Skip to comments.New Antarctic Evidence Reveals Past Melting
Posted on 07/22/2013 12:37:41 PM PDT by NormsRevenge
One of the wild cards in estimating future sea level rise from global warming is the enormous East Antarctic Ice Sheet, which holds more freshwater in its icy expanse than the whole of Greenland.
Some climate models predict the giant ice sheet will undergo relatively little change as the planet warms in coming decades, while others forecast significant melting. Now, a new study suggests parts of the East Antarctic Ice Sheet underwent significant melting during the Pliocene, a recent geologic epoch when climate conditions were similar to those of today.
During the Pliocene epoch between 5.3 million to 2.6 million years ago, geologic evidence indicates atmospheric levels of carbon dioxide were similar to modern levels of 400 parts per million (meaning that for every 400 molecules of air, one was carbon dioxide) and global temperatures were 2 to 3 degrees Celsius (about 3.6 to 5.4 degrees Fahrenheit) higher than they are now. Sea levels stood about 66 feet (20 meters) higher, according to ancient preserved shorelines.
To raise sea level that much, all of Greenland and West Antarctica had to be ice-free and parts of East Antarctica may have melted, modeling studies show. (The Antarctic ice sheet first started forming 34 million years ago.)
(Excerpt) Read more at news.yahoo.com ...
Damn you, al gore and the internal combustion engine..
This just in: Ice has apparently melted off-and-on since the beginning of time. More at 11.
Oh the huge manatee!!!
“400 parts per million (meaning that for every 400 molecules of air, one was carbon dioxide) “
Nice try, but WRONG. 400 ppm equates to 1 CO2 molecule per 2500 molecules of air. (Someone check my math.)
Curious that they didn't undergo serious melting during the Mideaval warm period, or the warm period before that.
Note that they aren't truly comparing similar climatic periods, but rather similar CO2 concentrations. We are supposed to presume that they are the same thing, but CO2 doesn't drive the climate. If it did, the Earth would run to the extreme of cold or hot and stay there, as there would be no mechanism to bring it back.
Wait, wait, wait, you mean that ice melts and then re-freezes again...no way!
“That means that...
our whole solar system...
could be, like...
one tiny atom in the fingernail
of some other giant being.
This is too much!
-one tiny atom in my fingernail could be—
-Could be one little...
Could I buy some pot from you?”
Paleogeologists estimate that long-term ice, such as exists in Greenland and Antarctica, has only existed about 5% of time in earth’s geologic history. There is also some evidence that glaciation has been world-wide in the past, but it has been infrequent. Of course, the location of the continental land masses changes over time, so there is always room for variation.
But it always changes. It’s not just the Medieval Warm Period. It’s also the longer Interglacial Period. 70,000 years ago, where I am now was under a mile thick sheet of ice. The world is a lot longer now than it was then. Man had nothing to do with it. It was all mastodon farts.
Not “longer,” but “warmer.”
I picked a bad day to stop sniffing glue.
Fred Flintstone's SUV was the culprit.
As the saying goes, 'Close enough for government work'.
Nice try, but WRONG. 400 ppm equates to 1 CO2 molecule per 2500 molecules of air. (Someone check my math.),
Define Air ?
East Antarctic ice sheet... East relative to what? The South Pole?
Will Durant summed it up long ago: "Civilisation exists by geological consent, subject to change without notice.
You are correct...
And, where, during the Pliocene epoch between 5.3 million to 2.6 million years ago, was the current continent of Antarctica positioned relative to the equator of earth at the time??
There are two statements here which are purported to be true:
... 400 parts [of CO2] per million [parts of atmosphere]
= 400/1,000,000 = 0.0004
or 0.04% of the atmosphere.
... meaning that for every 400 molecules of air, one was carbon dioxide ...
= 1/400 = 0.0025
or 0.25% of the atmosphere.
Question for Becky: does 0.04% = 0.25%?
Was the Pliocene melting due to Alley Oop driving an SUV or smoking too many cigars??
....................And, where, during the Pliocene epoch between 5.3 million to 2.6 million years ago, was the current continent of Antarctica positioned relative to the equator of earth at the time??......................
Now, I’ll partially answer my own question after a Google session.
During the Pliocene epoch, the warmer waters of the Pacific Ocean were contained within its own basin, as land bridges connecting (what’s now Alaska) to (Russia), as well as another more important land bridge at (Panama) were formed.
These land bridges allowed animals to pass between Asia and North/South America.
But, the primary impact to earth’s climate was for the land bridges to stop the warm waters of the Pacific to intermix with the rest of the earth. Thus, the effect was to drive warm currents south, either past the tip of (South America or (Africa), to intermix with the Indian and Atlantic oceans
Driving warm water toward the regions of Antarctica undoubtedly caused climate change at the bottom of the earth, with much more climate effect than CO2 concentration. However, cutting off the warm water directly flowing into the northern Atlantic would probably result in less northern plant life with which to absorb CO2. This was probably offset by warmer temperatures in the southern hemisphere, able to produce more CO2 absorbing plant life.
I’ll stop my conjecture now, as I don’t certainly don’t want to act like algore, blowing theories out of his ample ass!
Air is a mixture; there is no “air molecule”. 1 out of 2500 molecules is correct. O2, N2, H2O, CH4, AR, etc.
Air is a perfectly good term and you know it. Or do you say, “I need to get a breath of 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases”?
We’ve been in an ice age for 3 million years. The earth used to be 6-9 degrees hotter and there was no ice on the planet.
Say What? Millions of years? Somebody better tell God, since according to Him (the actual creator of heaven and earth) He created it THOUSANDS of years ago not millions.
You mean no snow???? How horrible! And monster bugs! Even worse!
“evidence indicates atmospheric levels of carbon dioxide were similar to modern levels of 400 parts per million”
why these scientists must tbe wrong, ‘cause according to today’s climate “concensus” such CO2 levels and temperatures were impossible back then; ‘cause there were no “gas guzzling” SUV’s “despoiling the planet” at that time /sarc
Thanks for posting,....these guys are still pumping the propaganda.