say is that the Arctic Ocean must have been isolated, or nearly cut off, from the Atlantic Ocean by land masses that later shifted into the present continents. Today, if you hop in a boat and head north in the Atlantic Ocean, you could go all the way to the Arctic Ocean. But back then it was more isolated, which prevented salt water from ocean surface currents from reaching there."
The beginning of the Paleocene-Eocene Thermal Maximum was marked by a huge release of a greenhouse gas, possibly carbon dioxide or methane, into the atmosphere. Methane, frozen in solid "methane hydrate" deposits on the ocean floor, might have been disturbed by some geologic event, such as mudslides or an earthquake, causing the gas to bubble to the surface. The methane would have then broken down into carbon dioxide in the atmosphere.
The resulting greenhouse effect caused global temperatures to rise by an average of about 5 degrees Celsius.
"This provides a beautiful natural experiment for understanding global warming and environmental change and is probably the best historical analogy for today's release of greenhouse gases from human-related sources," said Appy Sluijs, a doctoral student at Utrecht University's Institute of Environmental Biology and lead author on the other Nature paper. "There is no clearer evidence for greenhouse-gas-induced global warming in the geologic record."
"We now have a pretty good correlation between records of past warmth and higher carbon dioxide concentrations," Huber said. "What it tells you is that it's not too difficult to push the climate system to a warm state. This event was a large release of a greenhouse gas. That's why it's a good analog for today's greenhouse-gas emissions, and it shows without a doubt that if you pump a bunch of greenhouse gas into the atmosphere, the planet warms.
"If you work out the numbers, it's almost identical to what we are expected to do over the next few hundred years."
While the climate models had predicted that researchers would discover the Arctic Ocean's freshwater past, the models have consistently underestimated by at least 10 degrees how hot the Earth would have been during that time, Huber said.
The models fail to explain another puzzling fact. The temperature difference between the North Pole and the equator today is about 45 degrees C. But the difference appears to have been much smaller during the Paleocene-Eocene Thermal Maximum time frame. Otherwise, it would have been too hot for vegetation to survive in equatorial latitudes.
"We still haven't explained why the tropics stayed cool," Huber said. "Somehow, we have to explain how you can warm the poles up to 23 degrees Celsius without having the tropics rise to at least 50 degrees, which is 10 degrees too hot for plants to carry out photosynthesis."
He said the implications are troubling because current models may be providing optimistic predictions.
"Today's models underpredict how warm the poles were back then, which tells you something disturbing — that the models, if anything, aren't sensitive enough to greenhouse gases," Huber said. "At the same time, it is possible that other forces in addition to higher-than-normal greenhouse gas concentrations were involved, otherwise we can't explain how the tropics maintained livable conditions.
"People have conjectured that polar stratospheric clouds or hurricane-induced ocean heat transport might have played crucial roles in amplifying polar heating, but much work needs to be done to prove this. Mechanisms that feed back onto global warming are poorly understood and not well represented into our current generation of models. This should be of great concern and will continue to be debated and explored in future research.
"Even people who describe themselves as global warming skeptics can accept the fact that massive changes happened in the past because research shows that climate change is natural. But the real point is that not only is climate change natural, but it's also easy to set in motion. All it takes is an increase in the concentration of greenhouse gases."
Scientists may explore several issues in future work, including research aimed at explaining specifically why the temperatures were so high 55.5 million years ago.
"There is a fundamental discrepancy between what kind of climate we expect to result from high atmospheric greenhouse gas concentrations, and what kind of climate really prevailed during these ancient epochs," Sluijs said. "We, hence, need to improve our climate models. An important question is, what was seasonality like in the Arctic? Was there an as-large temperature difference between summer and winter as there is nowadays?"
Source: Purdue University
The movie "Day Before Tomorrow"--environmentalists and climatologists dream movie.
Wasn't Lech Walesa a North Pole?
I didn't know they had gas guzzling SUVs 55 million years ago.
The tropics temperature increased by only about 5 degrees Celsius while the North Pole increased by 43 degrees.
Clearly there is something wrong with the analysis. When things don't add up, then there is an error.
Perhaps the area sampled was farther South than they thought at the time and was also a shallow freshwater sea rather than ocean. Much of central North America was a shallow sea at the time. Perhaps this now Arctic ocean and Arctic plate location was tied into it at the time. That might explain it better.
Oh, so there must have been something else involved.
From the article: "People have conjectured that polar stratospheric clouds or hurricane-induced ocean heat transport might have played crucial roles in amplifying polar heating, but much work needs to be done to prove this. Mechanisms that feed back onto global warming are poorly understood and not well represented into our current generation of models. This should be of great concern and will continue to be debated and explored in future research."
Again, NOT greenhouse gas, and they don't really know enough about these processes at all.
From the article: "Even people who describe themselves as global warming skeptics can accept the fact that massive changes happened in the past because research shows that climate change is natural. But the real point is that not only is climate change natural, but it's also easy to set in motion. All it takes is an increase in the concentration of greenhouse gases."
Compare that last sentence, all it takes is an increase in greenhouse gas - but he said right before that, greenhouse gases alone do NOT explain it. And he ends by saying we can all admit these things happened in the past and climate change is NATURAL.
ping
Read the report.
The location drilled, the Lomonosov Ridge was likely attached to the Eurasian plate 56 million years ago, much of which was also shallow sea at the time, somewhat South of where it is now but still close to the arctic circle.
The Modelers now have a problem....
drill in the ground and know what was happening 50 million years ago?
can Huber tell me what I ate for lunch if I fart in his general direction?
An inconvenient report.
You might find this interesting.
55 Million Years ago, there was no Isthmus of Panama and a much less constrained Drake Passage. The ocean currents circled the Globe at the Equator and there was no Gulf Stream. I would imagine the climate to have been drastically different. To compare 55 million years ago with now (or with the next 1000 years) is apples and oranges. This tells us precisely nothing about what to expect assuming arthropgenic global warming is even happening at all.
How does the theory that at one time the earth flopped 90 degrees, putting the north pole at the equator?
Clearly these "experts" are guessing. They've discovered that the pole or poles at one time were much, much warmer. If the poles were as warm as they say they were from this recent evidence, how did the earth survive? The melting of the ice should have swamped everything. These guys aren't idiots, but it sounds like they're clearly puzzled by what they've found and can only resort to the usual global warming scare words as a conclusion. The upshot of it is that at one time the earth was much warmer. And the world survived added warmth. Imagine that! (smirk)
Would not an increase in atmospheric water vapor induced by such elevated temperatures serve as an equalizing blanket to more evenly distribute atmospheric heat over the planetary surface?
It seems to me that increasing the global average temperature would increase evaporative activity over the oceanic surfaces, driving more water vapor into the atmosphere. That increase humidity would increase the thermal conductivity of the atmosphere, while also increasing the incidence and size of clouds at all altitudes. Both taken together might well have a blanketing effect that, like the roof on a greenhouse, would serve to distribute local heat over a far greater area of the globe with an equalizing effect.
Do I need to detail for you the contradictions in this article? Or will you just stipulate that something is out of whack with that?
They have a correlation -- in this one instance, something might have caused methane ice trapped at the bottom of the sea to flood the atmosphere with Co2.
Now, did that Co2 cause the temp increase? Or, did whatever massive geologic event it was cause the temp increase, and the Co2 release was a by-product?
Suppose a long string of comets/space debris hit, and released the ice, and caused fires across the globe, and massive tectonic upheavals that created heat? I can imagine a thousand possible explanations for what happened.
They just don't know yet. Clearly their models -- the ones you folks so dearly rely on, are not even close to accurate.
This is just one more nail in the coffin for ya'll, it appears. It goes on and on about how bad the models are.
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