jecorbett wrote: Eddie_walters wrote: loathar wrote:Sure the water level will be lower. This is second grade science. Water expands and takes up more volume as it freezes. When it melts, it will take up less volume. Thus, not raising the water level in the jar. Floating sea ice, (like icebergs) have most of there mass below the water line. They have already raised the sea level all they're going to raise it just by floating in it. Whether they are solid OR liquid.Not quite. As ice floats, the amount of water displaced by the ice will weigh the same amount as the block of ice - that's why part of the ice is above the surface of the water. Once the ice melts, it will reduce in volume, but it will still weigh the same amount, so it would just fill the void where the ice was. The water level will remain the same.You are only partly right. The melted water will weigh the same as the ice, but it will take up less volume. Water expands when it freezes and contracts when it melts. Fill a plastic jug with water to the top, put on the lid, and stick it in the freezer. By the time if freezes solid, it will have broken open the jug. Ice occupies more space than liquid water. It is true of large or small amounts of ice.
Eddie_walters wrote: loathar wrote:Sure the water level will be lower. This is second grade science. Water expands and takes up more volume as it freezes. When it melts, it will take up less volume. Thus, not raising the water level in the jar. Floating sea ice, (like icebergs) have most of there mass below the water line. They have already raised the sea level all they're going to raise it just by floating in it. Whether they are solid OR liquid.Not quite. As ice floats, the amount of water displaced by the ice will weigh the same amount as the block of ice - that's why part of the ice is above the surface of the water. Once the ice melts, it will reduce in volume, but it will still weigh the same amount, so it would just fill the void where the ice was. The water level will remain the same.
loathar wrote:Sure the water level will be lower. This is second grade science. Water expands and takes up more volume as it freezes. When it melts, it will take up less volume. Thus, not raising the water level in the jar. Floating sea ice, (like icebergs) have most of there mass below the water line. They have already raised the sea level all they're going to raise it just by floating in it. Whether they are solid OR liquid.
Not quite. As ice floats, the amount of water displaced by the ice will weigh the same amount as the block of ice - that's why part of the ice is above the surface of the water. Once the ice melts, it will reduce in volume, but it will still weigh the same amount, so it would just fill the void where the ice was. The water level will remain the same.
You are only partly right. The melted water will weigh the same as the ice, but it will take up less volume. Water expands when it freezes and contracts when it melts. Fill a plastic jug with water to the top, put on the lid, and stick it in the freezer. By the time if freezes solid, it will have broken open the jug. Ice occupies more space than liquid water. It is true of large or small amounts of ice.
Brother Corbett, the question isn't whether ice has a greater volume than water, the question is, does an iceberg displace its own weight in seawater. Since an iceberg floats, the answer is yes. Removing the iceberg and replacing it with an equal weight of liquid seawater at 0 degrees Celsius will result in a net change in water level of zero.
Interestingly, as the water warms, its density increases until it reaches its maximum at 4 degrees Celsius. That is why colder water sinks through warmer water, but ice floats.
Chuck (who once received A in Naval Architecture)
OK - a correction. The sea level will probably rise when sea ice melts, because the sea ice is fresh water, and the sea water is obviously salt water. Sea water has a greater density than freshwater. http://www.physorg.com/news5619.html
Those of you who naively criticize the "environmental wackos" should keep in mind that some of them are in your midst. I am a conservation planner and I love trains. I have years of education and experience in environmental issues, and while there is certainly controversy surrounding some of these topics, the consensus of impartial experts is: 1) global warming is real and needs to be dealt with; and 2) mountaintop removal is ecologically devastating. Does that mean we should all go back to the stone age to save the environment? Of course not. But we all need to be aware of the costs and benefits of our lifestyle.
As for modeling unethical practices, I've considered that for my own layout set in the south in the 1950s. Signs of segregation would be everywhere, from separate bathrooms at the depots to divided passenger cars. My feeling is that I want to be as accurate as possible, and perhaps modeling those unethical practices will remind myself and others that they were there--we can't rewrite history and shouldn't whitewash it.
Yes, I'm aware that ice takes up a larger volume than the same weight of water. I've seen the effects on an engine that was left with water in it over winter!
However, this is why ice floats, and how it sticks out of the water when it floats. If it kept the same density as water, then it would be neutrally buoyant, and would therefore bob up and down in the water depending on current, water temperature etc. That's not the case - the ice will always float, and it will displace the same amount of water as the volume of the ice when melted.
jecorbett wrote: gilligan wrote: inch53 wrote: As far as ethanol or soy diesel being the answerer, it's not either. If all the corn and beans on all the available farm ground were made into fuel, it would supply less than 1/3 needed today. If that were to happen, what would you eat, all the ground is producing fuel. Honestly what is your beef with biofuels?First of all, all the available farm ground can not be used for corn or beans because of the climate. Second of all, most of your corn is not even used for food directly anyways, it is fed to livestock, and one of the bi products of corn ethonal is ground up corn mash used for livestock feed. Thirdly 1 acre of land has steadly produced more each year due to new hybrids and technologies so a breakthrough there would mean the statement of supplying less than 1/3 needed is not entirerly true in the future.Speaking for myself, I have no beef with biofuels. If they can be produced on a large scale at a reasonable cost and a car that can operate on it will cost comparable to a similar gasoline burning car, I'll be happy to go green, as in the color of money. Right now, that isn't an option I have. If that is going to happen, it will because someone develops a process that can produce biofuels and sell them profitably at a competitive cost. That's right. Good old American capitalism. The public will vote with their dollars if they want biofuels, if and when they are a practical solution. The same holds true for solar and wind power. If they can be made profitable and practical, they will be adopted. RIght now, those sources can only provide supplemental power. Sooner or later, alternative sources of energy will have to be found because fossil fuels are not an unlimited resource and what is still there will become more and more expensive to extract from the ground. All the cheap oil has been pumped. If this is going to happen sooner, it will because alternative fuels are cost effective. As someone once said, it's the economy, stupid.
gilligan wrote: inch53 wrote: As far as ethanol or soy diesel being the answerer, it's not either. If all the corn and beans on all the available farm ground were made into fuel, it would supply less than 1/3 needed today. If that were to happen, what would you eat, all the ground is producing fuel. Honestly what is your beef with biofuels?First of all, all the available farm ground can not be used for corn or beans because of the climate. Second of all, most of your corn is not even used for food directly anyways, it is fed to livestock, and one of the bi products of corn ethonal is ground up corn mash used for livestock feed. Thirdly 1 acre of land has steadly produced more each year due to new hybrids and technologies so a breakthrough there would mean the statement of supplying less than 1/3 needed is not entirerly true in the future.
inch53 wrote: As far as ethanol or soy diesel being the answerer, it's not either. If all the corn and beans on all the available farm ground were made into fuel, it would supply less than 1/3 needed today. If that were to happen, what would you eat, all the ground is producing fuel.
As far as ethanol or soy diesel being the answerer, it's not either. If all the corn and beans on all the available farm ground were made into fuel, it would supply less than 1/3 needed today. If that were to happen, what would you eat, all the ground is producing fuel.
Honestly what is your beef with biofuels?
First of all, all the available farm ground can not be used for corn or beans because of the climate. Second of all, most of your corn is not even used for food directly anyways, it is fed to livestock, and one of the bi products of corn ethonal is ground up corn mash used for livestock feed. Thirdly 1 acre of land has steadly produced more each year due to new hybrids and technologies so a breakthrough there would mean the statement of supplying less than 1/3 needed is not entirerly true in the future.
Speaking for myself, I have no beef with biofuels. If they can be produced on a large scale at a reasonable cost and a car that can operate on it will cost comparable to a similar gasoline burning car, I'll be happy to go green, as in the color of money. Right now, that isn't an option I have. If that is going to happen, it will because someone develops a process that can produce biofuels and sell them profitably at a competitive cost. That's right. Good old American capitalism. The public will vote with their dollars if they want biofuels, if and when they are a practical solution. The same holds true for solar and wind power. If they can be made profitable and practical, they will be adopted. RIght now, those sources can only provide supplemental power. Sooner or later, alternative sources of energy will have to be found because fossil fuels are not an unlimited resource and what is still there will become more and more expensive to extract from the ground. All the cheap oil has been pumped. If this is going to happen sooner, it will because alternative fuels are cost effective. As someone once said, it's the economy, stupid.
If im not mistaken i thought auto makers have come out with flex fuel vehicles that can operate on e85. And i think they are reasonably priced. Where i live i can go to the pump put in e10 gas which contains 10% ethanol, has a higher octane rating, i get the same gas mileage and it usually cost 2-5 cents cheaper than regular unleaded, i just can't go wrong there.
jecorbett wrote: jimrice4449 wrote:Jecorbet, your experiment is invalid! By adding water to the ice to the full capy of the jar you're preventing the ice from floating (as it is on the N Polar Ice Cap). For a valid experiment add water until the floating ice is just short of the lid and then mark the water level. After the floating ice has melted the water level will be exactly where it was when the ice was floating.Actually, I did pretty much what you suggested. I was probably a little less than accurate in the way I described it. When I said I filled the jar, what I actually did was fill it up to the bottom of the threads so there was room above the original water line for the ice to float. This was a wide mouth Mason so the ice had plenty of room to rise above the water line. I'll be happy to repeat the experiment, this time with just enough ice to cover the surface of the water. That way none of the ice will be trapped underneath other cubes and all of it will be floating. I will wager that the water level after melting will be lower than when the ice was floating on the surface. It will probably not be as great a difference as in the orignal experiment, but it will be lower. If I am wrong, well that happened once before.
jimrice4449 wrote:Jecorbet, your experiment is invalid! By adding water to the ice to the full capy of the jar you're preventing the ice from floating (as it is on the N Polar Ice Cap). For a valid experiment add water until the floating ice is just short of the lid and then mark the water level. After the floating ice has melted the water level will be exactly where it was when the ice was floating.
Actually, I did pretty much what you suggested. I was probably a little less than accurate in the way I described it. When I said I filled the jar, what I actually did was fill it up to the bottom of the threads so there was room above the original water line for the ice to float. This was a wide mouth Mason so the ice had plenty of room to rise above the water line. I'll be happy to repeat the experiment, this time with just enough ice to cover the surface of the water. That way none of the ice will be trapped underneath other cubes and all of it will be floating. I will wager that the water level after melting will be lower than when the ice was floating on the surface. It will probably not be as great a difference as in the orignal experiment, but it will be lower. If I am wrong, well that happened once before.
Sure the water level will be lower. This is second grade science. Water expands and takes up more volume as it freezes. When it melts, it will take up less volume. Thus, not raising the water level in the jar. Floating sea ice, (like icebergs) have most of there mass below the water line. They have already raised the sea level all they're going to raise it just by floating in it. Whether they are solid OR liquid.
random thought here guys... please don't kill me... I'm not a fancy earth-science specialist or anything of that nature... however I do have a limited understanding of how this all works...
Say we've melted the ice caps a bit (or for the sake of discussion, a lot), water level rises ~3 feet.. thats bad... now, what about all that *cold* water that has now found its way into the oceans (and or the ocean currents)? Wouldn't such a huge volume of cold water throw the ocean currents off, and (possibly) cool things that said currents would otherwise warm? I mean, in order for you to raise the ocean's level by three feet all over, you would need need a *lot* of water.. a lot of water that is then sucking heat out of the surrounding air/water/land until some form of equilibrium is reached...
-Dan
Builder of Bowser steam! Railimages Site
Shilshole wrote:Among the scientific community of physicists, chemists, geologists, biologists, atmospheric scientists, and oceanographers, the scientific debate as conducted in their respective journals and meetings regarding AGW and most of its likely physical, chemical, and biological impacts is essentially over, even though there are many details to be hashed out and refined. By contrast, there still remains a 'debate' in the popular media, perhaps in the interest of being 'fair and balanced', in which personalities are trotted out to proclaim one truth or another. The latter is very similar to the 'debate' over evolution, which the scientific community firmly accepted over a century ago (and the understanding of which is still being refined) yet continues to be challenged by one group or another using the popular press to present their generally unscientific objections.
Are you really trying to tell us that scientists are in agreement about the cause of AGW, as well as the severity and consequences. Because if that is what you are saying, nothing could be further from the truth. There are plenty of scientists who are skeptical about whether AGW is man made (excuse me but I can't afford those $50 words you like to throw around to impress us). They are also skeptical about the extent of it and whether there will be dire consequences from it. Even those scientists who do believe it is a man made problem and that it will be destructive to our way of life will tell you that there is a great deal of uncertainty about the scope of the problem because there are too many variables and things they just don't know. Man made AGW is at this point a hypothesis and any scientist worth his salt will tell you just that.
The evidence for AGW is a two-parter. The first part is, in the absence of other known factors, the dramatic rise of atmospheric CO2 as a consequence of the industrial revolution, in which copious quantities of CO2 were introduced into the atmosphere by the burning of fossil fuels. (Note that the concentrations of another greenhouse gas, methane, show the pattern with time as CO2 on the figure below the CO2 figure. The methane increase is attributed primarily to changing agricultural practices accompanying industrialization.) One could argue that some other source is responsible for the sudden increase in CO2; unfortunately, there is no evidence for other known sources, such as weathering of limestone, unusually voluminous volcanic activity, or some odd release from the oceans. So it's scientifically 'certain' that the increase in atmospheric CO2 concentration since the industrial revolution is anthropogenic.
Of all the statements I have read since this thread was begun, this one has to be the most illogical. We don't know what else could be causing the rising CO2 levels so therefore it must be industrial emisions???!!! All of made made emisions of CO2 amount to 6% of the total. To say that this additional 6% is the only part of the equation that could be causing the dramatic rises in atmospheric CO2 is hardly sound scientific reasoning.
Shawnee,
Relax, I've just completed a Reclamation Plan on our open pit mine and it will be better than the original site. The standards ensure it and the money is paid up front. But that's OK, we'll charge you more!
OTOH what does this have to do with the hobby? Isn't anyone having fun?
Ernie C
orsonroy wrote:INTERIOR of Greenland. 600 years ago it was settled, today it's an icy paradise. If all of that "non-floating ice" (pardon me, but my college professors always tought me to write to the masses, not in technospeak) was melted 600 years ago,
INTERIOR of Greenland. 600 years ago it was settled, today it's an icy paradise. If all of that "non-floating ice" (pardon me, but my college professors always tought me to write to the masses, not in technospeak) was melted 600 years ago,
You're quite mistaken or have been misled. If your college professors gave you that melting story, demand your tuition money back
As I said wrote previously, settlements were then, as now, on the coast, extending perhaps a few miles inland along the fjords. There were no settlements in the Greenland interior (how did they find them, if they're covered with ice?). The Greenland Ice Cap has been in continuous existence for, oh, at least the last 600,000 years. That's confirmed by several ice-coring projects, from which ice samples were retrieved to measure O-isotope ratios (as temperature proxies) and paleo-CO2 concentrations.
the current GW theories state that ocean levels would be higher (it's off the land and into the seas). If the ocean levels were higher, there would be no reason that archaeologists would be finding 600-2000 year old arrowheads and pottery shards on a narrow peninsula that's maybe 20 feet above sea level at it's highest point. The entire land mass is nothing but salt flats and a tidal bog, so you can't say that the Indians were living somewhere else...
Sorry, I can't follow your logic; you seem to be mixing localities at will. The world sea level in recorded history, including the time of the 600-2000 y.o. artifacts you're referring to, has remained essentially constant since a several-thousand-year rise accompanying the last deglaciation. (Greenland didn't participate in that deglaciation, but continental glaciers in Eurasia and North America did.)
And I can certainly say that Indians, or whoever, indeed lived there, or lived nearby and visited the site occasionally. Twenty feet is quite high; most of Bangladesh, with a population much greater than that of pre-Colonial Indian tribes, is at an elevation of less than 10 ft MSL. Pretty swampy, too.
No one in the scientific community has even attempted to answer this question: how can the ice melt and the sea levels DECREASE?Apparently, you haven't really looked very hard for an answer.The land surface isn't static. Some formally glaciated areas (Fennoscandia, Greenland, Canada, even parts of New England and the upper Midwest, for example) are still 'rebounding' upward since glaciers melted, and their mass was removed, from those areas 12-15000 years ago. Areas along some coasts are rising (Alaska, western South America, for example) in response to material being subducted beneath them. With both mechanisms, local sea level decreases with respect to the land. Other coastal areass (parts of the Gulf and Atlantic Coasts, eastern India, Bangladesh, for example) are 'sinking' in response to compaction associated with sediment loading and groundwater withdrawal, and local sea level rises with respect to the land even if global sea level remains constant. The general term you're looking for is 'isostatic adjustment'. The scientific community 'discovered' this principle about, oh, 100 years or so ago.So you're saying that the Peninsula (that stretch of land that Williamsburg and Jamestowne sit on) has risen over the past 600 years or so? Or at least over the first 200 years of that time, since the land at Fort James has actually SUNK by about three feet since 1607?
No one in the scientific community has even attempted to answer this question: how can the ice melt and the sea levels DECREASE?Apparently, you haven't really looked very hard for an answer.The land surface isn't static. Some formally glaciated areas (Fennoscandia, Greenland, Canada, even parts of New England and the upper Midwest, for example) are still 'rebounding' upward since glaciers melted, and their mass was removed, from those areas 12-15000 years ago. Areas along some coasts are rising (Alaska, western South America, for example) in response to material being subducted beneath them. With both mechanisms, local sea level decreases with respect to the land. Other coastal areass (parts of the Gulf and Atlantic Coasts, eastern India, Bangladesh, for example) are 'sinking' in response to compaction associated with sediment loading and groundwater withdrawal, and local sea level rises with respect to the land even if global sea level remains constant. The general term you're looking for is 'isostatic adjustment'. The scientific community 'discovered' this principle about, oh, 100 years or so ago.
No one in the scientific community has even attempted to answer this question: how can the ice melt and the sea levels DECREASE?
Apparently, you haven't really looked very hard for an answer.The land surface isn't static. Some formally glaciated areas (Fennoscandia, Greenland, Canada, even parts of New England and the upper Midwest, for example) are still 'rebounding' upward since glaciers melted, and their mass was removed, from those areas 12-15000 years ago. Areas along some coasts are rising (Alaska, western South America, for example) in response to material being subducted beneath them. With both mechanisms, local sea level decreases with respect to the land. Other coastal areass (parts of the Gulf and Atlantic Coasts, eastern India, Bangladesh, for example) are 'sinking' in response to compaction associated with sediment loading and groundwater withdrawal, and local sea level rises with respect to the land even if global sea level remains constant. The general term you're looking for is 'isostatic adjustment'. The scientific community 'discovered' this principle about, oh, 100 years or so ago.
So you're saying that the Peninsula (that stretch of land that Williamsburg and Jamestowne sit on) has risen over the past 600 years or so? Or at least over the first 200 years of that time, since the land at Fort James has actually SUNK by about three feet since 1607?
No, I'm not saying the land you're referring to has risen over the past 600 years. The rebound I referred to occurs in formerly glaciated areas, which Virginia was not.
What I am saying is that there has been no large-scale melting of continental glaciers to raise sea level in several thousand years; the melting of Greenland ice you referred to previously did not happen. Land sinking at the Virginia locality has nothing to do with glacier melting. Historical 'sinking' of the land along some coastal areas, including the Mid-Atlantic states southward to Georgia and along much of the Gulf Coast, is attributable to sediment compaction and regional tectonic conditions.
My question is still valid: MORE water volume in the oceans in 1400 due to less glaciation in Greenland's interior, which equals HIGHER sea levels. So why are we finding American Indian settlements from 1400 (and earlier) within 20 yards of the ocean? Wouldn't those areas have been under water in 1400, either by raised sea levels or lowered ground levels?
Well, since your question is based on a faulty premise, it is indeed invalid.
From what I'm discovering, the scientific community is largely ignoring the anthropological and archaeological evidence in favor of MANY recent, long-term temperature fluctuations over the past 160,000 years (roughly the existence of Homo Sapiens). Ice and tree core samples are fine, but you have to look at old settlements too, and that data's not being used at ALL.Once again, that's not a reflection of what's really available. Perhaps a visit to a library (big building, lotsa books) Yes, thank you for your wry wit. I've done so, and very few of the pop culture GW advocates ever mentions the little ice age or other near term temperature peaks (for example: it was warmer 2000 years ago than it is today, by over 5 degrees).
From what I'm discovering, the scientific community is largely ignoring the anthropological and archaeological evidence in favor of MANY recent, long-term temperature fluctuations over the past 160,000 years (roughly the existence of Homo Sapiens). Ice and tree core samples are fine, but you have to look at old settlements too, and that data's not being used at ALL.Once again, that's not a reflection of what's really available. Perhaps a visit to a library (big building, lotsa books)
From what I'm discovering, the scientific community is largely ignoring the anthropological and archaeological evidence in favor of MANY recent, long-term temperature fluctuations over the past 160,000 years (roughly the existence of Homo Sapiens). Ice and tree core samples are fine, but you have to look at old settlements too, and that data's not being used at ALL.
Once again, that's not a reflection of what's really available. Perhaps a visit to a library (big building, lotsa books)
Yes, thank you for your wry wit. I've done so, and very few of the pop culture GW advocates ever mentions the little ice age or other near term temperature peaks (for example: it was warmer 2000 years ago than it is today, by over 5 degrees).
Full bibliographic reference to the peer-reviewed literature, please. There is absolutely no evidence for a thermal event 2000 years BP, let alone one having a 5 deg increase.
When they do mention the archaeological evidence, they usually mumble something about sunspots and quickly move on.
Perhaps they're just humoring you.
[...]
Review the latest studies about Terra Preta de Indio, and especially the findings of the late James Petersen. The "black earth of the Amazon" was an Reply inch53 Member sinceFebruary 2005 From: hillbilly hide away and campground C, M-ville,ILL 2,153 posts Posted by inch53 on Tuesday, March 20, 2007 3:01 PM Back to trains, yes I would take a train more, if there were one through here that I could take to my VA appointments rather than drive. I know of several people that drive 30 mile to work that would use public transportation, if it was around, but it's not.As far as ethanol or soy diesel being the answerer, it's not either. If all the corn and beans on all the available farm ground were made into fuel, it would supply less than 1/3 needed today. If that were to happen, what would you eat, all the ground is producing fuel. Conservation is what I believe the only thing left, in all ways. That's something I believed in after I had to start paying the utility bills. I hate giving more and more money, for less and less service. As far as global warming, it's a theory, not a fact as seems to be promoted these days, as so many theories are. The theory of evolution is the first one to come to mind and even taught in school as fact.As far as a 100-year climate forecast, I don't trust them either. H,,, than can't even get a 12 hour forecast right, let alone anything that far outWhen it comes to expert opinions or polls, I have several questions I want to know about. 1, what is the back round of the expert.2, what was he trying to prove [or study] from the start.3, who provided the funding and how much did he make.4, what other studies were done on the subject, and their conculsions.When all we seem to get is the one-sided politically correct versions on a subject, you can be lead anywhere they want you to go. Me, I like to look at the whole pie, before I have a piece. Reminds me of the 1930's and 40's Europe. inch http://www.trainboard.com/railimages/showgallery.php/cat/500/ppuser/4309 DISCLAIMER-- This post does not clam anything posted here as fact or truth, but it may be just plain funny Reply Shilshole Member sinceAugust 2006 294 posts Posted by Shilshole on Tuesday, March 20, 2007 2:30 PM jecorbett wrote: Shilshole wrote:Realclimate's explanation isn't all that detailed, but the issue of lag time is a red herring. I offer the following quote from Realclimate:"The reason has to do with the fact that the warmings take about 5000 years to be complete. The lag is only 800 years. All that the lag shows is that CO2 did not cause the first 800 years of warming, out of the 5000 year trend. The other 4200 years of warming could in fact have been caused by CO2, as far as we can tell from this ice core data. The 4200 years of warming make up about 5/6 of the total warming. So CO2 could have caused the last 5/6 of the warming, but could not have caused the first 1/6 of the warming."The operative word here is COULD. Not definitely. Not probably. COULD. This hardly is indicative of any scientific certainty on this particular aspect of the issue which has been my point all along. There is so much about this issue the scientists don't know and the responsible ones will admit as much. There is so much about the global warming issue that is up for debate and speculation despite protests to the contrary.Um, they never asserted certainty. Nor do most scientists assert certainty. That's why scientific papers commonly use words like the data 'indicate' or 'suggest' thus and so.Like I said (see above), that blog entry isn't all that detailed. The T/CO2 lag time is a red herring. We're sourcing and modeling the effects of anthropogenic GHG concentration on interglacial conditions, not emerging from a glacial maximum. The lag-time argument confuses initiation of events (glaciation/deglaciation) with amplification of conditions. It also ignores that fact that CO2 is only one of several greenhouse gases, including methane and water vapor, that work in combination to increase temperature; that CO2 residence time in the atmosphere is longer than most or all of the others (the primary reason for urgency in dealing with CO2 loadings); and that CO2 residence time in the deep ocean is about the same duration as the lag time. The latter indicates that the amplification effects from CO2 won't become dominant until the atmosphere-ocean system reaches equilibration -- that's fine for helping the earth to come out of an ice age, but not so fine in our interglacial period, in which life has adapted to the current atmosphere-ocean equilibrium with respect to CO2 and other components.Another point that is often ignored in this debate. Life adapts to changing conditions. It is all part of the natural selection process. Conditions on earth are constantly changing. Life forms that adapt to the changes survive and those that can't become extinct. That is the natural order of things. 97% of all species of animals that have inhabited the earth are now extinct. Most of them became extinct long before man began walking upright. As species become extinct they are replaced by others that were more adaptable to the changes. That will continue to happen no matter what actions we take.That's nice. A bit nihilistic, irrelevant to the 'debate' and a logical fallacy, but nice. The oft-heard cry that "CO2 has been higher in the past so we're OK" is an attempt at misdirection. Indeed, atmospheric CO2 reached 7000 ppm in the Cambrian, about 540 my ago, prior to life on land. The most recent CO2 peak occurred in the Jurassic (about 160 my ago) and reached about 2300 ppm, a value from which it has more or less steadily declined. Atmospheric CO2 concentrations over the last 11,000 years (i.e., beginning prior to emergence of what we call 'civilization') have varied between about 260 and 280 ppm; over the last 800,000 years or so (i.e., during emergence of our last hominid ancestors), that range was between about 180 to 280 ppm, the low values obtaining during glacial maxima. The current concentration of CO2 in the atmosphere is about 380 ppm, and is projected to rise to between 450 to 550 ppm by 2050 at the current rate of increase. At no time in the past 600 million years, including emergence from the last glacial maximum, has the earth recorded as dramatic a rise in atmospheric CO2 concentration as at presentFor the sake of argument, let's accept the projections for the continued rise of CO2 levels. Let's also assume that this will contribute to global warming. This still does not make the case that either of these is going to be catastrophic for the earth.Yes, the earth won't care, nor does it have the capacity to care. Some people living on earth at the time might, though. And no assumptions are necessary -- if you've got some data that support cooling or no thermal effect as a result of increased GHGs, let the physicists and chemists know. Is the problem higher CO2 levels or is the problem warmer temperatures. Even at the highest end of the projection, CO2 will only comprise 550 parts per million of the atmosphere. Is that going to make the air unbreathable?The primary problem is elevated global temperature and its effects, with the highest increases toward polar regions. Note that the projection was for 2050, before the time today's grade school kids retire. Of course, following the No Action alternative, CO2 concentrations are projected to be in the 1100+ range by 2100. Perhaps some current societies can thrive at some level with average global temperatures 5 degrees above present; I think a 10 degree rise may be asking too much of civilization as we know it. Experimental results show that some plants may benefit from higher CO2 concentrations, up to several hundred ppm above current concentrations, above which they shut down; IIRC, poison ivy did quite well under elevated atmospheric CO2. If the effect of higher CO2 is a warmer earth, why is that going to be a bad thing. Humans have not only existed through periods of warmth equal or greater than current predictions, they have thrived. Why will things be different this time around.Actually, humans haven't existed through periods having temperatures greater than at present; we're now above temperatures (recorded by proxy) reached in the MWP. I suppose Reply orsonroy Member sinceMarch 2002 From: Elgin, IL 3,677 posts Posted by orsonroy on Tuesday, March 20, 2007 2:04 PM Shilshole wrote: orsonroy wrote: I only have one question about the whole "Global warming is going to melt all the ice and drown us all" theory. If Vikings were building farming settlements 600 years ago that today look like this: [snip]Um, that's the interior of Greenland. The settlements then, as now, were along the coast. A very good book on the subject is Collapse by Jared Diamond. In fact, all of his books are excellent.Right. INTERIOR of Greenland, where 600 years ago there were no glaciers. There are glaciers there NOW. Can't build a stone long house on ice, when the ice is covering up your building materials, can you? Nor can you grow your two staple crops, barley and cattle.That means that the ice in Greenland has INCREASED over the past 600 years or so, right? That means that the level of the ocean has DEcreased in that time. So how come in areas that are only a few feet above seal level, right ON the ocean, we're finding American Indian artifacts that are being carbon dated to between 1000 and 3000 years old? Because they lived near the coast? Lotta people do that today, too. INTERIOR of Greenland. 600 years ago it was settled, today it's an icy paradise. If all of that "non-floating ice" (pardon me, but my college professors always tought me to write to the masses, not in technospeak) was melted 600 years ago, the current GW theories state that ocean levels would be higher (it's off the land and into the seas). If the ocean levels were higher, there would be no reason that archaeologists would be finding 600-2000 year old arrowheads and pottery shards on a narrow peninsula that's maybe 20 feet above sea level at it's highest point. The entire land mass is nothing but salt flats and a tidal bog, so you can't say that the Indians were living somewhere else...No one in the scientific community has even attempted to answer this question: how can the ice melt and the sea levels DECREASE?Apparently, you haven't really looked very hard for an answer.The land surface isn't static. Some formally glaciated areas (Fennoscandia, Greenland, Canada, even parts of New England and the upper Midwest, for example) are still 'rebounding' upward since glaciers melted, and their mass was removed, from those areas 12-15000 years ago. Areas along some coasts are rising (Alaska, western South America, for example) in response to material being subducted beneath them. With both mechanisms, local sea level decreases with respect to the land. Other coastal areass (parts of the Gulf and Atlantic Coasts, eastern India, Bangladesh, for example) are 'sinking' in response to compaction associated with sediment loading and groundwater withdrawal, and local sea level rises with respect to the land even if global sea level remains constant. The general term you're looking for is 'isostatic adjustment'. The scientific community 'discovered' this principle about, oh, 100 years or so ago.So you're saying that the Peninsula (that stretch of land that Williamsburg and Jamestowne sit on) has risen over the past 600 years or so? Or at least over the first 200 years of that time, since the land at Fort James has actually SUNK by about three feet since 1607?My question is still valid: MORE water volume in the oceans in 1400 due to less glaciation in Greenland's interior, which equals HIGHER sea levels. So why are we finding American Indian settlements from 1400 (and earlier) within 20 yards of the ocean? Wouldn't those areas have been under water in 1400, either by raised sea levels or lowered ground levels?From what I'm discovering, the scientific community is largely ignoring the anthropological and archaeological evidence in favor of MANY recent, long-term temperature fluctuations over the past 160,000 years (roughly the existence of Homo Sapiens). Ice and tree core samples are fine, but you have to look at old settlements too, and that data's not being used at ALL.Once again, that's not a reflection of what's really available. Perhaps a visit to a library (big building, lotsa books) Yes, thank you for your wry wit. I've done so, and very few of the pop culture GW advocates ever mentions the little ice age or other near term temperature peaks (for example: it was warmer 2000 years ago than it is today, by over 5 degrees). When they do mention the archaeological evidence, they usually mumble something about sunspots and quickly move on.containing archeology and anthropology journals will dispel that notion.(oh: I'm an enviromentalist that DOESN'T buy into "man's killing us all". We've got to reduce the world population and polution levels, but because of overall sustainability reasons, not because of the hubris that leads people to believe that we have much of an effect on the overall environment. Anyone else wondering why there are more trees in the Amazon today than there were 1000 years ago?)Full bibliograhic reference to the peer-reviewed literature, please.Review the latest studies about Terra Preta de Indio, and especially the findings of the late James Petersen. The "black earth of the Amazon" was an industrial process to create arable soil in the region at least 1500 years ago, and which is part of a huge system of neolithic towns, canals and fields which is mostly overgrown with "old growth" forests.Look, I'm not denying that GW is real: we ARE warming up. But is man causing it? No. The planet (and apparently Mars too) warms and cools regularly, and according to it's own schedule. Is man polluting and overbreeding like mad? Sure, but what's that got to do with the climate? Not much, when compared to the effects of the sun and other things we don't even know we don't know about. Ray Breyer Modeling the NKP's Peoria Division, circa 1943 Reply Dave Vollmer Member sinceNovember 2003 From: Colorado Springs, CO 2,742 posts Posted by Dave Vollmer on Tuesday, March 20, 2007 1:30 PM loathar wrote: All of the sea ice on the planet could melt and the sea level would not rise one inch. That's a REAL good point. Like ice cubes in a glass of water. Once they melt, the level in the glass doesn't go up at all.(hadn't thought of that) If 95% of the worlds fresh water is locked up in ice, how is that ice melting going to cause a fresh water shortage? We can't use it where it's at now anyhow?It's the Greenland ice we need to worry about.That and simple thermal expansion of the oceans.But again, it's those pesky feedback loops, both positive and negative, that are so hard to quantify that make direct forecasts of actual conditions so difficult.Just got back from another departmental seminar on climate change. What's pretty much settled is that the observed climate change happening now can only be accounted for if both natural and human factors are considered.Beyond that, there are no gaurantees. That's the trouble with the doomsday scenarios. We can only say what our best model predictions are, knowing that those models have flaws.We can say with a fair degree of certainty that left unmitigated anthropogenic climate change with result in a very different planet than we're used to. We know this because it's happened before in the fossil and ice core records. Yep, there have actually been times in Earth's past history when there were NO polar ice caps.Not sure we want to live in that world, though. The good news is that it hasn't happened yet, and we can all do something about it right now with very little pain, from changing out our lightbulbs to driving a little less.I drive a Prius (as you might guess). Not a typical vehicle for a military officer, but having served in combat in the Middle East, I'm as reluctant to use as much gas because it perpetuates instability in the region as well as climate change. Modeling the Rio Grande Southern First District circa 1938-1946 in HOn3. Reply Shilshole Member sinceAugust 2006 294 posts Posted by Shilshole on Tuesday, March 20, 2007 1:24 PM fwright wrote: millrace wrote: There is really no debate about the existence of global warming itself and that humans are causing it.I, like jcorbett, am a skeptical fence sitter. So when you make blanket conclusions that are not necessarily supported by data, you weaken your entire position. You want to convince me that we have a crisis and that some action is needed on my part. Then convince me with valid reasoning.There's a difference between 'debate' and scientific debate. The latter is what's performed via peer-reviewed journals and scientific meetings and conferences by knowledgeable people. All conclusions reached from the process of scientific debate are tentative and constrained by data of varying quality. This thread and PR campaigns are examples of 'debate', in which those constraints are loosened and generally unqualified talking points are the foci. Among the scientific community of physicists, chemists, geologists, biologists, atmospheric scientists, and oceanographers, the scientific debate as conducted in their respective journals and meetings regarding AGW and most of its likely physical, chemical, and biological impacts is essentially over, even though there are many details to be hashed out and refined. By contrast, there still remains a 'debate' in the popular media, perhaps in the interest of being 'fair and balanced', in which personalities are trotted out to proclaim one truth or another. The latter is very similar to the 'debate' over evolution, which the scientific community firmly accepted over a century ago (and the understanding of which is still being refined) yet continues to be challenged by one group or another using the popular press to present their generally unscientific objections. I concur that global temperatures have been rising since the mini-ice age of the 1400s (? - could be off on my dates by 100 years). There is plenty of evidence that there was a lot more winter freezing of lakes and water ways several hundred years ago, and even 150 years ago. But that doesn't prove that global warming is caused by man's greenhouse gas emissions (the second part of your non-debateable statement).Here are plots of atmospheric CO2 concentrations over various periods of time: <http://www.epa.gov/climatechange/science/recentac_majorghg.html >. The middle plot, from about 9,000 bce to present, represents atmospheric CO2 concentrations since emergence from the last age. Up until very recently, concentrations were within a very narrow range, (260-284 ppm); the Medieval Warming Event shows as a tiny blip. Contrast that with the most recently shown values of about 335 ppm; that's as of 1998, and the concentration is now about 380 ppm. The evidence for AGW is a two-parter. The first part is, in the absence of other known factors, the dramatic rise of atmospheric CO2 as a consequence of the industrial revolution, in which copious quantities of CO2 were introduced into the atmosphere by the burning of fossil fuels. (Note that the concentrations of another greenhouse gas, methane, show the pattern with time as CO2 on the figure below the CO2 figure. The methane increase is attributed primarily to changing agricultural practices accompanying industrialization.) One could argue that some other source is responsible for the sudden increase in CO2; unfortunately, there is no evidence for other known sources, such as weathering of limestone, unusually voluminous volcanic activity, or some odd release from the oceans. So it's scientifically 'certain' that the increase in atmospheric CO2 concentration since the industrial revolution is anthropogenic. The second part is the known physics of greenhouse gases. The effect of GHGs is to trap heat, reaching the earth as solar radiation, within the atmosphere (some of that trapped heat is transferred from the atmosphere to, and stored in, the oceans). At low GHG concentrations, much of the heat is re-radiated to space; at high GHG concentrations, more of the heat is trapped. Even at low CO2 concentrations, water vapor and methane are effective in trapping some heat; however, because of their short residence times in the atmosphere (and in the case of water vapor, an upper concentration limit), CO2, with its longer atmospheric residence time, becomes more effective in *sustained* heat trapping, which is what we've seen since the beginning of the industrial revolution. How much of the warming is a natural cycle, and how much is caused by man's activity is still an open question in this skeptic's mind.Over the long term (i.e., decades and centuries), the current amount attributable to man's activities is whatever results from an additonal 100 ppm atmospheric CO2, less the amount attributed to unknown sources (increased solar radiation and cosmic ray flux are known sources, and are known not to be contributors to the latest temperature increase). There are additional feedbacks, such as decreased albedo, that may be anthropogenic and contribute to warming as well. Note also that anthopogenic cooling, by introduction of particulates and some aerosols into the atmosphere, also occurs; without enforcement of the Clean Air Act, and if developing nations don't control that component of emissions, some GHG warming effects were and will be masked. Interesting that you reject all the recorded anecdotal evidence (plant species growth locations, Viking explorations, records and histories of native civilizations in North and South America, etc) that the earth was warmer in the medieval period than it is now. Is that because the rapid change from warmer than now to mini-ice age in less than a thousand years without a significant contribution from man doesn't fit the models? Or is there another reason I don't understand?They're considered but rejected by most scientists partly because they're anecdotal and often internally conflicting, but primarily because they're not global, nor are they reflected in global temperature proxies. Sustained El Nino and La Nina events can yield warming (and cooling) effects, but they're only local or regional in extent. I'll excuse your ad hominem regarding scientists' fitting data to models. Reply IRONROOSTER Member sinceJune 2003 From: Culpeper, Va 8,204 posts Posted by IRONROOSTER on Tuesday, March 20, 2007 1:17 PM Regardless of where global warming is at, we already have more than the optimum number of people on the planet for quality of life. As the planet continues to get more crowded our quality of life will continue to decline. You can see this in the trash along the highways, pollution in the air/land/water, increasing land prices, highway congestion, declining resources such as crabs in the Chesapeake, etc. Sure, by being more efficient (we should strive to be, and there's vast room for improvement) we can support more people in the world than we have now (and better support the less fortunate ones we do have - especialy in places like Darfur). But that doesn't improve our quality of life. Just my which fell off my EnjoyPaul If you're having fun, you're doing it the right way. Reply jecorbett Member sinceNovember 2005 From: Utica, OH 4,000 posts Posted by jecorbett on Tuesday, March 20, 2007 1:07 PM loathar wrote: All of the sea ice on the planet could melt and the sea level would not rise one inch. That's a REAL good point. Like ice cubes in a glass of water. Once they melt, the level in the glass doesn't go up at all.(hadn't thought of that) If 95% of the worlds fresh water is locked up in ice, how is that ice melting going to cause a fresh water shortage? We can't use it where it's at now anyhow?To prove a point to a friend of mine, I filled a Mason jar with ice, then filled it with water. I screwed on the lid so evaporation would not be a factor. When the ice had melted, the water level had dropped over a quarter of an inch. Water expands when it freezes and contracts when it melts which is why there was less volume in the jar when the water was all in liquid form. Reply loathar Member sinceAugust 2004 From: Amish country Tenn. 10,027 posts Posted by loathar on Tuesday, March 20, 2007 1:02 PM All of the sea ice on the planet could melt and the sea level would not rise one inch. That's a REAL good point. Like ice cubes in a glass of water. Once they melt, the level in the glass doesn't go up at all.(hadn't thought of that) If 95% of the worlds fresh water is locked up in ice, how is that ice melting going to cause a fresh water shortage? We can't use it where it's at now anyhow? Reply PA&ERR Member sinceSeptember 2006 From: Ogden UT 1,055 posts Posted by PA&ERR on Tuesday, March 20, 2007 12:34 PM "No one in the scientific community has even attempted to answer this question: how can the ice melt and the sea levels DECREASE?"Its simple. Ice is less dense than water (that is why it floats).All of the sea ice on the planet could melt and the sea level would not rise one inch. Its the glacier ice that, as it melts and finds its way to the sea, will cause sea levels to rise. HOWEVER even the IPCC's worst case scenario has world sea levels rising (drum roll) 36 inches or so. -George "And the sons of Pullman porters and the sons of engineers ride their father's magic carpet made of steel..." Reply MidlandPacific Member sinceFebruary 2003 1,138 posts Posted by MidlandPacific on Tuesday, March 20, 2007 11:37 AM "There is more in heaven and earth, Horatio, than is dreamt of in your philosophy." http://mprailway.blogspot.com "The first transition era - wood to steel!" Reply jecorbett Member sinceNovember 2005 From: Utica, OH 4,000 posts Posted by jecorbett on Tuesday, March 20, 2007 11:33 AM Shilshole wrote:Realclimate's explanation isn't all that detailed, but the issue of lag time is a red herring. I offer the following quote from Realclimate:"The reason has to do with the fact that the warmings take about 5000 years to be complete. The lag is only 800 years. All that the lag shows is that CO2 did not cause the first 800 years of warming, out of the 5000 year trend. The other 4200 years of warming could in fact have been caused by CO2, as far as we can tell from this ice core data. The 4200 years of warming make up about 5/6 of the total warming. So CO2 could have caused the last 5/6 of the warming, but could not have caused the first 1/6 of the warming."The operative word here is COULD. Not definitely. Not probably. COULD. This hardly is indicative of any scientific certainty on this particular aspect of the issue which has been my point all along. There is so much about this issue the scientists don't know and the responsible ones will admit as much. There is so much about the global warming issue that is up for debate and speculation despite protests to the contrary.The lag-time argument confuses initiation of events (glaciation/deglaciation) with amplification of conditions. It also ignores that fact that CO2 is only one of several greenhouse gases, including methane and water vapor, that work in combination to increase temperature; that CO2 residence time in the atmosphere is longer than most or all of the others (the primary reason for urgency in dealing with CO2 loadings); and that CO2 residence time in the deep ocean is about the same duration as the lag time. The latter indicates that the amplification effects from CO2 won't become dominant until the atmosphere-ocean system reaches equilibration -- that's fine for helping the earth to come out of an ice age, but not so fine in our interglacial period, in which life has adapted to the current atmosphere-ocean equilibrium with respect to CO2 and other components.Another point that is often ignored in this debate. Life adapts to changing conditions. It is all part of the natural selection process. Conditions on earth are constantly changing. Life forms that adapt to the changes survive and those that can't become extinct. That is the natural order of things. 97% of all species of animals that have inhabited the earth are now extinct. Most of them became extinct long before man began walking upright. As species become extinct they are replaced by others that were more adaptable to the changes. That will continue to happen no matter what actions we take.The oft-heard cry that "CO2 has been higher in the past so we're OK" is an attempt at misdirection. Indeed, atmospheric CO2 reached 7000 ppm in the Cambrian, about 540 my ago, prior to life on land. The most recent CO2 peak occurred in the Jurassic (about 160 my ago) and reached about 2300 ppm, a value from which it has more or less steadily declined. Atmospheric CO2 concentrations over the last 11,000 years (i.e., beginning prior to emergence of what we call 'civilization') have varied between about 260 and 280 ppm; over the last 800,000 years or so (i.e., during emergence of our last hominid ancestors), that range was between about 180 to 280 ppm, the low values obtaining during glacial maxima. The current concentration of CO2 in the atmosphere is about 380 ppm, and is projected to rise to between 450 to 550 ppm by 2050 at the current rate of increase. At no time in the past 600 million years, including emergence from the last glacial maximum, has the earth recorded as dramatic a rise in atmospheric CO2 concentration as at presentFor the sake of argument, let's accept the projections for the continued rise of CO2 levels. Let's also assume that this will contribute to global warming. This still does not make the case that either of these is going to be catastrophic for the earth. Is the problem higher CO2 levels or is the problem warmer temperatures. Even at the highest end of the projection, CO2 will only comprise 550 parts per million of the atmosphere. Is that going to make the air unbreathable? If the effect of higher CO2 is a warmer earth, why is that going to be a bad thing. Humans have not only existed through periods of warmth equal or greater than current predictions, they have thrived. Why will things be different this time around. Reply 1234 Subscriber & Member Login Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more! Login Register Users Online There are no community member online Search the Community ADVERTISEMENT ADVERTISEMENT ADVERTISEMENT Model Railroader Newsletter See all Sign up for our FREE e-newsletter and get model railroad news in your inbox! Sign up
Back to trains, yes I would take a train more, if there were one through here that I could take to my VA appointments rather than drive. I know of several people that drive 30 mile to work that would use public transportation, if it was around, but it's not.
Conservation is what I believe the only thing left, in all ways. That's something I believed in after I had to start paying the utility bills. I hate giving more and more money, for less and less service.
As far as global warming, it's a theory, not a fact as seems to be promoted these days, as so many theories are. The theory of evolution is the first one to come to mind and even taught in school as fact.
As far as a 100-year climate forecast, I don't trust them either. H,,, than can't even get a 12 hour forecast right, let alone anything that far out
When it comes to expert opinions or polls, I have several questions I want to know about.
1, what is the back round of the expert.
2, what was he trying to prove [or study] from the start.
3, who provided the funding and how much did he make.
4, what other studies were done on the subject, and their conculsions.
When all we seem to get is the one-sided politically correct versions on a subject, you can be lead anywhere they want you to go. Me, I like to look at the whole pie, before I have a piece. Reminds me of the 1930's and 40's Europe.
inch
http://www.trainboard.com/railimages/showgallery.php/cat/500/ppuser/4309
jecorbett wrote: Shilshole wrote:Realclimate's explanation isn't all that detailed, but the issue of lag time is a red herring. I offer the following quote from Realclimate:"The reason has to do with the fact that the warmings take about 5000 years to be complete. The lag is only 800 years. All that the lag shows is that CO2 did not cause the first 800 years of warming, out of the 5000 year trend. The other 4200 years of warming could in fact have been caused by CO2, as far as we can tell from this ice core data. The 4200 years of warming make up about 5/6 of the total warming. So CO2 could have caused the last 5/6 of the warming, but could not have caused the first 1/6 of the warming."The operative word here is COULD. Not definitely. Not probably. COULD. This hardly is indicative of any scientific certainty on this particular aspect of the issue which has been my point all along. There is so much about this issue the scientists don't know and the responsible ones will admit as much. There is so much about the global warming issue that is up for debate and speculation despite protests to the contrary.
Shilshole wrote:Realclimate's explanation isn't all that detailed, but the issue of lag time is a red herring.
Realclimate's explanation isn't all that detailed, but the issue of lag time is a red herring.
I offer the following quote from Realclimate:
"The reason has to do with the fact that the warmings take about 5000 years to be complete. The lag is only 800 years. All that the lag shows is that CO2 did not cause the first 800 years of warming, out of the 5000 year trend. The other 4200 years of warming could in fact have been caused by CO2, as far as we can tell from this ice core data.
The 4200 years of warming make up about 5/6 of the total warming. So CO2 could have caused the last 5/6 of the warming, but could not have caused the first 1/6 of the warming."
The operative word here is COULD. Not definitely. Not probably. COULD. This hardly is indicative of any scientific certainty on this particular aspect of the issue which has been my point all along. There is so much about this issue the scientists don't know and the responsible ones will admit as much. There is so much about the global warming issue that is up for debate and speculation despite protests to the contrary.
Um, they never asserted certainty. Nor do most scientists assert certainty. That's why scientific papers commonly use words like the data 'indicate' or 'suggest' thus and so.
Like I said (see above), that blog entry isn't all that detailed. The T/CO2 lag time is a red herring. We're sourcing and modeling the effects of anthropogenic GHG concentration on interglacial conditions, not emerging from a glacial maximum.
The lag-time argument confuses initiation of events (glaciation/deglaciation) with amplification of conditions. It also ignores that fact that CO2 is only one of several greenhouse gases, including methane and water vapor, that work in combination to increase temperature; that CO2 residence time in the atmosphere is longer than most or all of the others (the primary reason for urgency in dealing with CO2 loadings); and that CO2 residence time in the deep ocean is about the same duration as the lag time. The latter indicates that the amplification effects from CO2 won't become dominant until the atmosphere-ocean system reaches equilibration -- that's fine for helping the earth to come out of an ice age, but not so fine in our interglacial period, in which life has adapted to the current atmosphere-ocean equilibrium with respect to CO2 and other components.Another point that is often ignored in this debate. Life adapts to changing conditions. It is all part of the natural selection process. Conditions on earth are constantly changing. Life forms that adapt to the changes survive and those that can't become extinct. That is the natural order of things. 97% of all species of animals that have inhabited the earth are now extinct. Most of them became extinct long before man began walking upright. As species become extinct they are replaced by others that were more adaptable to the changes. That will continue to happen no matter what actions we take.
The lag-time argument confuses initiation of events (glaciation/deglaciation) with amplification of conditions. It also ignores that fact that CO2 is only one of several greenhouse gases, including methane and water vapor, that work in combination to increase temperature; that CO2 residence time in the atmosphere is longer than most or all of the others (the primary reason for urgency in dealing with CO2 loadings); and that CO2 residence time in the deep ocean is about the same duration as the lag time. The latter indicates that the amplification effects from CO2 won't become dominant until the atmosphere-ocean system reaches equilibration -- that's fine for helping the earth to come out of an ice age, but not so fine in our interglacial period, in which life has adapted to the current atmosphere-ocean equilibrium with respect to CO2 and other components.
Another point that is often ignored in this debate. Life adapts to changing conditions. It is all part of the natural selection process. Conditions on earth are constantly changing. Life forms that adapt to the changes survive and those that can't become extinct. That is the natural order of things. 97% of all species of animals that have inhabited the earth are now extinct. Most of them became extinct long before man began walking upright. As species become extinct they are replaced by others that were more adaptable to the changes. That will continue to happen no matter what actions we take.
That's nice. A bit nihilistic, irrelevant to the 'debate' and a logical fallacy, but nice.
The oft-heard cry that "CO2 has been higher in the past so we're OK" is an attempt at misdirection. Indeed, atmospheric CO2 reached 7000 ppm in the Cambrian, about 540 my ago, prior to life on land. The most recent CO2 peak occurred in the Jurassic (about 160 my ago) and reached about 2300 ppm, a value from which it has more or less steadily declined. Atmospheric CO2 concentrations over the last 11,000 years (i.e., beginning prior to emergence of what we call 'civilization') have varied between about 260 and 280 ppm; over the last 800,000 years or so (i.e., during emergence of our last hominid ancestors), that range was between about 180 to 280 ppm, the low values obtaining during glacial maxima. The current concentration of CO2 in the atmosphere is about 380 ppm, and is projected to rise to between 450 to 550 ppm by 2050 at the current rate of increase. At no time in the past 600 million years, including emergence from the last glacial maximum, has the earth recorded as dramatic a rise in atmospheric CO2 concentration as at presentFor the sake of argument, let's accept the projections for the continued rise of CO2 levels. Let's also assume that this will contribute to global warming. This still does not make the case that either of these is going to be catastrophic for the earth.
The oft-heard cry that "CO2 has been higher in the past so we're OK" is an attempt at misdirection. Indeed, atmospheric CO2 reached 7000 ppm in the Cambrian, about 540 my ago, prior to life on land. The most recent CO2 peak occurred in the Jurassic (about 160 my ago) and reached about 2300 ppm, a value from which it has more or less steadily declined. Atmospheric CO2 concentrations over the last 11,000 years (i.e., beginning prior to emergence of what we call 'civilization') have varied between about 260 and 280 ppm; over the last 800,000 years or so (i.e., during emergence of our last hominid ancestors), that range was between about 180 to 280 ppm, the low values obtaining during glacial maxima. The current concentration of CO2 in the atmosphere is about 380 ppm, and is projected to rise to between 450 to 550 ppm by 2050 at the current rate of increase. At no time in the past 600 million years, including emergence from the last glacial maximum, has the earth recorded as dramatic a rise in atmospheric CO2 concentration as at present
For the sake of argument, let's accept the projections for the continued rise of CO2 levels. Let's also assume that this will contribute to global warming. This still does not make the case that either of these is going to be catastrophic for the earth.
Yes, the earth won't care, nor does it have the capacity to care. Some people living on earth at the time might, though. And no assumptions are necessary -- if you've got some data that support cooling or no thermal effect as a result of increased GHGs, let the physicists and chemists know.
Is the problem higher CO2 levels or is the problem warmer temperatures. Even at the highest end of the projection, CO2 will only comprise 550 parts per million of the atmosphere. Is that going to make the air unbreathable?
The primary problem is elevated global temperature and its effects, with the highest increases toward polar regions. Note that the projection was for 2050, before the time today's grade school kids retire. Of course, following the No Action alternative, CO2 concentrations are projected to be in the 1100+ range by 2100. Perhaps some current societies can thrive at some level with average global temperatures 5 degrees above present; I think a 10 degree rise may be asking too much of civilization as we know it.
Experimental results show that some plants may benefit from higher CO2 concentrations, up to several hundred ppm above current concentrations, above which they shut down; IIRC, poison ivy did quite well under elevated atmospheric CO2.
If the effect of higher CO2 is a warmer earth, why is that going to be a bad thing. Humans have not only existed through periods of warmth equal or greater than current predictions, they have thrived. Why will things be different this time around.
Actually, humans haven't existed through periods having temperatures greater than at present; we're now above temperatures (recorded by proxy) reached in the MWP. I suppose
Shilshole wrote: orsonroy wrote: I only have one question about the whole "Global warming is going to melt all the ice and drown us all" theory. If Vikings were building farming settlements 600 years ago that today look like this: [snip]Um, that's the interior of Greenland. The settlements then, as now, were along the coast. A very good book on the subject is Collapse by Jared Diamond. In fact, all of his books are excellent.
orsonroy wrote: I only have one question about the whole "Global warming is going to melt all the ice and drown us all" theory. If Vikings were building farming settlements 600 years ago that today look like this: [snip]
I only have one question about the whole "Global warming is going to melt all the ice and drown us all" theory. If Vikings were building farming settlements 600 years ago that today look like this: [snip]
Um, that's the interior of Greenland. The settlements then, as now, were along the coast. A very good book on the subject is Collapse by Jared Diamond. In fact, all of his books are excellent.
Right. INTERIOR of Greenland, where 600 years ago there were no glaciers. There are glaciers there NOW. Can't build a stone long house on ice, when the ice is covering up your building materials, can you? Nor can you grow your two staple crops, barley and cattle.
That means that the ice in Greenland has INCREASED over the past 600 years or so, right? That means that the level of the ocean has DEcreased in that time. So how come in areas that are only a few feet above seal level, right ON the ocean, we're finding American Indian artifacts that are being carbon dated to between 1000 and 3000 years old? Because they lived near the coast? Lotta people do that today, too.
That means that the ice in Greenland has INCREASED over the past 600 years or so, right? That means that the level of the ocean has DEcreased in that time. So how come in areas that are only a few feet above seal level, right ON the ocean, we're finding American Indian artifacts that are being carbon dated to between 1000 and 3000 years old?
That means that the ice in Greenland has INCREASED over the past 600 years or so, right? That means that the level of the ocean has DEcreased in that time.
So how come in areas that are only a few feet above seal level, right ON the ocean, we're finding American Indian artifacts that are being carbon dated to between 1000 and 3000 years old?
Because they lived near the coast? Lotta people do that today, too.
INTERIOR of Greenland. 600 years ago it was settled, today it's an icy paradise. If all of that "non-floating ice" (pardon me, but my college professors always tought me to write to the masses, not in technospeak) was melted 600 years ago, the current GW theories state that ocean levels would be higher (it's off the land and into the seas). If the ocean levels were higher, there would be no reason that archaeologists would be finding 600-2000 year old arrowheads and pottery shards on a narrow peninsula that's maybe 20 feet above sea level at it's highest point. The entire land mass is nothing but salt flats and a tidal bog, so you can't say that the Indians were living somewhere else...
Yes, thank you for your wry wit. I've done so, and very few of the pop culture GW advocates ever mentions the little ice age or other near term temperature peaks (for example: it was warmer 2000 years ago than it is today, by over 5 degrees). When they do mention the archaeological evidence, they usually mumble something about sunspots and quickly move on.
containing archeology and anthropology journals will dispel that notion.(oh: I'm an enviromentalist that DOESN'T buy into "man's killing us all". We've got to reduce the world population and polution levels, but because of overall sustainability reasons, not because of the hubris that leads people to believe that we have much of an effect on the overall environment. Anyone else wondering why there are more trees in the Amazon today than there were 1000 years ago?)Full bibliograhic reference to the peer-reviewed literature, please.
containing archeology and anthropology journals will dispel that notion.
(oh: I'm an enviromentalist that DOESN'T buy into "man's killing us all". We've got to reduce the world population and polution levels, but because of overall sustainability reasons, not because of the hubris that leads people to believe that we have much of an effect on the overall environment. Anyone else wondering why there are more trees in the Amazon today than there were 1000 years ago?)
Full bibliograhic reference to the peer-reviewed literature, please.
Review the latest studies about Terra Preta de Indio, and especially the findings of the late James Petersen. The "black earth of the Amazon" was an industrial process to create arable soil in the region at least 1500 years ago, and which is part of a huge system of neolithic towns, canals and fields which is mostly overgrown with "old growth" forests.
Look, I'm not denying that GW is real: we ARE warming up. But is man causing it? No. The planet (and apparently Mars too) warms and cools regularly, and according to it's own schedule. Is man polluting and overbreeding like mad? Sure, but what's that got to do with the climate? Not much, when compared to the effects of the sun and other things we don't even know we don't know about.
Ray Breyer
Modeling the NKP's Peoria Division, circa 1943
loathar wrote: All of the sea ice on the planet could melt and the sea level would not rise one inch. That's a REAL good point. Like ice cubes in a glass of water. Once they melt, the level in the glass doesn't go up at all.(hadn't thought of that) If 95% of the worlds fresh water is locked up in ice, how is that ice melting going to cause a fresh water shortage? We can't use it where it's at now anyhow?
All of the sea ice on the planet could melt and the sea level would not rise one inch.
That's a REAL good point. Like ice cubes in a glass of water. Once they melt, the level in the glass doesn't go up at all.(hadn't thought of that) If 95% of the worlds fresh water is locked up in ice, how is that ice melting going to cause a fresh water shortage? We can't use it where it's at now anyhow?
It's the Greenland ice we need to worry about.
That and simple thermal expansion of the oceans.
But again, it's those pesky feedback loops, both positive and negative, that are so hard to quantify that make direct forecasts of actual conditions so difficult.
Just got back from another departmental seminar on climate change. What's pretty much settled is that the observed climate change happening now can only be accounted for if both natural and human factors are considered.
Beyond that, there are no gaurantees. That's the trouble with the doomsday scenarios. We can only say what our best model predictions are, knowing that those models have flaws.
We can say with a fair degree of certainty that left unmitigated anthropogenic climate change with result in a very different planet than we're used to. We know this because it's happened before in the fossil and ice core records.
Yep, there have actually been times in Earth's past history when there were NO polar ice caps.
Not sure we want to live in that world, though. The good news is that it hasn't happened yet, and we can all do something about it right now with very little pain, from changing out our lightbulbs to driving a little less.
I drive a Prius (as you might guess). Not a typical vehicle for a military officer, but having served in combat in the Middle East, I'm as reluctant to use as much gas because it perpetuates instability in the region as well as climate change.
Modeling the Rio Grande Southern First District circa 1938-1946 in HOn3.
fwright wrote: millrace wrote: There is really no debate about the existence of global warming itself and that humans are causing it.I, like jcorbett, am a skeptical fence sitter. So when you make blanket conclusions that are not necessarily supported by data, you weaken your entire position. You want to convince me that we have a crisis and that some action is needed on my part. Then convince me with valid reasoning.
millrace wrote: There is really no debate about the existence of global warming itself and that humans are causing it.
There is really no debate about the existence of global warming itself and that humans are causing it.
I, like jcorbett, am a skeptical fence sitter. So when you make blanket conclusions that are not necessarily supported by data, you weaken your entire position. You want to convince me that we have a crisis and that some action is needed on my part. Then convince me with valid reasoning.
There's a difference between 'debate' and scientific debate. The latter is what's performed via peer-reviewed journals and scientific meetings and conferences by knowledgeable people. All conclusions reached from the process of scientific debate are tentative and constrained by data of varying quality. This thread and PR campaigns are examples of 'debate', in which those constraints are loosened and generally unqualified talking points are the foci. Among the scientific community of physicists, chemists, geologists, biologists, atmospheric scientists, and oceanographers, the scientific debate as conducted in their respective journals and meetings regarding AGW and most of its likely physical, chemical, and biological impacts is essentially over, even though there are many details to be hashed out and refined. By contrast, there still remains a 'debate' in the popular media, perhaps in the interest of being 'fair and balanced', in which personalities are trotted out to proclaim one truth or another. The latter is very similar to the 'debate' over evolution, which the scientific community firmly accepted over a century ago (and the understanding of which is still being refined) yet continues to be challenged by one group or another using the popular press to present their generally unscientific objections.
I concur that global temperatures have been rising since the mini-ice age of the 1400s (? - could be off on my dates by 100 years). There is plenty of evidence that there was a lot more winter freezing of lakes and water ways several hundred years ago, and even 150 years ago. But that doesn't prove that global warming is caused by man's greenhouse gas emissions (the second part of your non-debateable statement).
Here are plots of atmospheric CO2 concentrations over various periods of time: <http://www.epa.gov/climatechange/science/recentac_majorghg.html >. The middle plot, from about 9,000 bce to present, represents atmospheric CO2 concentrations since emergence from the last age. Up until very recently, concentrations were within a very narrow range, (260-284 ppm); the Medieval Warming Event shows as a tiny blip. Contrast that with the most recently shown values of about 335 ppm; that's as of 1998, and the concentration is now about 380 ppm. The evidence for AGW is a two-parter. The first part is, in the absence of other known factors, the dramatic rise of atmospheric CO2 as a consequence of the industrial revolution, in which copious quantities of CO2 were introduced into the atmosphere by the burning of fossil fuels. (Note that the concentrations of another greenhouse gas, methane, show the pattern with time as CO2 on the figure below the CO2 figure. The methane increase is attributed primarily to changing agricultural practices accompanying industrialization.) One could argue that some other source is responsible for the sudden increase in CO2; unfortunately, there is no evidence for other known sources, such as weathering of limestone, unusually voluminous volcanic activity, or some odd release from the oceans. So it's scientifically 'certain' that the increase in atmospheric CO2 concentration since the industrial revolution is anthropogenic. The second part is the known physics of greenhouse gases. The effect of GHGs is to trap heat, reaching the earth as solar radiation, within the atmosphere (some of that trapped heat is transferred from the atmosphere to, and stored in, the oceans). At low GHG concentrations, much of the heat is re-radiated to space; at high GHG concentrations, more of the heat is trapped. Even at low CO2 concentrations, water vapor and methane are effective in trapping some heat; however, because of their short residence times in the atmosphere (and in the case of water vapor, an upper concentration limit), CO2, with its longer atmospheric residence time, becomes more effective in *sustained* heat trapping, which is what we've seen since the beginning of the industrial revolution.
How much of the warming is a natural cycle, and how much is caused by man's activity is still an open question in this skeptic's mind.
Over the long term (i.e., decades and centuries), the current amount attributable to man's activities is whatever results from an additonal 100 ppm atmospheric CO2, less the amount attributed to unknown sources (increased solar radiation and cosmic ray flux are known sources, and are known not to be contributors to the latest temperature increase). There are additional feedbacks, such as decreased albedo, that may be anthropogenic and contribute to warming as well. Note also that anthopogenic cooling, by introduction of particulates and some aerosols into the atmosphere, also occurs; without enforcement of the Clean Air Act, and if developing nations don't control that component of emissions, some GHG warming effects were and will be masked.
Interesting that you reject all the recorded anecdotal evidence (plant species growth locations, Viking explorations, records and histories of native civilizations in North and South America, etc) that the earth was warmer in the medieval period than it is now. Is that because the rapid change from warmer than now to mini-ice age in less than a thousand years without a significant contribution from man doesn't fit the models? Or is there another reason I don't understand?
They're considered but rejected by most scientists partly because they're anecdotal and often internally conflicting, but primarily because they're not global, nor are they reflected in global temperature proxies. Sustained El Nino and La Nina events can yield warming (and cooling) effects, but they're only local or regional in extent. I'll excuse your ad hominem regarding scientists' fitting data to models.
Regardless of where global warming is at, we already have more than the optimum number of people on the planet for quality of life. As the planet continues to get more crowded our quality of life will continue to decline. You can see this in the trash along the highways, pollution in the air/land/water, increasing land prices, highway congestion, declining resources such as crabs in the Chesapeake, etc.
Sure, by being more efficient (we should strive to be, and there's vast room for improvement) we can support more people in the world than we have now (and better support the less fortunate ones we do have - especialy in places like Darfur). But that doesn't improve our quality of life.
Just my which fell off my
Enjoy
Paul
To prove a point to a friend of mine, I filled a Mason jar with ice, then filled it with water. I screwed on the lid so evaporation would not be a factor. When the ice had melted, the water level had dropped over a quarter of an inch. Water expands when it freezes and contracts when it melts which is why there was less volume in the jar when the water was all in liquid form.
"No one in the scientific community has even attempted to answer this question: how can the ice melt and the sea levels DECREASE?"
Its simple. Ice is less dense than water (that is why it floats).
Its the glacier ice that, as it melts and finds its way to the sea, will cause sea levels to rise.
HOWEVER even the IPCC's worst case scenario has world sea levels rising (drum roll) 36 inches or so.
-George
"And the sons of Pullman porters and the sons of engineers ride their father's magic carpet made of steel..."
"There is more in heaven and earth, Horatio, than is dreamt of in your philosophy."
http://mprailway.blogspot.com
"The first transition era - wood to steel!"
For the sake of argument, let's accept the projections for the continued rise of CO2 levels. Let's also assume that this will contribute to global warming. This still does not make the case that either of these is going to be catastrophic for the earth. Is the problem higher CO2 levels or is the problem warmer temperatures. Even at the highest end of the projection, CO2 will only comprise 550 parts per million of the atmosphere. Is that going to make the air unbreathable? If the effect of higher CO2 is a warmer earth, why is that going to be a bad thing. Humans have not only existed through periods of warmth equal or greater than current predictions, they have thrived. Why will things be different this time around.