Posted on 11/24/2005 5:05:51 PM PST by proud_yank
Ancient air bubbles shed light on greenhouse gases
By LAURAN NEERGAARD
Thursday, November 24, 2005 Posted at 2:45 PM EST
Associated Press
Washington — There is more carbon dioxide in the atmosphere today than at any point during the past 650,000 years, says a major new study that let scientists peer back in time at “greenhouse gases” that can help fuel global warming.
By analyzing tiny air bubbles preserved in Antarctic ice for millenniums, a team of European researchers highlights how people are dramatically influencing the buildup of these gases.
The remarkable research promises to spur “dramatically improved understanding” of climate change, said geosciences specialist Edward Brook of Oregon State University.
The study, by the European Project for Ice Coring in Antarctica, is published Friday in the journal Science.
Today, scientists directly measure levels of carbon dioxide and other greenhouse gases, which accumulate in the atmosphere as a result of fuel-burning and other processes. Those gases help trap solar heat, like the greenhouses for which they are named, resulting in a gradual warming of the planet.
Those measurements are disturbing: Levels of carbon dioxide have climbed from 280 parts per million two centuries ago to 380 ppm today. Earth's average temperature, meanwhile, increased about half a degree Celsius in recent decades, a relatively rapid rise. Many climate specialists warn that continued warming could have severe impacts, such as rising sea levels and changing rainfall patterns.
Skeptics sometimes dismiss the rise in greenhouse gases as part of a naturally fluctuating cycle. The new study provides ever-more definitive evidence countering that view, however.
Deep Antarctic ice encases tiny air bubbles formed when snowflakes fell over hundreds of thousands of years. Extracting the air allows a direct measurement of the atmosphere at past points in time, to determine the naturally fluctuating range.
A previous ice-core sample had traced greenhouse gases back about 440,000 years. This new sample, from East Antarctica, goes 210,000 years further back in time.
Today's still rising level of carbon dioxide already is 27 per cent higher than its peak during all those millenniums, said lead researcher Thomas Stocker of the University of Bern, Switzerland.
“We are out of that natural range today,” he said.
Moreover, that rise is occurring at a speed that “is over a factor of a hundred faster than anything we are seeing in the natural cycles,” Mr. Stocker added. “It puts the present changes in context.”
The team, which included scientists from France and Germany, found similar results for methane, another greenhouse gas.
Researchers also compared the gas levels to the Antarctic temperature over that time period, covering eight cycles of alternating glacial or ice ages and warm periods. They found a stable pattern: Lower levels of gases during cold periods and higher levels during warm periods.
The bottom line: “There's no natural condition that we know about in a really long time where the greenhouse gas levels were anywhere near what they are now. And these studies tell us that there's a strong relationship between temperature and greenhouse gases,” said Oregon State's Mr. Brook. “Which logically leads you to the conclusion that maybe we should worry about temperature change in the future.”
A lengthening history of greenhouse-gas concentrations should help climate specialists build better models about what the future might bring, Mr. Stocker said. It also may help answer additional questions such as how long ago humans started influencing greenhouse gas accumulations, and what impact other factors such as ocean currents play in the complexities of climate change.
Just a decade ago, scientists were not sure it was possible to trace greenhouse gas concentrations back so far in ice. Now, Mr. Brook is part of another international research team preparing to hunt an ice-core sample dating back a million years or more, hoping to reach eras when Earth's temperature was significantly warmer.
In one paragraph were talking about 'gradual' changes, in another, 'drastic changes'. After ice-coring (which is nothing new) seem to know pretty well that humans are having an impact, but on the other hand, this information is being used to build better models.
I also find it odd that none of the global warming articles in the MSM go into any great depth about what specifically greenhouse gases are. Always hear CO2 and occasionally methane mentioned, but nothing is ever really specific. Haven't they found fossils of dinosaurs and warm-weather sea life near Antarctica?
There are so many variables associated with the global warming phenomenon, it is hard to believe that anyone has found the 'cure' to a problem that we don't even know the exact roots of.
for your ping lists.
A blip on the geological timescale.
Well, I guess that means that all environmentalist activists will now
get serious about this global warming phenomenon.
And park their cars/SUVs and ride only bicycles.
And turn off their home heat/air and only use wind/solar for their home power.
And forgo their frequent flier status in those dirty old jet airliners.
And not go on ecotours, leaving a trail of burned fossil fuels and their
own thermal and bodily waste in their trail.
Then I'll think about taking them seriously.
Oh, and turn off their computers and never turn them back on again
until we're back into another "Little Ice Age"...
More manure masquerading as science.
So much effort in going into denying the obvious because it is so uncomfortable. If global warming and environmental destruction are true then...what? Spell it out.
I got yer air bubble right here.
I don't see the problem so many people are having with this article.
I won't pull your finger!
Whoa, whoa, whoa. Time out on the field. What do you mean a million years ago when the earth's temperature was significantly warmer??? If the earth was warmer a million years ago when there were far fewer humans and even fewer fossil-fuel powered automobiles, how could it have been warmer?
Hmmmmmmmmmm??? Maybe Ray Romano or Robin Williams will address that on the next installment of Up With The Earth or whatever that stupid show was called.
Did you happen to catch this paragraph:
The bottom line: “There's no natural condition that we know about in a really long time where the greenhouse gas levels were anywhere near what they are now. And these studies tell us that there's a strong relationship between temperature and greenhouse gases,” said Oregon State's Mr. Brook. “Which logically leads you to the conclusion that maybe we should worry about temperature change in the future.”
The vast majority of the article is spot on.
As long as these penci-necked geeks finance the research with their own money, more power to them.
They are financing their research with their own money, right?
Riiiiiiiiiiiight.
The problem that I have with many MSM articles on global warming is that reading their article, from a scientific perspective, there are so many variables that are left out.
For something like this I would ask: What was the temperature of the sun at the time, what were the chemical and physical properties of the ice/water, was diffusion of gas in the ice accounted for, besides CO2 and methane, what other greenhouse gasses were found, what were the conditions of the surrounding environment, what was the geological history of the region, etc......?
By saying this, I am not trying to argue whether or not humans have an effect on the climate, but the problem I have is that the press gives so few details, yet they love to conclude or lead us to believe that the world is coming to an end.
i agree
I think the extra CO2 is great for agriculture, and warmer temperatures would be welcome in the higher lattitudes.
Maybe if we all just stopped breathing.
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