December 31st, 2009, 11:36 AM
recently in the new its hereby said that the global warming has now became a serious issue .... day by day the temperature of the earth is increasing more than the desired amount ..... moreover it is said if its not being controlled the consequences may rise ....
Your point?
Btw - Major fail with your spammy sig.
Global warming is a huge threat to our planet it might destroy our planet in the future
The planet will survive. Many of the lifeforms living on it, however? Perhaps not.
If we can drag down the CO2, But earth will still get hotter in the future by the sun when it's begin to grow. But we can slow down the global warming.
And i think the earth take care of the CO2 itself (maby). And i think also that we overract with the global warming.
How exactly?Originally Posted by Spaceman
You think "maybe the Earth will take care of the CO2" is a good basis for policy?
Not really, I got that from a science magazine. And i got the idea from the magazine lolHow exactly?
You think "maybe the Earth will take care of the CO2" is a good basis for policy?. But if the earth would take care of the CO2 itself it should take million of years, I'm thinking about a asteroid collide and the dust came up the atmosphere, And it dissapeard, So actully i don't know
PS. ''maybe the Earth will take care of the CO2" was only an theory
And in the long run we are all dead.But if the earth would take care of the CO2 itself it should take million of years
Think about the next hundred years, and what kind of conditions our grandchidrens' generation will have to deal with.
July 1st, 2010, 09:04 AM
Global warming is the increase of the greenhouse gases (carbon dioxide and many more ) in the air which mainly comes from industries, cars and etc. The increase of this gas causes the temperature to increase too. That’s why you will find that the summers are hotter than they are in the past. The increased temperature melts the ice at the north and the south poles, leading to a rise in the oceans and seas around the world. In time to come, these water will tend to flood low-lying areas.
July 1st, 2010, 12:25 PM
Hmmm...
Is global warming still in the news? Seems to me it ended a few years ago. It's been damn cold here for June. I keep telling people "thank God for global warming or else it would really be cold!"
Seriously...
" in the air which mainly comes from industries, cars and etc."
Hmmm... is that the type of BS being taught in school? If you study at the Carbon Cycle, you see that man's output of CO2 is only 3% to 4% of what nature outputs.
"The increase of this gas causes the temperature to increase too."
Correlation does not equal causation. Our climate is complex, and other things factor in. Did you know since the Mander Minima, the solar output has increased by about 0.18%?
I'm not going to get into more here as this is a news thread. Anyone interested should read the appropriate threads in the "Environment Issues" and "Earth Sciences" forums. I will however link a recent article by a pretty smart man on the topic. Hey, it's new, and almost news:
The Cause Of Earth’s Climate Change Is The Sun (clean pdf format)
THE CAUSE OF EARTH'S CLIMATE CHANGE IS THE SUN (original blog with questions and remarks)
That is misleading to the point of being dishonest.
The net output of "nature" in the time scale involved is far less than man's - it has been close or equal to 0 for centuries.
I was speaking of gross output not net. There is controversy over the net result of each. If you wish to debate, please bring it to the proper forum.That is misleading to the point of being dishonest.
The net output of "nature" in the time scale involved is far less than man's - it has been close or equal to 0 for centuries.
Controversy? What do you mean? You are trying to mislead people!I was speaking of gross output not net. There is controversy over the net result of each. If you wish to debate, please bring it to the proper forum.That is misleading to the point of being dishonest.
The net output of "nature" in the time scale involved is far less than man's - it has been close or equal to 0 for centuries.
If you wish to debate, please bring it to the proper forum.Controversy? What do you mean? You are trying to mislead people!I was speaking of gross output not net. There is controversy over the net result of each. If you wish to debate, please bring it to the proper forum.That is misleading to the point of being dishonest.
The net output of "nature" in the time scale involved is far less than man's - it has been close or equal to 0 for centuries.
I don't wish to debate it. I'm telling you are deliberately trying to mislead people. There is no such controversy.If you wish to debate, please bring it to the proper forum.Controversy? What do you mean? You are trying to mislead people!I was speaking of gross output not net. There is controversy over the net result of each. If you wish to debate, please bring it to the proper forum.That is misleading to the point of being dishonest.
The net output of "nature" in the time scale involved is far less than man's - it has been close or equal to 0 for centuries.
I'm more concerned if the oil problem going on in the gulf is gonna effect the earth
once it's inside the Earth system if it not already.
What impact will it have. when it get mixed up in rain and so on....
It's killing the birds out on the gulf we happen to need those birds more then we realize. Just a thought
*************Terry Arceneaux******************
August 4th, 2010, 02:50 AM
Global warming is a real threat. Its the biggest enviormental issue ever. This can make a whole species of animal go extinct, make water levels rise drowning islands. It will kill many people, not now but in future generations, its almost like we are setting a death sentence to the earth and maybe even killing the people of the future. Also people may say humans did not begin it, but we did. All the machines that run on gas and inorganic stuff. We should switch our mode or getting energy, there are many ways.
http://www.globalwarmingsurvivalcenter.com/
What I'm trying to get at is how much of the oil in the gulf. how much of the Earth's system will be effected.
As the sun absorb some of this oil it's gotta work it's way into the Earth"s System.
Then when it rain. The oil gotta be getting into area on land where it couldn't when the oil was just in the gulf.
I think everything you put into the air or into the rivers gotta make it's way thru the rest of the world once it make it's way thru the Earth"s System No matter where you are living in the world.
Whatever you put in the air it's gotta have an effect on you no matter where you live in the world.......
Just a thought.................
October 16th, 2010, 12:12 AM
An exaggeration. It is more a decade to decade rise. The natural variability from year to year far exceeds the average rise in temperature per year. The crux of the problem is that it will take decades to transform our economic systems so they aren't dependent on fossil fuels; time to both raise temperatures and change precipitation patterns enough to do significant ecological damage.
It is colder here than usual.
Yes. It's called winter. If you look at yearly averages, your comment will very likely be immediately shown to be false.
I realise this is not the proper forum but I have a problem with people who don't think for themselves, but let others do their thinking for them. So maybe all of you who are so sure in your knowledge that you can just state something without proof can answer just one question for me.
I live in North America (Niagara region of Canada to be exact) and as late as 12500 yrs ago there was an ice sheet 1/4 mile thick as far down as the Ohio valley covering all of North America. This was the end of the last (of many through the ages) ice age. Shortly thereafter the temperatures rose significantly, the ice retreated north carving out the great lakes. Presently the ice sheet is north of Baffin Island and still retreating.
My one question is WHO WAS BURNING FOSSIL FUELS 12500 YRS AGO ?? For that matter who burned fossil fuels so as to raise greenhouse gas concentration at the end of the previous ice age ? Or the numerous ones before that ? Or is there some other cause for the temperature rise, which is small enough to be within the margin of error since accurate measurements have only been taken the last 50 yrs, and since the East Anglia research centre has been falsifying information, promoting confirming research/data and hiding contrary research/data.
Maybe the temperature rise is, as it was every previous ice age/warm-up cycle, a purely natural process and not man-made at all.
Perhaps if you thought for yourself you wouldn't ask such foolish questions. This one is wholly irrelevant.
The advance and retreat of the ice over the last few million years has been broadly related to known variations in the orbital and rotational characteristics of the Earth. While many details remain to be established and some topics engender lively debate the outline is not in dispute.
The recent changes in global temperature are superimposed on those reasonably well understood natural trends. They are clearly separate from them. Another natural, presently unidentified, explanation may be able to account for them, but the balance of evidence points strongly to anthropogenic carbon dioxide as the culprit.
En passant, the ice did not carve out the Great Lakes as it retreated, it did so as it advanced and stayed advanced. That kind of wooly thinking that reflects a total misunderstanding of mechanisms (or, at best an inability to structure cogent thought) calls into question your ability to absorb the data on climate change, or to think for yourself.
MigL - In another context (by analogy), your argument is roughly this: Animals and humans have been dying for millions of years all before the advent of cigarettes. It's simply not possible that cigarettes could lead to increased incidence of death.
Seriously? That's how your mind works, and you think that's a logical point?
Seriously thats how all of you guys think. You restate your position and you verbally attack the opposing viewpoint.
Ophiolite, were the great lakes there before the ice sheet ? NO!
Were they there during the ice age ? NO!
Were they there after the ice retreated ? YES!
Don't argue semantics, argue the point!
Iknow, not exactly. Your argument is that since people die of lung cancer due to cigarette smoking, all deaths are due to cigarette smoking. Totally disregarding all the deaths that occurred before people were smoking cigarettes.
No, my argument is that just because natural causes explained variations in the past does not mean they are sufficient to explain the changes in the present.
Very well. Explain why these mechanisms that have caused warming in the past are now insufficient to explain the current warming trend. Keeping in mind that accurate climate observations are only a recent undertaking. IE Don't say the warming rate has increased during the last century of fossil fuel consumption because the climate statistics for the previous century (1800s) are not that accurate. You can say it has increased during the last 30 yrs, compared to the previous 30, but I would argue that the sample period is not statistically sufficient to draw long term conclusions.
Don't forget that short term heat-up and cool down are also the norm. So although I will not state it as unequivocal truth because of lack of climatic record keeping, there are reports that the 17th century was extremely cold (climate wise), while a few centuries earlier the vikings settled Greenland and actually farmed the land. This is fact as farm houses and cultivated fields have been found.
I welcome the discussion, just don't insult me and simply state your position as ophiolite has done. Natural trends are not well understood as he states, no-one knows the cause of the last ice age or of the warming period that followed, so no-one can say where the natural cause stops and the man-made cause begins. And don't use computer simulations as proof because they are only as good as the data and boundary conditions used. Also those same supercomputers with accurate data cannot predict accurately the weather 3 days from now, never mind a decade or two. That's the problem with chaos theory, minute, insignificant variables can blow-up to overpower others which may have been assigned greater weight.
Why should I have to replicate here for you work which has already been done... work which you quote unquote skeptics largely ignore? No thanks. You're quite simply wrong.
I welcome the idea that the warming is natural. If that is your position, then it's up to you to show which natural phenomenon accounts for it.
Saying it's natural is not enough. Now, you have to show what about nature is making it happen. I welcome that discussion.
Another cop-out. You state that this time the warming trend is from a different cause than all the numerous other times before, yet its up to me to back up my argument and prove that its for the same reason as all the previous times ???
So if I should say water flows downhill because thats the way its always flowed and you say this time it flows downhill because of man-made circumstances, the onus is on me to prove that things are as they've always been ???
If that's the kind of flawed reasoning skeptics like me choose to ignore, then its with good cause.
Uhuh. You know, or I've just presented the information you request like 10,000 thousand times to others and have had it largely ignored each, and don't really feel like doing it again when the issue of primary cause of the warming is largely settled. That's another possibility.
I'll be the bigger man here, though. Below is data showing unequivocally that the sun is not the primary driver of the current warming trend:
http://www.nature.com/nature/journal...l/448008a.html
http://www.skepticalscience.com/sola...al-warming.htm
http://www.thescienceforum.com/viewt...=212900#212900
So, the sun is out. Cross that one off the list.
What other natural mechanism do you suggest is the cause of the warming trend if not the sun? Once you've put forth your suggestion, we'll show you why that is not sufficient to explain the warming trend, and we will repeat the process until you've run out of ideas and presentations. When we're done, we'll be left with the knowledge that the current primary driver is human activity and massive contributions of CO2 to the atmosphere.
You know... It's basic physics. We know that atmospheres with more CO2 tend insulate warm air more than those with less, and that the CO2 in our air is like a blanket helping prevent heat from escaping. We also know that we are adding several tons of CO2 to the atmosphere every single year. Plugging your ears and closing your eyes won't change that simple fundamental fact.
I'll make it even easier. Instead of going through all the myriad possibilities for the warming trend and you rebutting them all as you suggest. Why don't you just tell me the cause of the last ice age and the cause of the subsequent warm up? This way we'll only have to explore one possibility.
What's that ??? You say you don't know the cause of the end of the last ice age ? That's right, nobody knows why these natural cycles occurr. Then how can you be sure its not the same this time?
I've seen the same research you've seen, and some other which you, being closed-minded, consider the work of skeptics, and disregard. I'm not convinced I should give up my way of life and practically go back to the stone age, because of a theory that hasn't been proven.
But hey, I am open minded, so I'm giving you the opportunity to convince me. If you won't or can't, them maybe you are not as sure of things as you let on
I'll give you a hint. The cause of the last ice age is different from the cause of the current warming trend.
I'll repeat. Cop-out.
The mind simply boggles.
MigL - I am happy to entertain certain questions with you, and to elaborate on specifics where appropriate, but your question implies that you have zero understanding of the mountains of evidence and work which has already been done in support of my point.
If that is not enough to convince you, then frankly I'm not sure anything I post ever will. It's hard to use logic and reason to change the mind of a person who used neither to arrive at their position.
Ahhh, insults. The last recourse of those without a clue.
You allude to mountais of evidence, but other than a lot of handwaving, haven't privided a single piece. You are one of those people that is presented with an opinion, by however many, and you accept it without thinking critically. That's alright you are not alone. A lot of people have done that through the ages, The german people before WW2, those who bought into communism, and still do,etc. etc.
Think for yourself before someone does it for you.
Pretty simple. Because those astronomical forcing mechanisms aren't in effect right now. The primary factor being gradually reduced eccentricity and changes to precision. If anything we should be slowly cooling, but not by a rate we'd notice in our lifetimes.
If you want to understand the subject I suggest you start with the many historical summations available on line starting with Fourier who first identified the idea of gases effecting the radiation balance http://timelines.com/1824/joseph-fou...enhouse-effect
Maybe you should re-read the thread. I understand perfectly how greenhouse gases operate and am willing to explain to you what they do to the 'climate' of Venus. However by your "pretty simple" assertions you should be able to predict the beginning and end of the next ice age since the cause is astronomical forcing mechanisms, primary factor being gradually reduced eccentricity and changes to precision.
WHAT DOES THAT MEAN ??
Any 'astronomical forcing' is completely explaned by Kepler and Newton and predictions can be made. If 'Eccentricity' refers to orbit or axial rotation, those effects are also completely understood and can be extrapolated millions of years into the future or past. Yes, our knowledge of the mechanics of the Earth are well undestood. Yet no-one can predict the next ice age, or the cause of the end of the last. Why don't you enlighten us and tell us the specifics of these astronomical forcing mechanisms. No need to be vague, I'll undestand it, I have a degree in physics.
I gave up. They are unwilling to be scientific, and be skeptical first. They have never been able to properly model or predict, therefor the hypothesis isn't a valid theory. However, they have all this corrupted closed peer review processes that they claim proves everything. Why isn't it an open process?
Oh, please. There's a difference between being skeptical and being deliberately blind to data. You can publish anything you want, so long as it makes sense and doesn't break apart when scrutinized. You can't scream foul when your ideas lack merit. The process is open, but not open to false and nonsensical claims such as those you espouse.
Further, if you take your child to a hundred doctors and 98 of them say the child is ill, it seems to make sense to listen to the 98 and do something about it. You? And others like you? You feel some compulsive desire to listen to the 2 who say your child is just fine. It is simply repulsive to logic and good judgment.
"Corrupted closed peer review?" Yep... It is generally is much easier for the charlatans to scream indignantly about half-baked and unsupported conspiracies than it is for them to offer an argument which doesn't simply fall down completely under even remedial scrutiny and review.
You're a dying breed, Wild_Cobra, and I say good riddance. This issue was largely understood decades ago. The debate is not in whether or not human induced climate change is happening or if it will have an effect. The debate is about how much of an effect we will see (will it be "really serious" or will it be "catastrophic"), how quickly it will change the environment around us (will it be 50 years, 20 years, or is already in full swing), and how much worse we'll make it (will we double our CO2 contributions, will we take steps to change things, how significant will those steps be).
Don't get me wrong, Iknow, I enjoy a spirited discussion as much as the next guy, and I grant that your opinions may well be right ( I simply enjoy arguing ). All I've ever asked for from the global warming community, who are so sure of the cause of climate change, is if they've isolated all the variables to come to this conclusion. Unless you can discount other possible causes for climate change, you cannot say which is the true cause, and my assertion is that we don't know the other possible causes or how they work. Such as all the previous ice ages and their ending that has occured many times throughout history. Until someone has a valid theory for the recurring ice ages and their end, how can we be so certain the same mehanism is not at work now ???
It's iNow, not iKnow.
All known factors impacting the climate have been accounted for. The isolation you request has been completed, and the conclusion is that humans are having the most significant impact now. I concede that there may some other mysterious force of nature for which we've failed to account, but until that is put forth, humans are the ONLY remaining logical cause for the majority of the current change.
There are explanations for the past ice ages, and those explanations cannot account for the current trends.
First off you make a very broad statement and incorrect statement like "Yet no-one can predict the next ice age, or the cause of the end of the last," don't appear to be interested in researching the astronomical forcing yourself and then accuse someone of "being vague."
We have a pretty good understanding of what ended the last ice age....solar summer insolation of the Northern hemisphere (for models typically using 65N) neared a maximum and sufficient to melt the huge ice sheets. The next serious drop in Northern hemisphere insolation won't happen for another 50,000 years--that will likely mark the beginning of the next astronomically-forced ice age.
It's also been known, and upheld with modeling and past climate data for sometime.
" ...orbital variations remain the most thoroughly examined mechanism of climatic change on time scales of tens of thousands of years and are by far the clearest case of a direct effect of changing insolation on the lower atmosphere of Earth" (National Research Council, 1982).
You can root around in most good libraries for articles from the 60s and 70s about the subject. One recent article that compares the radiative forcing that ended the last ice age with the current period is below:
http://www.unh.edu/esci/people/pdf/l...eoscience1.pdf
The paper you mention describes Boreal insolation as one of the prominent factors for ending the last ice age. And that may be a possibility as boreal forests of extensive size will tend to affect the climate in numerous ways.
What about the previous ice age when no boreal flora had evolved yet, or the three previous known ice ages ??
If you do a simple 'Google' for ice age you get:
The causes of ice ages are not fully understood for both the large-scale ice age periods and the smaller ebb and flow of glacial–interglacial periods within an ice age. The consensus is that several factors are important: atmospheric composition (the concentrations of carbon dioxide, methane. The specific levels of the previously mentioned gases are now able to be seen with the new ice core samples from the Antarctic shelf over the past 650,000 years;[citation needed] changes in the Earth's orbit around the Sun known as Milankovitch cycles (and possibly the Sun's orbit around the galaxy); the motion of tectonic plates resulting in changes in the relative location and amount of continental and oceanic crust on the Earth's surface, which affect wind and ocean currents; variations in solar output; the orbital dynamics of the Earth-Moon system; and the impact of relatively large meteorites, and volcanism including eruptions of supervolcanoes.[citation needed]
Read that first line !!! Having theories and being able to make useful predictions are two different things. And if you can't make predictions with your theories it usually means you need to change or refine your theory.
The paper is consistent with identifying the primary driver, which is boreal insolation and an exploration of a positive feedback to that driver, which is the effect of the flora.
Boreal floral have been around for at least a couple hundred million years--in other words many ice ages ago (we've had a deep one about every 100,000 years or so). Doing comparisons before that have to consider different geographies, ocean current regimes etc--essentially a different planet.What about the previous ice age when no boreal flora had evolved yet, or the three previous known ice ages ??
In this case refinement to understand the feedbacks to better describe the amplitude, phase offset, and abrupt by-smaller shifts within the broader pattern of astronomical forcing and observed temperature/ice regimes.Read that first line !!! Having theories and being able to make useful predictions are two different things. And if you can't make predictions with your theories it usually means you need to change or refine your theory.
So the density of Boreal forests made ethe earth retain more heat and warm up significantly. O.K.
But I ask about the previous ice age and the cause of its end, and you say Boreal forests have been around for hundereds of millions of years. So if the Boreal forests and their insolation effect were already there, why did the ice age begin ???
Incidentally the first identified ice age occurred about 2 BILLION years ago, the next about 800 million years ago and the third about 400 million yrs ago. I could be wrong but Boreal forests are aspecific type of vegetation and as late as 200 million years ago dinosaurs were still snacking on ferns, a less evolved type of vegetation. There were no Boreal forests in the four previous ice ages, hell, during the first there was probably little or no vegetation at all !!!
It starts when astronomically-forced insolation over Northern Boreal latitudes is low--which allows ice to accumulate.
There have been 4 just in the past 500,000 years and probably dozens if not hundreds over the course of the planet's history. Most of these have been relatively short say 10,000-100,000 years like the one that ended ~12,000 years ago and the next one I referred to in 50,000 years. These are considered minor ice ages.Incidentally the first identified ice age occurred about 2 BILLION years ago, the next about 800 million years ago and the third about 400 million yrs ago. I could be wrong but Boreal forests are aspecific type of vegetation and as late as 200 million years ago dinosaurs were still snacking on ferns, a less evolved type of vegetation. There were no Boreal forests in the four previous ice ages, hell, during the first there was probably little or no vegetation at all !!!
Earth's major ice ages, which you seem to be shifting the discussion towards, span tens of millions of years; we are still in the Quaternary Ice Age.
Very well, back to minor ice ages. The predictions for the onset of the next one are, anytime, within ten thousand years, within twenty thousand years, within fifty thousand years, or possibly never again. Hhmmm. Sounds like the weatherman trying to predict tomorrow's weather.
Mathematical models are just that, they can give whatever results you want, because you input the variables and boundary conditions, ie garbage in, garbage out.
The point is, while we have several theories for the past ice ages, we have no idea which is the correct one if any, or which combinations of theories are corrct, if any.
You're basically arguing from a position of incredulity after demonstrating you know very little about the subject.
Milankovitch Theory is called such because it's entirely accepted by the climate (and others) community as a primary driver of climate; in other words a proven hypothesis. It was developed decades before computer climate modeling. Obviously other things can change global climate (e.g, configuration of continents, volcanic periods, etc.) but that does not invalidate the prominent role of astronomical forcing in the least.
All right, I'll make it simple. When will the next ice age start, plus/minus 1000 yrs ?? Give me an answer and back it up with two other sources also within 1000 yrs with a similar prediction. That shouldn't be difficult, should it, since your theories are "accepted and proven hypothesii', and have obviously made several test predictions which have panned out ( like other accepted theories such as quantum electro/chromo dynamics, special and general relativity and many others ).
Not as simple as you think. The reason is that accumulation of ice and cooling is rather gradual and takes many thousands of years, while the interglacial warming period is usually rather abrupt. As an example look at the last minor ice age (figure below); the past four ice ages show similar patterns. What I can tell you is the astronomical forcing is on a slight decline and we should be seeing a slow build up of ice already (as an aside some use the difference between temps now and that forcing to argue that man has been effecting climate for 8000 years--see Ruddiman hypothesis). Anyhow if you look at the astronomical forcing in the papers below you'll see there's a mild dip in about 20,000 years and a sharp and deeper plunge of forcing at about 50,000 years, which is probably the next certain ice age.
But to answer your question more directly.
In 50,000 years.
"An Exceptionally Long Interglacial Ahead?" Berger and Loutre, 2002
http://science-mag.aaas.org/content/...5/1287.summary
Abstract: “Today’s comparatively warm climate has been the exception more than the rule during the last 500,000 years or more. If recent warm periods (or interglacials) are a guide, then we may soon slip into another glacial period. But Berger and Loutre argue in their Perspective that with or without human perturbations, the current warm climate may last another 50,000 years. The reason is a minimum in the eccentricity of Earth’s orbit around the Sun…..”
Here's a presentation that's good to understand the subject better.
http://www.adm.dtu.dk/upload/institu...sac/wp_201.pdf
Berger et all, 2003
http://www.google.com/url?sa=t&sourc...-NlyoQ&cad=rja
"Simulation of long-term future climate changes with the green McGill paleoclimate model: The next glacial inception" (see their no further human influence scenario where rapid glacial expansion starts at 50,000 years, figure 8)
Anne-Sophie B. Cochelin · Lawrence A. Mysak ·ZhaominWang, 2004
http://www.google.com/url?sa=t&sourc...ElMIow&cad=rja
"Encyclopedia of paleoclimatology and ancient environments," Vivien Gornitz
http://books.google.com/books?id=yRM...orcing&f=false
Which is a rather important point I think is sometimes missed. If it were "natural," we'd very likely be seeing an overall cooling trend right now, not a warming one.
To supplement Lynx's post above, more here:
http://www.skepticalscience.com/head...termediate.htm
Worry about global warming impacts in the next 100 years, not an ice age in over 10,000 years.
And MigL - Pretty much every argument you're making, and likely those you'll put forward in the future, have already been addressed. Here's a nice roll-up below of each, including supporting references and data. Enjoy, as this level of detail and thoroughness would satisfy any "true skeptic" (unless, of course, you're not a true skeptic, but instead a denier):
http://www.skepticalscience.com/argument.php
.
I am not a denier, Inow ( correct spelling this time ), I am just as confortable arguing on the other side of the issue of man-made climate change, and have in the past. I'll be the first to admit that I don't know. What bothers me is how some people are so sure of their opinion to the point of being religious about it, and then expect others to do likewise.
All the articles presented by you and Lynx_Fox use a lot of mays, probablys and should have. And maybe my challenge to Lynx_Fox wasn't the best way to prove my point, which is that for every one of the 50,000yr predictions he has presented , there are an equal number which predict 10,000yrs, others of 20,000yrs and still others which say another ice age will never come.
The fact is that climate change is dependant on many factors, and, for example, even if the Earth is in a much more elliptical orbit for the next period, the sun may be in a more active period and negate the orbital forcing. These are just two factors, there are many, one of which is man-made green-house gas. There are so many factors in fact, that it falls in the realm of Chaos Theory.
That is why I don't make absolute predictions as to future climate change, but question those that do
Oh, and I don't call people who disagree with my opinion names such as denier, or accuse them of being deliberately blind to the 'truth', or that others demonstrate they know little about the subject.
They are immune to reasoning like that.
For a science forum, these people seem immune to that simple fact.
What facts do we have that this was a trigger. Were you there to see it? I have stated in the past, and I will again, the 65N theory cannot be right. Consider what the 65S is doing, primarily water, and the opposite effect on the southern hemisphere.
I say it's likely primarily from Eccentricity. Precession and Obliquity I doubt do much.
The sun is the driving force of all significant heat on the earth. There is a lag. The minimum ended about 1700 and the heat started increasing about 1750. The maximum ended about 1960, and we are now seeing cooling. Don't forget the unusual cold during the revolutionary war, which could easily be a lag after the cooling about 1820. Conservation of mass and energy must be maintained. Those espousing the AGW theory seem to discount this well established theory. Between eccentricity changes, and solar changes, this heat must be accounted for.
from above link:
Please do consider it! It's expressly because 65S is mostly water and can't form an ice sheet and change the albedo of the planet that's it's not an important factor. The Northern Hemisphere's vast land masses, near where it's already near freezing, are what allow ice fields to become glaciers and expanding ice sheets once there's insufficient summer sun to melt the snow away.
Also consider that the summer solstice forcing at 65N changes by as much as 100W/m^2. That's enormous! So significant that is was figured out well before computer models came along. If you review the models I've already posted you'll see they do quite well in capturing the timing of the past 4 minor ice ages. If you want a simple one that combines a very simple dynamic model with some stochastics read M. Crucifix and J.C. Rougier (2009), "A Bayesian prediction of the next glacial inception." The European Physics Journal - Special Topics, 174(1), 11-31. It's one more model that puts the next ice age at about 50,000 years from now.
http://www.mucm.ac.uk/Pages/Download...redictions.pdf
--
and we are now seeing cooling.
Frankly, besides being factually wrong, this seems very far from the majority of this thread's discussion.
Consider that the water absorbs most the solar radiation, therefore that 100 watt value change is significant for total heat accumulated bu the earth. This is where the eccentricity comes in. Lower eccentricity values have more total solar heating for an annual value. The greater the eccentricity, the greater the summer and winter differences between hemispheres, but the overall energy is less.Please do consider it! It's expressly because 65S is mostly water and can't form an ice sheet and change the albedo of the planet that's it's not an important factor. The Northern Hemisphere's vast land masses, near where it's already near freezing, are what allow ice fields to become glaciers and expanding ice sheets once there's insufficient summer sun to melt the snow away.
Also consider that the summer solstice forcing at 65N changes by as much as 100W/m^2. That's enormous! So significant that is was figured out well before computer models came along. If you review the models I've already posted you'll see they do quite well in capturing the timing of the past 4 minor ice ages. If you want a simple one that combines a very simple dynamic model with some stochastics read M. Crucifix and J.C. Rougier (2009), "A Bayesian prediction of the next glacial inception." The European Physics Journal - Special Topics, 174(1), 11-31. It's one more model that puts the next ice age at about 50,000 years from now.
http://www.mucm.ac.uk/Pages/Download...redictions.pdf
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and we are now seeing cooling.
Frankly, besides being factually wrong, this seems very far from the majority of this thread's discussion.
Isn't it reasonable that long term events require the consideration of such things?
I appears reasonable at first look but compare the difference in albedo between that ocean during it's summer solstice for land and sea.
Open Sea.
The albedo doesn't change because it remains open water.
Astronomical difference is 100W/m^2, which is about +- 25% change.
Land.
Albedo of Boreal forest ~10%, tundra ~20%, for fresh snow 90%, dirty snow ~60%. A difference of say 400%
Astronomical difference is 100W/m^2, which is about +- 25% change.
Total is something like 600% different in radiation absorbed between warm subarctic summer forest and cold glacial covered periods.
At those latitudes, the total change for open sea about 25%, for land it's >600%. That's the difference.
The signal in response to astronomical forcing in the Southern hemisphere is much smaller than that of the Northern hemisphere and it has to do with feedback of changing albedo.
Wow...
Sorry, but percentage of albedo differences do not reflect the final energy differences. You are really good at
convincing others of false premises. Besides, your numbers are in error:
Your boreal forest albedos matter on the dark and light cycle.
Now in reality, the ocean's albedo is about 10% only around 66 degrees, reducing to 0 perpendicular. At 43 and 87 degrees, where the differences would be calculated for 65N or 65S, it's only about 3% and 70%. Incidental angle matters.
I suggest you look into the factors more closely that matter on this sub topic. We cannot use average TSI. We must use the TSI at the declination of the area we are observing, and the albedos where some change by angles, and others change by other factors.
Trust me. If you look deeper, you will agree that 65N is more significant than 65N.
?
Your top chart shows what I'm talking about.
Boreal forest albedo is low, it's dark vegetation. By your chart 5-15%.
Snow albedo is high. By your chart 40-85%.
Instead of percentages lets look at absorbed Watts per square meter due to astronomical forcing and albedo changes.
So lets look at it over land.
At 65 latitude maximum astronomical-driven summer soltice forcing.
~450 W/M^2 * (1-albedo of boreal forest) = ~ 400 W/M^2 absorbed.
At 65 latitude for weak astronomical-drive summer soltice forcing.
~350 W/M^2 * (1-albedo of snow) = ~ 50 W/M^2 absorbed.
A huge difference or something like 350W/M^2 in absorbed solar radiation that only happens over land where cold summers can't melt the ice.
--
Lets look at your argument about water is albedo. First off it’s not 65 degrees, it's 65 - solar inclination during the summer solstice. That change in inclination between max astronomical forcing and minimum only changes by 3 degree. Look at your TSI water albedo chart: The TSI declination difference of 3 degrees results in only a very small change in albedo.
Let run a similar analysis as above.
Open Sea
At 65 latitude maximum astronomical-driven summer solstice forcing.
~450 W/M^2 * (1-albedo of ocean open) = ~ 400 W/M^2 absorbed.
At 65 latitude for weak astronomical-drive summer soltise forcing.
~350 W/M^2 * (1-albedo of ocean) = ~ 300 W/M^2 absorbed.
A total difference of 100W/M^2 absorbed is due almost entirely due to difference insolation by astronomical forcing. The albedo is roughly the same so doesnt' effect the difference between the two regimes.
--
Same conclusion. Boreal land surface latitudes are much more sensitive to astronomical forcing than open ocean because they change albedo between dark evergreen forest which absorb lots of sunlight and snow and ice which don't. The open ocean albedo don't change significantly due to astronomical forcing.
Not sure how I can make this any clearer. The simple differences in albedo explains the empirical observations and why there's a strong signal related to astromically-forced insolation at Boreal latitudes in the Northern hemisphere where there’s lots of land and a strong change to albedo, while there's not a significant signal for the Southern hemisphere which is mostly open ocean.
I have. Most of the work at the level we're discussing was done between 1940 and the early 70s. The work since has only reinfoced Milanchivic theory. Work since has focussed on understanding the discontinuities and sometimes rapid shifts within that broader pattern."Trust me. If you look deeper, you will agree that 65N is more significant than 65S."
Do you now see the point I' tryng to make.
All this data is subject to interpretation, and the slightest error ( I don't mean mistake but error due to limitations on the observations ie standard scientific error ), when fed into supercomputers to make prdictions is then multiplied and amplified.
I'll repeat, there may be hypothesis as to ice age starts and ends, but there is no valid theory, backed by observation and able to make repeatabe, accurate predictions, yet.
But according to Al Gore and the rest of you (sorry for the insulting comparison ), I should give up my way of lifeand go back to living in a tree house in the woods. The fact is that technology, developed with cheap power, ie 'fossil fuels' make possible the feeding of the half of Earth's population who do live like that ( tree houses or huts in forests ad deserts ).
While I'm ranting about 'fossil' fuels, do you know where the biggest deposit of 'fossil' fuels is located ??
The planet Jupiter's atmosphere has more ethane and methane than the rest of the planets combined, yet environmentalists use the term' fossil fuels' to imply that they come only from long dead fauna and flora.
Now Jupier does't even have a solid surface, so which dinosaurs and trees died millions of years ago to produce this ethane/methane ?
No. You seem to know little about the subject and aren't willing to learn enough to engage in a constructive conversation about it. I've layed out the basics as best I could to explain why astronomical forcing is considered to a primary driver for past climate and anwered your questions directly, for example showing you multiple references to next ice age starting in 50,000 years.
I'm not very interested in discussing the political aspects in this thread; it's not really a scientific subject and appears like just an attempt to derail the thread. In another thread perhaps.
Yeah. Yeah.Blah.Blah.
I've tried not to stoop to your level and call you names or accuse you of knowing little, but I guess I'm not setting an example for you.
I have a BSc degree from a real University, consider myself a critical thinker and give everyone I argue with the same qualification.
You however are a pompous ass, who believes his climate change 'religion' is the only one and anyone else who doesen't bow down before his god, hasn't got a clue.
You are exactly the kind of person I've talked about in previous posts, and unfortunately, there are an awful lot of you.
I'm sorry if I've lost my temper, but you're the one with a closed mind.
The point you're trying to make is that you cannot address the details, you focus on unrelated issues, and you ignore the facts because your ideology trumps reality.
That's not name calling. That's objective truth. Lynx_Fox has answered your questions clearly and accurately, and you then reply talking about Al Gore, the way some people use the term fossil fuels, and something about living in tree houses? Give me a break, dude.
Except the second pair, I show you the actual boreal forest range, and it doesn’t dip to 5%. Please stop using erroneous numbers. We wouldn’t want people to think you are being intellectually dishonest.
I agree. The final net result of each category is important. Not intermediate parts of the equation.
Except your concepts of math in this matter are incorrect. There is an approximate difference in direct solar radiation between the aphelion and perihelion. That is about 100 w/m2. By the time you account for reflection and absorption of the atmosphere, there is something like 49% of that making it to the surface. At a declination of 65 degrees, and considering 1366 w/m2 average, we have only 294 watts in early January, and 275 watts in early July. Even a declination of zero yields 695 vs. 650 watts. There is no 100 watt difference at the ground level.
You cannot pull the wool over my eyes.
I seriously doubt that when you cannot get the simple math correct.
Boreal isn't on your chart, but forest is which appears about 5-15%. Boreal forest are dark evergreens (go see some). Anyhow your quibbling, even if it's as high as 15%, it's a LOT less than snow and ice.Except the second pair, I show you the actual boreal forest range, and it doesn’t dip to 5%.
Huh? Declination is the angle of the sun to the equator. It's range based on the tilt angle for that time of year is plus to minus 22.1 degrees to 24.5 degrees. (currently 23.4)At a declination of 65 degrees, and considering 1366 w/m2 average, we have only 294 watts in early January, and 275 watts in early July. Even a declination of zero yields 695 vs. 650 watts. There is no 100 watt difference at the ground level.
To get the radiation at noon onto the surface is a pretty simple calculation of figure out how high the sun is at that time of year.
At 65 degrees latitude - 90-latitude + declination.
Summer solstice noon the sun will be at 90-65+23= 48 degree elevation.
During the winter solstice noon the sun will be at 2 degree elevation.
To get the watts at noon radiation on the surface it's simply the sin of the elevation angle * radiance. Even if we use your approximate numbers for what gets through the atmosphere ~1000W/m^2. To look at your Northern latitude numbers late June is about 700W/m^2 (at noon), versus almost zero for late December. The numbers in the simple example I used are daily average summer solstice radiation reaching the ground (which is more complex than calculating noon numbers).
--
The aphelion and perihelion are only part of the deal here.
Max insolation at boreal latitudes would be max tilt (so the sun is at max elevation angle)
Perihelion at the same time at the summer solstice.
Maximum eccentricity of earths orbit around the sun.
Getting some terminology wrong after not using such sciences for 30+ years in minor compared to sticking with math values that are incorrect, or cherry picking numbers to make your ideals work. Please do the complete math and see for yourself. Until you see what I'm speaking of, I am wasting my time with you. I do have better things to do than debate a topic with closed minds. Don't focus on just 65N or 65S, but various points of land and sea over time in that region.
You didn't just get terminology wrong, the quote "294 watts in early January, and 275 watts in early July," indicated you completely forgot to account to different tilt angle (actually declination) of the sun change with season---you know the very thing that makes the seasons!
65N only comes up because some 50+ years ago some folks started looking at geological ice age data and noticed it best fit the astronomically-driven insolation at 65N. (it's not a random number but derived by comparing observations of astronomic forcing, temperature and ice extent) (They didn't find that signal at 65S.) They started trying to figure out why. Looking at the geology of the last ice age they noticed the last retreats of the Pleistocene ice sheets in both North America and Eurasia was also at about the same latitude (NE of Hudson bay and Northern Scandinavia)(see figures below). Those high albedo ice covered latitudes during the ice age are today tundra with vast forest just to their South today--(Holocene tree line reconstructions Eurasia puts them as forest during the most recent peak insolation about 9K ago.)(http://hol.sagepub.com/content/9/3/253.abstract). Now they had an observed relationship between astronomical forcing, ice age extent, the temperature record, forest extent, and latitudes where ice sheets start and retreat to. You look at the strong albedo change impact during Northern summers and it tied them together. We're up to the early 70's, when Milankovitch cycles as a primary driver becomes widely accepted. Subsequent work has been focussed on sorting out the myriad of details of what happens within that broad pattern and understanding the multitude of feedbacks (e.g., as Co2, CH4, currents, forest changes at other latitudes etc etc.)Don't focus on just 65N or 65S, but various points of land and sea over time in that region.
Enough.
(on charts the Northern purple are the start and last retreat points of the last ice age)
OK, there you go, not understanding what I say again. I think you know what I mean, but am purposely twisting it.
The 294 watts in early January is in the southern hemisphere at an angle of 65 degrees. The 275 in early July is in the northern hemisphere at an angle of 65 degrees. This is to show your 100 watts per square meter is less that a 20 watt difference once you look at the 65 degree angle, and have your atmospheric and reflective losses.
If you keep twisting what I say to convince others you are right, when you are wrong, then you obviously cannot argue me with facts.
You see, I understand the old sciences too. I'm sorry you're stuck in the past. They couldn't measure the ocean like they can now. Since the absorption of sea water is more than vegetation on land, it becomes critical. 65S is more variable than 65N. Sorry that you must eliminate such facts to make your obsolete theories work.
I'm done with you since you ignore all reason.
Goodbye.
You could have said that. It didn't help clarify things when you continued to use 65 degree when most of the solar heating is during the summer when the sun rises to 40-45 degrees each day. Furthermore you are still ignoring the difference in albedo in the two regimes. The Northern latitude has huge areas where albedo switches from ice to forest (and back) while the Southern albedo doesn't change at all because it remains mostly open ocean. The signal exist at 65N because of that change in albedo and the large ice coverage resulting in radiation balance change for the planet; a signal doesn't happen at 65S where there's no change to albedo.
If you can't understand that huge difference in solar energy absorbed even when presented several examples and using your own albedo charts than I don't know what else I can do to convince you. I'm not going to waste anymore time explaining the basics of old and proven science.
You can read up on it from multiple sources or take a 1st year undergraduate course in climatology and several other related fields.
--
edit. This is an excellent short paper that summarizes the history of Milankovitch theory and points to the landmark papers and many developments since. http://earthweb.ess.washington.edu/r...efense_GRL.pdf
Sorry, been awaya few days ( thats all right I needed to calm down after you got me upset). But come on, you guys, you guys argue about differences of a few digits like you're talking abouta an exact science. And even funnier is that you consider albedo as a factor in warming/cooling for all the wrong reasons. Albedo is nothing more than a reflectivity coefficient. If you Mr, Fox and your lapdog, Mr IkNOWnothing ( who just parrots whatever you say ) knew any science you would know that a highly reflective surface heats up slower than a matte , dark surface BUT, they both reach the same end temperature. This is for incident radiation, sunlight, which has a Gaussian wavelength distribution centered on the visible spectrum. What you should be looking at is nocturnal re-radiation which occurrs mostly in the infrared and carries away most of the heat. In this case, which is greater than 50% of the time due to cloud cove and extreme latitudes, a matte/dark surface will lose heat quicker than a highly reflective surface and there is no end temperature ( other than absolute zero ). Some elementary examples ( I have to keep them simple for you two ) is the fact that 'dirty', dark snow will last until April while the highly reflective , white snow melts in March. This isn't because clean snow absorbs heat faster, btut because dark snow LOOSES heat faster and so doesn't melt. It's a more efficient radiator. That is also one of the reasons bodies of water stay warm in the fall and winter long after the groundis cold. Water being a less efficient radiator will keep more of its heat.
So tell me again how the albedo of boreal forests would help end an ice age ???
Boreal is a certain type of vegetation and evolved at a specific and well documented time ( fossil records ). I haven't done the researh, but I'd be willing to bet that the evolution of boreal type vegetation coincides more with the on- set of the last ice age rather than the end.
As to CO2 in the atmosphere, lets look at a very good example of the greenhouse phenomenon, the plane Venus. It has a dense atmosphere high in CO2 and , although much closer to the sun, surface temps are hot enough to melt lead. Venus has been known for thousands of years, long before telescopes, because it' s the brightest object in the night sky other than the moon. Let me break it down for you (simplify ), it reflects sunlight more efficiently than any other object in the sky. You see, the bond length of the CO2 molecule is easily excited in bending and vibration by infrared frequencies, just like water is to microwave frquencies ( and other substances don't heat up nearly as efficiently in a microwave oven ). So even though Venus reflects a large percentage of sunlight into space, it still manages to heat up to >600 degrees, Where does this heat come from ? Its re-radiated heat from the surface which is trapped and reflected by the CO2 layer, not the much reduced ( by reflection from the atmosphere ) incident radiation reflecting off a high albedo surface, and then getting trapped by the CO2 layer.
You will note I'm not de-bunking the greenhouse effect, it is real( I'm a scientist, I don't argue with facts ), I have problems with your contention that we have undisputably valid theories for the natural ice age cycles of our planet. There may be other factors involved in the present heat-up ( if any due to overzealous researchers trying to fit the facts to the theory, East Anglia ring a bell ???), and until we know I prefer not to be a lemming like your boy INOW.
If you have understood the point I'm trying to make, fine, if not, my apologies for not being clearer. This is my last post on the subject, you have your opinion, I have mine, because that's all we have right now, opinions not real facts. If we're still around at the start of the next ice age one of us can say 'I told you so'.
You're flat wrong. Any surface will warm until IR output equals the Short wave (SW) input. Because reflective surfaces absorb less SW radiation than non-reflective surfaces, they need to emit less IR to reach equilibrium and will therefore be cooler. Since most macro-scale natural surfaces emit as approximate black bodies that equilibrium temperature difference will be proportional to (1-albedo) ratio of the two surfaces raised to the 1/4 power (IAW Stefan–Boltzmann law). Reflective surfaces most certainly don't reach the same end temperature as non-reflective surfaces while the sun is shining.
Again wrong.Some elementary examples ( I have to keep them simple for you two ) is the fact that 'dirty', dark snow will last until April while the highly reflective , white snow melts in March. This isn't because clean snow absorbs heat faster, btut because dark snow LOOSES heat faster and so doesn't melt. It's a more efficient radiator.
First off your sentence is gibberish. But to get back to what I think you're trying to say, look at the link below that describe emissivity in the IR of fresh versus dirty snow. Dirty snow emits about 2% less than fresh snow. It absorbs at least 50% more SW radiation during the day. Dirty snow appears to last longer because the fresh snow becomes dirty as it melts particles within concentrate and settle down as the top layers melts.
http://books.google.com/books?id=o6X...page&q&f=false
Consistent anyhow, but also wrong. Water emissivity in the IR is more than 98%, making it more efficient IR radiator than most substances including that on land --so that's not the reason water bodies "stays warm in the fall." Water bodies change their temperatures slower because water has very high specific heat capacity and can be mixed down to several hundred meters deep by the wind, convection and other processes. Land surfaces, by comparison is made of rocks and soil which have much lower specific heat capacity and less effective processes (such as thermal conduction) to move heat to and from the layers below.That is also one of the reasons bodies of water stay warm in the fall and winter long after the groundis cold. Water being a less efficient radiator will keep more of its heat.
It's not just my contention, it has been the opinion of scientist for nearly half a century. Based on the your serious lack of demonstrated knowledge about even the most basic concepts involved in the subject you're "problem," isn't based on merit but your ignorance. Ignorance isn't of itself a problem--all of us are ignorant about most things--asserting your argument has merit rather than admitting your own ignorance IS A PROBLEM.I have problems with your contention that we have undisputably valid theories for the natural ice age cycles of our planet.
Way out of order. INOW has many times on this forum demonstrated he has a solid command of the basic physics and thermodynamics necessary to comment intelligently on a wide range of subjects including climate--you Sir haven't.lemming like your boy INOW.
Argument has been going on for quite some time now, Prince thinks issue is far from settled as certain members claim. To answer last question, Prince hypothesizes, "So advocates of one side can say: 'MATTER is SETTLED.'"I gave up. They are unwilling to be scientific, and be skeptical first. They have never been able to properly model or predict, therefor the hypothesis isn't a valid theory. However, they have all this corrupted closed peer review processes that they claim proves everything. Why isn't it an open process?
Now for Prince's question, "Why was mediocre undergraduate science student Al Gore chosen for mediocre slide show 'Inconvenient Truth' vs dotcomrade Lynx Fox?"
Finger, suggest you start another thread. This one is quite old and your comment has little to do with most of its content nor add any new information.
Because Al Gore is so good, he invented the Internet!
His Algorythms show how AGW works.
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