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Tom Curtis at 15:06 PM on 28 March 2012Solar Cycle Length proves its the sun
tompinlb @4, the fact that the researchers chose to examine the impact of a global effect using only very localized data screams cherry pick to me. If solar cycle length genuinely explains changes in surface temperatures, it would do so globally for the sun is a global influence. Why then did the researchers not apply their techniques to a global temperature index? My guess is that they did, and did not like the result, so they started looking around for a set of local data sets that would give them results they liked. Given the number of such local data sets, it was inevitable they would find something. -
bill4344 at 14:57 PM on 28 March 2012Skeptical Science hacked, private user details publicly posted online
I reckon it's worth keeping tabs on what they're up to with it, all the same! Also, you guys do science, and do it well; I make no great claims on science, beyond recognising who has the argument in this debate, but I do do people and language. And I'm doing this for me; certain combinations of bone-headed stupidity and breathtaking hypocrisy really, really piss me off! Especially when I think of the damage they've actually succeeding in doing already, and their plans to extend it, despite the fact that their imbecility should be apparent to any educated person in our post-Enlightenment world I don't usually bother with such ineducable types, but I've challenged them to deliver the alleged 'smoking guns' they've all happily convinced themselves they've found, Fearless Leader included; particularly anything that in any way supports the notion that SkS authors 'know the facts don't support them'. But - big surprise! - they've got nothing, and some of the marginally-less-deluded of them must be uncomfortably aware of this at some level. -
Stevo at 14:33 PM on 28 March 2012What We Knew in 82
Thanks for that, Rob. Nice ammo to use against the next person who tries to tell me that all those AGW predictions have been proven to be false, or that AGW is some kind of recently invented political scare tactic. -
tompinlb at 14:13 PM on 28 March 2012Solar Cycle Length proves its the sun
A new paper presents evidence that changes in solar cycle length can account for roughly 40 to 50 percent of the historic change in average temperature at a number of stations in coastal Norway. See Solheim Stordahl and Humlum, The long sunspot cycle 23 predicts a significant temperature decrease in cycle 24, in Journal of atmospheric and solar terrestrial physics, February 2012. The scientists have found that in this area, the solar cycle length is predictive of temperatures after a delay of 9 to 12 years, which delay they believe is related to the time frame for solar influences in the tropics to affect the north Atlantic ocean near Norway. They also make a very specific prediction that the extended length of solar cycle 23 will lead to significant cooling in their area of study. This theory will be tested as we see what happens with temperatures over the next ten years. If they are correct, then solar influence on temperature is much more significant, and the effect of co2 much less significant, than the consensus climate science would argue. -
scaddenp at 14:10 PM on 28 March 2012There's no tropospheric hot spot
Also note, that climate sensitivity isnt about CO2 forcing necessarily, but the sensitivity to any radiative forcing change. As TC notes, the water vapour feedback is established directly - some pretty fundamental physics would have to be wrong if not present. Your comments about "torturing data" are misplaced. The question is whether such measurements are able to show the model effect. Finally, "large and catastrophic effects" is rhetoric. Since this is a science site, perhaps its better to confine discussion to effects actually predicted by the science? (ie AR4 WG2). "Catastrophic" means different things to different people. ie for some it would be forced-migration from large deltas because of salt-invasion; while for others it appears to be higher taxes or fuel costs. The argument is that evidence to date suggests its cheaper to mitigate emissions now, rather than pay cost of adaption later. -
Tom Curtis at 13:56 PM on 28 March 2012There's no tropospheric hot spot
tompinlb @14: 1) The lack of a tropospheric hotspot shows the absence of the lapse rate feedback - a negative feedback. The absence of a negative feedback does not show that there are no significant positive feedbacks. 2) The Water Vapour feedback depends primarily on water vapour concentrations in the lower troposphere which are known by direct observation to have increased. The situation where you have a significant increase in WV in the lower troposphere but not in the mid and upper troposphere would result in a strong WV feedback and a weak lapse rate feedback, thus resulting in an overall stronger net positive feedback from the effects of WV. 3) The total effect depends critically on the actual change in the WV concentration profile, which is not well established so the net final effect cannot be absolutely nailed down. 4) Paleoclimate based estimates of climate sensitivity make no assumptions about the relative contribution of different feedbacks, and still cluster around the 3-4 degree C range per doubling of CO2. It may well be that the net feedback of WV (WV feedback - lapse rate feedback) is weaker than predicted by the models, by the net ice and snow albedo feedback is much stronger (which is almost certain). Focusing on just one part of the equation is no basis for ignoring the paleo evidence on climate sensitivity. -
Albatross at 13:51 PM on 28 March 2012Skeptical Science hacked, private user details publicly posted online
DSL @112, "Or maybe they'll continue to sit in the dark, contemplating climastrology while mathturbating." Bravo-- that actually made me laugh out loud. On a serious note, it is really unfortunate that the hacker/s in their zeal to try and intimidate SkS, went beyond the pale by not redacting peoples' private information. That act was truly malicious and uncalled for. As I have said before, these criminal acts only go to underscore the fact that this "debate" is not about science or facts for the fake skeptics, but doing whatever is necessary to continue to further their ideological agenda. -
Tom Curtis at 13:44 PM on 28 March 2012Skeptical Science hacked, private user details publicly posted online
DSL @112, sadly I expect your wrong. I expect the files related to preparing posts on SkS will be largely ignored, as will the files reporting on new scientific papers (except those by "skeptics"). It is clearly evident from the posts by those trawling the files that they have no interest in context, only in something that can be used to demonize SkS and its forum members. -
tompinlb at 13:41 PM on 28 March 2012There's no tropospheric hot spot
I think the argument is not that the tropospheric hot spot is unique to co2 forcing. Instead, I believe what is at question is climate sensitivity. As I understand it, the tropospheric hot spot would reflect the amplification of the co2 forcing by the positive feedback from water vapor that is assumed in the global climate models, through its effect on moist lapse rate. Regardless of how the data may be tortured, as in the "wind shear" argument cited above, all of the radiosonde data shows no evidence for a tropospheric hot spot. And without this tropospheric hot spot, the theory of water vapor multiplying the effect of higher c02 is disproven. Without higher climate sensitivity, the effects of increasing co2 on global temperatures are much more limited. Isn't this the real problem that the lack of evidence for a tropical hotspot presents for the anthropogenic global warming theory, ie. that the theorized high climate sensitivity to co2 increases will have positive feedback with large and catastrophic effects? -
DSL at 13:34 PM on 28 March 2012Skeptical Science hacked, private user details publicly posted online
Oh my god! A secret forum! The "secret forum," of course, reveals nothing of the sort. It is similar to the East Anglia emails, though, in that there is, here and there, more direct language describing the idiocy that is committed and/or bought-and-paid-for denialism (and simply bad science). The forum is so secret that I assumed its existence long before it was revealed to me, and I think that most people must have assumed that some sort of administrative level was required to organize, fact-check, and review the mass of articles. The idea that the primary posters here are using the forum to say things like, "Geez, we've sure fooled 'em with this AGW bit! Ha ha ha!" is simply absurd, and I eagerly await the monumental stupidity that will be required to twist rhetorically forceful bits out of the context of the forum. The thing is, though, I know a number of bloggers who are up to the task--whose very existence as bloggers, in fact, relies on that particular skill. Denialsville, ya got nothin', and so ya had to steal somethin'. One good thing, though, is that in searching for something to mutilate, these people will be forced to encounter the discussion and the science. Maybe a lightbulb will pop on. Or maybe they'll continue to sit in the dark, contemplating climastrology while mathturbating. -
Albatross at 13:15 PM on 28 March 2012Skeptical Science hacked, private user details publicly posted online
Bill @110, Thanks for the support. Don't fret too much on our behalf and let those who revel in using stolen personal information and take delight in others' misfortune, have fun in their own little dark corner of the internet. Rest assured, the SkS team are hard at work as we speak drafting new posts speaking to the science, and will contine to do what we do best-- refuting myths and misinformation disseminated by fake skeptics. Onwards and forwards. -
bill4344 at 12:24 PM on 28 March 2012Skeptical Science hacked, private user details publicly posted online
Thought I'd point out that the ever-dignified and responsible Bishop Hill has gone beyond merely linking to the leaked material (via Tom Nelson and the egregious Shub). Now he's made it the subject of a whole new post. First the man himself has a bit of a gloat and a 'you wish!' ramble -It looks like John Cook and co at Skeptical Science are in a bit of a tizzy because their secret forum has been exposed to public view. Their complaint is that they have been hacked though John Cook admits that their security is almost non-existent. What is interesting, in reading some of the excerpts from the forum posted here, is the similarities between the SkS secret forum and the Climategate emails - i.e. we know the facts don't support what we say but don't tell anyone! That's ok, guys, your secrets are safe with us ;-)
He's christened the event 'Opengate' (zero for originality, but at least the troops will have an easily-remembered shorthand reference for making future snide remarks), has commissioned yet another 'hilarious' cartoon from Josh, and all the little muckers are having a grand old time cherrypicking to their hearts' content in the thread. Now, Watts opposed using the hacked material, and there are two very good reasons for this - principle, and enlightened self-interest, which are not distinct, anyway. As a good example, state leaders don't generally commission the assassination of other state leaders they are in conflict with, if only on the simple basis that sauce for the goose is also sauce for the gander! The egregious Montford has effectively renounced any right whatsoever to complain should such an event occur targeting himself, or any of his similarly unprincipled cronies. It's that simple. -
barry1487 at 12:05 PM on 28 March 2012The Skeptical Science temperature trend calculator
Dikran @19 it is some comfort to know even the experts struggle with this. It is a devil of an issue in the climate debates. Hard to explain and easily misunderstood, when indeed it is even brought up, as it should be. Tamino has to be recognized as a great educator on this. RC, Open Mind and SkS, my top three sites on the mainstream explanation of the AGW issue. Cheers. -
barry1487 at 11:57 AM on 28 March 2012The Skeptical Science temperature trend calculator
Daniel @18 Well said. So it seemd to me. My point is that those caveats weren't clearly exposited when mainstream commenters introduced the matter to the lay audience. Hence, skeptics can now exploit the simplified version to advantage. I don't have any answers to the perennial balancing act in reporting science to the GP. It's a tough gig, particularly when there are commenters and pundits who are mining for any tittle that supports their agenda rather than helping to shed light on understanding. -
Doug Hutcheson at 11:46 AM on 28 March 2012An Open Letter to the Future
william @ 26 and pjamm @ 30, clay tablets are fragile and metal tablets are prone to be recycled. Perhaps stone tablets would be more durable. Perhaps they could be stored on a mountaintop somewhere in the Middle East. Maybe we could even boil down our warnings into a few simple rules: ten might do the job. In the arid regions, stone tablets on a mountaintop should be good for a few millennia, until the next tribe of lost souls discovers them. You never know, it might start a movement of some kind. -
Glenn Tamblyn at 11:21 AM on 28 March 2012HadCRUT3: Cool or Uncool?
GISTemp offers an interesting graphing facility that lets you look at land, ocean and combined data by year and latitude. This is SST's with a 3 year averaging. This does not include the adjustments made by Hadley recently that iis attempting to correct for different methods of sampling surface temps by ships in the past and the effect of changing proportions of ships using each method. This is most clearly seen during WWII with August 1945 having been identified as a point where a significant change in the mix of nations sampling SST'2 occurred. And the 'hump' in the 40's is reasonably defined and short duration. This is one of the issues the new Hadley SST series, which is one part of the upcoming HADCruT4 release
In contrast the early 20th century warming on land (again 3 year averaged) is a much gentler 'hump' over more years. And when we look at where the warming happened, it wasn't global. It was mainly high Northern latitudes.
This was happening at the same time as station coverage was increasing (grey areas don't have adequate coverage). So interestingly this warming in substantially the Arctic was occurring at the same time as station coverage was in flux - we didn't have truely global coverage till the late 50's.
Could the addition of new Arctic stations at a time when there was still no coverage in the Antarctic have introduced a bias in the record during this period. There are theories that suggest there is an oscillation between the Arctic & Antarctic with a roughly 1/2 century period. If Antarctica was colder at the same time the Arctic was warming, we wouldn't see it.
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barry1487 at 11:19 AM on 28 March 2012The Skeptical Science temperature trend calculator
Here's the exact quote. "For the next two decades, a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios" I think a reasonable range for "about" would 1.5C - 2.5C per decade. Almost always overlooked is the time frame stipulated - two decades is likely a long enough period for the signal to become apparent. Literally speaking, the estimate should be checked in 2026, 20 years after the 'projection.' And the prediction does not include the possibility of significant events that could skew the predicted trend from CO2 warming, like a series of major volcanic eruptions. For the die-hard skeptics, perhaps the forecast could have been qualified, "all other forcings being equal" or some such. -
Glenn Tamblyn at 10:19 AM on 28 March 2012HadCRUT3: Cool or Uncool?
Chris G Yep, circulation in the ocean is the big difference factor compared to land. Any fluid movement - natural convection, currents etc is a far more efficient transporter of heat than Conduction in a solid such as rock. wrt area weighting of station data, GISTemp uses a system much as you describe so that multiple stations in a region contribute a weighted average to that region. The regions are still gridded squares but they use realtively small sub-grids and allow stations from out-side those sub-grids to contribute to the weighting. Then the average sub-grids to produce larger grid-cells. Your comment about @5 about treating the temperature data as a surface with sample points is much the way I think of it. Map the Earths spherical surface onto a 2D grid. Then each met station is a point on that grid. And the height is the temperature (or better temperature anomaly) at that point. What you end up with is like a wonky bed-of-nails. Then lay a flexible sheet over the 'nails' and it adapts to the conrours created by the height of the nails. I'm sure disciplines like Topology would have some interesting math that could be applied to this. An important think to consider is the question of how 'flexible' the 'sheet' is. A really flexible sheet (imagine it as being like cling wrap) would drap down around the 'nails' so your profile would still look overly spiky. Too rigid a sheet might not flex anough and miss some of the nails. The 'rigidity' of the sheet is essentially an aspect of the climate that determines what level of sampling density we need to adequately determine the true contour. Just how much does climate vary from location to location and hence how close together do the nails need to be. Here the difference between the nails being Temperatures or Temperature Anomalies really matters. With working with temperatures there are local factors that mean relatively close locations can have very different temperatures, local changes in altitude being the most significant. So if we work with temperatures for our nails the 'sheet' is effectively very flexible and we need a high station density. However if we work with Temperature Anomalies, how much each station has changed compared to a baseline average of itself, then the variability between nearby stations is much less, and we can meaningfully work with fewer stations further apart - the sheet is stiffer. This idea really ties a lot of people up in knots and is the underlying driver for much of the 'Dying of the Thermometers', 'Its bad stations' type memes that have had so much traction. Most people can't get their heads around the difference between working with Temperatures and Temperature Anomalies. And Joe Public probably assumes that the calculations are done using Temperatures. I did a 4 part series on this nearly a year ago that goes through a lot of this. -
John Hartz at 10:09 AM on 28 March 2012Skeptical Science hacked, private user details publicly posted online
Riccardo & DB: Interpol will sort it all out in good time. -
Daniel Bailey at 09:12 AM on 28 March 2012Skeptical Science hacked, private user details publicly posted online
Just people making unsupported assertions... -
Riccardo at 09:02 AM on 28 March 2012Skeptical Science hacked, private user details publicly posted online
Who said that the attack came from Russian hackers? I don't think anyone knows at the moment. -
barry1487 at 09:02 AM on 28 March 2012HadCRUT3: Cool or Uncool?
Very clear explanation, thanks. -
Chris G at 08:46 AM on 28 March 2012HadCRUT3: Cool or Uncool?
Thanks KR, I came up with the basis of that algorithm when working on how to automate the detection of clusters of points on a grid; they jump out to a human eye - not so much to a computer. Coincidentally that was about the same time that Hansen published that paper. Not sure whether to be pleased to have come up with a similar solution, or embarrassed that I was unaware that was what GISS has been doing for so long. Guess I just figured they knew what they were doing and someone would have pointed out otherwise. Kevin, Thanks, I'll have a look. Yeah, complicated only if you think of it as trying to convert unequal grid cells to grid cells of equal size; not at all complicated if you simply calculate the surface area of the grid, and weight the grid that by compared to total surface area. Oh well, comment in haste... -
JMurphy at 08:08 AM on 28 March 20122012 SkS Weekly Digest #12
Good program on tonight called 'Global Weirding'. It had Kerry Emanuel, Katharine Hayhoe, Adam Scaife and Mike Lockwood (among others) trying to explain the strange things going on with the weather all around the world. The denialosphere must be apoplectic, especially as it was on that left-wing, UN-backed (supposedly) BBC ! -
TOP at 08:07 AM on 28 March 2012Skeptical Science hacked, private user details publicly posted online
@yocta The general tone here has been that this was some kind of attack on SkS for ideological reasons and yet it has previously been pointed out that the attack came from Russian hackers who would likely be more motivated by money, ego or status. Your acronym leaves out one letter, "S" for stepping stone. The real value to a group of hackers (having had my site hacked once) is to facilitate further cyber-shenanigans. A list of email addresses allows a hacker to attack those computers, installing bots that allow further attacks on other sites. SkS list has to be a real treat since the base is so large and diverse and so many are associated with educational facilities. At least it hasn't made it to wikileaks yet. -
andylee at 07:59 AM on 28 March 2012Peter Hadfield Letter to Chris Monckton
Cornelius, I grew up with hyperthyroidism until surgeons removed most of my thyroid at age 18. I didn't notice that there was anything 'wrong', nor was aware of it apart from my extreme appetite for food and precociousness. I benefited from having a system clock on turbo as a teenager discovering computers! Might explain that I found it difficult to settle and fit in anywhere because I was intellectually unsatisfied by most of my peers and became a maverick, but apart from that I really didn't consider that hyperthyroidism was a big deal. -
frankodwyer at 07:29 AM on 28 March 2012The Skeptical Science temperature trend calculator
"the IPCC projection of 0.2°C/decade" Can you give a reference for this? IIRC the IPCC report actually says "*about* 0.2C/decade" - while it may seem like a nitpick, the difference does matter as (for example) 0.17C is by any reasonable interpretation "about 0.2C", but it's not 0.2C. I think this "0.2C' claim actually originates with 'skeptics', and not the IPCC (as by exaggerating the IPCC claim and neglecting the uncertainty, it makes for an easier strawman to attack, at least in the short term). -
Albatross at 07:17 AM on 28 March 2012PMO Pest Control: Scientists
Rust @24, No surprises there. He and his conservative counterparts are continuing to be disingenuous to this day. This story on the muzzling on canadian federal scientists has just been posted on CBC. The narticle also contains these examples: "A group representing 500 science journalists and communicators across Canada has documented instances where they say federal scientists have been barred from talking about research funded by taxpayers. In addition to DFO scientist Kristi Miller, they cite: An Environment Canada team published a paper on April 5, 2011, in Geophysical Research Letters concluding that a 2 C increase in global temperatures may be unavoidable by 2100. No interviews were granted by Environment Canada's media office. Following the March 2011 Japanese earthquake and nuclear plant problems, Postmedia science reporter Margaret Munro requested data from radiation monitors run by Health Canada. Munro said Health Canada would not allow an interview with an expert responsible for the detectors. An Austrian team released data from the global network of radiation monitors, including stations in Canada. Other examples include: The 2010 case of Scott Dallimore, a Natural Resources Canada scientist who could not talk about research into a flood in northern Canada 13,000 years ago without getting pre-approval from political staff in the office of then-Natural Resources Minister Christian Paradis. Approval came after reporters' deadlines passed, according to Postmedia News. The 2011 case of David Tarasick, an Environment Canada scientist whose research showed an "unprecedented" loss of protective ozone over the Arctic. He was not available to talk with reporters when the research was published, and was interviewed three weeks later. "I’m available when media relations says I’m available," he told Postmedia News." Canadians need to take note of this abuse of science and scientists by the conservative government, it is their reputation and their tax dollars and potentially their safety that are being threatened. -
Paul D at 07:12 AM on 28 March 2012New research from last week 12/2012
Stefan Rahmstorf has published an article on Realclimate about the paper/article I mentioned @8: Extremely HotModerator Response: [DB] Fixed link. -
Kevin C at 07:07 AM on 28 March 2012HadCRUT3: Cool or Uncool?
Chris: Yes, the grid cells are weighted by area. An improved method, used by GISS, involves allowing the number of cells to vary by latitude to keep roughly constant area. It's pretty simple in practice. As well as GISS, you might want to take a look at what Nick Stokes has done in TempLS. He's looked at weighting each station by the unique area around it and loads of other nice stuff, some of which anticipated the ideas in BEST. Steve Case: Sorry, I'm talking about anomalies exclusively in the article. I was trying to remember to put the word anomaly in everywhere, despite the repetition, but missed some. Since the temperatures are always converted to anomalies before averaging, the difference in the absolute values disappears. Martin: The land/ocean bias is not enough on its own to explain the difference between HadCRUT3 and, say, GISTEMP. There is another major source of bias in HadCRUT3 as well - you have probably read about it elsewhere. Once we've looked at that I think you will have your answer. I started with the land/ocean bias because it is obvious and introduces the concepts. -
martin3818 at 06:30 AM on 28 March 2012HadCRUT3: Cool or Uncool?
A bias of 0.03°C - that doesn't seem to very much. Is that enough to explain why global warming seems to have stopped?Moderator Response:[DB] "Is that enough to explain why global warming seems to have stopped?"
Non sequiter. Please see the following post: http://www.skepticalscience.com/Breaking_News_The_Earth_is_Warming_Still_A_LOT.html
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william5331 at 06:17 AM on 28 March 2012New research from last week 12/2012
The suggestion that marine species may not be able to migrate quickly enough to keep up with the warming of the ocean is a tad strange. Many marine species are themselves mobile and the sessile members of the marine flora and fauna have pelagic larvae. At every spawning, they are spread far and wide and those that settle in favorable areas grow and prosper. If you have dived on coral reefs around the world you will have seen that the assemblages of animals are virtually identical in all of these. Quite a different situation from the assemblages of animals (pre human) on different continents and islands. -
DMCarey at 06:14 AM on 28 March 2012Peter Hadfield Letter to Chris Monckton
bibasir, Watching a tv wrestler pull a rabbit out of a hat would be an entertaining treat indeed -
HadCRUT3: Cool or Uncool?
Chris G - "I'm thinking that it should be possible to use an alternate method. I have one in mind where each station contributes a measurement that is weighted according to the distance from the station." What you are describing is the GISS method, as described in Hansen and Lebedeff 1987, where the measurement weighting is driven by the observed correlation of temperature anomaly with distance. Each measurement within a certain radius of a point (up to 1200km) is weighted by the distance correlation when calculating an estimate at that location. -
Chris G at 05:45 AM on 28 March 2012HadCRUT3: Cool or Uncool?
Steve (#8), I think you are taking those numbers from a graph showing monthly averages aggregated over the period from 1901-2000. No way to see if the difference is constant over the entire period, just given those numbers. Your graphs seem to show a divergence becoming more pronounced about 1980, but that is just the old eye-ometer. -
Paul Magnus at 05:25 AM on 28 March 2012The Skeptical Science temperature trend calculator
Can we have ones for : SLR, Extrem Weather, oil price....:) -
Chris G at 04:49 AM on 28 March 2012HadCRUT3: Cool or Uncool?
I see "Stephen McIntyre" posts a comment at the Nature site. It's good to be as accurate as possible, but let's not make a mountain out of a molehill; the larger upward trend is not changed much. -
muoncounter at 04:48 AM on 28 March 2012New research from last week 12/2012
shoyemore#14: "the latest offering in the cosmic ray theory of planetary climate," Please don't used the term 'theory' so loosely. As discussed here, cosmic rays may remove ozone. And here, 'ozone hole healing' leads to warming? So more cosmic rays -> less ozone -> cooling. Or more cosmic rays -> more clouds -> cooling. Or whatever you want it to be, using whatever model you want. As long as it doesn't include CO2. -
Chris G at 04:43 AM on 28 March 2012HadCRUT3: Cool or Uncool?
Dana (#7), I suspect you are talking about the difference between the methods used by US ships versus those used by British ships. http://www.nature.com/news/2008/080528/full/453569a.html Another form of bias introduced, this time by measurement method, rather than calculation method. I wonder how many will cry foul about the changes made at HADCRUT4 without really bothering to check on why the changes were made. -
Manwichstick at 04:43 AM on 28 March 2012New research from last week 12/2012
Agreed! RESPECT for the intro! -
Steve Case at 04:18 AM on 28 March 2012HadCRUT3: Cool or Uncool?
From the article: "Until 1980 the bias is small, because the land and ocean temperatures do not differ significantly. After 1980, the difference between the land and ocean temperatures becomes significant ... " Haven't land and ocean temperatures always been significantly different by around 7.5°C? What am I missing? Here's what NOAA says: Land Surface Mean Temp. 1901 to 2000 (°C) 8.5 Sea Surface Mean Temp. 1901 to 2000 (°C) 16.1 Source scroll down half way. Here's a graph I made some time ago that plots out the difference in trend between the two:
Here's one I made about the same time that plots just the difference.
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dana1981 at 04:18 AM on 28 March 2012HadCRUT3: Cool or Uncool?
I believe the mid-century 'hump' has been reduced in HadCRUT4, being primarily due to inconsistent sea surface temperature measurement methods at the time, which they have now adjusted for. -
Chris G at 04:12 AM on 28 March 2012HadCRUT3: Cool or Uncool?
WRT my #4, something is not quite right. I'd expect the WWII temperature hump to be more pronounced in the land than the sea, but that is not the case. -
Chris G at 03:59 AM on 28 March 2012HadCRUT3: Cool or Uncool?
I need to move on to other things, but it seems to me that deciding on a grid model, any grid model, presents its own challenges and shortcomings. I'm thinking that it should be possible to use an alternate method. I have one in mind where each station contributes a measurement that is weighted according to the distance from the station. Not sure how to explain the math, but I visualise it as a globe with a calculated height above it (false surface map/tent) where the height above the 'sphere' represents the temperature (or temperature anomaly). How much any station contributes its measurement to the temperature value any given point on the surface is a function of how close it is to that point, and how much other stations are also contributing their measurements to that point. Total weights for all stations at any give point is always scaled to 1. Once you have the contour of the surface defined, you can integrate over it any way you like, grid it out, whatever. Sounds complicated, but it would not be that difficult to program. -
Chris G at 03:21 AM on 28 March 2012HadCRUT3: Cool or Uncool?
Hmm, that spike in land percentage around WWII happens to coincide with the hump in the temperature record. I suspect the hump is a little exaggerated. Relative to GISTEMP, it is. Thanks Kevin, Now I'm thinking about the 5 degree grid. When it comes to the global averaging, and 5 degree cells are not all the some size, the math to weigh a fixed surface area size equally becomes complicated. IMO, you'd have to weigh surface area equally if you are talking about a global surface temperature average. -
Kevin C at 03:09 AM on 28 March 2012HadCRUT3: Cool or Uncool?
Chris: Yes, you are right about circulation being a critical factor in the slow warming of the oceans; i.e. you have to heat a lot more water because it keeps changing over. HadCRUT3 uses a fixed 5 degree grid. That also means that the high latitude cells are smaller than the equatorial cells, so you actually need a higher density of stations at high latitudes to achieve the same coverage. The common anomaly method used in CRUTEM3 also means that they lose stations as they go away from the baseline period (1961-1990). -
Chris G at 02:59 AM on 28 March 2012HadCRUT3: Cool or Uncool?
Nice job explaining the problem of making sure that a sample represents the population. Pretty simple coverage here, for sure, but there are entire courses on avoiding sampling bias. "How do you know your random sample is really random?" and so forth; so, good for this venue. Question regarding: "...as would be expected given the higher heat capacity of water." I'm thinking that the temperature difference would have more to do with the fact that water tends to circulate to depth more than land does; so, you get the same energy distributed over more mass. On land, there is less "buffering" because the surface warms, and it takes a long time for the energy to equilibrate to much depth. Water cp ~= 4.2 (J/(g·K) Silicate rock ~= 0.75 (J/(g·K) but rock is about 3 times more dense; so, the difference per volume is about 2x. So, yeah, a given volume of water has about twice the heat capacity. But, I'm still thinking it has more to do with circulation because if you put rocks in a bucket of water, they all come to the same temperature in not much time. "Land coverage in the HadCRUT3v record has been declining over the past 50 years." Really? I could see them making use of a different set of stations, for various reasons, but I would expect them to grid it out so that the actual land surface area coverage did not decrease. Oh, I think I get it. They like to pretend that areas with poor coverage do not exist (at least for the calculations) and the sea surface coverage has been increasing relative to land surface. Ah, alarm bells just went off on my sampling bias detector. Double counting the coastal cells does not really improve the situation either. Nice bit of showing that stratified populations need to be sampled independently, their means calculated independently, and then trend and other analysis performed. -
Dikran Marsupial at 02:55 AM on 28 March 2012The Skeptical Science temperature trend calculator
Barry, following on from what Daniel says, the "normal circumstances" for statistical significance tests include the period you are looking at being randomly chosen. In this case the period is not randomly chosen, the question that Phil Jones was asked was loaded by having a cherry picked start/end date, which biases the test towards the desired result. "Warmists" could similarly bias the test by starting the period in say 2000, and the fact that they don't (other than to show why cherry picking is a bad thing) shows who is seeking the truth and who isn't! ;o) IIRC Phil Jones actually gave a very straight answer to the question (no it isn't significant, but it is very close to being significant and that you need more data to be able to expect to reach significance). I suspect that much of the misunderstanding is due to some sceptics having only a rather limited understanding of what significance tests actually mean. Unfortunately they are not straightforward and are widely misunderstood in the science, and even amongst statisticians! ISTR reading a paper where the authors had performed a survey of statistics students understanding of the p-value, and compared that with the answers given by their professors. A substantial majority of the professors failed to get all five/six questions right (I would have got one of them wrong as well). So if you struggle with statistical significance, take heart from the fact that we all do, including statisticians! ;o) -
John Hartz at 02:47 AM on 28 March 2012New research from last week 12/2012
Ari: I love your intro! -
John Hartz at 02:46 AM on 28 March 2012New research from last week 12/2012
@Kevin C #18: Dumb questions: What the heck is the half-life of a scientific journal? How is it determined? By whom?
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