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The Woolly Mammoth  (Source: Corbis/Royal BC Museum, British Columbia)

Ancient humans hunted mammoths, which some think contributed to their extinction.  (Source: On Charcoal)

Researchers in a new study claim that the extinctions, possibly triggered by man, caused the birch trees to take over in regions of Siberia, causing a warming effect of as much as 1 degree Fahrenheit.  (Source: EW Birch Builders)
Mammoth extinction 10,000 years ago may have led to as much as a 1 degree Fahrenheit increase in temperatures

Christopher Doughty, a post-doctoral researcher at the Carnegie Institution for Science in Stanford, California, has led a team of researchers that has reached some controversial and unusual claims about mankind's role in changing the Earth's climate.

Doughty, in a paper published [PDF] in the journal 
Geophysical Research Letters, claims that the extinction of woolly mammoths may have triggered a cascade of effects warming Siberia and neighboring Beringia by at least 0.3 to 0.4 degrees Fahrenheit.  If these controversial claims prove true, it would likely be the first example of man influencing the world's climate in humanity's brief history as a species.

The report may change preconceptions about climate change, claims Doughty; "Some people say that people are unable to affect the climate, that it's just too big.  That's obviously not the case. People started to affect global climate much earlier than we thought."

Previous studies had indicated that mankind's development of agriculture 8,000 years ago could have changed the Earth's climate, but the effects of hunting in mankind's earlier days were not thought to have had significant impact.  The new study draws its basis from a previous study in the November 20, 2009 edition of the journal 
Science.  That study indicated that mammoths kept small trees in check, preserving grasslands.  With their extinction, the darker trees grew, increasing the overall darkness of the terrain, absorbing more solar radiation, and ultimately triggering a warming effect.

The issue with that study was that it posed a chicken-and-the-egg sort of conundrum; warming climates would encourage tree growth over tundra grasslands, but tree growth could also 
trigger warming.  Doughty claims in his new study that in the 850-year period where most of the mammoths disappeared from hunting, the levels of birch pollen increased by 26 percent.  Using modern elephant data, it was estimated that 23 percent of this increase came from the death of the mammoths, while the rest was caused by the heating trend itself.

The team then compiled vegetation loss findings and climate simulations to pinpoint how much of an impact the forestation increased had.  They found that it likely raised temperatures from 0.4 degrees F to the nearly 1 degree F.

Doughty admits in the study that it's not been conclusively shown that humans caused the extinction of mammoths in the first place (again, this is a chicken-egg riddle as warming climates could have pushed them to extinction, but their extinction could have warmed climates).  Man did hunt the beasts, and its the prevailing theory that we played at least a small role in their extinction.

The study was funded by NASA and the Carnegie Institution for Science.



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RE: Bull!
By Reclaimer77 on 7/5/2010 10:08:53 PM , Rating: 2
You guys are so confusing I can't tell who agrees with who. It just sounded like you were sort of supporting me, now you say you aren't?

This discussion has turned stupid all around. So you need "scientific credentials" if you don't agree with every theory? Especially one a stupid as this?

That strikes me as the worst kind of position, and I'm honestly saddened by how many here support it. I wonder if you would feel the same way if it wasn't an article that enforced a personal belief?

Also, by your logic, you should provide me "scientific credentials" if you SUPPORT this theory. Because how can you truly support something if you aren't an expert yourself?

All in all it's a very childish attempt to silence an opinion. And one that, by now, people should know won't work on me.


RE: Bull!
By LordSooooStupid on 7/5/2010 11:08:17 PM , Rating: 2
"You guys are so confusing I can't tell who agrees with who. It just sounded like you were sort of supporting me, now you say you aren't?"

I'm actually agreeing with you. A lot of reply's must be going on at the same time. I've noticed them to be all out of sorts.

Credentials are only as good as a persons honesty or morality.
Money can sure change minds.


RE: Bull!
By damonlynch on 7/6/2010 11:48:52 AM , Rating: 1
Reclaimer77, I'm going to say this for the last time in this discussion: your claim is that you are in a better position than esteemed scientific bodies to make claims about the validity of climate science than they are. You offer no evidence that you have any justification in doing so. You have demonstrated no track record in scientific analysis. Furthermore, you offer no evidence that you understand how science progresses. The onus is on you to put up or stop making a fool of yourself.

I, on the other hand, am not challenging the climate scientists that I know better than they do. There is no need for me to demonstrate my scientific skills for me to find their analysis compelling. Similarly, if I visit a dentist and listen to her / his advice, there is no need for me to demonstrate that I'm an expert in dentistry. I listen to what the dentist says, and in as much as possible, make an informed decision.

This is all very simple.


RE: Bull!
By Ammohunt on 7/6/2010 2:11:57 PM , Rating: 2
So by your own admission Reclaimer77's belief on this subject has just as much weight as yours. Someone here is more gullible though


RE: Bull!
By damonlynch on 7/7/2010 11:39:38 AM , Rating: 2
No, I didn't say that at all. Reclaimer77's scientific understanding is a joke. Critics such as yourself seem to totally lack even a rudimentary understanding of science, and yet don't hesitate to shoot your mouths off talking as if you know something.


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