Print 86 comment(s) - last by Arlosaurus.. on Jul 7 at 2:28 PM

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.

Comments     Threshold

This article is over a month old, voting and posting comments is disabled

So in conclusion...
By Amiga500 on 7/5/2010 1:14:35 PM , Rating: 3
We should continue to cut down the rainforests, as the darker vegetation is contributing to "global warming"?

In addition, we should also remove many other forests the world over, replacing them with grassland to graze methane producing cattle on?

Amiga is confused....

RE: So in conclusion...
By Scabies on 7/5/2010 1:20:25 PM , Rating: 3
I was just in the middle of starting a thread along these lines. It really seems like people are grasping at straws, but then somehow they get celebrated (and paid) for the tripe they come up with.

man killed all the mammoths
mammoths ate all the trees
trees make the world hot
Nobel Prize

I wonder if we can tax the neanderthal for this one-degree shift? Maybe Obama can land another prize for that one (he could just talk about it instead, that's cool too.)

RE: So in conclusion...
By JonnyDough on 7/6/10, Rating: 0
RE: So in conclusion...
By Reclaimer77 on 7/6/2010 11:22:01 AM , Rating: 2
You know the best thing for the earth would be for humans to do...nothing. And by that I mean stop eating.

Ok you go first. We're all right behind you on that.

RE: So in conclusion...
By JonnyDough on 7/6/2010 6:59:41 PM , Rating: 1
Or, we could just stop making so many more mouths to feed...

and by that I mean you. Don't reproduce.

"We are going to continue to work with them to make sure they understand the reality of the Internet.  A lot of these people don't have Ph.Ds, and they don't have a degree in computer science." -- RIM co-CEO Michael Lazaridis

Copyright 2016 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki