Prehistoric man began global warming (projectile barf alert!)

AP ^ | 12/11/2003 | AP

[EUPHORIC]

Date: December 11 2003

Measurements of ancient air bubbles trapped in Antarctic ice offers evidence that humans have been changing the global climate since thousands of years before the industrial revolution.

From 8000 years ago, atmospheric levels of carbon dioxide began to rise as humans started clearing forests, planting crops and raising livestock, a scientist said on Tuesday. Methane levels started increasing 3000 years later.

The combined increases of the two greenhouse gases implicated in global warming were slow but steady and staved off what should have been a period of significant natural cooling, said Bill Ruddiman, emeritus professor at the University of Virginia.

The changes also disrupted regular patterns that dominated the 400,000 years of atmospheric history that scientists have teased from samples of ancient ice.

"You have 395,000 years of history, which sets some rules, and 5000 years that break those rules," Professor Ruddiman said.

He briefed reporters on his theory at the autumn meeting of the American Geophysical Union on Tuesday. Further details appear in the December issue of the journal Climatic Change.

Previously, scientists assumed widely it was only with the onset of the factory age that human activity had any significant effect on the global climate. The prehistoric changes in carbon dioxide and methane levels have been noted before but were attributed to natural causes, Professor Ruddiman said.

"It's a great new idea we need to talk about and evaluate," said Bette Otto-Bliesner, a paleoclimate expert at the National Centre for Atmospheric Research, who was not connected with the research.

Atmospheric levels of carbon dioxide and methane naturally fluctuate, in part because of changes in the orbit of the Earth and the resulting variations in the amounts of sunlight.

But human activity apparently thwarted expected decreases in the atmospheric concentrations of both gases.

Leading the change was the revolutionary adoption, across both Europe and Asia, of agriculture and animal husbandry, Professor Ruddiman said.

Analysis of air trapped in ice cores drilled from the Antarctic ice sheet show anomalous increases in carbon dioxide levels beginning 8000 years ago - just as crop lands began to replace previously forested regions across Asia and Europe.

About 5000 years ago, the ice cores reflect a similarly anomalous rise in methane levels, this time tied to increased emissions from flooded rice fields, as well as burgeoning numbers of livestock, Professor Ruddiman said.

The prehistoric practices apparently overrode a build-up of ice that models predict should have occurred from 5000 years ago.

[EUPHORIC]

I can't figure out if I should say "Gimme a break" or "poppycock"...

[RightWhale]

There's another thread on this topic. There should be a way to join related threads.

[EUPHORIC]

Darnit!!! And I searched for this too!!!

[RightWhale]

Probably a different title. Same topic, though.

[Holly_P]

The prehistoric changes in carbon dioxide and methane levels have been noted before but were attributed to natural causes

Volcanos have contributed more pollution than mankind in all of history. They are "natural causes" As part of nature anything humanity contributes are also natural causes. The earth has an enormous and adequate ability to handle all causes and effects.

[RLK]

Are there Nobel Prizes for far-fetchedness?

[Holly_P]

Probably a different title. Same topic, though.

No doubt. This is an Associated Press story and they send it out to their gazillion clients and many of them change the title before publishing it.

[stands2reason]

Well I guess we should just kill ourselves, then? Or at least start living in the forests like wildmen...

[Holly_P]

Well I guess we should just kill ourselves

Nah, just kill all the "Chicken Littles" of the world.

[MediaMole]

Or at least start living in the forests like wildmen...

Looks like that won't help... What's you favorite flavor of Kool Aid?

[PropheticZero]

Must be some smart fellas to be able to extrapolate ice growth rates back hundreds of thousands of years ago from about 3000 years or so of recorded history, and what maybe a couple centuries of any interest.

[stands2reason]

Huh?

[HuntsvilleTxVeteran]

Did the Flintstones drive SUVs?

[troublesome creek]

I'm really puzzled now. At last night's 9-dwarf debate I heard that all our environmental problems were W's fault. I assumed "glo-bull warming" got started after the 2000 election.

[Publius6961]

How about "some people have way too much time on their hands"? And the speculative powers of a valley girl.

[DeepDish]

In my family we keep very accurate records, I must now confess that one of my distant ancestors was named AAaaaaaaamn. He was in a word gaseous in the extreme which led to three divorces and two separations. He was condemded by the village shaman in 8037 bc (thats before Christ for you Atheist bigots) and burned at the stake. But not after having sired 17 children. Eight of these children carried in their genes the disaster which plagues us today. Although the Beano corporation is still protecting the descendants the expenses are spiraling out of control and we will soon be outed in what they tell me will be called an endoslung, whatever that is.

[tbpiper]

I can't figure out if I should say "Gimme a break" or "poppycock"...

Whatever you say, don't say "bullsh*t", too much methane. You'll just make the 'problem' worse.

[ErnBatavia]

I'm a carrier also - our long ago relative was known as "Pffffffft", nickname reportedly "Bwaaaap"...

[MediaMole]

The article says man was causing global warming while still living as wild men in the forest.

Jim Jones used Kool Aid to off his followers in Jonestown.

Ergo, time to drink for the funny-tasting Kool Aid in order to save the plant.

[RightWhale]

Did you take acount of dendrochronology and ice core data? Science has become very powerful and far seeing, even into times when records consisted of making notches on sticks to count cattle. Granted, some still count cattle that way.