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Tom Dayton at 11:44 AM on 25 August 2010Station drop-off: How many thermometers do you need to take a temperature?
daisym, understandably you misunderstand the term "dropped" in "dropped stations." It does not mean deleting the data points. For more explanation, see: 1. The second paragraph of the Intermediate version of this basic post (which is linked in the green box at the top of this page you are reading now. Be sure to click the "Intermediate" tab when you get to that page.) 2. My comments here, here, and here. 3. See an actual example of a monthly temperature raw dataset containing not just temperatures for that just-passed-month, but also a large number of data points for months and even years in the past, which are what put the bump in the older end of the distribution of number of stations reporting. If you don't trust that example, then you can download the data yourself. -
Yvan Dutil at 11:36 AM on 25 August 2010Station drop-off: How many thermometers do you need to take a temperature?
@daisym The way data are processed removing station has little impact overall. First, climatologist work with the anomaly, which is insensitive to calibration or local climatology. Second, data a weigthed on a area basis. Otherwise, world temperature would be strongly weigthed on USA. As for inclusing data of new sensor, it my not be obvious for you but this is a very tricky process. In addition, data compilation and archiving have a very low priority for grant unless it becomes obvious this is a serious problem. Scientist in every field sufer from that problem. Actually, physicist (which climatologist are a subgroup) fare better than many other type of scientist. -
robert way at 11:25 AM on 25 August 2010Arctic sea ice... take 2
No the data is not available back to then for volume from the polar science center unfortunately. -
BDS2020 at 11:00 AM on 25 August 2010Arctic sea ice... take 2
Is the data available to take the volume chart back to 1950? Would be interesting to see data for the same period for both extent and volume. -
adelady at 09:52 AM on 25 August 2010Station drop-off: How many thermometers do you need to take a temperature?
daisym. You've got the story back to front. The climate *change* science is just an extension of the physics of stable climate. Nobody thought 90 or 150 years ago that working out the physical properties of carbon dioxide (and other greehhouse gases) would lead to where we are now. When all the basics were worked out, it was just wonderful that the earth and its climate were so perfectly suited to life as we know it. It *was* a parsimonious theory. Everything that was learned about the heat absorbing and emitting capacities of CO2 (and the other gases) explained the temperature and what was known of the earth's history. It is just an accident of history that the expansion of learning has coincided with the expanding release of so much CO2 from fossilised carbon compounds. There were other non-polluting technologies available 100 years ago. Had we pursued them instead of fire based power generation, climate science now would be just an interesting side interest of ivory tower intellectuals. -
kdkd at 09:32 AM on 25 August 2010Can't We At Least Agree That There Is No Consensus?
poptech #69 Your legend in your own mind approach is most tedious. However, thank you for your response. It does a very good job of confirming the validity of what I said at comment #61. Your understanding of science and the scientific process is most deficient. -
daisym at 09:29 AM on 25 August 2010Station drop-off: How many thermometers do you need to take a temperature?
#5: Context is everything. After collection of data for so many years, from so many places on the globe, it seems strange that the science elites decided against automated reporting efficiencies in favor of deleting 2/3 of the land data points. It's curious that they became parsimonious only after launching 4,000 ARGOS and other automated buoys, mostly in the Northern Hemisphere. There's another definition of "parsimony": Unusual or excessive frugality; extreme economy or stinginess. And there's another application of the law of parsimony which was somehow overlooked by the science elite: Stating the simplest of two or more competing theories is preferable and that an explanation for unknown phenomena should first be attempted in terms of what is already known. Theorizing that natural climate change dominates manmade influences would have been a simpler hypothesis to investigate. They way it was framed served to place the burden of debunking the hypothesis on the skeptics. Context is everything. How was the average global temperature record adjusted to replace missing data from Siberia after collapse of the USSR? It WAS adjusted, right, or did the world get that much warmer overnight? Ditto for urban heat island adjustments. -
NewYorkJ at 09:16 AM on 25 August 2010Hansen etal hit a Climate Home Run -- in 1981
The 1981 paper underestimated warming to a moderate extent. This tends to contradict assertions from the contrarian cult that Hansen is some kind of "alarmist". Regarding the 1988 Hansen paper, RealClimate has an update. Through 2009, the observed trend since projections started is 0.19 C per decade, vs 0.26 C per decade for Scenario B - a little behind but within margins of error. Hansen used 4.2 C for climate sensitivity. The climate sensitivity value for this model that best matches the observed trend is 3.4 C, with large error bars of course. Updates to Model Data Comparisons Annan has a recent post that looks at the 1988 model. While (as noted above) the model drifts a bit on the high side of observations (which Annan attributes to some combination of model characteristics of higher climate sensitivity, low thermal inertia, and lack of tropospheric aerosols), it has clearly demonstrated skill. AnnanResponse: Thanks for those links, I've added them to the list of resources on Hansen's 1988 prediction. -
JMurphy at 08:55 AM on 25 August 2010Can't We At Least Agree That There Is No Consensus?
Poptech wrote : "Did I list Pielke Jr.'s papers because I thought they supported his Hypothesis 1?" No, you listed them because you believed that they were sceptical about AGW (alarmist or not, depending on whether the title or the introduction to your little personal list is most descriptive), despite Pielke Jnr's own views that they shouldn't be on your list. He also suggested that you change the list to be YOUR list and not a list of sceptical papers, which your list isn't - except in your mind. By the way, the list is constantly discredited and any serious person can see this. You do not understand what peer-review is and very few of the papers and journals on your list are properly peer-reviewed. -
Hansen etal hit a Climate Home Run -- in 1981
robhon - No, Spencer in that link is demonstrating the presence of backradiation with an (uncalibrated to atmospheric spectra) infra-red thermometer. Spencer feels that cloud cover provides a negative feedback to global warming which minimizes the CO2 effect (something of a minority opinion), but he's well informed enough to speak clearly about how the greenhouse effect. His post on Yes, Virginia, Cooler Objects Can Make Warmer Objects Even Warmer Still is also worth reading; he shows that the greenhouse effect doesn't violate the 2nd law of thermodynamics, and that a cool object can make a nearby warm object warmer (when the cool object is itself warmer than the background temperature). -
Rob Honeycutt at 06:48 AM on 25 August 2010Hansen etal hit a Climate Home Run -- in 1981
muoncounter... Wow. Just read Spencer's backyard experiment. Am I missing something? Is he actually trying to claim there is NO greenhouse effect? -
GFW at 06:40 AM on 25 August 2010Southern sea ice is increasing
Hi John, found it! (partly thanks to Chris, partly to Stoat (William C.)) Chris, thanks - Manabe et al (1992) is exactly the paper I was remembering, and I finally found the place I saw it described. Bob Grumbine! http://moregrumbinescience.blogspot.com/2010/03/wuwt-trumpets-result-supporting-climate.html Now we have Liu & Curry (2010) that seems to be saying very much what Manabe et al said in 1992. Which I'd say is quite a coup for the latter. -
NASA-GISS: July 2010-- What global warming looks like
johnd - I believe the CO2 time scale for deep warming of the ocean is covered in CO2 lags temperature. It's not an instant effect, and in fact appears to lag 800-1000 years behind an immediate solar forcing, while water vapor has a 5-10 day feedback time constant. But when the CO2 does rise, it induces an additional water vapor feedback. "Production of water vapor from the ocean" is a bit of a misnomer - vapor pressure is determined by temperature, and there's constant vaporization/condensation all the time. Changing temperatures just change the equilibrium point. -
johnd at 05:11 AM on 25 August 2010NASA-GISS: July 2010-- What global warming looks like
KR at 04:49 AM, water vapour is produced when solar radiation warms the immediate surface of either the land or oceans, therefore it provides an immediate response to changes in solar radiation. However for CO2 to be released from the oceans the ocean waters have to increase in temperature, something that happens on a much longer time frame. Given the evaporation that produces water vapour transfers heat from the surface, creating a cooling effect, can you explain how it is not always the warming produced by the water vapour that leads to firstly more water vapour, and in turn even more water vapour before any CO2 at all is forced from the oceans. Would not the production of water vapour from the oceans surface have to cease before the ocean waters could warm at all? -
NASA-GISS: July 2010-- What global warming looks like
johnd - You do get a water vapor feedback to the solar forcing at the end of a glacial era. It's just that with increasing CO2 forced from the oceans, raising the temperature over the solar forcing, you then get an additional water vapor feedback from that temperature increase. -
johnd at 04:44 AM on 25 August 2010NASA-GISS: July 2010-- What global warming looks like
Ned at 19:41 PM, re "without a CO2 feedback amplifying it." You also don't get major forcing based on CO2 without water vapour feedback amplifying it, the water vapour being the major factor. Can you show why the water vapour feedback would not occur without any initial CO2 forcing, instead responding directly to other initial forcings such as solar forcing. -
CBW at 04:39 AM on 25 August 2010Station drop-off: How many thermometers do you need to take a temperature?
#10, Alexandre, you must know it's about the big money these fat cat scientists make. They have to pay for their fancy cars, yachts, and debauchery-filled gambling junkets to Monte Carlo. So they show less warming now so they can get even more money to show more warming later. -
robert way at 03:53 AM on 25 August 2010Medieval Warm Period: rhetoric vs science
Viau et al. 2006 uses 15,000 years of data and finds a 1050 year cycle with an amplitude of around 0.2°C I believe. Also pertaining to Arkadiusz Semczyszak's commentary. If you took the 1940s and kept the same temperatures as then for years and years then you would see the MCA/MWP. The same forcings and roughly the same amplitude. This is shown in numerous studies (same pattern of warmth even). But the current warming is beyond that of the 1940s and is much more global. I will have to find another reference I saw but they use cosmogenic exposure dating on surfaces revealed by glaciers in the Canadian arctic (on Baffin Island I think) and find that ice covered that area during the MCA/MWP. -
JMurphy at 03:24 AM on 25 August 2010Can't We At Least Agree That There Is No Consensus?
batsvensson wrote : "Can you explain what "the truth" is?" The 'truth' in this instance is : A quick count shows that they have 21 papers on the list by me and/or my father. Assuming that these are Hypothesis 1 type bloggers they'd better change that to 429 papers, as their list doesn't represent what they think it does. Roger Pielke Jr's Blog - Better recheck that list Which is a response to Poptech's belief that "Pielke Jr. made no request to remove papers..." I wasn't trying to claim knowledge of 'The Truth' - Heidegger gave it a go, though : Truth is correspondence. Such correspondence obtains because the proposition is directed to the facts and states of affairs about which it says something. Truth is correctness. So truth is correspondence, grounded in correctness, between correspondence and thing. The Essence of Truth And to carry on the philosophical theme, so-called skeptics remind me of the group of people (from Plato's Allegory of the Cave) who have lived chained in a cave all of their lives, facing a blank wall : Wouldn't it be said of him [that escaped and then returned to the cave] that he went up and came back with his eyes corrupted, and that it's not even worth trying to go up? And if they were somehow able to get their hands on and kill the man who attempts to release and lead up, wouldn't they kill him?" (Plato - The Republic, 517a) -
Alexandre at 03:08 AM on 25 August 2010Station drop-off: How many thermometers do you need to take a temperature?
gallopingcamel #4, Any hint why they mischieviously ended up with less warming after the drop off? -
dsleaton at 02:54 AM on 25 August 2010Station drop-off: How many thermometers do you need to take a temperature?
Wynnray, I'll provide some evidence for you. My dad died of oat/small cell cancer last year (97% of such cancer patients have smoked or are/were smokers). He smoked until the last week of his life, during which he was bed-bound, and I refused to give him his cigarettes (he was also on oxygen). He never stopped claiming that it wasn't the smoking. Indeed, and I think this part of the analogy fits in some respects with denialists, he once claimed that the cigarettes were killing the cancer. He once convinced a nurse (she also smoked) in the cancer ward to take him outside to have a cigarette (this was a short time before chemo/radiation took down the mass in his lungs to 2% of its original size -- it later came back with a vengeance). -
muoncounter at 02:44 AM on 25 August 2010Medieval Warm Period: rhetoric vs science
#22: "I don't think one can confidently diagnose the existence of an 1100 year periodic cycle from 2000 years of data" Point taken. I saw a low around 500 and another around 1600. Whether or not that repeats is not contained in these data. But if I was modeling these data, I'd start with that long period. I think its pretty certain that you would need higher frequencies to accurately describe what happened at the tail end. And then the question would be: what natural process provides those higher frequencies? And if not natural, then what man-made process? -
muoncounter at 02:36 AM on 25 August 2010Hansen etal hit a Climate Home Run -- in 1981
#9: See also Dr. Spencer's backyard experiment measuring the greenhouse effect. "This paper is more circumstational evidence" Circumstantial? A model run 30 years ago made a prediction of current events that worked reasonably well. In my old business, that would be called a successful experiment (aka an oil and/or gas discovery) and we would be taking $$$ to the bank. In my new (part-time) business, if I predict earth-surface cosmic ray counts based on 'space weather' observed by satellites, isn't that also a successful experiment? (no $$$ in muons, unfortunately). Why is climate science a field where people get called out whether they are right or wrong? -
enSKog at 02:14 AM on 25 August 2010Medieval Warm Period: rhetoric vs science
Re HR's comment "I'm still unconvinced that pasting the thermometer record on the end of a proxy reconstruction is totally valid" the thermometer record IS a proxy record, with the thermal expansion, electrical or optical properties of various materials used as a proxy to estimate the temperature of the atmosphere. They are, of course, very good proxies. -
chris at 01:34 AM on 25 August 2010Can't We At Least Agree That There Is No Consensus?
batsvensson at 00:38 AM on 25 August, 2010 no problem batsvensson; I suspect my post with slightly pompous actually! I think the essential problem relates... (i) .....a little to what you pointed out earlier; i.e. we have to be quite explicit about which specific element of the climate system and climate science we're referring to when we talk about consensus. ...and (ii) a little to the fact that much of what we know about the natural world has significant elements of uncertainty associated with it. So for example while there is probably quite a strong consensus amongst climate scientists that the climate sensitivity is unlikely to be less than 2 oC of warming per doubling of atmospheric [CO2] and also unlikely to be greater than 4 - 4.5 oC (without some poorly anticipated major positive feedbacks), and even that the most likely value is somewhere around 3 oC of warming.....you won't find any climate scientists (zero consensus) that consider that the climate sensitivity is 3 oC (per doubling of atmospheric [CO2]). So on most things (and especially those concerning future predictions/projections in the natural world), there simply won't be a "hard number" (just like there won't be a hard number in the prognosis of the survival time for someone diagnosed with lung cancer). Unfortunately uncertainty is something we have to live with and also understand and address maturely... -
batsvensson at 01:21 AM on 25 August 2010Can't We At Least Agree That There Is No Consensus?
JMyrphy wrote, "(fat chance, though, because you wilfully don't want to acknowledge the truth)" In what way does this claim (and similar claims you tend to do) support your argument? Is this to be regarded as a factual claim to be serious consider to support the "the truth" view? Can you explain what "the truth" is? Is "the truth" perhaps just a world view (of which some may work better than others – why is it then that other even thou they know "the truth" decided to opt for other less "better" truths)? The truth we have now is not the same truth that was around in the past, and most likely will not be the same truth in 500 years time. Science development has always been when the "truth" has been challenge, when people has broken with current thought and wisdom. Truth is very relative and maybe that should make us a bit more humble to knowledge because the guy next to you that disagree with you with "cray ideas" may be right, or (s)he may not. If one lean back on "the truth" and use that as the measurement stick then one will never be able to contribute with anything new or interesting to say. The point is, it is nobodies civil right to offend people just because they do not agree with common wisdom, the dissident may perhaps be an easy targets but that doesn’t change the fact that we perhaps should learn to be more respectful to each other. Perhaps with a respectful attitude towards each other a deeper understanding can be reached and in the end we may learn that we all been wrong. We know nothing, ands long we defend "the truth" we will learn nothing. -
wynnray at 01:04 AM on 25 August 2010Station drop-off: How many thermometers do you need to take a temperature?
If your doctor tells you that you will die in six months, if you don't stop smoking. Do you: A. Throw your cigarettes away and never light another one. (the doctor spent years in school and training so they could tell you this). B. Get a second opinion. (being cautious is a good thing, but the other doctor confirms the first's diagnosis), so you still quit. C. Tell the doctor he's full of shit, and just trying to manipulate you! You've been smoking for decades with no problems, why all of the sudden there's a problem? Hah! D. Get a second opinion, that doctor tells you you only have 3 months to live. Since the two doctors can't agree to the precise time left to you, niether of them know anything, so you ignore them both. C and D seem to be the common choices made! Well, Climate scientists are also doctors, they also spent years in school and training, and they all agree (the real scientists, not creationist morons), that this global climate changes are at least partially if not entirely human driven. We have our second opinion, many in fact. We and our children will pay for our lack of confidence in our own scientists. -
Hansen etal hit a Climate Home Run -- in 1981
factfinder - You ask where's the evidence for a greenhouse effect? Have you looked around on this site, or any others? Wiki on the greenhouse effect Radiative equilibrium Roy Spencer (noted skeptic) describing the GHE Another Spencer posting - "Cooler Objects Can Make Warmer Objects Even Warmer Still" Evidence for global warming Greenhouse effect with observed spectra Science of Doom gedankenexperiment on what would happen without the GHE (-18 C average temps) Introductory part-by-part overview of GHE There's tons more material out there, factfinder - this post was the result of ~90 seconds with Google. It's based on >150 years of spectroscopy, radiation physics, repeated observations, etc. Read up and enjoy the science. -
gp2 at 00:56 AM on 25 August 2010Medieval Warm Period: rhetoric vs science
wrong link, here is the correct one: grosjean et al. 2007 -
gp2 at 00:54 AM on 25 August 2010Medieval Warm Period: rhetoric vs science
Alpine glaciers tongue response lags temperature by several decades and nevertheless the great aletsch retreat is already greater than at medieval times, however some area are in equilibrium with decadal temperature fluctuation and the ice cover there is smaller than at any times in the last ~5.000 years. grosjean et al. 2007 "The critical point in the context of this paper is that leather requires permanent embedding in ice in order to stay preserved and, as it is observed today, deteriorates very quickly if exposed at the surface. In consequence, the finds at Schnidejoch suggest permanent ice cover at that site for the last 5000 years, more specifically from ca. 3000 BC until AD 2003. At first glance our conclusion differs from the conclusions drawn from exposed trees in the forefields of melting glacier tongues (Jorin et al.,2006). However, the conclusions by Jorin et al. (2006; see also by Hormes et al., 2006) refer to the AD 1985 level:‘glaciers in the Grimsel [and Alpine] area were smaller than at 1985 AD during several times for the last 5000 years’; while our conclusion reads: ‘in the year of 2003 AD, the ice field at Schnidejoch has reached the smallest extent since the last 5000 years’. This is not a contradiction. We argue that this difference is explained by the dissimilar response lags of the two types of archives compared: ice mass balance near the ELA (Schnidejoch) responds immediately to sub-decadal climate variations, while Alpine glacier tongues respond with a multi-decadal lag to climatology (20–60 years (Jorin et al., 2006); importantly this fact also applies to the study by Hormes et al. (2006)). Differences between the equilibrium states of fast and slowly responding climate archives are typically large during phases of rapid changes. Indeed while the ice field at Schnidejoch is in equilibrium with the state of the atmosphere of the most recent years, the glacier tongues have not yet fully responded to the excessively warm years of the last 15 years, when (1) solar radiation at the Earth’s surface has increased owing to brightening of the atmosphere (globally 6.6 W mÀ2 10 yrÀ1 between 1992 and 2002, Swiss Plateau 7.2 W mÀ2 10 yrÀ1; Wild et al., 2005), (2) anthropogenic greenhouse forcing with related strong water vapour feedback enhanced the downward longwave radiation in Europe (þ1.18 W mÀ1 yrÀ1, data 1995–2002; Philipona et al., 2005) which increased temperatures, and (3) negative trends in the specific mass balance of Alpine glaciers accelerated (Zemp, 2006). "Moderator Response: Please don't paste such long quotes. Summarize, make the particular points of relevance, and provide the link. There is no hard and fast rule about how long is too long, just a rule of thumb that if readers can easily click a link to see some text, give them that link with instructions of where to look once they get there. -
Yvan Dutil at 00:53 AM on 25 August 2010Medieval Warm Period: rhetoric vs science
Well, if you had a few hundred years of hot climate you would have trees much higher than those in MWP. However, trees have yet to go up. This is a long process but it is documented to be ongoing. -
wynnray at 00:46 AM on 25 August 2010Hansen etal hit a Climate Home Run -- in 1981
the sigmas are the Standard deviation of the data. An envelope of plus/minus one one sigma includes most of the date +/- 2 sigma is almost all data. In Statistical process control, the term "six sigma" is used (from IBM) to denote the ultimate goal of SPC that application is the inverse of this application as instead of expanding your data pool, it narrows it, which means no variation in output test criteria. Climate researchers have been sounding the alarm for 60 years. If you look at the global temperature data, I can see the effects of both world wars (second more than first) as well as the great depression! That tells me that we humans do have an effect on global temps. -
batsvensson at 00:40 AM on 25 August 2010Can't We At Least Agree That There Is No Consensus?
@Tom Dayton at 06:41 AM on 24 August, 2010 You seams to be referring to epistemology now, but I am not sure how you means this would be related to consensus in this case? -
batsvensson at 00:38 AM on 25 August 2010Can't We At Least Agree That There Is No Consensus?
@chris, at 07:04 AM on 24 August, 2010 Remember that words/definitions are shorthand signifiers for the things they describe. They are not the thing itself Ah, right. Thanks chris for the brief clarification and help sorting out my own confusion there. Apparently I got myself mislead with which labels should be attached to which description there. “balance of evidence” has nothing necessarily to do with climate models, It is not my intention to suggest the contrary. What I mean with hard evidence is, just as a wrote, something you get from an observation, i.e. a number. -
factfinder at 00:32 AM on 25 August 2010Hansen etal hit a Climate Home Run -- in 1981
Where is the scientific experiments and data proving the existance of the "Greenhouse gas effect" Hypotheses are fairy-tale until we see experimental data. This paper is more circumstational evidence if its true.Response: "Where is the scientific experiments and data proving the existance of the Greenhouse gas effect?"
The greenhouse effect has been directly measured for 50 years. Planes measuring the upward spectrum from 20km up find big "bites" taken out of outgoing radiation by greenhouse gases. This is confirmed by surface measurements that find corresponding extra radiation returning to Earth at those same greenhouse gas wavelengths:
Of course, you might be asking about the increased greenhouse effect. Eg - is rising CO2 levels causing an increase in the greenhouse effect and hence causing global warming. This is also directly observed by independent measuring systems: both satellites and surface measurements find less infrared radiation escaping to space and more radiation returning to Earth.
Change in spectrum from 1970 to 1996 due to trace gases. -
Arkadiusz Semczyszak at 00:25 AM on 25 August 2010Medieval Warm Period: rhetoric vs science
NH - MWP - or wants to Mann and Briffa - MCA. It's probably Spenser said: there was no MWP warmer than today? So it (probably) early medieval skeptics planted these trees, whose trunks are revealing Alpine glaciers, Alaska and Greenland ... -
Ken Lambert at 23:48 PM on 24 August 2010What caused early 20th Century warming?
muoncounter #35 In the absence of any anthropognic forcings prior to 1750AD, the only climate driver would be the various Solar cycles including the 11 year cycle, and multiple overlapping orbital cycles which have varied the Earth's exposure to the sun. Volcanic cooling is transient and significant in short bursts, but being randomly distributed in time cannot be counted as part of a natural forcing cycle. The Earth is most probably never in equilibrium, but if you are trying to separate and quantify the effects of CO2GHG forcing - you must be able to accurately tell us where we are in the cycle of 'natural' solar forcing. In 1750AD the Earth was warming out of the LIA but this says nothing about whether Solar forcing was above or below the 'midpoint' of the natural oscillation in 1750AD. If you look at the time series forcing curves for warming and cooling forcings, the positive areas under the curves indicate the total energy added to the earth system and the negative areas the energy subtracted from it. These theoretical AG forcings are baselined about a zero axis. eg. in 2005 CO2 forcing was posed at 1.66W/sq.m and total aerosol cooling at about -1.2W/sq.m (ref Fig 2.4 AR4). If you are going to add Solar forcing into this mix you also need a zero axis baseline so the forcings can be added or subtracted correctly. Is not a zero basline for Solar the 'equilibrium' TSI where in the absence of AG forcings (pre 1750AD) the Earth was 'in balance'? We had a Solar maximum up to 1960 and a slow drop off in TSI since then (ignoring the 11 year cycle which oscillates on top of the basic Solar forcing signal). The total energy above the 'zero baseline' has to be in the system somewhere to obey the first law. Land and atmosphere has tiny storage capacity compared with the oceans which has thermal lags (depending on depth) of 10's to hundreds of years. Heat stored in the oceans can be exchanged with the atmosphere and land in complex circulations and cycles (ENZO, AMO etc) Unfortunately, the measurement of OHC is unable to track this heat with current technology despite the greater coverage of Argo, and the purported forcing imbalances are not showing up in the oceans above or below 700m more than about 60% of the theoretical amount of 0.9W/sq.m and even this is in doubt. Small OHC increase means small imbalance over time, and small imbalance could mean Solar forcing only or a smaller CO2GHG effect that theoretically claimed. -
Ned at 23:35 PM on 24 August 2010What were climate scientists predicting in the 1970s?
In addition to the paper that gp2 cites, there was also a 2006 Science paper (Ramaswamy et al. 2006) that addresses this stepwise pattern. From the abstract: Observations reveal that the substantial cooling of the global lower stratosphere over 1979–2003 occurred in two pronounced steplike transitions. These arose in the aftermath of two major volcanic eruptions, with each cooling transition being followed by a period of relatively steady temperatures. Climate model simulations indicate that the space-time structure of the observed cooling is largely attributable to the combined effect of changes in both anthropogenic factors (ozone depletion and increases in well-mixed greenhouse gases) and natural factors (solar irradiance variation and volcanic aerosols). The anthropogenic factors drove the overall cooling during the period, and the natural ones modulated the evolution of the cooling. -
gp2 at 23:25 PM on 24 August 2010What were climate scientists predicting in the 1970s?
The stepwise cooling is explained here: Thompson et al. 2009 Also note that expected greenhouse gases cooling in the lower stratosphere is much lower than the observed trend: "The resulting analyses reveal that the distinct drops in global-mean stratospheric temperatures following the transient warming due to the eruptions of El Chichon and Mount Pinatubo are linearly consistent with con- current drops in ozone. We note that the several-year period after the eruption of Mount Pinatubo is unique in the global ozone record, insofar as it is the only pe- riod in which concurrent ozone decreases are observed across, not only the tropics and NH midlatitudes, but also SH midlatitudes. The analyses further suggest that the weak rise in global-mean temperatures between the eruption of El Chichon and Mount Pinatubo is consis- tent with the concomitant weak rise in ozone, and the results clarify that the seemingly mysterious rise in global-mean stratospheric temperatures since ;1993 is consistent with increasing stratospheric ozone juxta- posed on global-mean cooling of ;0.1 K decade. -
Berényi Péter at 23:15 PM on 24 August 2010What were climate scientists predicting in the 1970s?
#44 Ned at 22:59 PM on 24 August, 2010 it seems to happen in a curious stepwise fashion Steps are synchronous with major volcanic eruptions. -
Ned at 22:59 PM on 24 August 2010What were climate scientists predicting in the 1970s?
BP writes: The layer of stratosphere channel TLS (57 GHz) is sensitive for may be too low (peak sensitivity at 17 km), the divergence grows large only above it. Do we have upper stratosphere temperature time series? That is exactly one of the things I was skeptical about in your chain of reasoning, given that the trends at different heights in the stratosphere are quite different (at higher altitudes CFC-associated ozone depletion also complicates the analysis of temperature trends, something that wasn't anticipated in 1967). See Randel et al 2009, fig. 19:
Figure 19. Vertical profile of temperature trends for 1979–2005 derived from each of the individual SSU and UAH MSU4 satellite data sets, averaged over 60°N–°S. Vertical bars denote the approximate altitude covered by each channel, and horizontal bars denote two-sigma statistical trend uncertainties. Results are also shown for trends derived from radiosonde data averaged over 60°N–°S.
The solar cycle also has a much stronger impact on stratospheric temperatures.
The data from the mid to upper stratosphere are not as reliable as those from the lower stratosphere, for a number of reasons. They do show strong cooling (around 0.5C/decade in the middle stratosphere, even more at higher altitudes), but it seems to happen in a curious stepwise fashion that I'm not sure anyone has completely explained:
Figure 18. Time series of near-global average temperature anomalies derived from SSU data, for each individual channel (as noted). Data for channels 26x and 36x are shifted for clarity.
I am agnostic about the causes of that stepwise downward pattern. I wouldn't be surprised if it turned out to be partially due to an interaction between the CO2-induced cooling trend, stratospheric ozone, and the 11-year solar cycle (which as mentioned above has a stronger effect on stratospheric temperatures). On the other hand I also wouldn't be surprised if it was partially due to problems with the intercalibration of different SSU sounders on different spacecraft. Given all the uncertainty in the SSU record, I have generally been reluctant to draw much in the way of conclusions about temperature trends there, other than that they superficially seem to be more or less in agreement with what we expect.
Randel et al. (2009) and Shine et al. (2008) seem to be very relevant (and very readable).
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Berényi Péter at 22:20 PM on 24 August 2010What were climate scientists predicting in the 1970s?
#42 Ned at 19:24 PM on 24 August, 2010 sources that can be cited a bit more directly than your convoluted chain of telephony here Here is the original Manabe paper. Vol. 24, No. 3 Journal of Atmospheric Science, May 1967, pp. 241-259. Thermal Equilibrium of the Atmosphere with a Given Distribution of Relative Humidity Syukuro Manabe and Richard T. Wetherald Fig. 12 (Vertical distribution of radiative convective equilibrium temperature for various values of water vapor mixing ratio in the stratosphere) and Fig. 16 (Vertical distribution of temperature in radiative convective equilibrium for various values of CO2 content) show a possible cause. The layer of stratosphere channel TLS (57 GHz) is sensitive for may be too low (peak sensitivity at 17 km), the divergence grows large only above it. Do we have upper stratosphere temperature time series? -
theendisfar at 22:05 PM on 24 August 2010There's no empirical evidence
Moderator, If you're going to shut down the ability to post to a thread, can you please notify the audience? Thank youResponse: There is no feature to shut down posting on any thread. If your comments are not immediately appearing, just check that the number of comments isn't just over the 50 or 100 mark (or some other multiple of 50). Your comment might be appearing on the next page over. Or if it appears then is removed, it would be because its violating the comments policy. -
CBDunkerson at 22:01 PM on 24 August 2010Arctic Sea Ice: Why Do Skeptics Think in Only Two Dimensions?
Agnostic #9: Actually, extent does not DIRECTLY relate to albedo. Ice extent is the area of OCEAN containing at least X% (usually 15%) sea ice. So, an extent of 100 sq km might only have 15 sq km of actual ICE area. That said, there are actual ice AREA estimates as well and those are obviously relevant for albedo purposes. However, I still think volume is the most important factor to keep an eye on. If it continues dropping at the rate it has the past few years (unlikely) then we're only three or four years from all the ice being gone. More plausibly volume declines will level off in the next year or so once all of the multi-year ice has melted down to basically the same thickness as 'first year' ice. It'll be interesting to see how quickly that leads to the breakup of the mass of multi-year ice along the northern Canadian archipelago (the western fifth is already gone) and what that will do to Arctic currents and ice export. -
Yvan Dutil at 21:41 PM on 24 August 2010Station drop-off: How many thermometers do you need to take a temperature?
@gallopingcamel As I understand it. Nobody droped volontary 80% of the station. Essentially, validation process is long and tedious. You need time, manpower and computation capability to do that. Actually, a new version of the database is about to be released. This shoould close the gap. Expect an upward revision of the temperature change. This will certainly creates new claim of manipulation by skeptics. -
Yvan Dutil at 21:37 PM on 24 August 2010Dust-Up On Mars: Should Martians Be Sceptical of Global Warming?
Published in the Journal of Cosmology. This is a dump for crappy idea, whatever if the field of research. "Warming on Mars must therefore be real and be a result of a complex (including magnetic) solar activity (f. e .QBO). " This is a very farfetch idea that provide a lot of information about the structure of your logic. We have only a very few data point for Mars temperature. Also, I dont see any commun mecanism that could be invoke the have a comparable effect on MArs and Earth. In addition, in the observation perio, solar activities as gone done. In addition, nobody claim than Sun has no impact on climate. However, even the most supporting analysis claim that it cant exceed 50% and is much likely to be below 25% of the observed warming. -
Yvan Dutil at 21:29 PM on 24 August 2010Medieval Warm Period: rhetoric vs science
Ned, you are right. The bare minimum is to have a cycle with the length of the data span. This work only without any confonding factor. Maybe the thousand tears cycle comes from other data. -
CBDunkerson at 21:19 PM on 24 August 2010Pakistan flood: many more will die unless more aid is delivered quickly
Kernos #10: Did you not read any part of my comment except the last sentence? Killing off a few billion (or "thousand million" as you put it) non-industrialized farmers would not help slow global warming EITHER. They aren't the ones causing CO2 levels to increase. China and India have long had huge populations... but their CO2 emissions were virtually non-existent until they began to industrialize. The vast majority of their populations (in rural areas) still emit little CO2. Wiping out all of the Americas, Europe, and industrialized portions of Asia (your 'few billion' people) would have a major impact on global warming from CO2 emissions. But those areas have much better disaster preparedness and simply will not suffer those kinds of losses. The only places you get huge population growth and massive deaths from natural disasters are in poor rural areas which aren't contributing to CO2 emissions in any significant way. So again... no significant 'negative feedback' on CO2 emissions from natural disasters. At least not any time in the near future. Go out a hundred years or more and it might be a different story... depending on how much CO2 we've emitted and how well technology has kept up with allowing us to adapt to the climate. -
ProfMandia at 21:05 PM on 24 August 2010Hansen etal hit a Climate Home Run -- in 1981
Nice timing. Tom Fuller and others over at Bart's place are criticising Hansen for a supposed comment that he made about the West Side Highway being flooded today due to sea level rise in a Salon Magazine article. Fuller goes on to claim that Hansen has been discredited along with Dr. Mann. Going there now to post this link. Touche' -
Byron Smith at 20:59 PM on 24 August 2010Arctic Sea Ice: Why Do Skeptics Think in Only Two Dimensions?
I second the comments at #9. And also the concern for whether this post will date quickly (especially since it already refers to April and it is August). I thought basic level explanations were generally not going to include links to papers. Furthermore, I wonder about the register of "metric" and "satellite radar altimetry" in a basic level explanation. I think Graham does a great job, but a couple of improvements are possible in this one.
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