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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: When will the US catch up...
By LordSojar on 7/5/2010 4:03:11 PM , Rating: 1
quote:
Stop being a cry baby and be an individual. Nothing wrong with being different or better


Using the metric system has nothing to do with individuality.

There is nothing wrong with being different, on an individual level. This isn't a therapy session, it's the scientific community. Adding tedium to calculations for the sake of being different isn't being different, it's being annoying. No one is crying except those who cling to this ridiculous imperial system. And... the imperial system is far from "better".

The imperial/standard system is vastly inferior to the metric system, widely recognized by the scientific community; since it uses the simplistic base 10 system, values are incredible easy to manipulate. It's far more accurate, can easily be expressed in both macro and micro terms, and can be converted and understood quickly thanks to universal prefixes.

Had your post have had anything to do with the topic, it might not have come across so naive; but, since you are clearly here just to post inane bullshit and attempt to have it considered as part of some semi intelligent discourse, it comes across as such. Go away, troll.


RE: When will the US catch up...
By RaisedinUS on 7/6/2010 9:01:37 AM , Rating: 1
"since you are clearly here just to post inane bullshit and attempt to have it considered as part of some semi intelligent discourse,"

Self righteous prick, take your own advice. More BS has spewed from your keyboard than I have seen in a long time.
LordHypocrite know what's best for us aaa!

" Go away, troll. "
You first asshat.

" it's being annoying"

Yes you are, crybaby.

Obama called, he want's you to take another for the Team. GO TEAM!


By RaisedinUS on 7/6/2010 9:04:03 AM , Rating: 2
Well, that didn't work out too well.
I was going to say: Looks like the children are out but something went wrong with the post. Oh well.


By Arlosaurus on 7/6/2010 11:50:32 AM , Rating: 2
I love the irony of USians hanging onto the system of measurement used by a country whose system of government did not "meaasure up". Hehe.

It is not like the US even really uses the whole bushel of measures. The folks who argue the hardest for keeping the "English" are usually the ones who only use the most basic subset of measures. Almost anybody who has to collaborate internationally works either in both systems or just in SI.

But if people want to buy a litre of milk and then use 2 cups of it to make a cake then let them. Go with what you know and let other people do the same. All you are going to do by arguing about it is get everybody hot under the collar and that will just cause more global warming.


RE: When will the US catch up...
By Ammohunt on 7/6/2010 2:59:04 PM , Rating: 2
So why don't we adopt base 10 time keeping?


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