Guest commentary from Spencer Weart, science historian
Despite the recent announcement that the discharge from some Antarctic glaciers is accelerating, we often hear people remarking that parts of Antarctica are getting colder, and indeed the ice pack in the Southern Ocean around Antarctica has actually been getting bigger. Doesn’t this contradict the calculations that greenhouse gases are warming the globe? Not at all, because a cold Antarctica is just what calculations predict… and have predicted for the past quarter century.
It’s not just that Antarctica is covered with a gazillion tons of ice, although that certainly helps keep it cold. The ocean also plays a role, which is doubly important because of the way it has delayed the world’s recognition of global warming.
When the first rudimentary models of climate change were developed in the early 1970s, some modelers pointed out that as the increase of greenhouse gases added heat to the atmosphere, much of the energy would be absorbed into the upper layer of the oceans. While the water was warming up, the world’s perception of climate change would be delayed. Up to this point most calculations had started with a doubled CO2 level and figured out how the world’s temperature would look in equilibrium. But in the real world, when the rising level of gas reached that point the system would still be a long way from equilibrium. “We may not be given a warning until the CO2 loading is such that an appreciable climate change is inevitable,” a National Academy of Sciences panel warned in 1979.(1)
Modelers took a closer look and noticed some complications. As greenhouse gases increase, the heat seeps gradually deeper and deeper into the oceans. But when larger volumes of water are brought into play, they bring a larger heat capacity. Thus as the years passed, the atmospheric warming would increasingly lag behind what would happen if there were no oceans. In 1980 a New York University group reported that “the influence of deep sea thermal storage could delay the full value of temperature increment predicted by equilibrium models by 10 to 20 years” just between 1980 and 2000 A.D. (2)
The delay would not be the same everywhere. After all, the Southern Hemisphere is mostly ocean, whereas land occupies a good part of the Northern Hemisphere. A model constructed by Stephen Schneider and Thompson, highly simplified in modern terms but sophisticated for its time, suggested that the Southern Hemisphere would experience delays decades longer than the Northern. Schneider and Thompson warned that if people compared observations with what would be expected from a simple equilibrium model, “we may still be misled… in the decade A.D. 2000-2010.” (3)
The pioneer climate modelers Kirk Bryan and Syukuro Manabe took up the question with a more detailed model that revealed an additional effect. In the Southern Ocean around Antarctica the mixing of water went deeper than in Northern waters, so more volumes of water were brought into play earlier. In their model, around Antarctica “there is no warming at the sea surface, and even a slight cooling over the 50-year duration of the experiment.” (4) In the twenty years since, computer models have improved by orders of magnitude, but they continue to show that Antarctica cannot be expected to warm up very significantly until long after the rest of the world’s climate is radically changed.
Bottom line: A cold Antarctica and Southern Ocean do not contradict our models of global warming. For a long time the models have predicted just that.
(1) National Academy of Sciences, Climate Research Board (1979). Carbon Dioxide and Climate: A Scientific Assessment (Jule Charney, Chair). Washington, DC: National Academy of Sciences.
(2) Martin I. Hoffert, et al. (1980) J. Geophysical Research 85: 6667-6679.
(3) Stephen H. Schneider and S.L. Thompson (1981) J. Geophysical Research 86: 3135-3147.
(4) Kirk Bryan et al. (1988). J. Physical Oceanography 18: 851-67. For the story overall see Syukuro Manabe and Ronald J. Stouffer (2007) Journal of the Meteorological Society of Japan 85B: 385-403.
Seems to me that there is a fair chance of an ice-free North Pole this coming summer. That’s another milestone.
There was a 4 month long November in NW Europe (it still goes on). There was a constant flow of warm air from the Atlantic. Presumably it did not pile up at the North Pole. It got refrigerated crossing the dark zone (little cloudiness, lots of out-radiation) and moved then southwards. Perhaps the important feature was the stability of this flow feature.
Re #294/295 Guys, thanks for the comments. I have no doubt that future summer Arctic sea ice melt will be as severe as 2007 but it still stands that the contrarians are using the current NH cold winter for some to refute the arguments put forward by last summers climate scientists who were relating the story of sea ice melt that was 100 years ahead of schedule. Is this a freak weather event of part of a larger trend ?
If climate scientists want to state that summer 2007 thinnest sea ice was climate related and not weather then can they say that? James Hansen and James Lovelock are both talking about increased climatical +ve feedbacks that are not in the models or noticed in the paleoclimatic data (maybe). Remember the Earth has never had so much CO2 emitted in such a short space of time, there is not paleoclimatic equivilent to this speed of change although the systems responses will take time such as the oceans.
James Hansen is claiming a 350 ppmv CO2 level is required otherwise the planet becomes a different one. The IPCC’s work is good but conservative as science works by being skeptical and hence it takes a long time to know that you are right. It probably explains why the skeptics are still in the game.
The IPCC does not speak often enough on the subject, every 5 years is not frequent enough. James Hansen states that the data is out of date even before it is published.
#302, Pete, every cold snap, every snowflake triggers a contrarian attack, not to worry, the more they
write the more they look like a political party running for the post of media Climate (arm) Chairman. I’d like to add that they have a singular vu of the world, hell bent on misrepresenting climate as much as the environmental movement, which is largely very peaceful, ie Crichton’s book portraying
Environmentalists as crazed highjackers fits not the true recent image of Greenpeace activists placing a banner on top of a parked airplane at Heathrow airport. Climate is not simple, and requires some patience and a great zeal for exploration to understand it.
I read this article and, I am no scientist, but I feel that there’s some specious reasoning here. First climate models are given to us as the evidence for MMGW. Since when is a model evidence for anything? Would a model of any process be itself evidence for what will happen in the future in this process? I don’t see it, given that the point of the model is only to try to illustrate how a process works. The prediction of future behavior is only that, a prediction, and not quantifiable as “evidence”.
A model of,say, a satellite’s path is a good predictor of future movement when all factors are calculated in. But it seems strange to point to the model and say “Here is your evidence for the satellite’s future path”. So when one asks the MMGW people about evidence, it’s strange that they would simply use models.
So I’m holding out for real evidence that GW is MM. And I see only one way you could really ever provide it.
A model works as a good predictor only when the subject is no longer in dispute, and the model shows itself to always be accurate – the satellite is always right where you think it should be. As far as I can tell – despite consensus – this has not happened yet. If the models where complete then I could have an accurate forecast of the weather one year from today, could I not? Isn’t that the LEAST it should be able to provide before we go off saying we can forecast the temperature fifty years out? We can’t predict next March 2nd’s temperature with real accuracy because, as I understand it, the system is too complex to take what is happening today and extrapolate from it exactly what will happen next year.
Finally, I have to say that a warming trend that predicts cooling anywhere is another abuse of terminology – in this case the word “warming”.
I appreciate responses without ad hominem.
fflyod, you’re confusing weather and climate. Different models.
Try this: http://climateprogress.org/2008/02/11/how-do-we-really-know-humans-are-causing-global-warming/
“So I’m holding out for real evidence that GW is MM. And I see only one way you could really ever provide it.”
I agree that unnatural rates of GW (human induced or otherwise) is not yet proved, but given the predictions by scientist of what could happen were it to be true, and the sheer spread, volume and global dependency of our race, I think it’s incredibly irresponsible to take your chances.
As someone who isn’t a scientist, I think it would be wise to put your faith in those who know what they’re talking about. And most are n agreement that MMGW is real.
As a non-scientist, after reading all this, there is one thing I can say for certain:
Not one person on this blog KNOWS [sorry, no underlining] enough of all the variables to say what is going to happen.
There is obviously much we don’t know about how the oceans, land, sun, gases all interact. And it seems, about a thousand other variables.
“The wise man knows what he does not know.”
A little humility about future predictions might be in order.
Steve/Wayne Arctic,
I’d initially not viewed the Beaufort ice pack fracture as too much of an issue, I was more interested in it’s displaying the Beaufort Gyre. However now I see what may be a dispersing effect in the Beaufort Gyre due to lack of buttressing from Chucki and Beaufort seas. I’ve been looking at the latest image on the link Wayne posted to Canada Met Office, but I can’t get a historical perspective.
However Quikscat’s archive helps, http://manati.orbit.nesdis.noaa.gov/cgi-bin/qscat_ice.pl and that seems to show a lot of poorly resolved detail which looks like heavy fracturing for day 60 of 2008 and 2006 in the area N of Greenland to Banks Island. That said the Beaufort sea is much, much worse in 2008, and the ice seems to be being dispersed: which will make it more prone to melt(I think).
Zhang Rothrock and Steele’s pages at PSC are well worth checking out: http://psc.apl.washington.edu/IDAO/
Their model appears surprisingly good when compared with both Submarine and QuikScat. And the movie on that page “A movie of PIOMAS simulated sea ice thickness and satellite observed ice extent for summer 2007 ” is worth comparing to Quickscat for the end of October, (31/10/07=day 303). I fear Maslowski could be right.
But if I say any more I’ll spoil the post I’m working on for my usual haunt. ;)
#304, Floydo.
Models aren’t the clincher for me. What I see is stratospheric cooling, diurnal range trend behaviour and the mere fact of warming (substantial in terms of ocean heat content) when there’s no alternate explanation, then there’s the hundreds of primary peer reviewed papers I must have read. However the models are astonishingly powerful tools, and I take different results with different weightings to my conclusions.
You will never be able to predict weather 5 years in the future.
I’m afraid I view the matter of what is causing the warming as settled beyond all reasonable doubt – human activity, both land use change and emissions. You however are free to your opinion, I’m not here to persuade you: It’s a real physical process and frankly it matters not a jot what either of us think.
Well, Sgt., that’s why radically altering the atmosphere seems like a bad idea, now that we’re aware how little we know.
You wouldn’t have changed the filters on your gas mask, or the oil in your jeep, or the sights on your rifle, without knowing what difference it would make, now would you?
http://www.imdb.com/title/tt0034167/
Nor would your coal company be smart to change the planet’s atmosphere or ocean without knowing what would happen:
http://www.nature.com/nature/journal/v437/n7059/abs/nature04095.html
#308,Cobbly. would be good to see a later version of the same Quicksat, this will show ice fluidity, 2 well separated in time pictures gives a clue.
Sgt. York, You are indeed thinking about this like a nonscientist. What a scientist does is look at the physical system and determine what the important contributors are. In this case, we always knew that the early models of the ocean were inadequate, but they were all that could be handled computationally in their day. Upon putting in a somewhat more realistic model, the behavior of the models began to mirror what happened in reality–that’s science. Scientists analyse real systems to figure out which factors are most important. They then model the systems with the best models they can construct–i.e. those with all the most important factors included–and compare them to reality.
We need not know everything to make predictions with confidence. To abstract from recent headlines–if a person has been exposed to ricin, I do not need to know whether he has also been exposed to arsenic before I make a SWAG that he’s not having a good day.
I have been looking through the planetary temperature data sources. There does appear to be data which indicates global cooling. Is this significant?
This is a plot of planetary temperature anomalies, land and ocean (2003 to 2005 average Vs current.) There appears to be wide spread cooling. Is this change in temperature note worthy due to its magnitude, its rapidity, and to the extent of the cooling? The cooling seems to be affecting both hemispheres.
http://data.giss.nasa.gov/cgi-bin/gi…s=1200&pol=reg
This is a plot of ocean temperature anomalies only. I am not sure what the base is for this data but it also shows wide spread cooling.
http://www.osdpd.noaa.gov/PSB/EPS/SST/data/anomnight.2.28.2008.gif
The following is a link to NASA’s land + ocean by month temperature anomaly, summary.
http://data.giss.nasa.gov/gistemp/graphs/Fig.C.txt
Comments:
Based on the NASA Land + Ocean (Above Normal)
Average (2003 to Jan, 2008) = 0.55C (Above deemed normal.)
Global, Land + Ocean Temperature Jan, 2008 = 0.12C
The change in planetary temperature (ocean plus land) as compared to the five year average is = -0.43C (3.6 Sigma)
The data sources appear to show global cooling, which is consistent with regional meteorological observations. (i.e. Record snow fall, record cold weather and so forth.) What is causing this global cooling?
Re floydo @ 304: “I read this article and, I am no scientist, but I feel that there’s some specious reasoning here. First climate models are given to us as the evidence for MMGW.”
No, they are not, and this faulty assumption at the outset undermines your very understanding of the issue. The evidence for anthropogenic global warming is empirical, such as the steady measured increase in atmospheric CO2, and the also steady drop in atmospheric CO2 containing the radioisotope carbon 14. This means that the CO2 had to come from oxidizing carbon sources that are low in 14C. Because of how log ago oil and coal were formed, they are very, very low in 14C. This is just one example of the empirical evidence supporting the theory of anthropogenic global warming. Global circulation models, which are based on the known physics of greenhouse gases and the atmosphere, just help us understand what the possible and likely impacts of altering the atmosphere might be.
floydo: “Finally, I have to say that a warming trend that predicts cooling anywhere is another abuse of terminology – in this case the word “warming.”
Anyone who lives in the Great Lakes region understands very well how a warm winter results in more open water, which leads to higher snowfall, while a colder winter leads to more frozen over lake surface, which leads to lower snowfall. So it is with Antarctica. More snowfall does not mean it is colder, it means the opposite.
“fflyod, you’re confusing weather and climate. Different models.
Try this: http://climateprogress.org/2008/02/11/how-do-we-really-know-humans-are-causing-global-warming/
Comment by Hank Roberts — 2 March 2008 @ 2:36″
Yes, different models. And to me what seems to distinguish the two is that weather predictions are verifyable while MMGW climate predictions are not. Which is only to say that climate science is taken on faith!!
Mr. Astley writes:
> here does appear to be data which indicates global cooling.
> Is this significant?
Good question! No, it’s not significant (assuming you mean statistically significant). Look at the error bars.
A few questions to floydo, Sgt. York and all the people emphasizing uncertainties in our knowledge about climate change:
If you find unknown mushrooms in the woods, and somebody tells you it might be poisonous, will you take it home and eat it if there is nobody who can prove to 100% that it’s really poisonous? Or would you, perhaps, be cautious and wait eating until you know it’s safe?
If you wait in a train station and you see a lonely trunk near you and you hear something ticking inside, will you stay nearby, because there’s nobody who can really prove that it’s dangerous and it perhaps might be just harmless?
Why do many people react so strangely and completely inverse to dealing with danger and risk in everyday life when dealing with climate change?
314. floydo:
Actually not as different as you seem to think. They have a lot in common, like atmospheric physics and the general spatiotemporal modelling approach.
Have you noticed that numerical weather models are performing quite well nowadays? Even up to a week into the future. Each successful weather prediction over more than a couple of days validates the same code, physics, and math that’s also in the climate models. They contain largely the same ‘wisdom’ on how the atmosphere works, even if putting it to different use.
BTW one exclamation mark is plenty.
Re #312 (William Astley)
Seems La Niña sleeps around on this thread… remember the contraceptives, folks :-)
#310 Wayne,
I’m gradually downloading them at 10 day intervals, we’re up to day 63 now. Makes an informative slide-show. You can see the flow down towards the Fram Strait very nicely. I’ve also extracted the March and September hindcasts from the PIOMAS model video I refered to, but I need to do some viewing of those with the years mixed up to see if my suspicion is arguable – that the March 2 metre thickness contour could be used to predict the maximum extent in September – I stress I’m not convinced that is the case.
I’ve noted the brilliant presence of cities on the Quikscat plots, presuming this is due to radio reflectiveness. I’m wondering if Arctic ice movement could be tracked by using nets with reflectors (wires cut to the right length) pegged to the ice.
#312 William Astley,
At present there’s a La Nina which seems to be causing cooling (monthly anomalies took a down-turn in May June last year as the ENSO MEI index dropped). There’s also been a levelling of temperature increase before that for a few years (NOAA/CRU), which mainly seems to come from the Southern Hemisphere and that seems to broadly fit with Hadley’s DePreSys. There has now also been a notably cold winter in parts of the Northern Hemisphere.
Now to the bit I’ve dithered about posting for a while…
Due to the La Nina, I would strongly caution against concluding that the following effect is happening, however I have previously referred to a paper by Micheal Winton of GFDL, check out his homepage here: http://www.gfdl.gov/~mw/ The document is “Sea ice-albedo feedback and nonlinear Arctic climate change.”
In that paper, the Winton argues that models show that atmopsheric heat fluxes will not stand by in the event of a transtion to a seasonally ice-free Arctic state i.e. as the Arctic warms heat fluxes reduce in the models. He says that ‘the elimination of Arctic ice would impact the local environment but the models studied don’t show it would have larger scale climatic changes’. Crucially the models do not show step jumps in the long term average ratio of polar/global temperature. Yet in his figure 5 (Atmospheric Heat Convergence) discussed page 15, the implication is that atmospheric heat transport will reduce in response to Arctic ice loss (assuming the models are correct of course). So I’m wondering if the absence of larger scale temperature changes purely relates to temperature as the index, because if one considers atmospheric circulation surely a reduction in heat transport would have circulation impacts outside of the immediate Arctic region? Other research such as that summarised by Serreze et al 2007 shows Arctic ice has a wider role in Northern Hemisphere climate.
It’s been said before here and elsewhere that the current La Nina may be modified-by an atmospheric impact of the severe reduction of Arctic ice thickness and summer extent. I don’t know if we are seeing the result of reduced Arctic fluxes – I’d need access to a historical synoptic polar dataset to see if this could be argued. As I’ve not studied that region until recently, once again I lack the historical context in which to view current events.
Floydo says: “Yes, different models. And to me what seems to distinguish the two is that weather predictions are verifyable while MMGW climate predictions are not. Which is only to say that climate science is taken on faith!!”
They only need be taken on faith if you remain too ignorant to understand the science. Once you understand the science, the models are not only verifiable, but largely verified–as evidenced by the fact that every notable scientific body and professional society that has taken a position on the subject has backed the consensus science. Why not learn it?
Studying the Hadcrut3v series from the Hadley Centre, it would appear that we have just experienced the coldest January in about 15 years. In fact it deviated by -0.42 from the average January temperature variance over the previous 5 years.
I obviously know the arguments about extrapolating from such a tiny data point, but it does appear to fit into a trend of gradually declining global temperature variance seen since 2002. Even if we assume the rest of the year is at the average for the last 10 years, the unusually cold January will make 2008 the coldest year since 2001. It will also mark a decade since the earth’s hottest year, 1998, during which period the earth has cooled rather than warmed.
Now if we are going to get the predicted 2.5 degrees celcius rise in global temperatures for the 21st Century that has been predicted by many models, surely we should start to see a more obvious decade on decade warming trend than we are currently seeing?
Or is what we are seeing just “random variation” and that you cannot see global warming even over a decade of data. In which case, over what time period would the random “noise” be cancelled out and a general trend become more obvious?
If you were to say 15 or 20 years our problem then becomes that we simply have not been measuring global temperature long enough to reliably discern any kind of long term trend.
In which case we have to rely totally on the accuracy of the various climate prediction models when determining our climate change mitigation policies and ignore the actual measurements for about another 50 years or so until we have enough data to determine a real long-term trend.
Am I the only one who finds this a bit alarming? In what other area of our lives do we rely totally on scientific prediction when determining such major areas of policy?
Don’t get me wrong I am not a climate change denier. I went to the Hadley Centre site to find data to support the AGW case against a sceptical friend. However it would appear that the empirical record shows much more random variation over long timescales than I expected to see.
How do we know that the global warming “spike” of around +0.8 (variance) seen since WW2 is not simply a random flicker of noise in a much more long term global temperature trend? That is a genuine question, by the way – this is not a troll, I am genuinely puzzled.
[Response: Please read https://www.realclimate.org/index.php/archives/2008/01/uncertainty-noise-and-the-art-of-model-data-comparison/ – gavin]
As a lay person, the differences between climate models and weather models can be perplexing.
On Floydo’s point, if one were to ask the climate models at the annual pageant what the high temperature would be at the next years pageant, what sort of answers would come out of their ditzy little heads?
[Response: You would get a spread associated with the unforced variability in the global mean temperature – roughly a standard deviation of 0.15 deg C on top of the very small yearly increase in the long term forced trend (0.02 deg C). So the 5-95% range for next years anomaly would be something like -0.28 to 0.32 deg C (relative to some recent baseline). Note that for a proper forecast you’d need to assimilate the past changes in temperature which is something that the climate models in AR4 didn’t do, but is starting to be done more often. – gavin]
Re floydo @ 314: “Yes, different models. And to me what seems to distinguish the two is that weather predictions are verifyable while MMGW climate predictions are not. Which is only to say that climate science is taken on faith!!”
Oh dear, you really are hung up on this idea that anthropogenic climate change depends on model predictions, aren’t you?
A question for you: Is it the models themselves that you object to, or the atmospheric and greenhouse gas physics that they are based on, or the actual measured and observed phenomina?
First off, global circulation models do not make predictions of MMGW, as you insist on putting it, rather, they predict a range of expected climate changes for a specified change in initial conditions, regardless of whether those changes are caused by human action or by natural effects.
Second, those predictions most certainly are verifiable, in exactly the same way that short term weather predictions are, by simply comparing the predicted range of outcomes to what actually happens. It just takes longer to do than with a specific short-term weather prediction.
For example, a random explosive volcanic eruption was included in the early models, and the effects of the eruption predicted by the model, namely a short-term reduction of sunlight reaching the surface and consequent cooling due to the injected volcanic particulates and aerosols, matched the observed and measured effects of the 1991 Mt Pinatubo eruption. Another prediction was that while increasing greenhouse gases in the atmosphere will warm the troposphere, the stratosphere will cool. Again, this is what has been observed and measured.
To quote Hank Roberts, who is fond of saying: What do you base your opinion on, where do you get the information to form that opinion, and why do you trust that information?
#319 Cobblyworlds:
That would be corner cube reflections from the inner corners of buildings, they produce bright spikes in radar images.
Your netting proposal probably wouldn’t give back enough power, but using aluminum sheet corner cubes of the kind suspended under weather balloons would have a chance of success. They could even be air dropped.
Significant Warming of the Antarctic Winter Troposphere
Classé dans: Arctic and Antarctic Instrumental Record Climate Science— william @ 3:17 PM
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.
Not at all, because a cold Antarctica is just what calculations predict… and have predicted for the past quarter century.
Warming? Cooling? Anyway its good talking about Antarctica and model predictions
floydo,
As a fellow layperson, may I recommend either of Mark Bowen’s last two books, Thin Ice and Censoring Science? By reading these profiles of Lonnie Thompson and Jim Hansen, you’ll see how both the physics and empirical data bear out the GCMs. If you’re like me, you’ll begin to appreciate (at an elementary level) the beauty and elegance of current climate science.
Don’t worry about the models, for now. Read these histories and see where your thinking goes.
#324 Martin Vermeer,
Thanks for that Martin, cubes would be less attractive as with a higher profile they’d be at the mercy of the winds. Also the cost would probably be higher(although that would probably still be the smal when compared to installation). What made me think about it were some wire-on-netting dipole arrays I once had cause to build.
Ooops! My post #319 single quotes ” are paraphrases, posted from work – no access to that paper there.
#319 Cobbly, would be nice to see! About the surface cooling in North American side of the Pole, its not surprising here, given remarkably consecutive days of clear air ( a lot of work for me), is not Lindzen’s Iris effect, especially not cosmic rays which calls for more clouds at a solar minimum, the opposite is happening in North America’s side of the Pole, it is rather a tandem of systems (la Nina, thin Polar ice) creating remarkably steady planetary waves causing ripe conditions for clear air to occur at key locations. NE US coast was/is in continuous flow from the Southwest just as well, right now I marvel as to how steady, how predictable weather seem to manifest. If this keeps up, spring is easily foreseeable clear cold air with the coming high sun will turn into clear warmer air over the Arctic like during last years great melt (NAmerican side), NE US Coast will have much warmer continuous flows etc….
Re #308: Thanks, CW. Interestingly the PSC model projections went off the rails last summer along with everyone else (with the possible exception of Maslowski). It wasn’t just that they didn’t show such a sharp drop anywhere near so soon, but that the pattern of melt was so different. They don’t show the northern (easily navigable) NWP as open until something like 2040, making it some of the last ice to go. Consistent with that they show a general pattern of melt starting on the Siberian side and ending with the Canadian archipelago rather than working in from the Bering Strait region as we saw last summer. Is the difference Maslowski’s encroaching warm water? We shall see very soon.
Re #319: CW, when Winton says “the elimination of Arctic ice would impact the local environment but the models studied don’t show it would have larger scale climatic changes,” my first thought is that the northern GIS is very much local. My impression has been that this is the big climatological concern with regard to the sea ice melting (not to belittle the direct ecological changes and coastal effects such as enhanced permafrost melt).
In response to my comment:
NASA land + ocean temperature drops -0.43C, Jan, 2008. 3.7 sigma. (one sigma is .12C).
Is a -0.43C drop in planetary temperature significant?
https://www.realclimate.org/index.php/archives/2008/02/antarctica-is-cold/langswitch_lang/sw#comment-82020
Hank Robert’s comment #315 said:
>Good question! No, it’s not significant (assuming you mean statistically
>significant). Look at the error bars.
Hank, are you saying a -0.43C drop in land + ocean temperature is not significant?
Are you saying the data is incorrect? What error bars are you talking about?
http://en.wikipedia.org/wiki/Image:Standard_deviation_diagram.svg
Have you noticed that the solar magnetic cycle appears to have been interrupted? There are papers and current observations to support that statement.
How much and how quickly would the planet cool if there was a solar magnetic cycle interruption?
Others how made comments stating the planetary cooling of -0.43C was due to La Nina. What is causing the abrupt cooling of the ocean? Is this La Nina unusual? (See meteorologist’s comments)
http://global-warming.accuweather.com/2007/12/historic_la_nina_could_be_in_t.html
Witnessed and answered.
https://www.realclimate.org/index.php/archives/2007/04/ocean-cooling-not/
> what error bars?
Well, you can look those up easily. But for example, the green I-shaped bars on this chart are the uncertainty estimates:
http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif
“Global Annual Mean Surface Air Temperature Change
Fig A2 Line plot of global mean land-ocean temperature index, 1880 to present. The dotted black line is the annual mean and the solid red line is the five-year mean. The green bars show uncertainty estimates….. (Last modified: 2008-01-11)
Source: http://data.giss.nasa.gov/gistemp/graphs/
————–
Note the range of error is larger the farther back in time you go.
Re 331
From NOAA, sunspot cycle forecast of March 6, 2006: The scientists expect the cycle to begin in late 2007 or early 2008.
Forecast of April 2007: http://www.swpc.noaa.gov/SolarCycle/
At the moment, we are still right in the line of the forecasts, which expect the next cycle to be about similar than the last one. We still have to wait a couple of months more until we can say that the sun is out of the ordinary.
Considering that the temperature difference between the Maunder Minimum and the mid-20th century is in the order of 0.5-1.0 K (depending on the reconstruction), and that it is likely that about half of the cooling at that period is due to volcanic activity, a totally quiet sun will induce a cooling in the order of about 0.2-0.6 K. If neglecting further greenhouse warming, this would lead us at most back to 1950s,1960s values. More likely, it might just outweigh upcoming greenhouse warming for some time. And give us a nice temperature jump when the sun is back. If the sun really will keep quiet…
William Astley cites an irrelevant post by a weather man. Brett Anderson’s bio-blurb on the page says:
“Senior meteorologist with 18 years of experience at AccuWeather.”
To which I would add: “…and no understanding of physics.”
#331 William Astley,
Your last link above (an article from December) seems to imply an almost unheard of La Nina and starts off claiming to be a problem for AGW theory – yet doesn’t deliver! CFS continue to forcast a level LN continuation, and NOAA’s Multivariate ENSO index doesn’t suggest anything exceptional in either timeseries (fig 1) or comparison (fig 2). http://www.cdc.noaa.gov/ENSO/enso.mei_index.html
#329 Steve,
The Greenland Ice Sheet’s northern flanks will be a place to watch if current events are part of a non-linear transition to a new regional regime – a seasonally ice free Arctic. If this is a non-linear transition I would not expect it to be predictable at all. If a model correctly predicted the weather events of last year and so predicted the subsequent crash it’d be good luck, i.e. predicting the effect of last year’s weather on the ice-cap would be within the domain of ice modelling, but predicting the weather itself may not be. There’s a paper (by Bitz I think) that mentions weather having a greater impact on a thinner ice-cap. That understanding of weather “taking advantage of” the reduced ice thickness certainly ties in with my understanding of perennial ice being a stabilising (integrating) influence. And I suspect this year we will see less total volume together with ice-albedo feedback’s ~60% increase of absorbed shortwave over-riding any weather effects.
However what I’ve been trying to get my head around is what the consequences will be in terms of Northern Hemisphere circulation. For me all this talk of Polar Bears and regional ecology is not the biggest problem! There seems to be a real risk of changes that could impact climate south of 65degN. However as far as I can see there hasn’t been a modelling study investigating this scenario. As I’ve said before the Arctic going ice-free in 2070 after a great deal of global warming is not the same as an early loss of Arctic ice. And as we’re not talking about a problem that’s analysable in terms of superposition it’s impossible for an amateur like me to get anything meaningful from studies incorporating ice-cap changes into projections of mid-late 21st century climate change. I’m reading a lot of papers on the Arctic at present, perhaps I’ll find something relevant.
#328 Wayne,
My PC is ageing and losing function on the ‘net as time passes and I need to get a new one. The problem is a combination of frozen salary (economic situation) and long hours at work. The result – I can’t use my Flickr account, and can’t even e-mail now! So right now I can’t post any of that on the ‘net.
Can you (or anyone else) point me to a source of synoptic current weather conditions from a polar view?
I’m amazed at the good timing of IPY – one might almost suspect… ;)
In reply to Urs Neu’s #334.
>At the moment, we are still right in the line of the forecasts, >which expect the next cycle to be about similar than the last one. >We still have to wait a couple of months more until we can say >that the sun is out of the ordinary.
The forecasts that you noted are not valid if the solar cycle was been interrupted. Is the sun “out of the ordinary”, based on the evidence?
Urs, Cycle 23 was forecasted to end March 2007. The start of cycle 24 was extended to March 2008. The sun is currently spotless. The solar conveyor (term for the massive movement of plasma about the sun has slowed down by 70%.) There were 37 x-flares generated at the end of solar cycle 23 as compared to none for cycle 21 and 22. Each of these observations is consistent with an interruption at the region (tachocline) of the sun were the sunspot magnetic ropes are formed. The magnetic ropes float up through the solar convection zone to the solar surface, where they form sunspots.
This article notes the slow down of the solar conveyor. http://science.nasa.gov/headlines/y2…_longrange.htm
In addition there was analysis that predicted a change of the sun to solar magnetic minimum.
There were three recently published papers that predicted a solar magnetic cycle change to a Dalton or Maunder like minimum, for cycle 24: one analyzed on past solar barycentre motion which correlates with deep solar magnetic cycle minimums, a second based on an analysis of the paleo cosmogenic isotopes (again that correlate with deep solar cycle minimums), and a third based on a physical model.
The following is the 2004 paper that predicts the sun is heading towards a Maunder minimum based on an analysis of the paleo record of solar activity.
http://adsabs.harvard.edu/abs/2004ApJ…605L..81B
This the 2003 paper that predicts a solar cycle minimum based on a physical model.
http://adsabs.harvard.edu/abs/2003SPD….34.0603S
This is the 1987 Solar barycentre motion paper: Prolonged minima and the 179-yr cycle of the solar inertial motion by R.Fairbridge and J. Shirley
http://www.springerlink.com/content/w57236105034h657/
The solar barycentre motion theory hypothesizes that specific motions of the sun about its barycentre, interrupts the formation of the magnetic ropes at the solar tacholine (Tacholine is the interface to solar radiative zone and convection zone.) With the barycentre hypothesis a Maunder minimum is an interruption to the solar magnetic cycle as opposed to a slow down.
In reply to Cobblyworlds.
See the note at the end of your link. It seems to confirm the observation by the professional meteorologist.
http://www.cdc.noaa.gov/ENSO/enso.mei_index.html
“Therefore, a comparison figure of the seven biggest La Niña events since 1949 is shown above, with the most recent MEI values included as well. Although previous strong La Niña events got off to an earlier start, the present La Niña came on so strong so fast that the MEI almost caught up with the ‘pack’ of historic events.”
I have noticed that the sunspot activity is extremely low. NASA’s Hathaway noticed the slowing of the sun’s “conveyor belt” and predicted that the next sunspot cycle would be very low and that he had never seen such a slowing of the conveyor belt before.
http://science.nasa.gov/headlines/y2006/10may_longrange.htm
As for this current cycle there were competing claims. Some projected very intense sunspot activity and others projected very low activity. Judging by the current lack of sunspots it looks like the projections for a quiet sun were correct.
I find this exciting. The best competing theory for the current warming is solar activity. The solar folks however lacked a well understood mechanism to explain current warming. However if we get 20 years or more of low sun activity it will provide a natural experiment for us to observe. If it coincides with a cooling trend, then the solar hypothesis will gain respect. If not then the CO2 hypothesis will become more strongly supported, leaving its last competitor in the dust.
The barycentre stuff is just wacky. It’s astrology in drag.
Likewise Piers Corbyn. http://www.google.com/search?q=stoat+corbyn
So is the Marohasty blog that was hyping that stuff.
One of the scientists whose paper they were misrepresenting showed up and told them they had it backward. The last post says:
“… I’m highly surprised by this blog. It’s citing one of my papers (Abarca del Rio et al., 2003) where it is said exactly the inverse of what is said herein. In fact we showed that there was not a true relationship between solar activity, atmospheric angular momentum and length of the day, at these time scales (interannual time scales) …Not a sole one. Even the one which was the more believed, the one related with the decadal time scales, is only coincidental. I do not know if at longer time scales it is true, but at least in the cases which we investigated, the linear relationship investigated over more than a century, was coincidental.”
Thereafter all is silence.
… jennifermarohasy.com/blog/archives/002234.html
#338, William Astley,
How does it support the claim that the current LN is “looking more and more like an event that may make history.” as Joe Bastardi asserts.
Then again what is one to make of the statement: “The fact is the warmer it gets the harder it is to get warmer, unless there is some kind of increase in the total energy available.” Followed by the claim “It is the huge hole in the cheese of the global warming argument, that there is only so much water vapor that can be held before there is condensation.”
Perhaps the extra increase in total energy on a global basis could be provided by the increase of Greenhouse gasses due to human activity?
Tsk.Tsk.
What a daft suggestion.
Silly me. ;)
William Astley, if the Sun doesn’t go into some kind of unusual minimum over the next ten years or so, will you stop saying it’s variations in sunlight causing present temperature history?
Dr Olaf Orheim head of Norwegian IPY Secretariat:
“If Norway’s average temperature this year equals that in 2007, the ice cap in the Arctic will all melt away, which is highly possible juding from current conditions.”
Via IPY main site news, as reported by Xinhua press: http://news.xinhuanet.com/english/2008-03/01/content_7696460.htm
Re gusbob @ 339: “The best competing theory for the current warming is solar activity.”
There is no competition as it is not a dichotomy. If solar output should diminish it would, of course, clearly mean less insolation here on Earth, and thus lead to a cooling of the surface and atmosphere. However, that in no way undermines the physics of greenhouse gases. Greenhouse gasses would continue to make the surface and atmosphere warmer than it would otherwise be, and adding more would continue to make it warmer still. The two forcings can offset or reinforce each other, and thus amplify or mitigate the net warming or cooling, but they remain entirely independent of each other.
So, should we get 20 years or more of low solar activity it would be unwise to take comfort in it. Not only would it potentially lead to much human pain and suffering, but when the sun once again should become more active steadily increasing greenhouse gases would amplify that renewed energy input.
Accuweather meteorologist Joe Bastardi quoted @ 341:
“It is the huge hole in the cheese of the global warming argument, that there is only so much water vapor that can be held before there is condensation.”
No, that phenomenon is very much part of the body of the cheese itself.
Re 337, barycentre
One of the citations for the third (1987) paper provides a needed reality check:
Jager & Versteegh:
Abstract We examine the occasionally forwarded hypothesis that solar activity originates by planetary Newtonian attraction on the Sun. We do this by comparing three accelerations working on solar matter at the tachocline level: Those due to planetary tidal forces, to the motion of the Sun around the planetary system’s centre of gravity, and the observed accelerations at that level. We find that the latter are by a factor of about 1000 larger than the former two and therefore cannot be caused by planetary attractions. We conclude that the cause of the dynamo is purely solar.
#344
“So, should we get 20 years or more of low solar activity it would be unwise to take comfort in it. Not only would it potentially lead to much human pain and suffering, but when the sun once again should become more active steadily increasing greenhouse gases would amplify that renewed energy input.”
But this sun’s already at minimum isnt? If there is a very low cycle, then this will slow the rate of global warming thankfully but we are hardly going to see much cooling while CO2 continues to rise.
As you say though, we will really bake in the next cycle. Maybe William Astley is 80 and doesnt expect to be around in the next cycle.
Jim Eager wrote “There is no competition as it is not a dichotomy. If solar output should diminish it would, of course, clearly mean less insolation here on Earth, and thus lead to a cooling of the surface and atmosphere. However, that in no way undermines the physics of greenhouse gases.”
I must disagree. Although you are right in terms of insolation and CO2 both contributing in their own way, that is not my point. It is a matter of attribution and our weighting of those 2 factors which changes how we attribute cause and effect for the recent warming.
Paleoclimate studies typically attribute climate change to solar via cosmogenic nucleotide evidence. The sunspot activity and the sun’s magnetic field have doubled in the past 100 years. So I can not discount the sun for those reasons. But I am skeptical of solar because there is no clear mechanism. We have only been able to measure the sun’s activity for the past 25-30 years and we see there is was little difference in total irradiance(about 1%?). For that reason the IPCC further discounted solar effects. However if there is a drop in solar activity that we have not ever witnessed before, and that drop is greater than the 1% recently measured, then the IPCC’s discounting would have been premature and based on a not so “solar constant”. I do enough deep sky observing to accept that there are lots of variable stars, and likely the sun is more variable than some suppose.
Furthermore our recently measured change in solar activity only encompassed the peak of solar activity. Just as we argue that the southern hemisphere’s ocean maybe masking AGW, and providing ambiguities like a cooling Antarctica, it would be equally valid to argue that the oceans have masked the solar effect these past 50 years.
In this thread some of argued that global temperatures have leveled off the past decade. I was unaware of that. But if true then it would coincide with the peaking of sunspot acvtivity.
So if a decadal decrease in solar activity yields a decadal decrease in global temperatures, I think we will need to re-weight how much warming is attributed to solar. Yes it does not change the physics of greenhouse gases. But it changes our interpretation of how all the climactic factors interact and to which factors the climate is most sensitive.
Cobbly here:
Precisely. A seasonally ice-free Arctic will change NH weather, which will change climate – perhaps very quickly. Something along the lines of Pekka Kostamo’s observation perhaps…
Re Phil Scadden @ 347: “But this sun’s already at minimum isnt? If there is a very low cycle, then this will slow the rate of global warming thankfully but we are hardly going to see much cooling while CO2 continues to rise.”
Not if we enter a long-term Maunder-like minimum, as many come here to insist we are, but then that’s their argument, not mine.
Of course they also tend to forget that in addition to inducing warming, rising atmospheric CO2 will also acidify the oceans, and that a good percentage of the human population depends on the marine food chain.