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Global Warming 5 Million Years Ago In Antarctic Drastically Raised Sea Levels
An anonymous reader writes "As temperatures rise, scientists continue to worry about the effects of melting Antarctic ice, which threatens to raise sea levels and swamp coastal communities. This event, though, isn't unprecedented. Researchers have uncovered evidence that reveals global warming five million years ago may have caused parts of Antarctica's ice sheets to melt, causing sea levels to rise by about 20 meters."
It is well known that sea levels have been going up and down throughout the ages. The question now is whether or not we are acelerating these variations and whether life can adapt to them fast enough.
Or, we COULD say "Middle Miocene ice age 15 million years ago drastically lowered temperatures, lowered sea level 20m" as well, couldn't we?
Then it warmed, and melted, and sea levels rose. (The subject of the OP.)
Then it froze again, and sea levels dropped, since the last ice age ended only about 11,000 yrs ago.
It's almost like this shit is cyclic.
-Styopa
That was a long time before the bronze age.. Nobody was burning fossil fuels and dumping CO2 into the air. SO.... How does something like this happen? Can you believe there is some kind of natural process that we don't yet understand going on?
Problem with all of this is that if the process cycles are in the millions of years, it's going to be impossible to really know if your models are accurate because you only have a few thousand years of recorded history to validate your models with. Plus, you don't know if the system has been disturbed by some outside forces, say a meteor strike (think meteor crater) or volcanic eruption.
Interesting evidence guys, please keep looking into this..
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
Has anyone identified the high water mark? Apparently the continental shelf indicates the low mark - with all that extra land mass. This whole thing is cyclic, and we should not be surprised that it was a bad idea to build huge cities along the coastline of today. OK maybe surprised, but lets not pretend we can stop it.
How many thousands of years did it take for that warming... the equivalent of *one* century? But no, zillions of barrels of oil and coal, burned, can't *possibly* affect the whole world's climate, no, no....
mark
Can we finally admit that, yes, global warming is happening and, no, humans are not likely the cause?
Not unless you want to delude yourself.
Before anyone smugly proclaims that this proves humans aren't responsible for climate change, remember that it's possible for some phenomenon to have multiple causes. It's entirely possible for there to be both natural and man-made causes for variations in climate. Giving examples of natural causes doesn't do anything to weaken the argument against anthropogenic climate change in this epoch.
If climate change is currently man-made, or partially man-made, or being made worse by human activity, then it's still worth bending every effort to slow or reverse it.
If you build it, nerds will come. Soylentnews.org
It's idiocy like this that causes software to suck so badly. Faced with a bug report that has the same symptoms as a previous solved bug, the issue is marked as "resolved".
It is possible to have events with broadly the same symptoms that actually have different underlying causes. (Although as others point out the timescale of the symptoms is massively different).
It's been repeatedly. proven. that climate change is not caused by the actions of man
According to IPCC's WORST-CASE estimates (from which they have recently backed off), sea levels were not projected to rise by more than about a meter over the next 100 years.
I daresay we can adapt fast enough to that.
A quick review of cities in the US at or around sea level where 20M rise would be a disaster include...
LA, SF, SD, SJ, Portland, Seattle, Honolulu, Houston, Miami, Jacksonville, DC, Baltimore, Phili, Newark, Boston. That is probably about 1/2 the US population. Insurance even if you have it will not be useful, the companies will default. Insurance is for sharing risk. If 50% of your policy owners experience disaster, the company will not have the resources to pay it out. Life will certainly adapt, but probably in a Mad Max kind of way. Although I am not sure I buy the 20M number by 2100. That implies close to 6in/year and we are running closer to 1in/year. Obviously the faster the rise the more difficult to adapt. Although faster might cause us to abandon places like New Orleans instead of moating it like the netherlands does.
That would be too obvious. Last sentence below seems to have some importance:
“The interglacials and glacials coincide with cyclic changes in the Earth's orbit. Three orbital variations contribute to interglacials. The first is a change in the Earth's orbit around the sun, or eccentricity. The second is a shift in the tilt of the Earth's axis, the obliquity. The third is precession, or wobbling motion of Earth's axis.[1] Warm summers in the northern hemisphere occur when that hemisphere is tilted toward the sun and the Earth is nearest the sun in its elliptical orbit. Cool summers occur when the Earth is farthest from the sun during that season. These effects are more pronounced when the eccentricity of the orbit is large. When the obliquity is large, seasonal changes are more extreme."
"Beware of he who would deny you access to information, for in his heart, he dreams himself your master."
As temperatures rise
Temperature isn't rising.
scientists continue to worry about the effects of melting Antarctic ice
Scientists are presently worried about the credibility of their models, because reality has failed to comply.
Of course humans are the cause of global warming: Any idiot can see that average global temperature is inversely correlated with the number of pirates. There's good news though: libertarian Somalia has taken the lead on increasing piracy in the world, thus proving that rational self-interest will always solve environmental problems.
I am officially gone from
I'm sure that scientists get money from movies and books about global warming. Totally. Sure.
Sorry to burst your bubble, but if anyone's getting money from climate change research, it's oil company-funded research denying that anything's happening.
See what happens when dinosaurs industrialize and drive cars!
*Repent!Quit Your Job!Slack Off!The World Ends Tomorrow and You May Die!
The paper is about the melting of the Antarctic ice sheet, not about sea levels.
There are no socioeconomic problems that can't be solved by a good 20 meter rise in the sea level.
Have gnu, will travel.
40 years ago we were going into a deep freeze according to our climate "scientists"
So you've only got 30-40 years to explain the sudden reversal in terms of human behavior.
You don't have the whole of the industrial age because our course has recently reversed according to climate "scientists."
Work Safe Porn
Did you mean 'man is THE ONLY possible cause for a gloval wearing'?
I have gloves, when I wear them I do feel a certain amount of warming, so I guess you're good.
Never mind.
No brain, no pain.
I am betting the berths for those tankers were not designed for water thats 20m higher than it is now. People shrug their shoulders and say, who cares if Marthas Vineyard drowns? But we do not have the infrastructure in place to keep anything working if the sea levels rise.
That was nicely done.
Climatologists generally agree the natural trend was (relatively slowly) taking us into another ice age. I think this means the overall natural contribution to global warming is less than zero.
What is also unnatural is the rate of warming, which appears to be orders of magnitude faster than anything since the dinosaurs were wiped out (not counting smaller variations less than 2C).
People need to remember that sea levels have risen about 130m in just the last 20000 years (and go up and down by that amount about every 100000 years).
The article makes an interesting point, namely that there may be some additional sea level rise if temperatures go up again, but that's always been expected.
Just to be clear -- you are arguing that human agriculture starting at a small scale in a few places was the cause of the end of the last ice age?
We know correlation != causation but it's really hard to imagine someone arguing that the causation there goes in the other direction, which is the "reverse" that you refer to.
Please explain why you are sure that the cessation of the ice age, with an accompanying moderation in temperature, is not what permitted human agriculture -- and not the reverse. Please describe an experiment to falsify your premise.
The experiments have already been run many times by nature.
Take a look. The release of carbon dioxide brings the end of great ice ages happens at intervals of about 75,000 during the last 800,000 (it has happened 11 times). The development of agriculture clearly post-dates this most recent natural CO2 and temperature surge.
Now agriculture has almost certainly helped maintaining this inter-glacial period by gradually clearing land that stored carbon as forest.
In fact we had a recent episode when pandemic disasters reversed this process of land clearing, causing a dip in atmospheric CO2, and precipitating the event know as the "Little Ice Age". First the Black Death and Central Asian population by a third starting in 1346, then the greatest pandemic even in world history (a series of them actually) depopulated the New World starting in 1492. This second collapse of agricultural civilization was much larger than the Black Death, but followed before recovery from same.
Humans have been manipulating global climate for 10,000 years.
Second class citizen of the New Gilded Age
"I tell you what it is. It's your quote un-quote pollution control. I heard on talk radio you don't even need 'em. It's just the latest nazi government plot. Open your eyes, man, they're trying to control Global Warming. Get it Global. That's U.N. Commissars code for telling us what the temperature is gonna be in our outdoors. Let it warm up I say. See what Butchros Butchros Ghali Ghali thinks of that. We'll grow oranges in Alaska." - Dale Gribble
"Post hoc, ergo propter hoc" has a long tradition in argument.
Seems to me then that if the choice is between global warming and global cooling, I'll take global warming. Thank you for you time.
And of course this is not the choice at all. It is about how much global warming will occur and how fast.
Second class citizen of the New Gilded Age
I'm pretty sure you typed that wrong. If what you meant to say was "Please explain why you are sure that the cessation of the ice age, with an accompanying moderation in temperature, is what permitted human agriculture [This is the assertion he makes, that consistent temperatures allowed/was favorable for farming] -- and not the reverse. [Are you suggesting that farming permitted the cessation of the ice age and moderation in temperatures?] Please describe an experiment to falsify your premise." I might be able to help with an experiment to test if moderation in temperature helped facilitate farming; otherwise please clarify what you are asking.
To the possible suggestion that human farming could have ended the ice age and moderated temperatures I can only suggest you go try and farm on a glacier and see how that works out. After you have sufficiently tested the farming on ice theory for the melting of glaciers and cessation of the ice age I believe we could create an experiment to test if consistent environmental conditions are conducive to more productive farming (and thus more favorable to cities and civilization).
First create an artificial controlled environment (Control) that exactly matches the conditions in a designated location (that has successfully maintained farming for an extended period of time) while removing variables such as pollution, vandalism, and other external hazards that would not effect the other environments.
At the same time we will create another artificial controlled environment (Variable) where the weather conditions will randomly selected (in a way to still coincide with the seasons, and within reasonable limits of annual extremes over the past 8,000-10,000 years) from year to year. The first year will be identical to the first year in the control environment with random selection beginning in year 2. This won't perfectly replicate long term variations (and the effects) in environment but should sufficiently test the effect of variability of environment on agriculture.
I propose one more artificial controlled environment (Constant) that has perfectly predictable weather conditions from year to year. Thus all years will have the same conditions as the first year of the control.
Further we can measure the performance of these environments in relation to the selected location to further control for possible unforeseen factors and for comparison to real world conditions.
The environment to have produced the greatest yields with the lowest costs/losses over an extended period (say 20-40 years) will be deemed the most successful and conducive to agriculture.
If you are proposing that cities and civilization either arose independently of agriculture or facilitated agriculture (instead of agriculture facilitating cities/civilization) our conversation is over and I would refer you to the extensive studies of early human civilization.
I'll meet you at the intersection of "Should be" and "Reality"
Unfortunately your link has nothing to do with glacial periods or ice ages. It only shows an graph of the temperature at antarctica.
Also: is it a mean temperature? What is the graph supposed to mean? As it is slightly above zero degrees most of the time, the graphbmakes no sense at all anyway.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Dinosaur flatulence.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
...First the Black Death where the European and Central Asian...
Second class citizen of the New Gilded Age
Funny that I knew that the most simplistic, mindless interpretation of the info in this article would be put forth by deniers. But it moves into the realm of sadness that it would be comment 1 & 2.
Ain't this what we call acceleration ?
We are sure of it because of the options presented it is the only one that makes sense. If the development of agriculture could moderate temperature, then the high levels of agriculture we see today would be moderating temperature.
Also, archaeologists have found tools and whatnot indicating that humans were cultivating crops long before it became widespread. The theory that a fluctuation climate prevented them from flourishing fits with the fact that they did not flourish until the climate stabilized.
Not everything can be subject to experiment. Talk to some astrophysicists, you'll learn about how you can make observations of things that have already happened, and then infer some deeper meaning. Of course an idiot will make the wrong inferences, but with enough observations to control for other factors you can still get a pretty good answer.
Is 1563649 a prime number?
5000 years. And it records an asteroid strike, in case you didn't notice. And the evidence of the asteroid strike seems to match a crater SE of Madigascar, and chevron-shaped mountains on the shores of southern Madigascar, including ocean-bottom fossils welded to asteroid-proportion metals.
Oh, and it also seems to match 8' of river mud all dating to 5000 years BP, and also to a worldwide epidemic of pyramid building that shortly followed, and also to accounts of Burmese fisherman who described a great wave passing under them, and when they returned to shore, everything was gone.
I suspect it really happened.
And how, exactly, did No know to build an ark?
Correct Horse Battery Staple: 72 bits of entropy. Enter "Correct H" into google. When it generates the phrase, that's
If that was true the glacial and interglacial periods would be completely predictable and ... well, we had a few thousands of them during the prvious 5 billion years and not only ... 4? Or is it 5?
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Please explain why you are sure that the cessation of the ice age, with an accompanying moderation in temperature, is not what permitted human agriculture -- and not the reverse.
I believe the previous commenter IS proposing that retreating glaciers and moderate temperature DID permit agriculture. Or are you proposing that agriculture, planting seed in snow and ice, caused the cessation of the ice age and moderation in temperature? FYI, we are still in an ice age known as the Quaternary period which began roughly 2.6 million years ago. The glaciation on the order of 100 000 years of which I think you are referring is the Late Pleistocene era. This was a time when Neanderthal, mammoths, and saber-toothed tigers roamed the earth. They died out as glaciers such as those around the Great Lakes and the Baltic retreated and sea level rose 35 meters to roughly its present level. The moderate Holocene period beginning about 11700 years ago through present saw moderate flucatuations +/- 0.5 C (though the temperature rise of the past 150 years is unprecedented in the past 10000). It is possible that modern humans killed off the Neanderthal and megafauna during this Mesolithic age of human technology (ie stone age). Perhaps they caused the global temperatures to rise 2 C in a short period of time around 12000 years ago. A more likely explanation (given that we've actually seen evidence) is that the Earth collided with numerous meteorites. Incidentally, the resultant megatsunamis are a likely explanation for the Noah and Gilgamesh flood myths.
3E51A207
Those would be jokes sir.
Unfortunately your link has nothing to do with glacial periods or ice ages. It only shows an graph of the temperature at antarctica. Also: is it a mean temperature? What is the graph supposed to mean? As it is slightly above zero degrees most of the time, the graphbmakes no sense at all anyway.
We are still in the Quaternary ice age and have been for 2.6 million years. The link most certainly has something to do with glacial periods, at least eight of them, on the order of 100 000 years. On thousand year scales, we can easily deduce ice volume and how much of the Earth is frozen from global average temperature. Ice cores from around the world correlate on decade scales, perfect correlation on 100 000 year scales. The reason Antarctica is more interesting than say Greenland is simply because Antarctica is deepest, oldest, most stable. The temperature is variation from mean. Plus and minus 5 C is quite significant. It's more than the difference between a glacial and interglacial period -- precisely what the graph demonstrates for you.
3E51A207
In antarctica the temperatur fluctuates between -20 and -90 degrees. The graph you showed is between -5 and +5 degrees.
So, the link and the graph and your argument makes no sense at all.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Knowing that there was warming so long ago pushes back the horizon in a set of political values we had formerly thought of as being much more recent. The researchers are now looking for supporting evidence, such as golf courses, tax cuts and municipal bond portfolios, from the period.
And how, exactly, did No know to build an ark?
Who cares? He lived to tell his grandkids a whale of a tale! If you and your lovely wife alone survived while all others did not, you'd likely ascribe divine inspiration as well.
3E51A207
It is by no means guaranteed that the sea level rise will be limited to 1 meter per century, even for this century. The IPCC predictions are conservative, don't include melting ice cap contributions, and assume that we would be more aggressively cutting emissions by now. From a paper on the subject:
"Rahmstorf (2007) made an important contribution to the sea level discussion by pointing out that even a linear relation between global temperature and the rate of sea level rise, calibrated with 20th century data, implies a 21st sea level rise of about a meter, given expected global warming for BAU greenhouse gas emissions. Vermeer and Rahmstorf (2009) extended Rahmstorf's semi-empirical approach by adding a rapid response term, projecting sea level rise by 2100 of 0.75-1.9 m for the full range of IPCC climate scenarios. Grinsted et al. (2010) fit a 4- parameter linear response equation to temperature and sea level data for the past 2000 years, projecting a sea level rise of 0.9-1.3 m by 2100 for a middle IPCC scenario (A1B). These projections are typically a factor of 3-4 larger than the IPCC (2007) estimates, and thus they altered perceptions about the potential magnitude of human-caused sea level change.
Alley (2010) reviewed projections of sea level rise by 2100, showing several clustered around 1 m and one outlier at 5 m, all of which he approximated as linear. The 5 m estimate is what Hansen (2007) suggested was possible, given the assumption of a typical IPCC's BAU climate forcing scenario. Alley's graph is comforting, making the suggestion of a possible 5 m sea level rise seem to be an improbable outlier, because, in addition to disagreeing with all other projections, a half-meter sea level rise in the next 10 years is preposterous.
However, the fundamental issue is linearity versus non-linearity. Hansen (2005, 2007) argues that amplifying feedbacks make ice sheet disintegration necessarily highly non-linear. In a non-linear problem, the most relevant number for projecting sea level rise is the doubling time for the rate of mass loss. Hansen (2007) suggested that a 10-year doubling time was plausible, pointing out that such a doubling time from a base of 1 mm per year ice sheet contribution to sea level in the decade 2005-2015 would lead to a cumulative 5 m sea level rise by 2095."
Additional caveats and quid quo pros follow in the paper, but it's safe to say that there's a bunch of scientists who would not bet much money on at most a meter of rise in this century.
Nonsense, use the interactive melt map located somewhere on the internet.
Find where the new shore will be.
Buy a lot of property.
Crack open a beer, man you're gonna be rich!
*Repent!Quit Your Job!Slack Off!The World Ends Tomorrow and You May Die!
That's what drives OUR cars.
*Repent!Quit Your Job!Slack Off!The World Ends Tomorrow and You May Die!
You're right, the "look a bird" tactic didn't work and we all still stared at the elephant.
*Repent!Quit Your Job!Slack Off!The World Ends Tomorrow and You May Die!
Unfortunately your link has nothing to do with glacial periods or ice ages. It only shows an graph of the temperature at antarctica. Also: is it a mean temperature? What is the graph supposed to mean? As it is slightly above zero degrees most of the time, the graphbmakes no sense at all anyway.
LOL... Sigh. Not sure this guy has his tongue in his cheek or is actually as obtuse as he appears.
The graph gives the mean temperature in Antarctica along with the CO2 concentrations versus time. This does show the ice ages. Low temperatures imply an ice age. Warm temperatures imply an interglacial period. The CO2 concentrations slightly lead in time. Given what we know about the physics of the greenhouse effect, this graph gives strong evidence that CO2 is a prime cause of global warming.
Really, sometimes I think posters to this board should have to pass some form of IQ test and a literacy test. It provides support for my "tongue in cheek" hypothesis that the self esteem movement has caused idiots and buffoons to believe that their ideas are on par with those of their more educated betters. In the past, they would have just sulked in the shadows realizing that they just aren't too bright.
This and no other is the root from which a tyrant springs; when first he appears as a protector - Plato (423 to 327 BC)
If "adapting" means "build a 1m seawall around New York", then sure, just as soon as people stop arguing. It's not going to happen around every coastal city & town in the US though, so that's a massive cost to relocate all those prime coastal buildings and infrastructure. But the real damage comes from occasional storm surges like Hurricane Sandy; add 1m to that and half the city would be flooded. And of course, strong storms like that will also get more common.
Then there's the developing world; no seawalls for them. Saltwater surges ruin essential cropland and will displace millions in places like Bangladesh, creating a flood of starving refugees and political turmoil. Some island nations are already becoming unviable (q.f. Tuvalu).
Yes, we can and will adapt. But it's sure as hell going to cost a freaking bundle to do so - and the price will be in human suffering for countries that can't afford the dollars. Far cheaper to mitigate the changes ASAP, as the costs are rising every year we delay.
Why would anyone engrave "Elbereth"?
If you look at thatt graph again you will see the temperature is varying between -5 and + 5 degrees. This hardly can be the mean temperature at antarctica. Perhaps it is the deviation from the long time average? As I said in a different post: antarctica summer temperature is riughly -30 degrees, winter temperature down to -90. I hardly believe you can craft an average temperature over the year and over the area of antarctica that is ABOVE zero degrees.
Your terminology is not consistent either.
Ice Age: one or both poles are covered with ice (so by that definition we live in an ice age right now)
Glacial Period: this is was the layman calls an ice age, especial a big part of the northen hemisphere is covered with ice.
Interglacial Period: the time between two Glacial Periods, like now. So we right now live in an ice age and in an interglacial.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
More likely the coastal cities will dredge vast banks of sea-floor to form a giant, closed harbour (with locks to let shipping in/out) that drains at low tide. Holland already has experience of building these to reclaim land.
London, for example, will build up the sub-surface sand banks between Essex and Kent.
I expect after this that the sea within the banks will be massively reformed to build new land for development, vast Venices of concrete. Yeah, more development on low-level land, rather than less.
Solar, but tire manufacturing was much the same. In the end they had to get too close to the tar pits for petroleum....
*Repent!Quit Your Job!Slack Off!The World Ends Tomorrow and You May Die!
Thought I would research the London case - http://flood.firetree.net?ll=51.4438,-359.6106&zoom=9&m=20
Yeah, the way to save London in this scenario is to dredge (a vast amount) from Southend southwards to the spit of 20m+ land from Sheerness.
The far more reasonable 5m sea level rise would have you damming between Shoeburyness and the Isle Of Sheppey and then probably to the east of Faversham. http://flood.firetree.net/?ll=51.5020,0.6225&zoom=11&m=5
The fens might need the same doing, despite a lack of a vast city to save: http://flood.firetree.net/?ll=53.0000,0.4526&zoom=10&m=20
Sorry Holland: http://flood.firetree.net/?ll=52.2405,6.0700&zoom=8&m=20 ... oh dear, 5m isn't much better: http://flood.firetree.net/?ll=52.2405,6.0700&zoom=8&m=5 and 1m is devastating: http://flood.firetree.net/?ll=52.5422,6.2568&zoom=8&m=1
Yeah. I didn't know about the Koran,.. just the epic of gilgamesh. And the Bible. And the Burmese. And I forgot, but some would contend that it's encoded in the ancient Chinese language (boat is written something like box and eight people...I don't remember) But it's multple sources, not just ancient records. It's the river mud, and the chevrons, and the worldwide pyramid construction all at the same time.
And yes, there could be other explanations, but occam's razor seems to point to an asteroid strike.
One other thing... if the asteroid hit in the ocean, it would have thrown lots of water into orbit around the Earth. When Noah came out of the boat, he would have seen a semi-permanent 360-degree rainbow around the earth. In other words, not just any rainbow, but *wow... a lasting rainbow*.
Correct Horse Battery Staple: 72 bits of entropy. Enter "Correct H" into google. When it generates the phrase, that's
If it runs out of patience, it'll be ruthless.
Casteism
Just to be clear -- you are arguing that human agriculture starting at a small scale in a few places was the cause of the end of the last ice age?
We know correlation != causation but it's really hard to imagine someone arguing that the causation there goes in the other direction, which is the "reverse" that you refer to.
The Ice Ages are caused by perturbations in the Earth's orbit AND only occur if the general temperature of the Earth is low enough. We still had the same perturbations during the warm dinosaur ages.
Based on the orbit, the next ice Age should have been starting 8-10,000 years ago. It didn't.
Now don't go getting your knickers in a knot by saying early humans couldn't have put out enough CO2 to stop an Ice Age without first understanding that all the other Ice Ages started from a minor change in orientation and albedo and a slightly longer snow cover from year to year.
The Am. Inst. of Physics has a nice set of articles about the actual science. http://www.aip.org/history/climate/index.htm
The article abstract doesn't reveal how sudden the sea (eustatic) level change was, only dating it to a wide interval of time. Other research on more recent climate change gives time scales of decades to a couple of centuries of large change. 5 MYA Pliocene geography was different than now. The land bridge connecting North and South America hadn't fully formed yet and so the warm equatorial current could get into the Eastern Pacific. The dynamics of cooling would be different although the layout of continents was well on its way to cooling the global climate overall. 20 M or about 60 feet of sudden eustatic sea level rise would drown most cities on the coasts of the world. If this happens suddenly, within a couple of decades, the effects would be very hard on us.