Posted on 01/21/2005 7:09:59 AM PST by Zon
Two hundred and fifty million years ago, the majority of life on earth may have suffocated.
The "Great Dying," a catastrophic event that killed 90 percent of Earth's marine life and 75 percent of the life on land, was caused by a combination of warmer temperatures and lower oxygen levels, according to a recent study by researchers at the University of Washington.
In other words, the extinction was precipitated by global warming, rather than an asteroid collision, the reigning theory.
The findings, to be published in the magazine Science, are largely based on comparisons of fossils found in South Africa's Karoo Basin and in China. Chemical, biological and magnetic materials found in the fossils from both sites are quite similar. Further, there is a lack of evidence in the Karoo fossils pointing to a sudden collision between planetary objects.
"The marine extinction and the land extinction appear to be simultaneous, based on the geochemical evidence we found," paleontologist Peter Ward said in a statement. "Animals and plants both on land and in the sea were dying at the same time, and apparently from the same causes--too much heat and too little oxygen." Ward believes that continuous volcanic eruptions from an area known as the Siberian Traps bathed the planet in methane, which warmed temperatures. Concurrently, oxygen levels in the atmosphere dropped to 16 percent, the equivalent of living on a 14,000-foot mountain. Scientists and the public have debated the causes and dangers of global warming for years. While a number of scientists believe that global temperatures rise and fall in cycles, many believe human activity is currently contributing to an upward spike in temperatures.
Either way, things are getting warmer. A spring-summer sea lane running across the top of Siberia is expected to open in a few years.
The mass extinction occurred at the boundary between the Permian and Triassic periods at a time when all land was concentrated in a supercontinent called Pangaea. The dinosaurs went extinct at a later time, but many reptiles expired in the Permian extinction. Later, the Permian creatures were reincarnated as Texas crude oil.
Ward believes that continuous volcanic eruptions from an area known as the Siberian Traps bathed the planet in methane, which warmed temperatures. Concurrently, oxygen levels in the atmosphere dropped to 16 percent, the equivalent of living on a 14,000-foot mountain.
If that's true, environmentalists are the least of our problems. They need to get a clue.
Actually the leading theory is that there was a series of cataclysmic volcano eruptions that pushed up so much CO2 and SO2 that it killed most life off.
But that would not fit with their agenda. Global Warming my a$$. Most of the northern hemisphere is cool temperate climate. We could use more warming to make those areas more arable and habitable.
So, dinasaurs drove SUVs?????
Actually the leading theory is that there was a series of cataclysmic volcano eruptions that pushed up so much CO2 and SO2 that it killed most life off.
The paragraph I quoted in my response at #1 says basically that.
And the ending of the ice age was a bad thing??? Humanity would not be where it is today if north america was still frozen. And it was only 12000 years ago. Even if humans help tip things some, what difference does it make? there are so many parts of the equation its just as much fate and the flip of a coin. Nature doesnt have a brain and decide what is best for specific life forms on earth and change the weather for them. The suns energy output is probably the biggest contributer to global change. We will never control that.
This happened long before dinosaurs. It was the trilobites and their backyard barbecues.
So, dinasaurs drove SUVs?????
Yep, big ones the size of volcanoes. Sport Utility Volcanoes
Maybe, but they could not build big enough boats, e.g. arks.
The so called "great extinction" was due to the "Great Flood", which God caused,because of mans incredible wickedness.
Don't "scientists" and "geologists" ever wonder how billions of creatures got buried in the first place, including ammonite fossils near the top of Mount Everest?
Oh yeah, mud pits and swamps...
Global warming is clearly the only cause for the ice floes on the Hudson River this morning.
This doesn't jive with an earlier "theory" which stated that the arctic was warmer, causing a increase in oxegen producing plant life in the polar regions, which is what contributed to the formation of oil deposits believed to be in the arctic.
While I believe and evidence suggests that the earth warms and cools in cycles, man has little to no impact on this.
spit in the bucket so to speak. The koyoto accord does NOTHING except transfer wealth from this continent to developing third world and china, which will only produce MORE greenhouse gasses, not less. In short, it's a stupid plan. Even here, with a constantly growing population, we will never reduce what we produce, we may get better and cleaner, but the rates will increase proportional to the population, as it will all over the world, even faster thanks to the koyoto accord accellarating growth in Koyoto exempt third world countries, which include China, already one of the biggest polluters in the world.
More likely Global Winter than Global Warming. The oceans recede when a lot of the precipitation around the earth gets locked up as ice and snow on dry land, instead of returning via rivers to the sea.
The top of Mount Everest is Marine Limestone and there isn't much wonder about how that happened.
India slammed into Asia at the highest continental drift speed known (a real movement we can still measure right now with GPS; it's still plowing into Asia at this moment) and a lot of the sedimentary rock in the ocean that used to exist between India and Asia was plowed up and shoved into the highest mountains on earth.
This same motion of the Indian plate was the cause of the Sumatran quake and tsunami as well.
Both more likely. A shorter period of an extreme cooling caused by the Sulfur Dioxide in the Massive Siberian Traps eruption, followed by a long period of extreme warming from the greenhouse gases expelled by the eruption.
I read a thread here yesterday, if I remember correctly, said that around 60,000 years ago so much of Earth was covered with ice that sea-level was about 200 feet lower than today.
A very good book on the Permian extinction; pretty much tracks with what Ward is saying.
This is incorrect -- impact extinction is not the "reigning theory" for the Permo-Triassic extinction. Impact extinction has only be definitely documented for the Cretaceous-Tertiary extinction, 65 my ago. There is no general agreement on the cause of this massive "mega-extinction" 250 my ago, except for one thing: It was NOT global warming caused human-induced CO2 emissions.
That'll teach those dinosaurs not to become dependent upon fossil fuels.
NEWSFLASH!!
WE'RE ALL GONNA DIE!!
In related news, an unnamed source close to (some government-funded agency or other) announced today the discovery of a potential long-term solution to the energy needs of the world.
( "Soylent Gas"??? )
"Extreme Global Climates"
You heard it here first.
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