may be due in part...
possibly even promote...
may have grown...
was likely covered...
Talk about a leap of faith! 
Posted on 10/30/2003 5:04:39 PM PST by Dales
LIVERMORE, Calif. -- A trio of scientists including a researcher from the Lawrence Livermore National Laboratory has found that humans may owe the relatively mild climate in which their ancestors evolved to tiny marine organisms with shells and skeletons made out of calcium carbonate.
In a paper titled "Carbonate Deposition, Climate Stability and Neoproterozoic Ice Ages" in the Oct. 31 edition of Science, UC Riverside researchers Andy Ridgwell and Martin Kennedy along with LLNL climate scientist Ken Caldeira, discovered that the increased stability in modern climate may be due in part to the evolution of marine plankton living in the open ocean with shells and skeletal material made out of calcium carbonate. They conclude that these marine organisms helped prevent the ice ages of the past few hundred thousand years from turning into a severe global deep freeze.
"The most recent ice ages were mild enough to allow and possibly even promote the evolution of modern humans," Caldeira said. "Without these tiny marine organisms, the ice sheets may have grown to cover the earth, like in the snowball glaciations of the ancient past, and our ancestors might not have survived."
The researchers used a computer model describing the ocean, atmosphere and land surface to look at how atmospheric carbon dioxide would change as a result of glacier growth. They found that, in the distant past, as glaciers started to grow, the oceans would suck the greenhouse gas -- carbon dioxide out of the atmosphere -- making the Earth colder, promoting an even deeper ice age. When marine plankton with carbonate shells and skeletons are added to the model, ocean chemistry is buffered and glacial growth does not cause the ocean to absorb large amounts of carbon dioxide from the atmosphere.
But in Precambrian times (which lasted up until 544 million years ago), marine organisms in the open ocean did not produce carbonate skeletons -- and ancient rocks from the end of the Precambrian geological age indicate that huge glaciers deposited layers of crushed rock debris thousands of meters thick near the equator. If the land was frozen near the equator, then most of the surface of the planet was likely covered in ice, making Earth look like a giant snowball, the researchers said.
Around 200 million years ago, calcium carbonate organisms became critical to helping prevent the earth from freezing over. When the organisms die, their carbonate shells and skeletons settle to the ocean floor, where some dissolve and some are buried in sediments. These deposits help regulate the chemistry of the ocean and the amount of carbon dioxide in the atmosphere. However, in a related study published in Nature on Sept. 25, 2003, Caldeira and LLNL physicist Michael Wickett found that unrestrained release of fossil-fuel carbon dioxide to the atmosphere could threaten extinction for these climate-stabilizing marine organisms.
Talk about a leap of faith!
may owe...Huh??? The press release contains the kind of qualifiers you'd expect a careful scientist to make, and you sneer at it as being evidence of a leap of faith???
may be due in part...
possibly even promote...
may have grown...
was likely covered...Talk about a leap of faith!
If instead they said something like "Earth's temperate climate definitively owes its existence to the rise of marine animals with calcium carbonate shells...", would you not be complaining about the scientists' arrogance for daring to make such a definitive statement about the past? Would you not then solemnly intone the common creationist mantra: "This scientist shows more faith in godless materialism than the most ardent believer in God..."?
What, you say you would never do that? OK, then what should the scientist have said in order for you to not blurt out, "leap of faith"?
A nice Scientific American article on the Snowball Earth hypothesis, which has gained considerable acceptance. (But some people think it was really only a "Slushball Earth.")
The fossil record shows ... the abrupt appearance of fully-formed species --- exactly what the creation model predicts.
14 posted on ... 10/30/2003 12:15 PM PST by--- f.Christian
And the historical record shows the abrupt appearance of fully-grown adults. Ever see Stalin's baby pictures? Neither did I. Hmm...
Someone's going to go with Slurpee Earth or something, but I vote for Vanilla Popsicle Earth. (Haven't had one in 30 years, but I know I used to like them.)
Oh for goodness sake..and all this time I thought it was me.
Correct. I prefer not to engage in useless exercizes of futility.
"...then what should the scientist have said in order for you to not blurt out, "leap of faith"?"
I was just making an observation, that's all. I don't speak for speculators...in science, finance, or war.
2) It would be wrong to try to guess my position based on me posting this thread.
Guess? I can tell, with 100% certainty. You're a Nazi. </sarcasm>
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