But in this modern era, even a big (Pinatubo) eruption only causes a short cooling period. Now, if we could initiate a new flood basalt episode...
(There may be some drawbacks to the implementation of that idea.)
Posted on 11/29/2005 1:00:49 PM PST by cogitator
Two new studies of gases trapped in Antarctic ice cores have extended the record of Earth's past climate almost 50 percent further, adding another 210,000 years of definitive data about the makeup of the Earth's atmosphere and providing more evidence of current atmospheric change.
The research is being published in the journal Science by participants in the European Project for Ice Coring in Antarctica. It's "an amazing accomplishment we would not have thought possible" as recently as 10 years ago, said Ed Brook, a professor of geosciences at Oregon State University, who analyzed the studies in the same issue of this professional journal.
"Not long ago we thought that previous ice studies which go back about 500,000 years might be the best we could obtain," said Brook, who is also the co-chair of the International Partnerships in Ice Coring Sciences, a group that's helping to plan future ice core research efforts around the world.
"Now we have a glimpse into the past of up to 650,000 years, and we believe it may be possible to go as much as one million years or more," Brook said. "This will give us a fuller picture of Earth's past climates, the way they changed and fluctuated, and the forces that caused the changes. We'll be studying this new data for years."
As the data become more solid about the atmospheric conditions of the past, it's becoming increasingly clear that the current conditions of the past 200 years are a distinct anomaly, Brook said.
"The levels of primary greenhouse gases such as methane, carbon dioxide and nitrous oxide are up dramatically since the Industrial Revolution, at a speed and magnitude that the Earth has not seen in hundreds of thousands of years," Brook said. "There is now no question this is due to human influence."
The ice cores being taken from Greenland, Antarctica and other sites provide an invaluable record of Earth's past climates, researchers say. By testing the gases and trace elements found trapped in these cores, scientists gain a better understanding of how climate and atmospheric gases interact and evolve.
"We predict, for instance, that rising levels of greenhouse gases will warm our climate," Brook said. "There's evidence that this is happening right now, and it would be interesting to find out if the same thing has happened at times in the distant past. And there are also concerns we're exploring about rapid shifts in climate."
Analysis of the older cores just removed from Antarctica, Brook said, are consistent with some of the quick changes in methane and carbon dioxide levels that are related to abrupt climate change. However, it also appears that the natural climate cycles in the distant past -- the development and retreat of Ice Ages, for instance -- were smaller in magnitude and had less fluctuation in atmospheric gases than what the Earth is now experiencing.
There are critical questions that work of this type may help answer, researchers say. One of the most obvious is the relationship between increasing levels of greenhouse gases and global warming. But there are also concerns that the Earth's climate may have changed very abruptly at times in the past, in complex interactions between the atmosphere, ocean currents and ice sheets.
Past studies of gases trapped in Greenland and Antarctic ice cores have suggested that Earth's temperature can sometimes change amazingly fast, warming as much as 15 degrees in some regions within a couple of decades. At the same time, there are concerns about the change of major ocean currents, such as those in the North Atlantic Ocean, that are responsible for the comparatively mild climate of much of Europe. If that "thermohaline circulation pattern" were to abruptly shut down, as has happened at times in the past, it could plunge much of the European continent into a climate more closely resembling that of central Canada.
According to Brook, continuing research will help to address many of these questions. The international committee he co-chairs, which involves representatives from 17 nations, is considering such work as a very deep ice coring project in Antarctica that might provide a record of atmospheric gases 1.2 million years ago, or even further back in time. Other studies are also anticipated in Greenland and the Arctic.
Some of these projects will require drilling in challenging locations on very old ice, Brook said, at considerable cost in initiatives that require international cooperation.
"Ice cores are the cornerstones of global change research," Brook said. "They have played a central role in showing how closely climate and greenhouse gas concentrations were linked in the past, and they are demonstrating also that very abrupt climate switches can occur."
I don't think that's accurate at all. One of the main reasons these guys do the coring is with the knowledge that they want to accurately measure the concentration of trace gases in the trapped bubbles. By making the statement you're making above, you're impugning the methodology of an entire community of scientists that has being doing this type of study for years. That's very bold of you. While I admire your audacity, I'd have to consider your comment as having little support until you published a critique addressing their methodology.
Right now, industry produces 10 times more atmosphereic Carbon Dioxide per year than volcanoes do, so pollution has been producing more CO2 than volcanoes for quite some time.
And, of course, volcanoes produce huge amounts of Sulfur Dioxide, which blocks sunlight and cools the earth, so overall volcanic eruptions tend to cool the earth.
Does it? If so, how large part of the total Earth emission of CO2 the industry makes, do you know by any chance?
But in this modern era, even a big (Pinatubo) eruption only causes a short cooling period. Now, if we could initiate a new flood basalt episode...
(There may be some drawbacks to the implementation of that idea.)
This research must be fundamentally flawed. A good test might compare gas from old ice to gas in new ice. But they are saying that the glaciers are retreating. If the ice is retreating, there is no way to capture current ice samples to compare the history to. So they are comparing gases stored in old ice to gases sampled some other way. Sounds like bad science to me.
Water vapor is a climate feedback, not a climate forcing. As the global temperature warms, relative humidity will increase. The reason water vapor is a feedback is the high variability of water vapor concentration in the atmosphere.
Well, the Russian Academy of Sciences does not agree with you and, nothing personal, but for this subject I will go with their analyses.
Granted, ice core sampling today complies with the guidelines that you suggest, but the older cores, which were never intended for that type of test were initally and erroneously used to validate the "man-is-at-fault" faith.
They set out to find proof and, lo and behold, they found it!
200 years ago we had no weather data. Hell, even 50 years ago our weather data globally was suspect.
The newest core is from a site in Antarctica, and they are comparing its results to results from other sites.
I thought the main intent of seeking these samples was the organisms--"extremophiles", etc.--although I felt a bit eirie about thawing out ancient bacteria...
Actually I was mistaken; Industry actually contributes a lot more than 10 times as much CO2 as volcanoes...
It's actually 10 billion tons of CO2 a year from human activity, only 110 million tons a year from volcanoes, or somewhere in the vicinity of 100 times more CO2 from human activity.
You don't need a "current ice sample"...you can just sample the atmosphere directly.
I don't understand what you mean about glaciers retreating; these are ice caps, not glaciers, and they're drilling in the center of them where they're not melting.
How far back does "today" go? I.e., has Lonnie Thompson been doing it right since he started collecting cores on far-flung peaks? Is the Siple Dome data good, or flawed? I will assume that the Vostok core data is good, since it's been collected in the past decade with climate study at the forefront.
What would be of interest is what cores/studies the Russian Academy of Sciences considers erroneous -- and whether or not data from these cores is still utilized in paleoclimate analyses and modeling.
The new site for the old sample, which still may be comparing apples to oranges. Excuse my ignorance, but are gas concentrations uniform around the globe at all times? Also, the main point I was trying to make is that there are no new ice samples, because it’s melting, right?
Gas concentrations are fairly uniform around the globe. CO2 varies seasonally, but the bubble samples don't have that level of resolution.
There are still places where ice is accumulating, such as the center of Greenland. The ice edges on Greenland are retreating (it appears).
That might not be a good comparison. The conditions whereby air bubble get captured in ice need to be controlled or accounted for a good experiment.
It's not melting everywhere, just on the edges.
You are still accumulating yearly ice layers in the middle of Greenland and Antarctica every year.
It would mean almost two tons of CO2 by person per year or 10 pounds per person per day. How large part of natural emissions people produce, I wonder.
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