The “iconic” Antarctic temperature trends are the large warming seen on the Antarctic Peninsula, which has had various repercussions including the collapse of several ice shelves (some documented in a previous post). Elsewhere, though, the pattern of surface warming is more complex – trends are smaller, and while more are positive than negative they are generally not significant – see this map. Contrary to what you might have heard, this is in general agreement with model predictions.
But meanwhile, there is a record for the upper atmosphere derived from radiosondes, which we have been working on – finding old datasets and digitising them to fill in gaps. What this shows is that around East Antarctica there is a general warming of the troposphere, greatest at around mid-height (at 600 hPa) at 0.7 ºC/decade over the last 30+ years.
In itself, this is an interesting observation. The obvious question is, what does it mean? Is this natural variability; is it a response to global warming, or to changes in ozone; or something else? Ozone is unlikely, because this is winter (which conveniently means that the radiosonde temperature corrections, often a source of potential trouble, are not a problem). Two ways of trying to interpret the record are to see what GCMs run for the same period show; or to look at the re-analyses (essentially, the archived outputs from the weather-prediction models). The latter, of course, incorporate many of the radiosonde observations that we are using, and so don’t count as independant. Despite this, the ECMWF re-analyses show *greater* trends than we see in the observations; and a maximum trend over West Antarctica (which has no radisonde stations to allow us to verify this). A climate model (HadCM3, with an ensemble of four members) shows similar patterns to the observations, but this time too little warming; and a good deal of variation between the ensemble members. So neither of these is helps much with the interpretation.
So we are currently left with an open question; hopefully, this will stimulate us and other researchers to explain it in the future.
[Quick addendum: the paper itself is available via this.]
Re: #50
Thanks for the kind thoughts, Alastair.
As for a reply from Christy, et al., I think they will just ignore the paper and hope it goes away. After all, they just went thru a review that took more than 2 years. Maybe William will summarize the feedback he’s heard so far.
Thanks, llewelly!
Dr. Connolley-
Re: http://www.nsf.gov/news/news_summ.jsp?cntn_id=100385&org=NSF&from=news has the cause of the Larsen B Ice Shelf detachment been determined? Are there any local tropospheric warming contributions attributable to this as well (either thermal direct, or by sub-surface GHG release becoming aerosols)? And please comment on the distribution of temp sampling w.r.t. the troposphere proximity to above, Mt Erebus and others — I know geothermal factors are characteristically low, and are typically not factored into GCMs (unless cataclysmic); however some comment on such local factors is of interest?
[Response: The Larsen B collapse is within the area of surface warming, though the exact reasons for the collapse aren’t clear. Erebus, etc, don’t matter as far as I know – their heat may be significant very very locally, but no more (probably not even locally, since they are ice covered) – William]
“[Response: I would say that the astromonical forcing of the 100 hyr cycle is pretty well agreed on (though there are suggestions its the plane of the orbit). And everyone seems to agree that you need amplification from CO2 and stuff to explain turning a weak signal into a strong one. But to say that the details of the mechanism are well understood, no – William]”
This is not proven since over the long haul the heat deficit/surplus from the Malinkovitch cycles register as a reduction/increase in ice cover on a virtual one to one basis. Now it might be us putting abiotic carbon into the atmosphere will change this. But so far you would have to be going out on a limb here.
Re 54 True. The big amplification is from the major greenhouse gas water vapour, but those professional scientists like William, don’t appreciate being told simple truths by amateur scientists like me!
Cheers, Alastair.
If there is more precipitation off the ocean due to CO2-based warming you might be getting more snowfall . The snowfall would tend to release a lot of latent heat into the mid-Troposphere. But the extra snow and cloud cover might leave the temperature at ground level lower.
Or it could be a sort of competition between the Malinkovitch cycles turning bad on us(in the Southern Winter, Northern Summer) and extra warming making its way down from the top of the Troposphere.
Why is it a big mystery. You make a few hypotheses in parallel and then you go about developing, testing them and altering their ranking in accordance with what you find.
Since the effect of Greenhouse gasses is not additive but Logarithmic, and since water vapour overwhelms all else the effect of CO2 will only be significant where the air is dry.
Dry air tends to be cold air on this planet. It is THIS small but cumulative addition to the energy retained by the weather system that CO2 is likely to make.
And a good thing too. At least for the forseable future since the natural tendency is towards glaciation which would be an unmitigated disaster.
The most important text for understanding the current goings-on is not any text on science. But a book written in the 1840’s by a fellow called Charles Mackay.
Its called: “Memoirs Of Extraordinary Popular Delusions And The Madness Of Crowds”
You can read it online here:
http://www.econlib.org/library/mackay/macExContents.html
Re 55, 56, 57
We are all aware of the prime importance of water vapor (radiative impact, latent heat, etc..)
However, regarding the importance of CO2 vs H2O:
It turns out that, in essence the GHGs with longer residence times (CO2) ends up controling the mean amount of water vapor presnt in the atmosphere. This has been covered on this site before. Please see Water vapor: forcing or feedback https://www.realclimate.org/index.php?p=142 . It can also be reached via the highlights side bar.
Oh…Re 57. There is alrady way more than enough CO2 around to stave off any possible glaciation !
Cheers,
Dave
The point is that because of the Logarithmic nature of the greenhouse effect CO2 will only tend to be significant where the air is dry. That is why when you look at the stats you cannot clearly divine the CO2 effect. Because its not some powerful one-off effect. Its a tiny cumulative effect. Tiny cumulative effects are more to be feared then one-off shocks. Its a minute-in minute-out relentless accumulation of extra Joules. But really taking it one year at a time it has to be pretty miniscule.
Still to be fair. Tiny cumulative effects are GOING TO ACCUMULATE and could be very serious over the long haul. Its just that in the next few thousand years there are greater risks to worry about.
“Oh…Re 57. There is already way more than enough CO2 around to stave off any possible glaciation !
Cheers,
Dave”
Prove it. Eveyones just taken this Mantra up arbitrarily. You don’t know this. And neither does Steve Bloom not Gavin nor Stefan. You are making it up and ten of you saying it ten times won’t make the spell.
Trolls don’t footnote. Give us your references, please. With no cite and no name, it’s impossible to tell if one person posted the first idea then two more came along, copied the false name and posted other ideas trying to make fun of the first one — or if this is one person who thinks it makes sense in three different ways.
What is your source for your ideas, where did you read them, who are you quoting? Can I find your ideas in sci.environment? I admit I use a killfile there regularly, it’s possible I never saw your ideas there.
Re: 60. “Prove it.” “You are making it up…” ad nauseum.
This appears to indicate a fundamental misunderstanding or lack of knowledge about the basic scientific process. Science is about hypotheses, theories, and gathering/testing/modeling evidence to support theories. “Proof” is a *mathematical* concept. Those are very important differences that ought to be clear before the words “prove it” are toss around haphazardly.
Theories for glaciation are not supported. Theories for global warming are well-supported by data gathering, testing and modeling. Which is not “making it up”. Furthermore, science requires that modeling or experimentation be repeatable. So ten people “saying” it ten times is good science if the experiment is repeated with similar results.
D.
Thanks new D, (Dan?). That clear insight is a good reminder of how a discussion should proceed on a scientiofic site.
TT
” when you look at the stats you cannot clearly divine the CO2 effect”
Hmm. I can see it pretty clearly…
Re 60.
“Prove it”, you ask (demand ?)
Well “prove” that we are due for an ice age anytime soon…
I’ll be a bit lazy and cut and pase from a Wikipedia article: Note the last line.
“We are in an interglacial period now, the last retreat ending about 10,000 years ago. There appears to be a folk wisdom that “the typical interglacial period lasts ~12,000 years” but this is hard to substantiate from the evidence of ice core records. For example, an article in Nature [2] argues that the current interglacial might be most analogous to a previous interglacial that lasted 28,000 years. Nonetheless, fear of a new glacial period starting soon does exist (See: global cooling). However, many now believe that anthropogenic (manmade) forcing from increased “greenhouse gases” would outweigh any Milankovitch (orbital) forcing; and some recent considerations of the orbital forcing have even argued that in the absence of human perturbations the present interglacial could potentially last 50,000 years.”
Besides for more detail please see…http://www.sciencemag.org/cgi/content/summary/297/5585/1287
Furthermore, if there was ever ever any “imminent danger” of sliping into an ice age (for instance an observed sustained high-latitude cooling trend or something like observed wide-spread glacier growth for a change !). Then a suitable deliberate injection of GHGs could be called for and would be well within our power to pull off. That is, unless you think ice ages descend overnight or something.
Dave
Right so no evidence from the campaign against warmer winters for the Siberians. Wiki is no evidence. Since the global warming fraudsters have their section locked down. And have even gone so far as to confuse ice ages with glaciations to mislead the public.
Now for this science article:
“CLIMATE:
An Exceptionally Long Interglacial Ahead?
A. Berger and M. F. Loutre
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.”
Notice that there is a question mark in the very title of the article!!!!. So this glib confidence is competely without merit. The article itself implies the following.
The article assumes that glaciation MAY NOT occur with or without human-produced CO2. Right there we have something entirely implausible. One imagines the writer has miquoted the researchers. I’d accept the ….may not occur WITH human CO2 but the idea that we wouldn’t start icing over without it is foolish. Since the ice always oscillates back and forward and the fact that this cycle is milder would only make the ice grow more slowly.
In summary the level of certitude that this new Mantra is conveying is without merit. The burden of proof is on you guys not me since we know the norms of the climate over the last 3 million years and the norm is for us to be in catastrophic iced over conditions. If something has changed you would have to prove it. Mostly its the irrational level of certitude that I object to here. As if a single article written in the last few years is completely decisive.
Over the long haul the heat deficits/surpluses conveyed by the Makinkovitch cycles sooner or later registered as an increase/decrease in the amount of ice. If that’s changed then the evidence for the change is something that’s been a little hard to track down.
There is another very strange focus going on and that is the focus on average ground air temperatures. We have Buckleys chance of putting that together for thousands of years ago. Its hard enough to sort such a thing out today. We ought to be thinking in terms of the total energy retained by the system. The level of ice being a pretty good if delayed barometer for this.
If this is the focus then it may add an argument for the other side. Though air temperatures have increased only marginally this does not mean there hasn’t been a lot of “global warming”. Since the melting of ice implies a massive retention of extra Joules. Either right now or as a delayed reaction to extra Joules retained in the past.
So how about cutting out the absurd statments of certitude and try and gather evidence and let the chips fall as they may. As things stand we have to assume that the ice could start moving the other way on us at any time. The slightly less severe nature of the cycles this time round does not alter that unless it can be shown that the CO2 will (mercifully) overide.
Re 66.
Your position is a bit like sitting in your house on a warm day in July (in the NH)
knowing that winter will eventualy come so we should have the heat turned up now.
Within 100 GHF levels have the potential to cause us alot of nastiness. On the other hand, within the next 100 yrs you can not seriously argue for the glaciers starting to march forward. Just what type of mechanism would be behind such a thing ?
re: 66. Once again you talk about “proof” after it has been clearly explained to you what the scientific method is about. To repeat, “proof” is mathematical. Simply repeating your statement does not lend itself to any valid “proof” that it is true. The overwhelming evidence, data and modeling, in fact, show that the scientific conclusions that have been reached are valid with a very high degree of likelihood. That is how the scientific process works. And has always worked.
D.
Dan:
You are in no position to lecture me on the scientific method. I want evidence not proof. You have not brought any forward.
David:
“Within 100 GHF levels have the potential to cause us alot of nastiness.”
No that’s incorrect. CO2-based warming can only be benign (at the very least until all the ice is melted). We would expect to have more arable land, more rainfall, less extreme weather events, greater access to untapped resources and greater crop yields.
” On the other hand, within the next 100 yrs you can not seriously argue for the glaciers starting to march forward. Just what type of mechanism would be behind such a thing ?”
Wrong again. This is the default position until we know that CO2 will overide. I think it probably will overide but I don’t know and your lack of evidence suggests that neither do you. The mechanism would be the same as for all ice build-ups and declines. The Malinkovitch cycles of course.
Supposing we had a thirty year drop-off in solar activity. This could easily combine with the cycles to kick the march of glaciers off. This is a serious risk whereas overheating is not a serious risk at all. Can you think of any time that you know for sure the planet was too warm? Not for sure and not in the last 100 million years right? Its a bit like being too rich.
People are acting like economic forecasters who have the habit of merely extrapolating what’s going on now into the future. But things can turn bad for us at any time. A few very cool Northern Summers and freezing Southern Winters and you guys will be predicting doom on the glacial side and demanding money.
re: 69. Excuse me? Yes, apparently I am in the position to “lecture” you on the scientific method since you are clearly not aware of what it means or what the process is. Either learn about it or stop repeating the same mantra with nothing to support it. Furthermore, you specifically asked twice for proof and now say you did not? Let’s see, from your post 60: “Prove it.” From your post 66: “The burden of proof is on you guys…”. Gee, there’s that “proof” word again.
Again, for the third time (sigh!), 1. “proof” is mathematical, case close. And 2. the scientific evidence is absolutely overwhelming. For starters, read the IPCC reports for evidence. Goodness, there are probably thousands of studies by climate scientists that are readily available for your persusal. Studies that are based on hypotheses, evidence gathering, testing, and repeatability. In other words, the scientific method. You now change your tune and ask for “evidence” as opposed to “proof”? Well, there it is. You can easily find the links on the internet. All those studies are based on evidence.
D.
“Excuse me? Yes, apparently I am in the position to “lecture” you on the scientific method since you are clearly not aware of what it means or what the process is.”
You are not excused since you are repeating the unfounded allegation as if you have the power of second site or mind-reading. I know what the scientific process involves. And no global warming fanatic is guilty of it. Let us see some evidence.
The question is “What will win out”. Since the natural tendency is toward glaciation and the extra CO2 is going the other way then this is a quantitative matter. The articles written by global alarmists seldom seem to do no more then state opinions. We want to see which competing force wins out. Which means estimates of Joules added by CO2 and Joules subtracted by the cycles turning South on us.
The other thing is if CO2 wins that is a good thing indeed. And still no cause to waste money on your petty fears.
Dear “Lord”
“No that’s incorrect. CO2-based warming can only be benign (at the very least until all the ice is melted). We would expect to have more arable land, more rainfall, less extreme weather events, greater access to untapped resources and greater crop yields.”
Ya want to present some “proof” of this ? There will be winners and losers as things change…But note: Unthawed Tundra does not become useful land overnight. More extreme events are forcasted…not less ! Greater crop yields ? Not in any of the papers I have seen. Unfortunately inceased CO2 levels do not autimaticaly mean more plant growth. Also, do not forget about sea level rise.
Here in the Netherlands our own reginal climate model work shows we will have problems with sea level rise, wetter winters but dryer summers. Its going to make water level managment here tougher than it already is ! On the plus side we will likely have more good beach days along the North Sea…if the beaches can be maintained against possible increased erosion.
“Supposing we had a thirty year drop-off in solar activity. This could easily combine with the cycles to kick the march of glaciers off. This is a serious risk whereas overheating is not a serious risk at all. Can you think of any time that you know for sure the planet was too warm? Not for sure and not in the last 100 million years right? Its a bit like being too rich.”
The paleoclimate records do not support anything like you are saying. Take a look at some of the links that can be accessed through this site.
“People are acting like economic forecasters who have the habit of merely extrapolating what’s going on now into the future. But things can turn bad for us at any time. A few very cool Northern Summers and freezing Southern Winters and you guys will be predicting doom on the glacial side and demanding money.”
1) Unlike economic forecasters we have valid physical theories to base our models on and better and better observations to test them with.
2) The rest is a bit much seeing as you are the one seeming to hold the alarmist view that if we ever stop pumping up the GHG levels that we are all gonna freeze without warning !
“More extreme events are forcasted…not less ! ”
They are forecasted in error if they are assuming CO2-based warming. This should be blindingly obvious.
“Greater crop yields ? Not in any of the papers I have seen.”
For goodness sakes then. Read some more papers. But by Jove I thought this was common knowledge. What does it take to maintain such ignorance?
http://www.co2science.org/scripts/CO2ScienceB2C/Index.jsp
“Unfortunately inceased CO2 levels do not autimaticaly mean more plant growth.”
Dead wrong. How could you be so wrong. Amazing!
” Also, do not forget about sea level rise.”
A small problem in the wider scheme of things.
These studies that you refer to. They pretty much amount to an internet assertions tsunami. Where is added Joules from CO2 contrasted against reduced Joules from Milankovitch?
Nowhere. Which shows how political and unscientific the subject has become.
This very thread shows the war of Joules. The warming in the Mid-Troposphere is almost definitely a CO2 based phenomenon. And its right where you would expect it to be. Mid-Tropsophere. Because the extra Joules accumulate all over the globe at the top of the Troposphere (or at the bottom of the Stratosphere) and so you would expect the extra warmth, by the time it reached the Antarctic to be where it is. Alternatively it might be the result of extra snow due to extra precipitation off the warmer oceans, indirectly itself a result of global warming.
But there is a war of Joules going on. Because what this threads article did not emphasise is that the radiation in this area is reducing in the Winters. So more warmth from one source. Less warmth from another.
Show me the study where the maths is done to see which force will dominate the war of Joules.
re: 71
Based on every post you have made in this thread, you have not shown any evidence whatsoever that you know the scientific process at all. In fact, quite the contrary. I find that quite sad since you have the opportunity to learn more through your own research on the web of peer-reviewed science.
To continue to repeat your mantra, after you have been given specific references (e.g. the IPCC report) in response to your request, is nothing less than intellectual dishonesty. For the last time, the studies are based on gathered data, i.e. evidence. They are repeatable. Thus they follow the scientific method. The apparent fact that you do not understand the scientific method does not mean that they do not follow it.
Finally, talk about “mind reading”: “my petty fears”? After investigating the “scientific method”, please check out “hypocrisy”.
D.
re #73 etc.
Your question is taken up at
http://amper.ped.muni.cz/gw/articles/html.format/orb_forc.html
(Google is your friend.)
See also
http://en.wikipedia.org/wiki/Image:IPCC_Radiative_Forcings.gif
“Joules subtracted by the cycles turning South on us”
are zero, global average. That is why this forcing doesn’t appear on such charts.
The Milankovic cycles only redistribute where the solar energy hits the earth. The consensus is that glacial cycles are driven by continental glacial growth which is kicked off by weaker summer insolation due to changes in fine details of the earth’s orbit.
The forcing numbers LOCALLY are large in the high latitudes, ten or twenty watts per square meter, so LOCALLY the glacial forcing would be cancelled out, if we were in a period where an ice age would be likely. However, even then the high latitudes would be in a context where the rest of the world was substantially warmer than normal. So even with an orbital configuration VERY favorable for ice sheet growth, which would win, which amounts to whether new glaciers would form on the North American landmass, is not a slam dunk.
But the orbital configuration, it turns out, is not favorable, as the Czech astronomer explains.
Anyway, the empirical evidence is pretty overwhelmingly against your suggestion at this point. Since ice is retreating everywhere except possibly the deep interiors of the two great ice caps, glaciation is clearly not in any danger of kicking in right now, purely on observational evidence. And global warming is just starting. We have decades of increase in greenhouse gas and decades of ocean thermal lag ahead of us.
In short
1) it isn’t time for a glaciation
2) ice is retreating everywhere already
3) there’s plenty more greenhouse warming in the pipeline
so your point is decidedly moot. If we were going into a period of very low high-latitude summer insolation it might be a practical question.
“They are forecasted in error if they are assuming CO2-based warming. This should be blindingly obvious.”
Huh ?
“” Also, do not forget about sea level rise.”
A small problem in the wider scheme of things.”
Not where I stand ! (Currently about 1 meter below current sea level)
Re: CO2 ferilization:
I don’t think its all as rosy as painted by the (seemingly one sided) material from the CO2 science site. Please see:
https://www.realclimate.org/index.php/archives/2004/11/co_2-fertilization/
“These studies that you refer to. They pretty much amount to an internet assertions tsunami. Where is added Joules from CO2 contrasted against reduced Joules from Milankovitch?”
The orbital parameters are well understood enough to know that within the next few 1000’s of years no orbital induced forcing is going to bring about an ice age. Go to your local university lib and look at a copy of something like “An introduction to Atmospheric Radiation”, 2nd Ed. K.N. Liou, Int. Geophys. Series Vol 84 for a start. Check out the IPCC material also.
You miss (or resuse to accept) the key point that. The rate of change of the Milankovitch type forcings just does not occur at anything like the anthro GHG forcing we are now applying.
I’ve got to try to sleep now…hate insomina….
Dear Lord, a.k.a. Graeme Bird,
you certainly have a lot to offer on the next glaciation and the wonders of accumulating CO2; good for plants (to a point, then not) curbing the glaciation habit (way too fast for my way of thinking and particularly for the farmers in Northern India and Bangladesh.
And,
I came upon a few interesting contributions to the Mises Economics Blog of April 2, 2006..about the time the Lord showed up at RealClimate. Do you recognize the following exerpts?
It read in part,
So in the interim the ice oscillates back and forth. So if we could have magically melted the ice by 70 000 years ago we likely wouldn’t have had much in the way of catastrophic glaciation in the interim.
And likewise if capitalism does this for us and we get through the next 10 000 years we should be home free.
There is a limit to this BANK OF COLD model. The ice isn’t ever going to get near the equator. And if it was all melted and the oceans warmed one would expect the amount of heat radiated off to increase. So such a model can only go so far and be relevant to some degree.
But it ought to be good enough to say that if one is coming up to the danger time period then its helpful to get all the ice melted off in advance.
Posted by Graeme Bird at April 2, 2006 01:12 PM
Sound familiar? Then, a next post on Mises Economics Blog at the link below…copy it to the address box. It worked for me.
Forget proofs Tom. Evidence would be nice. And its evidence that CO2 release will overmatch glaciation that we are after. Lets not change the subject.
How do you like this for an essay title?:
CO2. LORD OF CREATION.
Posted by Graeme Bird at April 2, 2006 09:01 PM
http://72.14.203.104/searchq=cache:ZK6yyJYxWEYJ:blog.mises.org/mt/comments%3Fentry_id%3D4842+%22Graeme+Bird%22+AND+climate&hl=en&gl=us&ct=clnk&cd=4&ie=UTF-8
Lord Graeme, if it is not too much of a bother, would you provide some references of your evidence. They will help this reader.
And, did we catch Graeme Bird with his radar detector on?
John McCormick
“What does it take to maintain such ignorance?
http://www.co2science.org/ …”
Yep. Industry funded sites that publish opinion/PR. See instead the peer reviewed journals recommended to you above.
As Mr. Reagan said — trust, but verify. Always read the footnotes and look for new science on the subject. Google Scholar and PubMed will help; any good reference librarian will help much more. The Internet is not your best source for reliable info.
Check the list of the coal companies’ recommended sources
http://www.lignite.com/Links.htm
Read some history — here’s a decade ago, sound familiar?
http://www.ucar.edu/communications/quarterly/summer96/insert.html
“What does it take to maintain such ignorance?
http://www.co2science.org/ …”
Yep. Industry funded sites that publish opinion/PR. See instead the peer reviewed journals recommended to you above.”
Right. I asked the question and right there you show us just how indeed this level of ignorance is maintained. Its anti-capitalist bigotry ehanced ignorance. The fact is it doesn’t matter who finances the site. CO2 has always and will always improve plant yields. It is afterall what plants breathe.
Michael Tobis. That study from Jans Holland looks like what I was after. But don’t you suspect some sleight of hand here?!!!. I mean we get this regular cycle of glaciation and now he’s saying that all of a sudden they’ve stopped for 620,000 years. Lets not be too gullible here. What we really want to find is where he’s put the trickery into it. Why is he for example mixing up data from actual bases with estimates of how the Malinkovitch cycle will go.
But yes that is the kind of thing I’m after. Have you got any more?
Michael Tobis sez:
“1) it isn’t time for a glaciation
2) ice is retreating everywhere already
3) there’s plenty more greenhouse warming in the pipeline”
Excellent news if true. One hopes then that you and your crowd won’t be holding your hand out for government money given such a favourable outlook. One hopes you won’t be burdening business with regulations or taxation and scaring the small children given such a fortuitous outlook.
But to tell you the truth I’m unconvinced on number 1. As you can see above. Its a pretty hard ask to imagine that we go 20 plus cycles nearly all of them at 60 000 to 100 000 years for glaciations and nearly all of them 6000 to 10 000 years for interglacials and just as this scientific freakshow develops then someone finds out that we are suddenly due a 620 000 year interglacial..
20 cycles of 6 000 to 10 000
Then out of a clear blue sky a sudden 620 000 year break.
Yeah right.
Michael there is a few bridges I can sell you are cut price rates.
Ah, him.
re #80
Planetary orbits are well understood. If you would like to find fault with the graphs, do the calculations, or at least find someone else who has done them. Those are the rules. They’ve worked well enough in the past. Why should they fail now?
You are asking for a much bigger exception than that the glacial forcing is small. You are asking for the right to disbelieve any scientific evidence that doesn’t suit your purposes, without doing the work to refute it. And you are anticipating unlimited use of a scarce resource (a moderated discussion list) to promote your untested ideas.
You also say things like “our side” and “you guys” which constitutes prima facie evidence that you are taking some approach other than a scientific one.
This is not a high school debating club; this is the actual, real fate of the world we are talking about. Please get serious or go away.
There’s ample room for your sort of noise on usenet and numerous other open discussion lists. I don’t think the realclimate editors are under any obligation to let your postings through indefinitely.
Re #80 Ray, Gavin, et.al.
The votes are coming in. Please dump Lord Graeme into the Bozo Bin. Enough pollution.
We’ll recognize his spew when he tries to sneak in under the radar. Then, we can appeal to you to dump his next a.k.a.
Keep the conversation on track. Time and space are important.
John McCormick
re: 83. Absolutely. There is no excuse for beligerence, subsequent lack of apologies, and gross intellectual dishonestly from anyone who will not make an effort to learn the basics about the scientific process. Or who will not follow up on specific scientific references when they are provided to him.
Haight Ashbury street wisdom: “Never get into an argument on the street — passers-by see the mutually continued argument and won’t know or care that one of you is sane.”
From the troll FAQ (you know how to find it):
“… How do I know if I’m being trolled?… Generally, if you get the feeling that you simply have to respond, you probably shouldn’t….”
“The most important message of the Troll FAQ is …” read the FAQ.
Trolls don’t footnote.
As there is no question global temperatures change over time, as does precipitation, the current change (increase) in temperature is not unprecented except in speed. Considering a term often used is ‘interglacial’ and we are in an interglacial period, if we attempted to completely negate the influence of man on global climate, when would we return to an ice age in the northern hemisphere? Is an ice age, by natural causes to be preferred to global warming? Or do those who prefer to think man is the enemy also believe man can completely control the climate?
[Response: I’m not at all sure you’re right to say “the current change (increase) in temperature is not unprecented except in speed” (and even if true it wouldn’t be very reassuring). Current T’s are the highest we have good measurements for; its not at all clear that T has been higher, globally, any time during the current interglacial. As to the return of ice ages… without us, it would probably be 30kyr off (from astronomical considerations). “completely control the climate” is a strawman; and we have already emitted enough CO2 – William]
Re 86.
Even without anthro GHG emissions an ice age is a long way off…
The text below has been cut and pasted from http://www.aip.org/history/climate/cycles.htm (aip == Americian Institute of Physics, the well-respected Americian professional society for Physicists). It’s quite a good discussion looking at the history of the scientific undestanding of climate. I would recommend reading the whole thing.
“After 1988 =>after88
Looking at the rhythmic curves of past cycles, one could hardly resist the temptation to extrapolate into the future. By the late 1980s, most calculations had converged on the familiar prediction that the natural Milankovitch cycle should bring a mild but steady cooling over the next few thousand years. As climate models and studies of past ice ages improved, however, worries about a swift descent into the next great glaciation � what many in the 1970s had tentatively expected � died away. Not all ice ages were the same length, for the orbital elements differed in each. Improved calculations said that the next ice age would probably not reach its maximum for a few tens of thousands of years. [Ice core studies published in 2004 gave further evidence that a cycle like ours was likely to stay warm for many thousands of years].(53*)
The scientists who published these calculations always added a caveat. In the Antarctic record, CO2 levels over the past 400,000 years had cycled between about 180 and 280 parts per million. The level in the late 20th century had now climbed to 350 and was rising still. Greenhouse warming and other human influences seemed strong enough to overwhelm any natural trend. We might not only cancel the next ice age, but launch our planet into an altogether new climate regime. …..”
53. E.g., Berger (1988), p. 649; see Falkowski et al. (2000); Berger and Loutre (2002) discusses a long interglacial. The new Antarctic record of climate went back more than 700,000 years, through a previous cycle where the orbital elements had been similar to those in our own cycle. EPICA community members (2004). BACK
Cheers,
Dave