EAST ANTARCTIC MYSTERIES: Even the most snow-covered place on Earth has patches of snow-free ground. In Antarctica, a series of parallel valleys lie between the Ross Sea and the East Antarctic Ice Sheet. Known as the Dry Valleys, they are swept free of snow by nearly relentless katabatic winds -- cold, dry air that rolls downhill toward the sea from the high altitudes of the ice sheet.
Image: Jesse Allen, using data provided courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team
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ERICE, Italy—If you think of Earth's poles as fraternal twins, the Arctic has been the wild one in recent years, while the Antarctic has been a steady plodder. Withered by summer heat, Arctic sea ice has shrunk to record low coverage several times since 2005, only to rebound to within 95 percent of its long-term average extent this winter. By comparison, Antarctica, with some 90 percent of the world's glacial reserves, has generally shed ice in more stately fashion.
However, emerging evidence from an Antarctic geological research drilling program known as ANDRILL suggests that the southernmost continent has had a much more dynamic history than previously suspected—one that could signal an abrupt shrinkage of its ice sheets at some unknown greenhouse gas threshold, possibly starting in this century. Especially troubling, scientists see evidence in the geological data that could mean the vast East Antarctic Ice Sheet, which holds at least four-fifths of the continent's ice, is less resistant to melting than previously thought.
ANDRILL, a collaboration among scientists from Germany, Italy, New Zealand and the U.S., obtained the evidence from a 3,734-foot-long core extracted in 2007 from the seafloor on the southern McMurdo Sound, near Antarctica's Ross Island.
A prior core, extracted from the McMurdo Ice Shelf between October 2006 and January 2007, indicated that the West Antarctic Ice Sheet has frequently advanced and retreated. As ANDRILL scientists met here April 6-11 to integrate core results, the geologists and climate modelers pondered the hints of dynamism observed in the much larger East Antarctic Ice Sheet.
Contrary to what climate simulations suggest, David Harwood, the program's co-chief scientist, says, "nature seems to give us a record that the ice sheets are coming and going."
The southern McMurdo Sound core yielded clear evidence of some 74 cycles of ice sheet buildup and retreat during a 6-million-year stretch starting in the Miocene Epoch some 20 million years ago. The unexpected ice-sheet dynamism has ANDRILL climate modelers considering what input or software adjustments would make the simulation produce the kind of dynamism seen in the geological record. Their model currently indicates that even if the imperiled West Antarctic Ice Sheet succumbs to current warming trends, the much larger East sheet should stubbornly resist melting. According to the simulation, the East ice sheet melts only when atmospheric carbon dioxide levels are at least eight times higher than preindustrial levels. The ice sheet’s so-called hysteresis, or resistance to change, is now in doubt.
Modeler and geologist Robert DeConto of the University of Massachusetts, Amherst, says the policy implications are grim. "Our models may be dramatically underestimating how much worse it's going to get," he says, noting that many population centers worldwide are within a few meters of sea level. Looking at signs of meltwater in the early Miocene, DeConto says, "we're seeing ice retreat faster and more dramatically than any model predicts."
Antarctica's ice sheets contain roughly two-thirds of the world's fresh water. A meltdown of the West Antarctic Ice Sheet alone would boost sea levels by an estimated 20 feet, but if the East sheet were to also succumb, along with the Greenland ice sheet, sea levels could rise by more than 200 feet. This would be catastrophic for major population centers near sea level, such as New York City, much of Florida and nearly all of Bangladesh. No one expects the ice sheets to disappear overnight—even the worst timelines span centuries—and uncertainty about their fate remains, but radar altimetry from NASA satellites indicates that melting is under way in some parts of the East sheet, as well as in much of the West sheet. Researchers say the effects of melting ice sheets could be apparent within a lifetime as undersea currents are disrupted and weather patterns shift.
DeConto's collaborator, climate modeler David Pollard of Pennsylvania State University, says the answer to the puzzling disparity between model predictions and the core data could lie in an erroneous assumption about Antarctica itself. For example, Pollard says, some parts of the land underlying the East ice sheet might be much lower than currently believed. In that case, if warming oceans strip away the surrounding ice shelves, significant chunks of the ice sheet could slide into the ocean. Subglacial lakes, which form as glaciers slide over depressions, may have an underappreciated role, he added. DeConto says polar stratospheric clouds also need further study. There are indications, he says, that they act as infrared reflectors, which might contribute to ice sheet melting in ways not yet accounted for in models.
Whatever the cause, the key evidence for ice sheet dynamism in the Antarctic comes from the core's lithographic record. Sedimentologists have studied its facies, the visible characteristics that distinguish each stratum, for indications of how warm or cold the surrounding environment was. The McMurdo Sound facies repeatedly vary from "ice proximal," where fractures, scraping and larger grain size indicate a glacier rumbling by, to "ice distal," where laminated sediments and marine fossils speak of lapping waves in an ice-free marine environment.
Numerous other lines of evidence from the core support the idea of wide climate swings in Antarctica's past. There are spikes in the amount of pollen found within the core, for example, indicating flowering plants nearby. Levels of various organic molecules repeatedly rise and fall in the column, showing that microorganisms and shellfish flourished in the warmer periods and receded during cold times. The presence or absence of clasts—chunks of sedimentary rock carried along and deposited by glaciers—also indicates a fluctuating Antarctic climate. Co-chief scientist Fabio Florindo of Italy's National Institute of Geophysics and Volcanology notes that surges of magnetic mineral in the core may also mark warming trends. Reviewing the record, sedimentologist Christopher Fielding of the University of Nebraska-Lincoln says that in its warmest periods Antarctica must have resembled Patagonia today, where winters average a few degrees below freezing and summertime highs occasionally reach 80 degrees Fahrenheit.
However, Fielding, DeConto and others agree the core data is not conclusive. The McMurdo Sound core offers a pinhole view of East and West Antarctic Ice Sheet behavior, but at the price of extreme difficulty of interpretation. Scientists expect that firmer answers will emerge from other Antarctic research, including a hoped-for third ANDRILL project planned for Coulman High, also in the vicinity of Ross Island.
Harwood, a University of Nebraska geoscientist, says there is already evidence enough for policymakers to take action against global warming in hopes of preventing a dramatic Antarctic meltdown. "This core is going to be studied for the next 20 to 30 years," he notes, but already, he adds, the Miocene-age evidence it contains strongly suggests that it would be a mistake to count on ice-sheet stability in the Antarctic. "We see two or three periods of ice-sheet collapse, including one that looks abrupt, with very rapid deglaciation."
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53 Comments
Add CommentJust 20 feet (6.2 m) of sea level rise (the amount expected if the West Antarctic Ice Sheet melts) would be catastrophic for many coastal cities, Florida and Bangladesh. 200 feet (the amount expected if the East Antarctice Ice Sheet Melts) would drown every coastal city wordlwide and redraw the coastlines.
Reply | Report Abuse | Link to this"We see two or three periods of ice-sheet collapse, including one that looks abrupt, with very rapid deglaciation."
Reply | Report Abuse | Link to thisAnd this all happened naturally before human activity with CO2 fluctuating vastly; yet our Governments are forcing us to believe that they can control the warming by cutting human activities. They are so naive. that they will spend a fortune and achieve nothing.
At least you associate global warming with carbon dioxide. Increasing levels of CO2 will affect climate whether it comes from volcanism or oxidation of fossil fuels. Your argument suggests that the carbon dioxide contribution from oil and coal conversion by humans does not count.
Reply | Report Abuse | Link to thisAt least you associate global warming with carbon dioxide. Increasing levels of CO2 will affect climate whether it comes from volcanism or oxidation of fossil fuels. Your argument suggests that the carbon dioxide contribution from oil and coal conversion by humans does not count.
Reply | Report Abuse | Link to thispoosta7- What data do you reference that attributes the changes in total atmospheric CO2 to human activities? Personally, I have been reading about the Suess effect (which measured the ratio of carbon 14 in atmospheric CO2), but this has not been able to be used since the early 1940's. The method of measurement referenced in the IPCC report of 2007 measure the ratio of carbon 13 to atmospheric CO2 and the calculation seems to have a HUGE margin of error.
Reply | Report Abuse | Link to this"What data do you reference that attributes the changes in total atmospheric CO2 to human activities?"
Reply | Report Abuse | Link to thisSeriously?
Here we go again. The deniers come out claiming that past warming, when humans couldn't possibly have had any effect, proves that we can't be effecting it now, and the AGW proponents bring out evidence that says we have an effect now. The evidence so far is that CO2 has an enormous impact on the world's temperature, and the evidence is also that solar output has not changed appreciably in the time since the Industrial Revolution (that is a fact deniers, you can put the "sundidit" argument away). In 1859 it was PROVEN that CO2 traps Infrared radiation, so logically if more CO2 goes into the atmosphere, it should raise the temperature. Obviously, the temperature has changed in the past without human input, and if all possible routes hadn't already been explored that would be a legitimate argument. However, we know what those mechanisms were (for the most part). Volcanoes produce cooling effect, so maybe there have been fewer volcanoes. Nope, the number of volcanic eruptions has stayed about the same in recent history as in the past few millenia. Increased solar output increases temperature. Too bad solar output hasn't increased in the last 200 years. The Earth's orbit changes, changing the amount of radiation the Earth receives from the sun. Those changes happen on scales of hundreds of thousands of years, not nearly fast enough to account for the observed warming. Unknown sources of CO2 or other GHGs are causing it. Uh-huh, and where is this source? How are billions of tons of CO2 getting into the atmosphere from some magic source while the billions of tons from us are not? Provide a source and then come to the debate.
Reply | Report Abuse | Link to thisRegarding the article itself, this is fairly disturbing information, because a 200 foot sea level rise would redraw coastlines and displace billions of people. But hey, maybe we could raise the temperature enough to open up new real estate on Antarctica, and send a few hundred million people there.
We didn't need a pack of humans littering and drilling holes in vulnerable ice sheets to tell us the obvious. A denier is not without agenda. We're at a time when we need ideas on how to move forward.
Reply | Report Abuse | Link to thisblewis - it was so obvious that most scientists were surprised by this result. You should go educate scientists on the other obvious things you know too, and save them tons of work and research.
Reply | Report Abuse | Link to thisI dont see anything surprising. What's surprising is scientist willing to cut through vulnerable ice sheets to verify what we already knew. Humans need to stay out of these areas. Is smoke, litter, and damage worth this. Do you think the one million cars driving through glaciers have any effect or is it the bad oil companies. I say the latter.
Reply | Report Abuse | Link to this@fisixisfun & Natedog- There is certainly evidence that non human related production of CO2 varies over time in the planets history and probably has a much greater impact than does human activities. Please read the this link http://www.scientificamerican.com/article.cfm?id=soils-emit-carbon-dioxide
Reply | Report Abuse | Link to thisRegarding the opposite site of the discussion, which is the evidence that any increase IS caused by humans, the "evidence" is extremely weak as far as I can determine. The entire conclusion is based upon the initial analysis of the ratio of 14C to 12C and 13C . Using this method was invalidated since the 1940's due to human released 14C. The current method looks at the relationship between 12C and 13C. That method has many assumptions built into the calculations and has a very large margin of error. It simply seems far to inaccurate to come to the stated conclusions.
Please, show me the math to help me understand where I am incorrect in understanding how the ratio of 12C and 13C and how that proves that the cause of rising CO2 is all due to humans? I am not a denier, I am trying to be objective and the case does not seem to hold up.
Sisko, one does not need fancy math to understand that man has contributed a great deal to the current volume of CO2 in our atmosphere.
Reply | Report Abuse | Link to thisTake a look at primary metal ore processing and purification methods. All of them involve dumping carbon monoxide and pure oxygen into molten metal ores to draw out impurities. Guess what the main byproduct is. Go on, guess.
Are you also aware of what the biggest hallmark of the Industrial Revolution was? I'll tell you: a tremendous upsurge in coal-based refinery processes. Ore smelting. Starting in the mid 1800's. The total output of iron and steel processing alone, across the globe, has been rising ever since.
Your arguments that humans cannot have contributed any significant amount of CO2 to the atmosphere are a joke.
David Watkins: '"We see two or three periods of ice-sheet collapse, including one that looks abrupt, with very rapid deglaciation."
Reply | Report Abuse | Link to thisAnd this all happened naturally before human activity with CO2 fluctuating vastly; yet our Governments are forcing us to believe that they can control the warming by cutting human activities. They are so naive. that they will spend a fortune and achieve nothing.'
How is it that you jump to the conclusion that all happened before human activity with Co2 fluctuating vastly? Reading and comprehending what you read are two different concepts. Its people like you that want to see what you want and ignore the science that are delaying policy changes. This is exactly why Government needs to deal with scientists, not ordinary folks. If the problem was a deadly viral epidemic the government would deal with medical experts, not with Joe the Accountant, so why should this be any different?
I'm not a scientist, but as an engineer, I've read numerous sources that bring to light irrefutable evidence of not just climate change but exploitation of our natural resources and destruction of our ecosystem. Perhaps you should try and get educated on the facts before you state your blind opinion as fact.
David Watkins: '"We see two or three periods of ice-sheet collapse, including one that looks abrupt, with very rapid deglaciation."
Reply | Report Abuse | Link to thisAnd this all happened naturally before human activity with CO2 fluctuating vastly; yet our Governments are forcing us to believe that they can control the warming by cutting human activities. They are so naive. that they will spend a fortune and achieve nothing.'
CO2 has not fluctuated "vastly" in 650,000 years. The atmospheric concetration has been steady for all this time until the Industrial Revolution in 1750. Only since then, with human activity has the CO2 concetration rapidly accelerated. So, we are either facing the next natural cycle of our planet, in which case there is nothing we can do, just wait to freeze over or drown, OR, this is not a major natural cycle, in which case WE are responsible for the CO2 levels and We need to do something about it.
It seems to me that without the facts of science in your hand you should not be sharing a blind opinion and further hampering the already skeptic climate. Please, at least read formal articles of science if you are interested before sharing your expert opinion. Let those references not be the NY Times, or USA Today. There are plenty of documented technical documents, dissertations, etc., available free online, or search University archives, or even Nature, Science, Scientific American, or government literature such as the Energy Information Administration.
Its people like you that want to see what you want and ignore the science that are delaying policy changes (that and lobbying interests). This is exactly why Government needs to deal with scientists, not ordinary folks. If the problem was a deadly viral epidemic the government would deal with medical and biological experts, not with Joe the Accountant, so why should this be any different?
I'm not a scientist (at least not in the natural sciences), I'm an engineer , I've read numerous sources that bring to light irrefutable evidence of not just climate change but overpopulation, exploitation of our natural resources, failure of our food distribution systems, and destruction of our ecosystem. Perhaps you should try and get educated on the facts before you state your blind opinion as fact. You let firefighters put out fires and you put your faith on them, then let scientists take care of this problem.
I think the experiment does tell us something new. It was thought that Antarctic Ice was pretty stable despite global warming, but now we are learning that it may not be, and the consequence of that might be a 200-ft sea level rise (over a couple of centuries granted).
Reply | Report Abuse | Link to thisIn general, you are right, for those that choose to be educated in the facts, we do not need any more convincing. However, I'm always open to more science, specially, if it can help me understand something better so i can address it better.
There is much more to this than just global warming. Overconsumption, ocean acidification, water scarcity, etc., all related to a common cause.
To David Watkins:
Reply | Report Abuse | Link to thisAs the article states; "evidence of some 74 cycles of ice sheet buildup and retreat during a 6-million-year stretch..." SIX MILLION YEAR STRETCH, this is one of the key indicators of man made climate change. Each cooling and melting period took 80,000 years or so. The industrial revolution occured in the late 18th century, THAT IS LESS THAN 300 YEARS AGO. SO, in conclusion, you have changes that occured over tens of thousands of years, occuring in a fraction of the time.
Oil companies are only able to do that because YOU support them by consuming endless amounts of oil.
Reply | Report Abuse | Link to thisThis is not prove everything but it certainly gives you an idea to the validity of the science. Take any formal report (EIA. IEA, IPCC) and look up the number of coal-burning power plants and the average output, the emissions per hours then consider the length of operation in years. We could add other sources, but coal is the biggest contributor today, so we can stick with coal. Add up all of the CO2, then divide by 2 to take into account what gets absorbed by our oceans. You can then count cars and average emissions since the early 1900's. Then add forest fires from deforestation (currently accounts for 8~10% of global emissions)... how is that atmospheric concentration coming along so far? Some will get absorbed by plants and trees, but that is a decreasing sink considering we've destroyed over 40% of our forests worlwide, including the rich tropical forests in SouthEast Asia and Amazon. Let's not forget nitrogen fertilzers, which contribute to N20, a gas 310 times more potent than CO2 in absorbing solar radiation. I do not need to have account of every gram or know a formula that helps explain every gram of CO2. This is just common sense. You can back up this simplistic analysis with CO2 maps of coal plants around the US and how they affect air quality and CO2 concentrations. I could go on. How do I know? I'm writing my thesis on sustainability of primary energy and alternative fuels. There is not room for skepticism (except with stupidity) when practically all scientists agree on the major points of climate change. There is no corporate agenda here. In fact, many corporate interests (in the dirty energy industry..surprise surprise) are lobbying against science.
Reply | Report Abuse | Link to this@Galaxy_man- I have not stated that humans have not affected the environment or that we have not increased CO2.
Reply | Report Abuse | Link to thisWhat I am pointing out is that humans are not the only source of CO2 being released into the atmosphere, and that we are really a minor player to the overall CO2 levels in the atmosphere. Please read the link:
http://www.scientificamerican.com/article.cfm?id=soils-emit-carbon-dioxide
It sites over 400 studies confirming what I have written here regarding release of CO2 by non human activities. My concern is that politics will push us to eliminate/restrict CO2 emisions when the data does not support the action.
@Just Say No to CO2- You wrote: "There is not room for skepticism (except with stupidity) when practically all scientists agree on the major points of climate change."
Reply | Report Abuse | Link to thisI completely disagree. There in significant debate as to the percentage of impact that humanity has had on any climate change. The more data we get the more we understand the science and see that there is much more going on than simply blaming human released CO2.
Yes, the climate is changing...duh
Yes, humans are effecting climate....duh
Is human released CO2 the largest factor driving climate change- the data does not support that conclusion
galaxy_man- I am sorry for your inability to read and understand, so I will further explain. My prior comment was completely consistant. I stated that:
Reply | Report Abuse | Link to this1. Humans have affected the environment and have released CO2
2. Sources other than humans have also released CO2 and in much larger amounts than have humans (and I provided a link to over 400 studies showing that)
3. The data does not support any claim that all CO2 changes are due to humans
What is the point of your "name calling". It makes you look silly and weakens the respect others might have for your position.
Harwood states: "Contrary to what climate simulations suggest, nature seems to give us a record that the ice sheets are coming and going."
Reply | Report Abuse | Link to this"Contrary to simulations". So, here we now have more data to feed into the climate models to make them more accurate.
Contrary to c-connection's interpretation, the earth has been warming for well over 10,000 years, since the end of the last ice age. That it is being accelerated by man's addition of CO2 is suggested by the data by correlation. No causal proof exists to my knowledge, but as this article proves, we don't have all the relevant data.
I so wish all the bickering back and forth between the deniers and warmies would stop. Let the scientist determine what is going on so we can act accordingly.
"Is human released CO2 the largest factor driving climate change- the data does not support that conclusion "
Reply | Report Abuse | Link to thisThe data overwhelming supports the conclusion that human activities are directly responsible for the global warming we are currently experiencing.
We are all perfectly aware of the fact that climate change can and does occur due to natural phenomenon, we are also fully aware that none of those catalysts are currently engaged. No increase in solar radiation, no increase in geothermal activity, nothing accept the increase in green house gasses due to the burning of fossil fuels, and other human activities.
@Natedog --You wrote: The data overwhelming supports the conclusion that human activities are directly responsible for the global warming we are currently experiencing.
Reply | Report Abuse | Link to thisWhat data?
I have provided links that demonstrate that to be an incorrect statement. Please try to be fair and draw your conclusion based upon facts and data and not a preconceived opinion.
The average temp. of the antarctic is -55 degrees, for it to melt it would take a 87 degrees temp. increase, if that happens we will not be around to see it.
Reply | Report Abuse | Link to this"I have provided links that demonstrate that to be an incorrect statement. Please try to be fair and draw your conclusion based upon facts and data and not a preconceived opinion."
Reply | Report Abuse | Link to thisNo, you did not demonstrate it to be incorrect in and shape or form. You mention that you have been reading about the Suess effect, but clearly only superficially because you fail to realize that it also measures C13 ratios. You make some claim that the method can no longer be used (why?), make another claim that the method used by the IPCC (which you fail to name) is erroneous (how?) and somehow in your mind all this patched together constitutes a a falsifying demonstration?
Not only is that incredibly faulty reasoning, it is a complete and utter insult to the scientific method.
I have a degree in Environmental Engineering, I have spent countless hours studying environmental models, mastering biology, thermodynamics, mathematics, material sciences, etc and what does that earn me? Some guy telling me to stick to the facts. Sisko, I don't think you would know the facts if they hit you in the head.
Natedog- You completely failed to address the link I provided that demonstrates that the amount of CO2 emitted by soils does vary over time and can account for differences in total atmospheric CO2 to a much larger degree than does human activities. I will provide it again and would appreciate what you think about it since you have studied the issue. http://www.scientificamerican.com/article.cfm?id=soils-emit-carbon-dioxide
Reply | Report Abuse | Link to thisAdditionally, your point on the Suess effect completely failed to address what I had written.About the Suess effect I wrote "it is based upon the initial analysis of the ratio of 14C to 12C and 13C . Using this method was invalidated since the 1940's due to human released 14C. The current method looks at the relationship between 12C and 13C. That method has many assumptions built into the calculations and has a very large margin of error. It simply seems far to inaccurate to come to the stated conclusions.
Please, show me the math to help me understand where I am incorrect in understanding how the ratio of 12C and 13C and how that proves that the cause of rising CO2 is all due to humans? I am not a denier, I am trying to be objective and the case does not seem to hold up.
Regardless of what you may believe, I am completely objective on the issue of climate change and am open to accept new information if provided. I respect that you have studied the issue, but please help me understand the case that humans have caused the total (or the vast majority of) the CO2 increases in the atmosphere. I have shown you links to data that show over 400 studies that demonstrate that there are significant variances in natural CO2 emission levels from soil. Please look at the relationship of 12C and 13C and please explain how the relationship between these two stable isotopes can prove humans have caused the CO2 increases....good luck, because the math is not there
Please show me the math and help me understand. I am not a scientist but I do like to surf the net and think about things.
Reply | Report Abuse | Link to thisThe CIA World Factbook states that America uses about 20 million barrels of oil a day (2009). This constitutes about a quarter of world use; that means the world uses on average about 80 million barrels a day. At 42 gallons a barrel this gives us less than 3.4 billion gallons a day; in metric, at almost 159 litres to a barrel, we get 12.7 billion litres a day. If it were water in those barrels - since one millilitre of water by volume equals one gram in mass, and likewise a cubic meter would be a metric tonne - we would have 12.7 billion kilograms a day.
However, oil's density is less than water, so we only consume, as a planet, (using the density for Crude Oil, 32 degree API of 862 kilograms per square meter) about 11 billion kilograms everyday, or more simply, 11 million metric tonnes (about 12 million US tons of oil a day).
In the oxidization process the light hydrogen in the various oil hydrocarbon chains links with oxygen to form water, while the carbons each link with two oxygens to form CO2. Because by mass hydrocarbons are carbon rich, and since in its new recipe the carbon is less than a third of the mass (atomic weight of 12 verses the 16 of oxygen), we end up getting two to three times the mass in carbon dioxide after consumption (24 to 36 million tons a day) depending on the makeup of the hydrocarbons.
This is billions of tons a year for oil alone. Coal also adds a significant amount (try taking a jog in half of China's developing cities and you will become acutely aware of this!) as does natural gas. All the forest fires can be ignored because they are part of the carbon cycle. But as far as sequestered carbon is concerned, every year several square kilometres of oil is oxidized, which would fill a container the size of a small mountain; does this result in 3 times as many square kilometres of CO2 after oxidization?
No. It is a gas, so it doesn't stick around in square meters or square inches or even square miles. It disappears completely: out of sight, out of mind.
Also, help me understand the ratio of 12 and 13C as I am wondering where the increases, since the Industrial Revolution, of atmospheric CO2 are coming from.
Addendum: I am not a geometer! Several times I wrote square meters, inches etc., each time meaning not 2 dimensional area but the 3 dimensional unit of volume, cubic meters, inches etc.
Reply | Report Abuse | Link to thisNow that I have been so humbled, I am unfit for sarcasm. Clearly then - with no sarcasm - this is what I think: we, humans, in recent times, have burned what amounts to a small mountain range of oil - a source of carbon that has hitherto been inert in recent geological time - and if we trust grade school chemistry we must accept that we have put a colossal amount of carbon dioxide into our atmosphere. Imagine the shipping lanes of the oil tankers and all the pipelines as being long wicks - it all gets combusted at some end user, is gasified, and ultimately changes the concentration of our atmospheric gases.
Reject my earlier cheekiness about isotope ratios, but don't reject the simple and obvious mathematics which should weigh more heavily than arcane sources of reasoning and evidence. There are carbon sinks to be sure and a natures carbon cycle is tremendous and awe-inspiring, but let's not also forget the enormity of the human carbon contribution. It has taken aerobic life millions of years to get the levels of oxygen we need to breathe; it took millions to biologically sequester carbon, and a hundred to return much of it (as we are now scraping up the tar sands).
Just as metals have different heat capacities, gases trap heat differentially. With everything else remaining the same in recent times, it really is natural and intuitive to correlate sudden temperature changes with the sudden introduction of billions of tonnes of carbon dioxide into our atmosphere. And remember, even if one piece of evidence in the above is not perfectly understood or agreed upon, it does not mean the whole 'theory' (in the sense of the 'theory' of evolution) of human-influence climate change is utterly bogus. The scientific method does not work that way.
If you find some problems, please come up with a competing theory for the change in climate that has as much explanatory power while being as parsimonious as possible. Rational skepticism is always healthy, but simply being 'anti' is a vacuous position when we are faced with a crisis; please offer something more constructive in place of what you reject. And if you automatically reject something based on a pre-conceived belief (other than the belief that science 'works' which can reject superstitious explanations) let me show you the exit door to this science forum. You need to preach to another choir.
Addendum: I am not a geometer! Several times I wrote square meters, inches etc., each time meaning not 2 dimensional area but the 3 dimensional unit of volume, cubic meters, inches etc.
Reply | Report Abuse | Link to thisNow that I have been so humbled, I am unfit for sarcasm. Clearly then - with no sarcasm - this is what I think: we, humans, in recent times, have burned what amounts to a small mountain range of oil - a source of carbon that has hitherto been inert in recent geological time - and if we trust grade school chemistry we must accept that we have put a colossal amount of carbon dioxide into our atmosphere. Imagine the shipping lanes of the oil tankers and all the pipelines as being long wicks - it all gets combusted at some end user, is gasified, and ultimately changes the concentration of our atmospheric gases.
Reject my earlier cheekiness about isotope ratios, but don't reject the simple and obvious mathematics which should weigh more heavily than arcane sources of reasoning and evidence. There are carbon sinks to be sure and a natures carbon cycle is tremendous and awe-inspiring, but let's not also forget the enormity of the human carbon contribution. It has taken aerobic life millions of years to get the levels of oxygen we need to breathe; it took millions to biologically sequester carbon, and a hundred to return much of it (as we are now scraping up the tar sands).
Just as metals have different heat capacities, gases trap heat differentially. With everything else remaining the same in recent times, it really is natural and intuitive to correlate sudden temperature changes with the sudden introduction of billions of tonnes of carbon dioxide into our atmosphere. And remember, even if one piece of evidence in the above is not perfectly understood or agreed upon, it does not mean the whole 'theory' (in the sense of the 'theory' of evolution) of human-influence climate change is utterly bogus. The scientific method does not work that way.
If you find some problems, please come up with a competing theory for the change in climate that has as much explanatory power while being as parsimonious as possible. Rational skepticism is always healthy, but simply being 'anti' is a vacuous position when we are faced with a crisis; please offer something more constructive in place of what you reject. And if you automatically reject something based on a pre-conceived belief (other than the belief that science 'works' which can reject superstitious explanations) let me show you the exit door to this science forum. You need to preach to another choir.
First of all, a person who makes wild claims without any tangible proof while simultaneously denegrating the words of others on the same basis, such as yourself, is a hypocrite and deserves no respect from others in a logical debate.
Reply | Report Abuse | Link to thisSecondly, trying to put me on the defense for name-calling which did not take place does nothing more than reveal the weakness of your position. For your reference, a troll is a person who attends forums and posts inflammatory and unfounded remarks for the sole purpose of inciting rage and meaningless prattle. Much like Ann Coulter. It now appears that this is what you are trying to accomplish.
In spite of what many wish to claim here, humanity is not the main source of CO2 being released into the environment. As Squish points out, yes humans are releasing CO2 into the environment. The fact is, human released CO2 makes up only a small percentage of the total CO2 being released each year into the atmosphere.
Reply | Report Abuse | Link to thisInteresting how those responding to my comments have completely ignored the link I repeated posted which sites over 400 studies proving my comments that there are natural variations in CO2 emissions. They fail to address the scientific points I raise and only seem able to throw out stupid insults.
The nice thing about this AGW debate is that by 2020 we should have a definitive answer. I expect that the answer will be that the world climate will be slightly cooler and the oceans will not have risen even a centimeter.
Reply | Report Abuse | Link to thisAll of this will take place despite human adding to the trace gas (.0003 or so by weight carbon dioxide) in the atmosphere.
There are ways to bet this proposition. The Chinese are running around the world buying up all the fossil fuel properties they can find. China and Russia both are about to dramatically expand off shore drilling in the Gulf of Mexico just outside our territorial waters.
Re Watkins: Since you don't believe human activities affect GW it is obvious the governments are not forcing you, or anyone else to believe it. But because natural factors have caused abrupt and extreme GW in the past does not mean our present activities are not now causing it at least partially. Natural factors could even counteract and overwhelm our contribution by cooling (e.g.volcanic ash, etc.). Nevertheless data show our activities do have an effect. The question is how much and we should do what we can to counteract that and not add to whatever nature may be doing.
Reply | Report Abuse | Link to thisWell said, fisixisfun. You said all that needs saying for me and others who are convinced human activities are contributing to GW.
Reply | Report Abuse | Link to thisThe carbon in the atmosphere has had a declining 13C/12C ratio since the mid to late 19th century. Fossil fuels have low 13C/12C rations. The additional CO2 is most likely to be coming from fossile fuel combustion.
Reply | Report Abuse | Link to this@Jay Dee Are- The basis of the belief that the additional CO2 is caused by humans is focused around the ratio of 14C to both 12C and 13C. (which can not be done for the last 60 years) If you look at the ratio of 13C to 12C over time it is VERY difficult to build a case for any CO2 increase being due to humans.
Reply | Report Abuse | Link to thisThe most critical information I found in this article was the several comments made by 'climate modelers' indicating that the ice core data did not match the predictions of their simulation models. They are attempting to determine how best to 'tweak' model processes or 'fudge' model parameters so as to verify their models.
Reply | Report Abuse | Link to thisFollowing construction of a model, it must be verified: demonstrated to predict actual historical conditions based on historical data. A model that cannot demonstrate this minimal capability is useless for predicting future conditions - it is unreliable.
Once a model has been successfully verified, it should be validated: shown to be reliable in predicting short term future events or conditions based on a variety of actual recent data. Once this has been reliably demonstrated, the model can be considered useful for predicting long term future events or conditions.
A model can be considered proven when its long term predictions have been demonstrated to be accurate. If at any point in this process requires modifications to better represent actual processes being predicted, the verify/validate/prove process must start all over again: the model is once again unreliable.
That the modelers have not produced a model that faithfully represents critical climate processes does not surprise me, as I know it is an extremely difficult problem given its extremely complex dynamics.
The most significant issue here is that decisions have already been made based on the predictions of not just unproven or unvalidated, but unreliable, unverified models.
I admit I'm just recalling the critical steps in the production of a reliable model from about 20 years ago, when I abandoned efforts to produce and maintain reliable models of very large scale computer systems, as their critical processes are subject to dynamic significant changes. I'm sure that much has been learned in the past 20 years, but apparently much has also been forgotten...
I disagree. Check the data at ORNL's CO2 site and the tree ring data at the University of Arizona's tree ring-site. The CO2 content in the atmosphers has been increasing since the mid 19th century and the 13C/12C ratio has been going down over the same period, as one would expect if fossil fuel combustion were contributing significantly to the atmospheric CO2.
Reply | Report Abuse | Link to thisSo if CO2 drives the climate, why then from the 1940s to the 70s did temperature decrease despite rising CO2 levels? Explain how the medieval warming period got warmer than it is today If CO2 levels lag behind temperature change by 800 years but continue the warming trend, then shouldn't those levels increase into oblivion? There is more CO2 in the atmosphere, however, by how much has it heated up? There far more things that impact the earth's climate than CO2 levels. How much radiation the earth vents into space, solar wind that shields earth from cosmic rays, rays that produce rain clouds. The ocean absorbs an releases radiation, wind also effects the amount of radiation CO2 can absorb. Is climate change occurring? Of course it is, but its a cycle that has been going on since before there were people, before we came out of the cave. All the mass hysteria is getting old.
Reply | Report Abuse | Link to this"The southern McMurdo Sound core yielded clear evidence of some 74 cycles of ice sheet buildup and retreat during a 6-million-year stretch starting in the Miocene Epoch some 20 million years ago." So that means that these cycles ended some 14 million years ago? Or am I just reading this wrong?
Reply | Report Abuse | Link to thisThere are ancient stories that say the Great Flood that occured around 10,500 BC was caused by the Antarctic ice sheet sliding into the sea and creating huge tsunamis thousands of feet high that traveled around the globe covering the land. The article does not give dates for "We see two or three periods of ice-sheet collapse, including one that looks abrupt, with very rapid deglaciation." but, if the date for the abrupt ice-sheet collapse coincides with the story's date, it could be seen as confirmation of those stories.
Reply | Report Abuse | Link to thisA 100 years ago Wood performed an experiment that demonstrates that greenhouses heat up and stay warm by confining heated air rather than by trapping IR.
Reply | Report Abuse | Link to thishttp://globalwarmingnot.blogtownhall.com/2009/02/03/greenhouse_theory_disproved_a_century_ago.thtml
A CO2 molecule absorbs IR at specific frequencies. The IR energy drives motion of the carbon and oxygen. The chemical bonds vibrate and stretch. Eventually the molecule relaxes and emits lower energy radiation in microwave or longer wavelengths. A single CO2 molecule can absorb and re-emit a billion IR photons at the right frequency in one second.
Of the 186 billion tons of CO2 that enter earth's atmosphere each year from all sources, only 6 billion tons are from human activity.
Taking water vapor into consideration and using the data and formulae from the 2007 IPCC report, the DOE, the EPA, several universities and independent climatologists, the global warming contributions (based on concentration and potency) of atmospheric constituents are:
95% is from water vapor
5% is from 5 green house gasses (GHG)
Only 0.28% is from man-made GHG
Therefore 99.72% of GW is natural
Only 0.117% is from man-made CO2
Only 0.066% is from man-made Methane
(Reducing the 22% of US man-made GHG by 17% by 2020 as called for by HR 2454 would reduce GW by 22% of 17% of 0.28% or by 0.010472%, or about one part in ten thousand.)
But NASA supported spectral calculations and many other scientific experiments show that the radiation absorption capacity of CO2 at its principal wavelengths is well above saturation levels, so an increase in CO2 will have little or no warming effect.
The earth has cooled for 11 years and will cool for another 20 years before warming for 30 years just as it has for the two previous 60 year cycles independent of increasing green house gasses.
http://www.appinsys.com/GlobalWarming/GW_Summary.htm
It was warmer than now for hundreds of years during both the Medieval and Roman Warm periods. Global temperatures are now recovering from the Little Ice Age that started about 1350.
Analysis of climate records from various sources for millions of years reveals that CO2 increases always follows global warming and never precedes it. Therefore CO2 has never caused any of the hundreds of Global Warming periods.
http://www.geocraft.com/WVFossils/greenhouse_data.html
A better and more recent theory is that an ice jam between Greenland and Canada collapsed causing floods around the world, including the Mediterranean, Black and Caspian Seas. There is much evidence that Noah's ark ended up in Turkey between the Black and the Caspian Sea.
Reply | Report Abuse | Link to thishttp://www.noahsark-naxuan.com/1.htm
http://www.noahsark-naxuan.com/6.htm
The Arctic ice extent is compared to the mean since 1979. In 1979 Arctic ice was at an extreme not seen since Captains Franklin’s expedition in 1845. Since then many expeditions have successfully transited the Northwest Passage in both directions several times. Arctic ice has since returned almost to the record extent.
Reply | Report Abuse | Link to thishttp://www.pbs.org/wgbh/nova/transcripts/3307_arctic.html
Antarctic sea ice extent is at the greatest since reports by Captain Cook over 200 years ago.
http://www.newsmax.com/insidecover/global_warming_ice_age/2008/04/24/90591.html
http://iceagenow.com/Antarctic_Ice_Sheet_growing_enough_to_lowe_sea_levels.htm
http://www.theaustralian.news.com.au/story/0,25197,25349683-11949,00.html
Has anyone monitored the extent of sublimation of the ice sheets? This would probably require weighing test samples in situ at regular intervals.
Reply | Report Abuse | Link to thisThe 1859 experiment was followed by experiments by Wood 100 years ago. About 100 years ago Wood performed an experiment that demonstrates that greenhouses heat up and stay warm by confining heated air rather than by trapping IR.
Reply | Report Abuse | Link to thishttp://globalwarmingnot.blogtownhall.com/2009/02/03/greenhouse_theory_disproved_a_century_ago.thtml
A CO2 molecule absorbs IR at specific frequencies. The IR energy drives motion of the carbon and oxygen. The chemical bonds vibrate and stretch. Eventually the molecule relaxes and emits lower energy radiation in microwave or longer wavelengths. A single CO2 molecule can absorb and re-emit a billion IR photons at the right frequency in one second.
Of the 186 billion tons of CO2 that enter earth's atmosphere each year from all sources, only 6 billion tons are from human activity.
To see how ridiculous many of your other conjectures are, see my comments 43 and 45.
I don't see how an ice jam like that would be sufficient to cause a global flood. It seems to me, a breaking ice jam would tend to be much more localized and would peter out fairly quickly as the initial momentum of the break spread out. On the other hand, tsunamis can carry their momentum vast distances and overwhelm barriers on land when they meet them, although no living human can have seen tsunamis on the scale triggered by the whole Antarctic ice sheet, if it happened, so it's impossible to say what the effects would actually be. But there are those that believe it's effects have been misinterpreted as signs of ice ages. As for the evidence for Noah's Ark, it's far from conclusive at this time, which is why the search continues.
Reply | Report Abuse | Link to this"Complete melting of ice in Antarctica and Greenland, over a period of centuries, could raise sea level over 200 feet."
Reply | Report Abuse | Link to thisAnd if my car evaporated on a hot day, my garage would be nearly empty. Please explain how the ice sheets could possibly melt over a period of centuries--the massive energy has to come from somewhere.
You have almost understood global warming and then you give up. I can largely agree with most of what you claim allthough I would dispute some of the numbers but I do not want to split hairs.
Reply | Report Abuse | Link to thisYour main argument seems to be that CO2 is a weak GHG and cannot have the effect that is claimed by GW theory.
The sun has a nuclear fusion engine at it's core at ~15 million degrees C. The surface of the sun is at 5700 degrees Celsius.
So the sun's surface temp is only 0.00038 of the core temp.
Ironically and purely cooincidentally that number is precisely the same as the very recent CO2 concentration in the atmosphere on planet earth.
The sun is 98% or more hydrogen and helium. Gravity maintains this huge solar atmosphere which keeps the core at the proper temperature to maintain the fusion process. Remove the solar atmosphere, expose the radiation at the core to empty space and the fusion will stop at once.
One could call this solar warming.
The sun, roughly a sphere, radiates or spreads out in all directions and strictly geometrically speaking less than 1 part in 2 billion or 0.5 ppb or 0.000000005% of all this radiation reaches our planet . A very tiny or puny amount. How can that have any effect??
The earth without the sun would probably be at ~ -200 degrees Celsius (~70 Kelvin) or less. Add the sun but remove the atmosphere and ocean and the temperature would be about -18 degrees Celsius. So the sun's radiation, that 0.5 ppb increases the temperature here on earth by 200 degrees Celsius roughly and on average.
This alone should stop any argument based on the fact that because something is small with respect to something else that small thing can have no effect on things.
The 0.0380% CO2 in the atmosphere is much larger proportion than the 0.000000005% of solar radiation that reaches the planet.
The solar radiation gets partly reflected, about 30%, immediately back into space, then some of the radiation gets defused all through the atmosphere, then a fairly large portion just heats water, rock, sand and soil. Then probably less than 10% or 0.05 ppb reaches trillions of plants and other photosynthetic life. Then the plants get eaten by trillions of animals of all kinds. Some of the trillions of animals are billions of human beings and two of the human beings are you and I. I do not know about you but I consider myself a very important effect of this 0.0000000005 of 0.00000000005 of 0.000... ppb. Indeed a very tiny quantity can have a very large effect.
Continuing the consequences of tiny effects let me walk you through some observations regarding the (your) largest contributor to global warming more specifically water, H2O, vapor, steam, rain, fog, snow, sleet, ice.
Reply | Report Abuse | Link to thisIncidentally the weakest Green House Gas (GHG) seems to also be CO2 the smallest force in global warming that is if you admit that it has any warming effect at all. Thus methane ozone etc. are all stronger green house gases than CO2.
If we have an ocean full of water (ignoring continents for now) and an atmosphere and sunshine then the sun will warm the water, vaporize it and send it up into the atmosphere to start the global warming.
The net effect according to you is that water vapor is 95% responsible for the global warming. The global warming currently has the planet's average temperature at 15 degrees Celsius. So we come from -18 to +15 because of the atmosphere with vapor ignoring all other ghgs because their effect is so small. But this is the average temperature. The extremes are something like -70 C in Antarctica and +50 C in the Sahara or Death Valley or whatever desert you like.
But water has many different forms within these temperature ranges. When the sun warms the tropics more than the poles the water vapor will get carried by the winds towards the poles. Most of it will condense and fall out as rain and fog along the way and no longer contribute to warming. Not to worry the very next day the sun will vaporize some more water.
But some of the water will reach the poles and fall out as snow and some of the water in the polar ocean will freeze especially in the winter. When the snow falls on the ice it maximizes the albedo and more sunlight gets reflected into space without having any warming effect at all.
This will drop the average temperature on the planet and less water will evaporate as a consequence, it will eventually reach the poles as snow and more polar ocean will be frozen and get covered by snow and the planet's albedo will increase and reflect more sunlight and cool the planet further and we are in a snowball effect litterally towards a snowball earth. The net result from the strongest greenhouse gas is total ice cover across the whole planet. If you add a continent on the south pole called Antarctica the process will only speed up and indeed the most southern continent has been covered by ice the earliest and the longest.
So notwithstanding the very strong GHG we end up with a frozen planet given sufficient time. This is what has been happening for the last 50 million years.
Continuing ... But this is not quite what has happened in the last 50 million years. Yes we started out then with the planet much warmer than today and no permanent ice caps at the poles and we started a slow cooling descent towards the ice ages mainly because of decreasing CO2 from 1500ppm to 170 ppm at the last glacial maximum.
Reply | Report Abuse | Link to thisThe main reason for the "not quite" is the other 5% (according to you) of GHGs, the methane, ozone, nitrous oxides, chlorofluorocarbons and what have you AND CO2.
They do not behave like water within the temperature ranges of -70 to +50 on our planet. The main culprit is the smallest, weakest, tiniest effect called CO2 . Why ?
Well for example methane, CH4, is a strong ghg is present in ppb instead of ppm and gets converted to CO2 in about 10 years. The other GHGs either do not persist very long or have an even smaller concentration than methane in the atmosphere. This does not nullify their effect it is just not as persistant as CO2.
CO2 does not condense, it does not fall out as rain or snow and especially does not increase the planet's albedo. CO2 does not form clouds or turn into ice and snow and reflect sunshine like water does and thus CO2 ONLY warms the planet.
Thus the warming effect of CO2 is very small but persistant and IF you increase the amount of CO2 in the atmosphere continuously it will have a slightly larger and larger effect and warm the planet and melt the ice and melt the snow and decrease the albedo and reflect less sunlight and warm the planet and vaporize the oceans and heat up the upper atmosphere and the watervapor will escape from the planet into space and you will have a total desert instead of a snowball . The tiniest GHG will warm the planet the most.
Now, this is not going to happen at all mainly because we will not be able to add CO2 continuously and things are a little more complicated than what I describe here, thankfully.
Nevertheless we could potentially create quite a disaster or catastrophe if we are not careful.
But this should help you understand that CO2 with the tiniest effect of the green house gasses can have the largest warming effect on the planet in the long run.
It isn't whether, or not man is contributing that is the primary point of this article, or David's comment. The evidence found in this core points to at least 74 cycles of warming and cooling (so far) and there's a whole lot of other evidence from all over the world that says the same thing; that the earth has done this MANY times in its long history and will do so many times AFTER man has died out, or left for the stars (as if). That humans are contributing is not in question (every bit of flatulence contributes), but the draconian measures being foisted on the people of the world will lead to immediate down-turns in the quality of living for billions ... and this is all on the misinformation that man is CAUSING global-warming. We ARE NOT the cause, but we may be giving it a push. So, what do we do when all is done that can be done to reduce GHG output and the melt-down still comes?? The world needs the truth; we need to understand that this is a natural cycle that we are possibly speeding up; AND, we need to prepare for the change in our way of life that WILL come, eventually, NO MATTER WHAT! I think David's comment points clearly to the difference between honest scientists and those with political agendas ... Even The Geo-scientist, Harwood, quoted at the end, who acknowledges the evidence of multiple even catastrophic meltdowns, ignores the evidence in his ridiculous statement that," there is already evidence enough for policymakers to take action against global warming in hopes of preventing a dramatic Antarctic meltdown". Prevent?? Didn't he also say,"We see two or three periods of ice-sheet collapse, including one that looks abrupt, with very rapid deglaciation." Very rapid! In other words catastrophic! His statement regarding what the data shows and then what he says regarding, not what we should do, but WHY, is unbelievably dishonest and clearly agenda driven. His statement if taken at face value indicates that WE are at fault, when in reality we are probably doing no more than POSSIBLY speeding up the inevitable. I believe that what David's comment was saying could be paraphrased as follows: The only truth worth knowing is the whole truth, knowing anything less only sends us into a panic and leads to bad decisions, and really bad law. And for a scientist to offer anything less makes him/her a politician ... the dirtiest word I know. We need to prepare for the melt-down that WILL happen whether we give it a nudge, or not and we need scientists to get OUT of the business of politics and back to reporting truth.
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