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CBDunkerson at 03:57 AM on 21 September 2010Video update on Arctic sea ice in 2010
Some interesting developments the past few days. First, what the NSIDC thought was the end of the melt season after 9/10 turned out to just be a 5 day bump. Since then extent has begun declining again and is now below the 9/10 'minimum' and just a hair's breadth above the 2008 low extent. If it drops any further it will tie 2008 for the 2nd lowest result after 2007. Second, PIOMAS just updated their anomaly graph thru 9/14 and shows an anomaly of about -9,500 km^3. Subtracting that from the 13,400 km^3 September baseline would yield 3,900 km^3. However, that baseline value is a monthly average while the anomaly is a daily value and 9/14 is likely close to the minimum for the month. Thus, when the 2010 monthly average is computed it will probably be around 4,000 km^3... still FAR below the previous record low of 5,800 km^3 set in 2009. I did some math based on various statistics they cite on the main page (e.g. "September Ice Volume was lowest in 2009 at 5,800 km^3 or 67% below its 1979 maximum") and came up with some stats on ice loss rates; Max (1979): 17,600 km^3 Mean: 13,400 km^3 Min (2010): 4,000 km^3 Rate: -425 km^3 per year Given that long term rate the ice would be gone in September in 10 years. If the rate over the past decade (~-1000 km^3 per year) continued it'd be four years. If the rate continued to increase as it has been it's just two years. So, I'm calling 2016 +/- 4 years for the Arctic sea ice to be gone except for a few bits and pieces. If the long term trends continued then there'd be no ice even in APRIL (the maximum extent) in about 50 years. -
JMurphy at 03:49 AM on 21 September 2010The contradictory nature of global warming skepticism
CBDunkerson wrote : "If you look at the graph you can pretty easily come up with alternating periods of about 30 years each with 'increasing' and 'decreasing' temperatures; 1850-1880: increasing +0.1 C 1880-1910: decreasing -0.25 C 1910-1940: increasing +0.5 C 1940-1970: decreasing -0.1 C 1970-2000: increasing +0.5 C 2000-2010+: 'flat'" Actually, and without trying to be sarcastic and belittling, we can use the 'Baz' scale to determine the reaction to each of those trends, just by using the sort of logic Baz has used to assert that he no longer believes the earth is warming : 1850-1880: increasing +0.1 C ("Hm, looks like AGW is real") 1880-1910: decreasing -0.25 C ("Hang on, it's not warming !") 1910-1940: increasing +0.5 C ("OK, it is happening. I'm a 'believer'") 1940-1970: decreasing -0.1 C ("Wait a minute, it's not warming...again") 1970-2000: increasing +0.5 C (Oh, perhaps it is. I'll give it another 5 years") 2000-2010+: 'flat' ("Ah ha - it's not warming. Prove it, using a 5 to 10 year trend !) -
CBDunkerson at 03:04 AM on 21 September 2010The contradictory nature of global warming skepticism
CBD #309: "The reason I didn't choose 1940 to 1950 is because the first period of warming was entirely natural!" Not precisely accurate. MOSTLY natural yes, but not "entirely" natural. Most of the 1910 to 1940 warming was due to increased solar activity, but the enhanced greenhouse effect was also starting to have an impact during that timeframe. I like to turn the 'natural cycles' bit back on the 'skeptics'. If you look at the graph you can pretty easily come up with alternating periods of about 30 years each with 'increasing' and 'decreasing' temperatures; 1850-1880: increasing +0.1 C 1880-1910: decreasing -0.25 C 1910-1940: increasing +0.5 C 1940-1970: decreasing -0.1 C 1970-2000: increasing +0.5 C 2000-2010+: 'flat' From this, it seems like the 'increasing' periods are showing more warming over time while the 'decreasing' periods are showing less cooling... or in the current cycle NO cooling. Which is the sort of pattern you would see if an accelerating warming trend were overlaid onto a regular oscillation. The temperature varies up and down due to a lot of different factors. If the 1910 to 1940 warming had ONLY been solar forcing then temperatures should have dropped back down to the prior level when solar activity declined... they didn't. That 1940 to 1970 period also had alot of aerosol pollution that is believed to have contributed to the cooling. Sorting out all the factors and how much of an impact they've had is a complicated mess... but if we were only dealing with various natural oscillations overlaying each other the long term average would be flat. Instead, it shows pronounced warming. If we ignore the underlying science you are correct... no one can say from the graph alone whether this is a brief fluctuation like others in the past which will be followed by a return to warming OR if we have now hit a peak and temperatures will begin to go back down. But we don't have JUST the graph alone to base our decisions on. We know from direct satellite measurements that there is currently an energy imbalance with more energy coming in to the climate system than is going out. We know that wavelengths of IR blocked by greenhouse gases are being measured in increasing concentrations at the surface and decreasing amounts in space. We know that long settled (~140 years) physics tells us that the increasing CO2 levels we are measuring will produce continued warming. In short, we know for a fact that the total climate system of the planet is continuing to accumulate heat. It has been settled unquestioned science for over a century and we are getting direct measurements of it happening. The fact that the SURFACE AIR TEMPERATURE hasn't reflected that ongoing accumulation much for the past decade is something we call 'weather'. The historical record shows that such fluctuations happen all the time. Right now the heat mostly isn't in the lower atmosphere (though the poles are an obvious exception)... but we KNOW it is still accumulating and thus it is inevitable that it will eventually impact surface air temperatures. -
The contradictory nature of global warming skepticism
Baz - you have been continuing to claim that 10 years of data is enough for you to conclude that warming has stopped. Given the noise in the data, seasonal variations, the Pacific oscillation, etc., 10 years provides very little statistical significance. You agreed with the 20-30 year range earlier in this thread; what happened to that agreement? Essentially you are arguing that the 10 years you have focused on (low statistical significance, very little support for anything but short term noise variations, still within the 2 sigma variations around the previously established trend) is more relevant than the 30 year, highly statistically significant (99.9999 confidence? Way less than a fraction of a percent chance that it's not warming, and we've just picked up noise?) record of a warming trend. That argument really doesn't hold up, Baz. At all. I suspect you're suffering from confirmatory bias. If we don't see warming over 20-30 years, then we'll have strong support for the trend to have stopped or paused. That just hasn't happened yet. What you're looking at is equivalent to a a few cool days in early June (weather) - and from those claiming that summer isn't coming. -
dana1981 at 02:54 AM on 21 September 2010A detailed look at Hansen's 1988 projections
Sense Seeker - I didn't provide the actual atmospheric concentrations of the various GHGs, but I did provide the actual radiative forcing associated with them, which is what matters for these calculations. Also Hansen '88 provided his formulas for dT but not dF, so I used Myhre for the dFs, which are reasonably close to Hansen's values. Ken Lambert - as the GISS forcing link only provided data up to 2003, I extrapolated to 2010 to get a value of approximately 1.06 W/m2. Several commenters have stated that the actual temperatures have run close to Scenario C, which completely misses the point, and I would suggest re-reading the rebuttal. Actual emissions have not been very similar to Scenario C, so comparing to Scenario C rather than B doesn't make sense. Albatross - yes, Scenarios B and C were very similar (perhaps identical, I'd have to go back and look) up until 2000. -
Rob Honeycutt at 02:36 AM on 21 September 2010The contradictory nature of global warming skepticism
Baz... What Phil Jones was saying is you'd need a few more years of data to achieve statistical significance, not that the rate would need to be higher. -
The contradictory nature of global warming skepticism
CBD. I've only read the first page so far, but it seems I'm leaning against Ken Lambert at post 12. The reason I didn't choose 1940 to 1950 is because the first period of warming was entirely natural! Man-made warming began in 1975 according to Tamino. When I see this: http://woodfortrees.org/plot/hadcrut3vgl/from:2001/plot/hadcrut3vgl/from:2001/trend ...I see a flattened temperature. I see no warming for 10 years. I see warming stalled, maybe stopped. Now we can argue about one data set, or the 'science' of only using 10 years until we're both blue, but THAT is what I see. I see that black line in the graph above and I wonder if the warming has stopped - and I'm not the only one. If there's no heat in the oceans then me, and others who think 'unscientifically' like me, are going to be right; and you, and others here, are going to be wrong. You cannot say at this stage that I am wrong in that belief, neither can I say you are. Only time will tell the truth. -
CBDunkerson at 02:25 AM on 21 September 2010The contradictory nature of global warming skepticism
Baz #306: "I don't accept 10 years of flattened temps is conducive to continued global warming." Take a look at the full HadCrut temp graph back to 1850;
This clearly shows DECLINING temperatures from 1940 to 1950. Why didn't that 'disprove man made global warming'? Or the 'flat' period from 1960 to 1975? Why didn't the steep rise (0.2 C per decade) from 1980 to 2000 'prove' that we were in for 2 C additional warming by 2100 even assuming no acceleration of warming? Ditto the 0.5 C rise from 1910 to 1940... surely that meant we were in for continued 0.167 C per decade warming, right? Yet the drop in temperatures from 1880 to 1910 clearly indicated that we were heading into an ice age.
There have been fluctuations, both up and down, more pronounced and/or prolonged than the 10 year 'level' period you are stuck on... so what is so 'special' about this particular minor fluctuation?
Even setting aside the statistical issues... your position just isn't consistent with the historical record.
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The contradictory nature of global warming skepticism
CBD, I need some time to read that! -
The contradictory nature of global warming skepticism
JMurphy. "Irrational". The two sentences are not the same. Read them again. Re continuing warming. If you've read my posts then you'll see that I've said quite a few times that I accept bumps in temp along the way. I don't accept 10 years of flattened temps is conducive to continued global warming. -
CBDunkerson at 02:04 AM on 21 September 2010A detailed look at Hansen's 1988 projections
angusman #22, scenarios B and C and the actual temperature record are all very similar to each other through 2005. Since 2005 actual temperatures have been roughly in line with scenario C (below in some years, above in others). However, that is FAR too short a time frame on which to judge the validity of the model. If actual results continued tracking along scenario C for 15+ years then the model would be off significantly. If the warming being seen this year continued then we'd be back 'on track' closer to scenario B. That said, Hansen's 'short term' climate sensitivity factor in 1988 was definitely too high and thus his results should be expected to go further off as time goes by. Hansen 2006 essentially explained HOW the 1988 analysis got it wrong... so to say that 2006 is itself wrong... would seem to be arguing that Hansen 1988 was correct. :] -
The contradictory nature of global warming skepticism
Daniel Bailey. Oh dear, you seem to have missed B in that BBC link and gone straight to C. Try again, Daniel, because YOU ARE WRONG. See MichaelM's quote above your post. MichaelM. Thanks, but I'm not confusing anything with everyday use! Prof Phil Jones states that the trend from 1995 to 2009 is not statistically significant. I didn't say it, he did. -
Albatross at 01:23 AM on 21 September 2010Global warming and the unstoppable 1500 year cycle
Addressing even the most bizarre myths put forward by "skeptics" is important, and IMO, does not amount to arguing a straw man as some are suggesting here. Only the other day I was reading a CBC forum on the Arctic ice and "skeptics" were parroting Singer. How he can claim to have any credibility (and even more astounding, how people can still buy into his "science") on climate science is truly bizarre. -
angusmac at 01:22 AM on 21 September 2010A detailed look at Hansen's 1988 projections
A close look at Figure 3 shows that temperatures are actually running below Scenario C - the zero-increase in CO2 from 2000. This decline has not happened. Therefore, the only conclusion that can be made from present day temperature readings is that Hansen (1988 & 2006) got it wrong. -
Albatross at 01:19 AM on 21 September 2010A detailed look at Hansen's 1988 projections
Wonder if Michaels is going to retract the misleading and erroneous testimony that he gave before US House of Representatives? I mean in the spirit of accountability,transparency and rigor that he demands of the IPCC? Excellent job Dana. Am I correct in understanding that emission scenarios B and C were the same up until 2000? -
archiesteel at 01:14 AM on 21 September 2010The contradictory nature of global warming skepticism
@Baz: "Please retract the "liar", and I've never said I am irrational." I'm not retracting anything, as you keep repeating the same debunked fallacious statement. Oh, and you did claim to not being rational. Not rational = irrational. "Re 'Where's the heat?' So 3 years is good enough for you?" Of course not, it's not statistically significant. It should be enough for you, however, since you originally claimed a five-year period was enough for you to change your mind about the warming. I can't believe you walked right into that one, too. What are you hoping to achieve, here, exactly? Get on people's nerves until they become rude so you can then complain how AGW proponents are ill-mannered? "I say again, the last 10 years of HadCRUt is flat." And I say again, that is cherry-picking, especially since other cycles (such as the PDO and TSI) are having a cooling effect during that period. Please pick a statistically-relevant period and base your opinion on this, otherwise my choice of the last three years (which shows where the "heat" is) is just as good as your choice of five or ten years. You've been unmasked, Baz. At this point, the wise thing to do would be to just stop commenting on the science until you've shown you actually understand it. Anything else is just digging yourself deeper in your own hole. "I didn't "carefully cherry-pick" that period, it was done by Phil Jones here" Another lie? The period was picked by the BBC journalist, not Phil Jones. Jones made a point of saying the warming trend was still there during that period, though it really was at the 92% degree of confidence. Of course, this was all before 2010, one of the warmest years on record, so who knows. Again, you've exhausted everyone's patience, here. Come back when your argument is scientifically relevant. -
Rob Honeycutt at 01:09 AM on 21 September 2010The contradictory nature of global warming skepticism
Baz... I think you're actually not understanding the definition of "statistically significant." Statistical significance in climate is less a function of the rate of warming or cooling and more a function of the length of time. If you look at the current warming from the past couple of years it's coming at a very high rate. I don't know the figure off hand but say it's 0.45C/decade. That is still not statistically significant because it's just part of the noise. The up and down normal to the climate signal. Statistical significance is this: Confidence = signal over noise X square root of the sample size. That essentially means the climate is very noisy so in order to have confidence that you are looking at the actual "signal", and not just noise, you have to have a fairly large sample. In climate it's 20 to 30 years of data. That's why I said, when you're talking about the "flattening" temps you are talking about data that is not statistically significant. -
rzwilling at 01:05 AM on 21 September 2010Hansen's 1988 prediction was wrong
Hi there - I'm relatively new to commenting here so apologies if I'm missing something. I've read through dana1981's Advanced and Basic versions of this rebuttal, and something important appears to be omitted from this Basic version - namely that Pat Michaels was misleading in saying that "That model predicted that global temperature between 1988 and 1997 would rise by 0.45°C." Together with Peter Hogarth's updated chart (above), it appears that even though Hansen overestimated the sensitivity parameter, his Scenario C projection is not far off from the GISS measured temperatures. I'm not sure if it's too late to make any updates to the rebuttal, but the key conclusion here might be that Hansen's 1988 projections - even though based on far less data than we have now - were within the range of what has actually been observed. Furthermore, the measured warming provides support that Hansen had the fundamentals of climate science correct, namely that human factors are driving GHG emissions and causing global warming that is significant enough that it can be directly measured over just a few decades - not centuries from now. -
Tom Dayton at 01:00 AM on 21 September 20102nd law of thermodynamics contradicts greenhouse theory
KnuckleDragger, it's best to not use the term "reflect" at all, even as a convenient shorthand, because as Riccardo wrote it has a particular meaning that is different from absorption-emission. CO2 does effectively zero reflection at the wavelengths we are concerned with here, at CO2's concentrations in our atmosphere. -
archiesteel at 01:00 AM on 21 September 2010Should The Earth Be Cooling?
@KL: So, in other words, your entire argument rests on admittedly incomplete/imperfect ARGO readings? Given the overwhelming evidence in support of AGW theory, it seems to me this would indicate deficiencies in measure OHC, not problems with AGW theory. Unless, you know, you already have decided in your mind AGW theory is wrong, then I guess confirmation bias will cloud your judgement regarding this issue... -
archiesteel at 00:53 AM on 21 September 2010Global warming and the unstoppable 1500 year cycle
@Ann: you won't see this happening, because many "skeptics" change positions depending on the current argument. The goal is to keep an aura of confusion around the debate. Now, there is a small minority who holds steadfast views on AGW, but you don't often hear from them on Internet forums... -
Riccardo at 00:23 AM on 21 September 2010A detailed look at Hansen's 1988 projections
Scrooge, natural cooling is ignored in GCM. It happens on a time frame of millennia which usually is not considered. -
Riccardo at 00:19 AM on 21 September 2010A detailed look at Hansen's 1988 projections
Ken Lambert, still confusing forcings and feebacks, do you? Anyway, Hansen calculation also are "the result of ALL the forcings - both radiative and feedbacks." (sic). And within 5%. -
Scrooge at 00:09 AM on 21 September 2010A detailed look at Hansen's 1988 projections
First I want to say that to be able to come up with those projections in 1988 is remarkable. I think I was still using an Atari 800 at the time. Now this may be a stupid question but as discussed in a previous post, is the idea that we should be naturally cooling incorporated into the model. Of course I assume it is but just one of those nagging questions. -
Ken Lambert at 23:55 PM on 20 September 2010A detailed look at Hansen's 1988 projections
Riccardo #16 Unfortunately the measures 'air surface temperature' and GISS and HADCRUT3 temperature anomalies are the result of ALL the forcings - both radiative and feedbacks. Claiming that Hansen was out by only 5% on half the story when the feedbacks (particularly WV and CO2 interaction) are the least understood is the missing part of this article. So we are closest Scenario C with the temperature record?? -
Howard at 23:54 PM on 20 September 2010It's the sun
I say the Sun is the dominant factor in climate change. If you read the new work by Frederick Bailey, on the soon to launched web site www.solarchords.com and his books, you will see the background to two discoveries, one is, what drives sunspot production, the pattern has been discovered and this led to a much greater discovery i.e. It has been cleary shown that the generally accepted value of 1AU for the Earth - Sun distance around the ecliptic plane has been found to be wrong. This work clearly shows that sunspots per se do not influence climate change but because the way they are produced, they are indicators that the AU value is changing and it is this that affects the climate. Because the two events are closely linked in time, people thought that sun spots cause climate change, they do not. This also led on to investigate why does not the TSI measurements reflect the findings made. This site clearly states here; http://www.skepticalscience.com/acrim-pmod-sun-getting-hotter.htm "There is no single continuous satellite measurement of Total Solar Irradiance" In researching the this and other sites I soon realised why the TSI variation that should be seen has not been identified, because only the variation in the output of the Sun is being measured, not the total output or TSI. The variation is then appliked to the standard figure of 1368w per Sq M and allowing for the expected orbital position. Bailey's work clearly shows the reason for the historical hot and cold periods etc. -
Ken Lambert at 23:39 PM on 20 September 2010Should The Earth Be Cooling?
Yooper #58, #61 The critical measurement is the TOA imbalance which nets all the heating and cooling forcings. Ref Fig 2.4 of AR4 which gives a total net anthropogenic forcing of +1.6W/sq.m. To this number is then added the climate responses which mainly consist of radiative cooling (from a raised Earth temperature of 0.75 degC as per S-B) of about -2.8W/sq.m and WV and Ice Albedo Feedback of about +2.1 W/sq.m. (Ref Dr Trenberth Fig 4 'Tracking the Earth's global energy) The sum is then +1.6 -2.8 +2.1 = +0.9W/sq.m All the heating and cooling forcings are acting in concert. S-B is emitting IR, Aerosols and clouds are reflecting incoming Solar heat, while CO2GHG are supposedly trapping Solar heat at lower levels (the mechanism is more correctly slowing down the transfer rather than 'trapping' heat) which tends to raise the equilibrium temperature as the analogy of a better insulator increases the T1-T2 temperature difference for a given heat flux transferred. What is certain is that CO2GHG forcing (currently claimed at about 1.6W/sq.m) is logarithmic with CO2 concentration, and S-B radiative cooling is exponential (proportional to T^4). Where these forcings and the others cross is where the forcing imbalance is zeroed and the new equilibrium temperature approached. The CO2GHG theory hangs on the interaction of WV and CO2 in the atmosphere and what will be the surface temperature rise for a unit rise in the IR emitting temperature of the Earth as seen from space. For the first law to be satisfied, most of heat flux 'imbalance' of 0.9W/sq.m should show up in the oceans due to the tiny relative storage capacity of the land and atmosphere (about 5%). OHC is proving most elusive to measure but Argo is the best we have at the present and the latest Willis analysis is not finding the 'missing heat' below 1000m. Here is the story on sea level rise: Thanks to HumanityRules nice summary: quote; "I've found 4 papers looking at closing the sea-level budget around 2003-2007. The latest is from this year. Basin patterns of global sea level changes for 2004–2007 You-Soon Chang, Anthony J. Rosati, Gabriel A. Vecchi Journal of Marine Systems 80 (2010) 115–124 Chang, like the others, calculate the steric and mass components using ARGO and GRACE and compare it to the total change calculated from altimetry. They handily summarize the 4 published attempts to close the sea-level budget in a table. Chang et al (2010) STERIC −0.11±0.22 MASS 0.70±0.34 TOT 2.67±0.52 Willis et al. (2008) STERIC −0.5±0.5 MASS 0.8±0.8 TOT 3.6±0.8 Leuliette and Miller (2009) STERIC 0.8±0.8 MASS 0.8±0.5 TOT 2.4±1.1(2.7±1.5) Cazenave et al. (2009) STERIC 0.37±0.1 MASS 1.9±0.1 TOT 2.5±0.4 Chang and Willis fail to close the budget and interestingly fail with pretty much the same numbers. Leuliette and Cazenave manage to close the budget but by very different means. Leuliette through an equal contribution from steric and mass. Cazenave primarily (80%) through mass." Note Leuliette is the only one of the 4 analyses to get equal mass and steric. Error bars are very wide on all analyses. More mass means less OHC content increase and most coming from ice melt which sinks very ittle heat compared with the claimed imbalance. Yooper - when you have supped on this - please refrain from belching on about my 'misunderstandings', Happy to debate you on any or all of the above. -
Riccardo at 23:37 PM on 20 September 2010A detailed look at Hansen's 1988 projections
Ken Lambert, it's way too easy to talk about apologia without even bothering to look at the details on how things work. This attitude just highlight the unwillingness to learn the science but still dismissing it. The feedbacks are, indeed, feedback, not forcings. Why should they be listed in the same table as the forcings? The albedo, water vapour feedbacks and others are the results of the full calculations and are not parametrized. -
CBDunkerson at 23:29 PM on 20 September 2010The contradictory nature of global warming skepticism
Baz, I dug around in the archives for a good writeup I remembered on statistical significance in the temperature data set. If you read the linked article you may better understand why these 'short term trends' you are relying on are not considered statistically valid trends at all. Ironically, you are dismissing a warming trend since 1995 which has greater than 90% confidence in favor of a 'flat' trend since 2001 which has much lower statistical significance. -
Riccardo at 23:27 PM on 20 September 2010A detailed look at Hansen's 1988 projections
Sense Seeker, #10 in this post there's a comparison of Hansen's calculation in 1988 not a thorough comparison of model results. How could he know the actual emissions in the future? Someone else could do now some new calculations with actual emissions and best available model now, but this is a different story. A good idea for a new post ;) #13 the model is not on radiative forcing alone, it's much more than this; it is called a General Circulation Model (GCM). Radiative forcings come from radiative tranfer codes that are pluged into the GCMs. I think you should dig a little bit more on GCMs; NASA GISS provide a lot of informations (and the code itself) that I'm sure you'll find intersting. -
CBDunkerson at 23:05 PM on 20 September 2010The contradictory nature of global warming skepticism
Baz #296: "Okay, there seems to be some mis-reading here again. Rob, first of all, 0.12 c per decade is NOT statistically significant - ask CBD if you don't believe me." Ask me? Ok. You appear not to know what "statistically significant" MEANS. It has nothing to do with the degree of warming, only the confidence that this warming represents a statistically valid trend rather than merely being an artifact of random fluctuations. A warming trend of 0.12 C per decade could be either statistically significant (the usual confidence level is 95%) or not depending on the data from which it is derived. -
Ken Lambert at 23:04 PM on 20 September 2010A detailed look at Hansen's 1988 projections
I clicked the link to NASA-GISS for the +1.1W/sq.m 2010 relative to 1984 forcing here: http://data.giss.nasa.gov/modelforce/RadF.txt and found data only to 2003 and nothing like +1.1. Please explain the calculation? My eyesight must be playing tricks for I see the actual temperatures running close or below Scenario C not Scenario B. Is that what you meant? And what of the climate responses - where is the estimate of WV and Ice albedo feedback and radiative cooling feedback? Seems like a contrived Hansen apologia with only half the story to me. -
JMurphy at 23:04 PM on 20 September 2010The contradictory nature of global warming skepticism
Spot the differences : Baz : "Please retract the "liar", and I've never said I am irrational." Baz : "Archiesteel - I never claimed to be rational!" So, if you don't claim to be rational and have never said you're irrational, what do you claim to be ? Baz : "You say, "You seem to be arguing that if AGW theory is correct then the temperature would have to increase at a near constant rate." No, I've never said that, not once." Baz : "With no volcanoes the global temp should be ramping up and away." Baz : "How so - against ever-increasing emissions of CO2 and methane? Why isn't the temperature rising Guy?" Baz "Because when warming didn't continue at the same pace (around 2005) I began to question if I was right about my beliefe in warming." So, temperatures should be "ramping up and away", "rising", continuing "at the same pace" but that doesn't mean the same as "at a near constant rate" ? I think you are getting more confused with every post and that is highlighted by this quote from your penultimate post above : "...0.12 c per decade is NOT statistically significant..." What does that mean ? -
Daniel Bailey at 23:00 PM on 20 September 2010The contradictory nature of global warming skepticism
Re: Baz (296, 297)"CBD, Try getting your facts right if you're going to accuse others. I didn't "carefully cherry-pick" that period, it was done by Phil Jones here http://news.bbc.co.uk/1/hi/8511670.stm Happy?"
Ok, you got my interest with your use of "cherry-pick". Let's actually look at what your cite says, shall we?"C - Do you agree that from January 2002 to the present there has been statistically significant global cooling? No. This period is even shorter than 1995-2009. The trend this time is negative (-0.12C per decade), but this trend is not statistically significant."
The time period in question, 2002 to present, was actually brought into play by the commentator, BBC's environment analyst Roger Harrabin (who put questions to Professor Jones, including several gathered from climate skeptics). So you're wrong on that part. I also see that Professor Jones said the period in question was "not statistically significant". Wrong again, sir. You seem to have a severe mental block about statistical significance and trends (it must be that cherry-flavored icing on all the graphs). Dude, you seriously have to get over your trying to force the data to say what it simply doesn't say. The evidence shows you're wrong, the science shows your wrong and your own source you cite to support you shows you're wrong. If you think you're right and everyone else (including experts with lifetimes of experience in the field) say you're wrong, maybe it's because you are wrong... The Yooper -
MichaelM at 22:53 PM on 20 September 2010The contradictory nature of global warming skepticism
quoting Phil Jones:"I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level. The positive trend is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods. "
Baz You are confusing the statistical usage of 'significance' with its everyday use. He is not saying 0.12c/decade is unimportant, he is saying that he can only say it is 0.12C with slightly less than 95% confidence. -
The contradictory nature of global warming skepticism
http://woodfortrees.org/plot/hadcrut3vgl/from:2000/plot/hadcrut3vgl/from:2000/trend http://woodfortrees.org/plot/hadcrut3vgl/from:2001/plot/hadcrut3vgl/from:2001/trend http://woodfortrees.org/plot/hadcrut3vgl/from:2002/plot/hadcrut3vgl/from:2002/trend Flat -
The contradictory nature of global warming skepticism
Okay, there seems to be some mis-reading here again. Rob, first of all, 0.12 c per decade is NOT statistically significant - ask CBD if you don't believe me. As for flat, well that would be here then: http://woodfortrees.org/plot/hadcrut3vgl/from:2001/plot/hadcrut3vgl/from:2001/trend Now, you can always shoose different years and time frames if you want to! It's not exclusive. Whether it's VERY slightly up, or VERY slighty down, it's flat! CBD, Try getting your facts right if you're going to accuse others. I didn't "carefully cherry-pick" that period, it was done by Phil Jones here http://news.bbc.co.uk/1/hi/8511670.stm Happy? Re volcanoes, you know perefctly well I was talking about cooling volcanoes (the Iceland puff never did anything) as it was written clearly in 289, not any little puff (which are always happening somewhere in the world). Talk Pinotubo. As for comments, you must also see that I have taken great pains to answer genuine questions actually posed. If I missed one of your posts then it was as I was replying to others at the time. I'll leave others to judge that. You say, "You seem to be arguing that if AGW theory is correct then the temperature would have to increase at a near constant rate." No, I've never said that, not once. archiesteel: Flat? http://woodfortrees.org/plot/hadcrut3vgl/from:2001/plot/hadcrut3vgl/from:2001/trend Please retract the "liar", and I've never said I am irrational. Read back and check what I actually said on that. Re 'Where's the heat?' So 3 years is good enough for you? I say again, the last 10 years of HadCRUt is flat. -
Sense Seeker at 21:22 PM on 20 September 2010A detailed look at Hansen's 1988 projections
There is one more thing I don't understand. The calculations did not use Hansen's model, but a set of equations from a different source (Myhre et al 1998). Comparison with the forcings as established (beyond doubt, is seems) with an unexplained NASA method, and then conclude that Hansen's model was almost accurate... I am sorry, I can see Hansen got it about right, but this posting adds little to my understanding. -
Sense Seeker at 21:15 PM on 20 September 2010A detailed look at Hansen's 1988 projections
And if you want to test Hansen's scenario B as a prediction, rather than the underlying model, you needn't bother with any calculation. You can just read if from the graph. -
Tenney Naumer at 21:14 PM on 20 September 2010A detailed look at Hansen's 1988 projections
Once the data for 2010 are used, his accuracy will have been prophetic. -
Sense Seeker at 21:09 PM on 20 September 2010A detailed look at Hansen's 1988 projections
Ricardo, you are mostly right but not completely. (Unless I missed something more, which is of course now a non-negligible option.) Shouldn't Table 1 give the realised Greenhouse Gas (GHG) Concentration in 1984 and 2010, rather than the one from Scenario B? The calculations seem to be based on scenario B, not the realised emissions. The real ones may be most like scenario B compared to A or C, but are unlikely to be identical. If you only want to test the model, you need to use the observed emissions as input. -
Riccardo at 20:46 PM on 20 September 2010A detailed look at Hansen's 1988 projections
Sense Seeker, you missed something. Two quotes from the post: "Scenario A assumed continued exponential greenhouse gas growth, which did not occur." "Hansen's Scenario B has been the closest to the actual greenhouse gas emissions changes." -
Sense Seeker at 20:26 PM on 20 September 2010A detailed look at Hansen's 1988 projections
Something here does not make sense. Nowhere do you mention what the actual emissions WERE over the intervening period. You cannot simply compare one of Hansen's scenarios with what actually happened in terms of outcomes, if you do not take into account the inputs. If the temperature curve nicely follows Hansen's scenario B, but the emissions increased exponentially (i.e., according to scenario A), Hansen's model was overestimating by a much larger margin. -
RobertS at 18:41 PM on 20 September 2010How we know the sun isn't causing global warming
Dana1981, I still don't think your section on the D-O events is particularly convincing, especially with regards to the so called "timing flaw" you mention. For the sake of argument, if the LIA was the last cold phase of the D-O cycles, we could place the MWP as the peak of the last warm-phase, and subsequently the Earth should be warming now. Remember, the 1470 figure is the periodicity -- the time interval between peaks (or troughs). The Earth was in a trough several hundred years ago, and it should now be heading towards a peak (i.e. warming). So the fact that the LIA may have been the most recent cold phase of the D-O cycles does not preclude them from adding to the recent warming; quite the opposite. Please see my previous post on this thread for my reasoning on why D-O events cannot have had anything more than a negligible affect on global temps over the past few centuries. -
Philippe Chantreau at 18:05 PM on 20 September 2010Jupiter is warming
And Bob, let's not forget that Venus is warmer than Mercury, which is closer to the Sun... -
Philippe Chantreau at 17:58 PM on 20 September 2010It's cosmic rays
Continued from the thread mentioned above: HR, the word would be laughable but, really, what is there to hang on in the Duplissy paper itself? What paper since Duplissy has been published using CLOUD data? References? Anything yielding more conclusive results? The point was not to reveal problems in the experimental design, but the problems were uncovered nevertheless. If those ultra clean walls can release vapors susceptible of corrupting the results, I don't even want to begin imagine what happens in the real atmosphere, where CCN are already present by the hundreds per cubic cm. -
Philippe Chantreau at 17:41 PM on 20 September 2010A South American hockey stick
HR, the word would be laughable but, really, what is there to hang on? What paper since Duplissy has been published using CLOUD data? Do you have something of any substance? The point was not to reveal problems in the epxerimental design, but the problems were uncovered nevertheless. -
Riccardo at 17:30 PM on 20 September 20102nd law of thermodynamics contradicts greenhouse theory
KnuckleDragger, to explicitly address your first question on absorption/reflection, thinking in this terms could be confusing. In everyday life we call reflection the "bouncing back" of light from a solid or liquid surface. In a gas there's no surface and it could be hard to understand how "reflection" may occur. I think it's easier to think in terms radiation absorption/emission. Quoting from the post: "Any substance that absorbs thermal radiation will also emit thermal radiation; [...]. The atmosphere absorbs thermal radiation because of the trace greenhouse gases, and also emits thermal radiation, in all directions." The backward emitted radiation is what you (and others) call reflection. So, the answer to your question is that CO2 at high concentration is a good absorber and reflector. -
Global warming and the unstoppable 1500 year cycle
Here is a question to the skeptics: why don’t you provide a classification of the different climate theories held by climate skeptics ? People who don’t believe in global warming have entirely different convictions from those who do believe the earth is warming due to natural causes. In fact, these 2 points of view are as different as any skeptic theory is from the AGW theory. In order to advance the discussion, the classification “climate skeptic” is just not enough. F.i. the alternative theories could be named: NoGW, NatGW (with subclassifications: NatGW_solar, NatGW_ocean_currents, …), NonCatAGW (non-catastrophical AGW), etc. AGW is just one of the many possible climate theories – with an overwhelming amount of evidence on its side … -
caerbannog at 16:52 PM on 20 September 2010A detailed look at Hansen's 1988 projections
One thing that folks should keep in mind is that your typical el-cheapo Best-Buy/Walmart/whatever laptop has more computing horsepower than what Hansen had available to him to conduct his climate-modeling simulations back in 1988. This should put things in perspective here, and also give folks a fuller appreciation of Hansen's genius.
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