| THIS IS A READ-ONLY ARCHIVE FROM THE SORABJI.COM MESSAGE BOARDS (1995-2016). |
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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. SOURCE |
I am not too sure I have one. The words Bullshit came to mind right away, though. And maybe if not bull shit, then "so what" comes to mind. 8 thousand years of using trees to live, as tools and warmth and cooking and shelter, then the only alternative would be to just lie on the ground and die. |
I watched the old, classic X-Files episode, "Ice," this morning....about the alien worm trapped in the Arctic ice cap and brought to the surface by ice-core-drilling scientists. This has to be one of the gems of the early seasons. |
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Um, nowhere in that article was there social criticism, only descriptions of an atmospheric effect and speculations on the potential cause. Don't be such a defensive pussy. |
and of course, there were other things happening about 8000 years ago too, and consider that there was no agriculture at all in the western hemisphere, I'm a little suspect too about agriculture being the sole cause, but then the article doesn't mention any statistics, so we can't really judge how much it rose 8000 years ago, can we? But overall, I think the science is sound, and that it's likely an effect from anthropogenic impacts on the environment. so, yeah, global warming. Saved us from another Ice age, if you want a positive spin on it, which would have radically changed the course of human history and none of us would be here arguing about it right now. |
what about the *giant robots*??!! scientists: so silly, so forgetful |
I would. |
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My arguments span many dimensions of reality. Fnord. |
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sem, puhleeze. we western hemisphericals have been busting aggie for longer than anyone. and wasn't it earlier this year that german scientists proved with the magical religion reality of science that global warming is directly correlated with the rise and fall in frequency of solar storm activity? i bet howard dean gives mean blowjobs. |
and I can't speak to your global warming idea since you didn't provide a link and a google search turned up no hits on that. Maybe you should ask the Flat Earth Society about that one! I have no idea about Dean's fellatio abilities. I figure he can't have as much practice as the current dynamic duo, with their lips permanently attached to oil industry penii. (ok, that's not fair. There are plenty of other industries that have their dicks in Bush and Cheney's mouths as well.) |
I'm having a hard time believing that early man was clearing forests to such a degree that they were screwing up the atmosphere, unless our atmosphere is more delicate than I thought. How many trees can a tribe of people clear with handtools? |
but again, the rates weren't published. so even a little rise at 8000 BP counts as a rise. |