Posted on 12/02/2002 10:42:56 AM PST by Junior
CHICAGO (AP) - Jennifer McElwain will spend the next year chipping her way through more than a ton of sediment and plant fossils at the Field Museum, hoping to find rock-solid evidence of global warming (news - web sites)'s ecological toll.
McElwain, a paleobotanist at the natural history museum, led a team of scientists who collected more than 1,000 fossils during a one-month expedition to Greenland funded by the National Geographic (news - web sites) Society.
The fossils span a period of mass extinction and recovery that started more than 200 million years ago a period some scientists blame in part on high levels of carbon dioxide that led to global warming. By examining the pores on the leaves, she hopes to predict roughly what would happen to today's plants and animals if carbon dioxide in the atmosphere doubles during this century, as some predict.
"It could be that we find plants are really happy, and they sail through extreme warming," McElwain said. "I don't think that's going to be the case."
A former researcher at the University of Sheffield, England, McElwain has previously studied a lesser collection of ancient ferns, ginkgoes and other fossils from before the age dominated by dinosaurs. She found that as the years progressed during the mass extinction between the Triassic and Jurassic periods, the number of pores per leaf declined.
Laboratory research on modern plants shows they respond to high levels of carbon dioxide by developing fewer pores to suck up the gas. And many scientists believe carbon dioxide spewed from volcanoes in the Atlantic Ocean as the continents drifted apart.
Surviving plants also developed smaller or segmented leaves, which McElwain thinks indicates major global warming as the gas trapped heat. Small leaves release more heat, helping plants stay cool.
The specimens hacked centimeter by centimeter out of Hurry Fjord in eastern Greenland now await unpacking in a museum storage room. The fjord's 990-foot cliff is a complete record of Triassic-Jurassic plant life, laid down in layers by stream sediments and cut open by glaciers.
A protective resin helps leaf fossils retain some of their original material instead of being replaced by rock entirely. As McElwain removes their paper wrapping and brushes their surface, some flake off the rock altogether, making them ready for the microscope. Some of them came loose as soon as the rock was hammered from the fjord.
"When it was windy, you opened the rock and there were 200 million-year-old leaves flying around," she said.
Others will have to be removed with acid before McElwain can count pores.
She and a student will spend the next year studying fossils from increments of time to see how many species disappeared or lost dominance and which others took their places. If she can determine the changes wrought by a gas increase similar to the current one, it may indicate how the world will change this century.
"That's the idea," she said. "The problem with the idea is that the plants that were around 200 million years ago are very different. So we can be guided by the past, but we can't really compare it directly to the future."
There are competing theories on what led to the disappearance of life in the period McElwain is studying.
Some scientists think a layer of iridium around the Earth from the period of the extinction indicates a meteor impact blacked out the sun much like the one often blamed for the later extinction of dinosaurs. Or it could have been a combination, with a meteor blast kicking up volcanoes.
Lawrence Tanner, geology professor at Bloomsburg University in Pennsylvania, acknowledged that carbon dioxide build-up and global warming are the prevailing theories for what's viewed as Earth's third-largest extinction. But he thinks it's just as likely that the opposite global cooling killed off plants and the animals that relied on them.
"My view is (volcanic) sulfur emissions were even more important," Tanner said. Sulfuric acid droplets help cool the planet, as they did temporarily after the 1991 eruption of Mount Pinatubo in the Philippines.
"I may be completely out of the park on this one, but it is a factor that hasn't been accounted for," Tanner said.
He also believes the sulfur may have been the real cause of the decline in leaf pores. McElwain dismisses that as untested, and Tanner agreed there have been no experiments testing sulfur's influence on pore density, though he intends to conduct some. He's planning his own fossil excursion to Greenland.
"It's the least studied of mass extinctions, and suddenly people are very interested," McElwain said.
Well, isn't that objective of her.....
OTOH, perhaps this will finally provide that long-sought evidence that humans were around 200 million years ago. After all, CO2 levels can only change via human activity.
Well, isn't that nice. Are the happy plants the ones with a 'Have a Nice Day' smiley face on the undersides?
"....and they sail through extreme warming," McElwain said. "I don't think that's going to be the case."
Good to see that she's using the scientfic method here. Wouldn't want the results to be skewed.
Sheesh. Who's funding this "scientist"?
[This ping list for the evolution -- not creationism -- side of evolution threads, and sometimes for other science topics. If you want to be included, or dropped, let me know.]
If a "normal" sized volcano causes global cooling, what happens with a super volcano?
So...they're going to base this new study on something else that has not been proven? Dumb!
Ever thought she just might be trying to communicate with the average, scientifically-illiterate Joe out there?
Perhaps age has fuzzed my memory, but when I was a kid, I thought it was a good magazine. Read it in the dentist's office recently and found that it was a piece of eco-garbage. "Save the whales, save the baby seals, people are the root of all evil, blah blah blah.".
The photography was nice, though.
I could start a list, if anyone would like.
"Its a morbid observation, but if everyone on earth just stopped breathing for an hour, the greenhouse effect would no longer be a problem." -Newsweeks Jerry Adler in December, 1991.
Ray Romano and Denis Leary make a movie...
It's so much easier to win a discussion when only one side is there eh Patrick? So much for fairness from your side.
In the interest of real fairness let me say that there is tons of EVIDENCE DISPROVING EVOLUTION and if you check the thread you will see that the evos can't refute it.
Always taking my statements out of context and misrepresenting them. What I have said is that fossils cannot prove evolution for the simple reason that they do not provide sufficient information about a species. It does not give us their DNA, it does not tell us how they lived, it does not tell us what their internal organs were like and much much more except in very rare and very exceptional cases. In fact, most of the fossil evidence is not even complete skeletons but partial ones and sometimes just a few teeth. To construct a whole species out of so little data is totally dishonest and story telling, it is not science by any stretch of the imagination.
LOL!!
But how to implement it?
It's probably all in the presentation....."Mr. Gore, this is for the good of the Earth." etc etc etc
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