Posted by: Christine Johnson | June 23, 2006

In Response to Local Man

Is global warming real? Or is it all just cyclical?

Let’s look at some evidence.

Prehistoric reptiles in the balmy Canadian Arctic

By: Tamar Simon, December 21, 1998

You think we’ve had a mild winter so far? Well, a fossil discovery in the Canadian high Arctic shows that this is nothing. After finding the bones of a prehistoric, cold-blooded reptile called champsosaur near the North Pole, scientists are rethinking their theories on the Earth’s climate 90 million years ago — and turning up the heat.

The fossils were found in the summer of 1996 on Axel Heiberg Island by a team led by geophysicist John Tarduno of the University of Rochester. The Canadian island lies within the Arctic Circle, just over 1100 kilometres from the North Pole, and on a day like today would likely experience temperatures of 30 to 40 degrees below zero Celsius. But according to Tarduno, the discovery of the bones — including tibia, vertebrae, femur and jaw bones from several different champsosaurs — shows that the now-chilly north once had a climate more conducive to building that backyard pool.

“It’s surprising and extremely interesting,” Tarduno says. “It’s something of a puzzle.”
The first piece of the puzzle was uncovered when Tarduno took his team of students up to Axel Heiberg to take samples of hardened, unusually thick volcanic rock on the island. “The lava flows [found there] are ten metres thick, ten times the thickness of flows today,” Tarduno explains. “That represents extremely vigorous volcanic activity. “

While on the island, the team found transitional rock right on top of the lava and below some marine rock — a type of sediment ideal for preserving fossils.

“I bet the students we’d find fossils,” Tarduno recalls. “Within five minutes one of my students pulled up a femur and said, ‘Like this?'”

The bones were then given to Donald Brinkman, the vertebrae paleontologist at Alberta’s Royal Tyrrell Museum, for analysis. It turned out to be an easy I.D.: the champsosaur, a well-studied crocodile-like reptile with a long snout, lots of teeth, well-developed limbs and a semi-aquatic lifestyle. Champsosaurs lived in the late Cretaceous period 92 to 86 million years ago, just at the end of the dinosaur period. The Axel Heiberg champsosaur was large — over two metres long.
But while champsosaur fossils have been found in Asia and North America, they have never been found this far north. And that’s where the mystery lies — because, as Brinkman puts it, the average Axel Heiberg temperature is “cold!”

“This is an ectothermic reptile,” Brinkman explains. “Dinosaurs could generate heat to control body temperature, but this wouldn’t have been able to.”

Therefore, for a champsosaur population to survive on the island, the mean annual temperatures in the high Arctic during the late Cretaceous period must have been about 14 degrees Celsius — much warmer than the zero degree mean previously assumed. But according to Tarduno, adjusting our view of late Cretaceous Earth to include a high Arctic that feels like present-day North Carolina throws all our assumptions about global climate into turmoil.
“When we think of global climate, we look at the [North and South] poles to equator gradient,” Tarduno explains. “This fossil evidence shows that the [assumed] mean annual Arctic temperature of zero degrees couldn’t have been. But if the near polar climate was warm, the entire Earth would be warmer than previously thought.”

“It’s interesting for climate modelers,” he adds. “Polar regions are extremely important to determing how the whole global climate works. How did the equator not overheat?”
While continental shifts might mean Axel Heiberg was farther south 90 million years ago, Tarduno and Brinkman say it would still have been above sixty degrees latitude, in what is considered high Arctic. They say that the new evidence suggests that there was probably a lesser range of global temperatures from the equator to the poles than was previously thought. They also say that the fossils show there may have been a Cretaceous “greenhouse effect” caused by all the volcanic activity.

“We can’t avoid the fact that these fossils are sitting right on top of this extremely large volcanic eruption,” Tarduno says. “It’s very reasonable to suggest that so much CO2 was dumped into the atmosphere that it overwhelmed the system, causing global warming.”

Tarduno hopes to return to the Arctic this summer to look at different localities in the same latitude, to look for other evidence of the prehistoric climate. In the meantime his study, co-authored by Brinkman, Paul Renne of the Berkeley Geochronology Center and Pat Castillo of the Scripps Insitute of Oceanography, can be read in this week’s issue of the journal Science.

Or this:

New Fossil Study May Resolve Prehistoric Climate Paradox

…Climate models consistently predict that high carbon dioxide levels 70 million years ago, during the Late Cretaceous and Eocene epochs, caused a greenhouse effect that led to universally higher temperatures on Earth—when the poles were ice-free and heat-loving animals such as crocodiles and turtles roamed as far north as the Arctic Circle. …

Or this:

Evidence for Extreme Climatic Warmth from Late Cretaceous Arctic Vertebrates

J. A. Tarduno*, D. B. Brinkman, P. R. Renne, R. D. Cottrell, H. Scher, P. Castillo

Abstract

A Late Cretaceous (92 to 86 million years ago) vertebrate assemblage from the high Canadian Arctic (Axel Heiberg Island) implies that polar climates were warm (mean annual temperature exceeding 14°C) rather than near freezing. The assemblage includes large (2.4 meters long) champsosaurs, which are extinct crocodilelike reptiles. Magmatism at six large igneous provinces at this time suggests that volcanic carbon dioxide emissions helped cause the global warmth. …

Global warming: cyclical, and having nothing to do with Man.

And the fact that these things have been known for nearly a decade only makes me firmer in my belief that those scientists who tout this stuff are full of it. It’s like a cult, and they are determined to brainwash us all into believing it.

Remember to get your stories into ABC so they can have some really bad science based on solicited anecdotal evidence.

Advertisements

Categories

%d bloggers like this: