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Comments 111301 to 111350:
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RSVP at 00:10 AM on 1 September 2010Urban Heat Islands: serious problem or holiday destination for skeptics?
"...results in a slightly warmer envelope of air over urbanised areas when compared to surrounding rural areas.." Why not express this in degrees centrigrade? -
Tom Dayton at 00:03 AM on 1 September 2010The surprising result when you compare bad weather stations to good stations
No, omnologos, the definition of a "bad" site does not mean the site fails to correctly measure anything. The siting guidelines do not even include the label "bad." The label "bad" was invented by Watts to exaggerate the shortcomings of some stations, in Watts's desperate attempt to discredit AGW. -
omnologos at 23:49 PM on 31 August 2010The surprising result when you compare bad weather stations to good stations
@adelady and @Dappledwater: I understand my description of the logical issue is too short and cryptic. I will try to reformulate it. Basically if a measurement site needs to follow certain guidelines, then if it doesn't follow those guidelines it should not be included with those sites that do follow those guidelines. Or alternatively, if those guidelines are shown not to matter, then what is the point of the guidelines in the first place? "The warming signal is so significant it shows up in both good and bad sites" is not an answer: if a site is "bad", then by definition it does _not_ correctly measure anything. Same regarding "consistent measurement": a consistently-bad measurement is consistently wrong, again by definition. If a trend appears and it is "right", it's just pure luck with no scientific value or basis (unless, once again, somebody is able to show that the guidelines really don't matter). The above is valid for any measurement setting, not just temperatures. Hopefully nobody wants to destroy the foundations of "measurement science" this side of Galileo. -
bobconsole at 23:34 PM on 31 August 2010Climate's changed before
Lung cancer existed before cigarettes were invented too. Does that fact invalidate cigarette induced lung cancer? -
Rob Painting at 23:28 PM on 31 August 2010Sea level rise: the broader picture
Ken, that set of posts was entertaining. And yet here you are still banging on the same old drum. -
Ken Lambert at 23:10 PM on 31 August 2010Sea level rise: the broader picture
And lo and behold: Here's the quote from #42: "Chris and I have debated the TOPEX - Jason satellite transition - and if the two trends are linearized - there is a flattening in the Jason record closer to 2.0mm than 3.2mm per annum often quoted over the combined record. There is also the probably of an offset error in the transition." -
The empirical evidence that humans are causing global warming
Unrecovered - Exactly, I was talking about the transient state. However, given the thermal inertia of ocean warming, that transient can last for a long time... The 0.9 W/m^2 is on the edge of measurement tech right now, but the difference in emission spectra is measurable and clear. And, very importantly, indicates that conditions on Earth have to change in order to radiate the same amount of energy as before that spectral change (reduction), primarily by warming up. -
Rob Painting at 23:08 PM on 31 August 2010The surprising result when you compare bad weather stations to good stations
Omnologos @ 10 - "The graphs show there is something effecting an upwards trend in both "well sited" and "poorly sited" stations." Yes, global warming. The warming signal is so significant it shows up in both good and bad sites. A more interesting question is why the bad sites show less warming, which is why you should read the intermediate version here -
Ken Lambert at 22:56 PM on 31 August 2010Sea level rise: the broader picture
BP #19 Another interesting post. We dealt with the Jason-Topex in the 'Astronomical Cycle' thread here: http://www.skepticalscience.com/news.php?p=3&t=141&&n=232 I came up with a similar flattening of Jason and an offset between the two linear trends of Jason and Topex from a pencil and ruler analysis. -
adelady at 22:54 PM on 31 August 2010The surprising result when you compare bad weather stations to good stations
omnologos Correct measurement of temperature isn't the prime requirement for climate trends. Consistent measurement is the important issue. For climate trends we're only interested in the change in temperatures rather than the temp itself. That's why it's important when a new and better thermometer is installed at a site, the first thing that is done is to note the records accordingly. The new temperature recordings mustn't be allowed to falsely show a change in actual temperatures. -
muoncounter at 22:51 PM on 31 August 2010Human CO2: Peddling Myths About The Carbon Cycle
#14: "there is far greater capacity to sequester CO2 than is fully realised. " If, by sequester, you mean temporarily house within the plant growth for half of the annual cycle. Take those cycles out and you're still left with an uptrend
-- which is not, as far as I can see, part of the annual cycle. What is left that is also increasing from year to year and is also the right multiple of the annual atmospheric increase?
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Rob Painting at 22:34 PM on 31 August 2010Sea level rise: the broader picture
JohnD - note the familiar figures (although unrelated) , from Church et al 2006: Sea level rise around the Australian coastline and the changing frequency of extreme sea-level events "Australian sea-level records for the period 1920-2000 clearly indicate a rise in relative mean sea level. Averaged around Australia, the rate of increase is about 1.2 mm per year. This value is less than the global increase in eustatic sea level for two reasons. First, the sea-level rises presented here are relative sea level and do not include any correction for ongoing crustal motion. To estimate eustatic sea-level change from the data from the Australian sites, the rates of sea-level rise would typically need to be increased by about 0.3 mm per year. Second, at least for the period 1950 to 2000, sea-level rise off western Australia less than the global average (Church et al. 2004), possibly as a result of the trend to more frequent, persisent and intense ENSO events since the mid-1970s." -
omnologos at 22:28 PM on 31 August 2010The surprising result when you compare bad weather stations to good stations
This poses a logical issue. The graphs show there is something effecting an upwards trend in both "well sited" and "poorly sited" stations. But if "poor siting" doesn't matter, _either_ the USHCN guidelines are useless/unimportant for a correct measurement of temperatures and there is no such a thing as "poor siting" (i.e. "warming" can be detected whatever the quality of the siting) _or_ the USHCN guidelines are useful/important for a correct measurement of temperatures, and therefore the upwards trend can't be ascribed to an actual "warming". ?? -
Rob Painting at 21:52 PM on 31 August 2010Sea level rise: the broader picture
Almost forgot, these guys also found: An Anomalous Recent Acceleration of Global Sea Level Rise Some quotes: "If the early twentieth-century acceleration is global in scale, we speculate that it differs from the recent acceleration in that the Northern Hemisphere apparently contributed significantly to the early event but little to the recent event." BP take note of the above. "1) the global sea level rise rate has accelerated from 1.5 mm yr prior to 1990 to a present day rate close to 3.2 mm yr" & "2) the acceleration in global sea level is accounted for primarily by the tropical and southern oceans, because of a phase change in the way the two regions covary: out of phase during relatively steady global sea level trends, and in phase during the trend increase" Which gels with the satellite altimetry and Seaframe stations mentioned in Ned's post @ 38. -
johnd at 21:43 PM on 31 August 2010Sea level rise: the broader picture
Dappledwater at 21:09 PM, the article referenced was about the establishment of the Tidal Reference Frame For Queensland. It utilised the established rate of sea level rise averaging 0.0003 metres, 0.3mmm per annum for the Australian continent (Mitchell, 2002). It detailed the implementation of the tidal datum epoch (TDE) which is the interval recommended for the calculation of datums. The TDE is normally longer than 18.6 years in order to include a full lunar nodal cycle, so looking for trends should only be looked for over multiple TDE's. From another source, the Permanent Committee for Tides and Mean Sea Level (PCTMSL) recommended that a 20-year TDE, 1992-2011 inclusive, be adopted for the determination of Lowest Astronomical Tide and Highest Astronomical Tide, so you see we are not at the end of that period yet. -
CBDunkerson at 21:26 PM on 31 August 2010Can humans affect global climate?
Singer is the worst of the worst. Cigarettes are not harmful. Asbestos is good for you. Acid rain does not exist. There is no ozone hole. Name a just plain crazy wrong 'scientific' position of the last thirty years and chances are he has been one of its prime proponents. That said, the statement quoted above is classic Singer. Pretty much everything he says takes some minor element of 'truth' and uses it as the foundation for a complete lie. In this case, "one-twentieth of a degree by 2050" is an extremely low, but not completely impossible, estimate while "imperceptible effect on future temperatures" is an outright lie. This is because most of the warming between now and 2050 is already 'locked in'. Complying with the Kyoto benchmark (1990 emissions levels by 2012) and sticking to that level would very likely have more than a 0.05 C impact on the 2050 global temp anomaly, but it would also mean at least 1 C difference in 2100 and even more further out. -
Ned at 21:10 PM on 31 August 2010Sea level rise: the broader picture
Miekol writes: Is science sea levels different to island sea levels? and links to Jo Nova's website, where Ms Nova writes about sea level data measured at a network of stations on various South and Southwest Pacific islands. We discussed that network of stations recently in another thread. If you ignore Ms Nova's selective and misleading analysis, and look at the full data for all of the islands in the network, you will find individual trends ranging from +3.2 to +8.6 mm/year (ignoring one outlier of +16.8 mm/year). The mean is +5.4 mm/year and the median is +4.9 mm/year. This compares very well with the satellite-derived sea level trend, which is only +3.3 mm/year (over the past two decades) for the world as a whole but higher in the Southwest Pacific. For some unfathomable reason, Ms Nova fails to quote the annual reports from this network of stations: The net sea level trends are positive at all sites, which indicates sea level in the region has risen over the duration of the project. The sea level rise is not geographically uniform but varies spatially in broad agreement with observations taken by satellite altimeters over a similar timeframe. [...] The sea level trends from SEAFRAME stations are mostly higher than the global average rate, but this is consistent with higher rates in the southwest Pacific measured by satellite altimeters -
Rob Painting at 21:09 PM on 31 August 2010Sea level rise: the broader picture
JohnD - I didn't understand at all what his original post was about. As far as Australia is concerned the trend is lower than the global average as at 2003 it was 0.9 mm (1.2mm when two outlier stations were removed) per year from a 25 year record of 32 sea level stations around Australia. Australian Mean Sea Level Survey 2003 National Tidal Centre Bureau of Meteorology At the BOM site you'll find the Australian Baseline Sea Level Monitoring Project, however it's only been running since the early 90's, Here's their latest annual report: ANNUAL SEA LEVEL DATA SUMMARY REPORT JULY 2008 - JUNE 2009 You'll have to google the first link, it's not working. -
huntjanin at 20:58 PM on 31 August 2010Sea level rise: the broader picture
I'm compiling a list of "sea level poster-children," by which I mean cities that are now facing or in the future will face problems due to the rising seas. This list now includes about 35 cites, located in 17 countries. It is too long for use in my book on sea level rise, so I want to cut it down. Please feel free to give me your own candidates for "sea level poster-children." -
michael sweet at 20:57 PM on 31 August 2010The surprising result when you compare bad weather stations to good stations
It is known that sometimes the adjustments for urban heat island introduce biases into the trend. They compare urban stations to nearby rural stations. If the urban station shows more increase they adjust it lower. If the urban station shows less increase they keep it. You would expect some urban station to be higher just by chance. This causes the adjusted values to underestimate the warming. Deniers claims that adjustments raise the trend are false. I think they do the adjustments in an attempt to get the best information possible. As pointed out above, the trend is much larger than the adjustments so it really doesn't matter much. -
johnd at 20:21 PM on 31 August 2010Sea level rise: the broader picture
Dappledwater at 20:16 PM, do you have the records for Australia which would be relevant to what Meikol posted about originally? -
Rob Painting at 20:16 PM on 31 August 2010Sea level rise: the broader picture
Scarping the bottom of the barrel huh Meikol?, Jo Nova?. From GLOSS, here's Suva, Fiji:
Marshall Islands
American Samoa
Looks like more than a bit of sea level rise since 1993 to me. Of course if you remove the "anomaly", the sea level rise - like Gray has, of course you won't see any sea level rise!.
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JMurphy at 20:12 PM on 31 August 2010Sea level rise: the broader picture
miekol wrote : "Is science sea levels different to island sea levels?" Don't know what that means but science at Joanne Nova's site (which you have just linked to) is different from science in reality. See : How Jo Nova doesn't get past climate change, How Jo Nova doesn't get the CO2 lag, How Jo Nova doesn't get the tropospheric hot-spot, A Scientific Guide to the Skeptics Handbook. Is that the best you can do ? -
johnd at 20:06 PM on 31 August 2010Sea level rise: the broader picture
miekol, mariners operate in real world conditions ;-) -
Argus at 20:04 PM on 31 August 2010Arctic sea ice... take 2
doug_bostrom, After a long series of insinuations and subjective guesswork on your side, about the real "meaning" of my words, you finally approach at least one of the topics I wanted to have a discussion around. That's good. But was all your arrogant language necessary? If I bring up facts not covered in the top post, does that imply that I "want to create an impression of doubt"? Would you thus like to exclude everyone who doesn't agree with you or the post author, from asking questions? Is it wrong to "wonder"? Do I also have to provide all the answers to be allowed to write comments? I certainly am "interested in improved understanding", why else would I bring up matters not discussed yet, and ask questions not answered yet? What is wrong with "leaving the question hanging in the air"? Again, do I have to have the answer as well, before I comment? And I still wonder why your revered Arctic report adresses only heat input, and not heat output. -
miekol at 19:31 PM on 31 August 2010Sea level rise: the broader picture
Is science sea levels different to island sea levels? http://joannenova.com.au/2010/08/south-pacific-sea-levels-no-rise-since-1993/ -
miekol at 19:28 PM on 31 August 2010Sea level rise: the broader picture
Sorry I didn't realize mariner sea levels are different to science sea levels. -
Rob Painting at 19:06 PM on 31 August 2010Sea level rise: the broader picture
BP, I don't know where you live, but down here in the Southern Hemisphere, citing Bob Carter doesn't bolster credibility, quite the reverse. -
Paul D at 18:28 PM on 31 August 2010The empirical evidence that humans are causing global warming
re: the label 'less heat escaping to space'. Would it be more accurate to say that the 'heat is delayed from escaping to space'? As was pointed out by others, even if you add more GHGs eventually an equilibrium is reached and just as much heat as before escapes! The only alternative is that the missing energy is emitted at a different frequency which balances the in/out equation, or is that what is implied? If you consider extra insulation of a home, you have to reduce the energy input to maintain the same temperature as you had before, because the insulation causes a delay. If you turn off the heating then eventually the energy will escape. The time between turning off the heating and the house temperature reaching the same temperature as outside is the delay. The more insulation the longer that delay or 'gradient'. Sorry about the analogy! -
Berényi Péter at 16:24 PM on 31 August 2010Sea level rise: the broader picture
#24 doug_bostrom at 15:03 PM on 31 August, 2010 By the way, did you notice that 3mm/year is right in the ballpark for global sea level change observations? Of course, if you express the same number as 0.0003 meters it sounds terribly small 0.0003 meter is 0.3 mm. It is a well established fact the average rate of sea level rise along the Australian coast is of this order of magnitude and no, it is not in the ballpark. If recent global estimate of ~3 mm/year is correct, the entire Australian continent should be rising at an alarming rate. BTW, I have not used New York (as a single tide gauge) for computing rate of sea level change but for assessing acceleration. That's a different game and in tectonically stable locations accuracy depends more on the length of record than on anything else. Modern acceleration term in isostatic rebound is minuscule. -
johnd at 16:20 PM on 31 August 2010Sea level rise: the broader picture
doug_bostrom at 15:39 PM, I was referring to your inflating of the figure quoted in the article by a figure of 10. Is the article wrong, or did you unconsciously inflate it because you thought that it had to fit the ballpark figure you had in your mind. Is this a case where failing to focus on tiny portions of data might lead to false conclusions? By the way, the article is most relevant to the discussion, as it mentions, the small slow changes due to climate change is what initiated the work described. -
Tom Dayton at 15:46 PM on 31 August 2010The surprising result when you compare bad weather stations to good stations
No, johnd, random sampling is not alone the only good way to eliminate bias. Randomization always should be used, but only to attempt to reduce leftover biases that cannot or might not be reduced by systematic approaches. The decision of when to attempt to make systematic adjustments is informed by the confidence in identifying systematic sources of bias, and by the difficulty and expense of preventing or systematically compensating for them. Examples of excellent candidates for systematic adjustment are the movement of a temperature station, and its daily measurements being switched from morning to afternoon. This is all basic science and statistics. -
Doug Bostrom at 15:39 PM on 31 August 2010Sea level rise: the broader picture
Good question, JohnD. I didn't get the relevance either. Perhaps Miekol can explain. -
archiesteel at 15:32 PM on 31 August 2010The empirical evidence that humans are causing global warming
factfinder and mscavazz, I suggest you review the Comments Policy as your post are inflammatory in one case and off-topic in the other. -
johnd at 15:29 PM on 31 August 2010The surprising result when you compare bad weather stations to good stations
Jeff Freymueller at 13:17 PM, it really goes back to the principles devised to facilitate the acquiring of unbiased representative samples for any form of laboratory analysis. The degree of accuracy of the final result is determined by the refinement of the process of randomly taking samples rather than any concern about what variations might be in any individual sample. -
johnd at 15:13 PM on 31 August 2010Sea level rise: the broader picture
doug_bostrom at 15:03 PM, 3mm/year may be right in the ballpark, but what is the relevance? -
Doug Bostrom at 15:03 PM on 31 August 2010Sea level rise: the broader picture
Try to be a little more serious, or little less desperate to create an impression, Miekol. You're citing a web page concerning tidal predictions for mariners, thereby making yourself sound needlessly silly. By the way, did you notice that 3mm/year is right in the ballpark for global sea level change observations? Of course, if you express the same number as 0.0003 meters it sounds terribly small, certainly true when our concern is safe navigation of ships today, tomorrow, next year. That's actually not the point here. Perhaps you should read more carefully above, where it is suggested that focusing on tiny portions of available data leads to false conclusions. -
miekol at 14:33 PM on 31 August 2010Sea level rise: the broader picture
The following is taken from a government report:- "Because the sea level rise is very low, averaging 0.0003 metres per annum for the Australian continent (Mitchell, 2002), the 15 to 19 years of readings available from Queensland tidal stations is not sufficient to calculate a reasonable estimate of sea level change. Accordingly an adjustment of 0.0003 metres per annum is made to the mean sea level within the tidal reference frame. The allowance is been calculated from the central date of the observation period at each station to the central date of the tidal datum epoch (31 December 2001)." http://www.icsm.gov.au/SP9/links/msq_tidalreferenceframe.html -
Rob Painting at 13:28 PM on 31 August 2010Sea level rise: the broader picture
HR @18 - That Wenzel & Schroter fail to capture the acceleration in global sea level reflecting the rapid warming in the early to mid 20th century suggests some problems with their gap filling methods. If anything their technique seems to smooth out the entire record. This is what I mean:
The early to mid century global sea level acceleration is evident in Church & White 2006
And Jevrejeva 2006:
And also is seen in Vermeer & Rahmstorf 2009 (modeling global sea level to global temperature)
I'd expect some aspect of that rapid rise in temperature to show up in the global sea level, via thermal expansion, but there's no trace of it in Wenzel & Schroter, the whole period seems smoothed out.
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scaddenp at 13:18 PM on 31 August 2010The empirical evidence that humans are causing global warming
Johnd - The rate at which water vapour enters the atmosphere is surely dependent on the surface temperature - dependent on the radiation from both the sun AND from the atmosphere (ie the GHG effect). -
Jeff Freymueller at 13:17 PM on 31 August 2010The surprising result when you compare bad weather stations to good stations
#1 johnd, your question was pretty nearly answered several months ago, for example by Zeke Hausfather, and several others. I don't recall anyone having taken randomized sets of stations with sufficient global coverage, but unadjusted or adjusted matters very little, nor do several selection criteria for stations that people have proposed. So I suspect you are right, because the adjustments and any station biases are simply smaller than the warming signal. -
Phila at 13:14 PM on 31 August 2010The surprising result when you compare bad weather stations to good stations
Would it make sense to add something about the meaning of "anomaly" to this entry? That seems to be a sticking point for a lot of amateurs, and "skeptics" are very good at exploiting the confusion that arises. -
Rob Painting at 12:41 PM on 31 August 2010Sea level rise: the broader picture
BP, I don't expect one tide gauge is going to reveal anything useful about global sea level trends, given the trends vary from region to region, but I do note that your 3rd figure (global sea level) matches well to ENSO events. -
Doug Bostrom at 12:23 PM on 31 August 2010The surprising result when you compare bad weather stations to good stations
I suspect adjustments have something to do with our fascination for units of measurement, JohnD. You could certainly confirm you hypothesis about a constantly morphing collection of instruments with a bit of work; folks like Hausfather et al have beaten a nice, flat path for the rest of us to follow. -
Doug Bostrom at 12:03 PM on 31 August 2010Sea level rise: the broader picture
A single tide gauge, Peter? Surely you can do better. The isostatic and tectonic situation around New York is not simple so attempting to use a single gauge proves little. ( Vertical crustal movements along the East Coast, North America, from historic and late Holocene sea level data ) Shortcuts to conclusions via tide gauges are probably not available, a lot of work has to be done for inferences about rates of change. It's the same deal with satellites. We rely on a very intricate and fanatical effort for establishing the validity of measurements. See for instance this item on using GRACE and Argo measurements to further establish confidence in Jason data: Closing the sea level rise budget with altimetry, Argo, and GRACE. As you can see, from that paper there does in fact appear to be a slowdown in sea level rise ~2004-2008, rendering your concerns slightly less concerning as well as emphasizing the point in the article above that picking short periods from long datasets is usually unproductive. I could in turn ask, what do we see after 2008? Maybe a resumption of a higher rate, maybe not. Use a longer straightedge. -
Jim Meador at 11:30 AM on 31 August 2010The surprising result when you compare bad weather stations to good stations
All of the adjustments are described here. -
Jim Meador at 11:28 AM on 31 August 2010The surprising result when you compare bad weather stations to good stations
The United States Historical Climatology Network (USHCN) is the older of two surface temperature measuring networks in the US, and it is valuable because it is a continuous record stretching back more than 100 years. Over the years changes do occur at each station, and the adjustments are meant to make current readings compare meaningfully to the older measurements. For instance the stations are moved, or the instrument is changed, or the time of day that the measurement is taken changes. All of the adjustments are described here... http://www.ncdc.noaa.gov/oa/climate/research/ushcn/ushcn.html#QUAL Note also that this study pertains to the US HCN surface record only, and does not cover the entire globe. -
Chemware at 11:05 AM on 31 August 2010The empirical evidence that humans are causing global warming
Suggested correction to point (3): (We know this because the two types of carbon have different chemical properties.) Err, no. They have the same chemical properties. They have different physical properties, specifically different 13C : 12C ratios. -
Berényi Péter at 11:03 AM on 31 August 2010Sea level rise: the broader picture
Posted by doug_bostrom at 10:26 AM, Monday, 30 August, 2010 observed sea level rise is already above IPCC projections and strongly hints at acceleration No, there is no acceleration. Sea level rise is fairly linear. Let's have a look at the New York tide gauge, for example:
Acceleration can be computed by fitting a least square quadratic form to data. Acceleration is twice the coefficient of the quadratic term.
For New York it is 0.001 mm/year2 since 1900. That is, sea level rise got faster by 0.1 mm/year in a century, which is equal to zero for all practical purposes.
Of course it is possible the southern tip of Manhattan is accelerating upward at the same rate sea level rise is supposed to accelerate. However, it is extremely unlikely.
There is no substantial tectonic activity in the region, the island is a huge granite rock stable enough to carry the weight of the city and vertical movement due to post-glacial rebound, if anything, is decelerating as time goes by (New York is close to the neutral line where no vertical movement occurred after the Laurentide ice sheet melted away).
As for more recent times, global sea level is measured by satellites.
The trend line looks impressive, but if we draw a separate trend line for the TOPEX and Jason eras, a considerable deceleration is seen. On top of that, there is a hint of a 4 mm offset error between data from the two satellites (at the beginning of 2002). If it is taken into account, the trend is decreased for the full period.
BTW, I can believe acceleration values derived from satellite measurements, but absolute rate of sea level change also depends on the selection of the reference point set. As acceleration of vertical land movement is much smaller on these timescales than linear rates, it is easier to have a reference set with zero average acceleration than one with zero rate of change.
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johnd at 10:59 AM on 31 August 2010The surprising result when you compare bad weather stations to good stations
That raises the question as to why adjustments are necessary to individual records. By rights a random selection of sufficient stations that represents consistent global coverage, that is constantly changed should provide a consistent global record of temperatures over time irrespective of which individual stations are in each selected mix.
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