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John Brookes at 12:00 PM on 31 January 2011Latest GRACE data: record ice loss in 2010
I read recently that readings from GRACE were not being properly corrected for the rebound of the land as ice mass above it vanished. Do we know if the current estimate is corrected for this? -
apiratelooksat50 at 11:54 AM on 31 January 2011Ten temperature records in a single graphic
Glenn @ 111 Thanks for backing me up. Knowing my stance, I purposely was hands off. The only faculty guidance they got was from the librarian who was running the computer lab. She believes in AGW. This survey was completely student driven. I would be interested if the readers of this website would redesign the questions. I will even resend the survey to the original participants. -
apiratelooksat50 at 11:50 AM on 31 January 2011Ten temperature records in a single graphic
Muon @ 109, Yep, that's pretty much our curriculum. And, I'm sure that your impressive research and insight also showed you that in Unit 2 they learn about "Natural Ecosytem Change" including "Climate Shifts, Species Movement and Ecological Succession". All of which are natural and have occurred many times throughout Earth's history. When we teach (you, me, or anybody else) a student Unit 2 about natural climate change and the mechanisms and results of such, if we do our job correctly they should question the proposed mechanisms of artificial climate change. -
pdt at 11:46 AM on 31 January 2011Sea level rise is exaggerated
So, is there simply no answer to my question (post 105), or is the question so undeserving as to not warrant a response? I didn't really find anything on a Google search. It seems like sea level should be predictable from temperature change and land-ice loss. Has someone looked at that? Perhaps it's the other way around, one could measure the average sea temperature by a combination of land-ice loss and sea level rise. Anyone? -
apiratelooksat50 at 11:34 AM on 31 January 2011Ten temperature records in a single graphic
Michael Sweet @ 112 First, that is a different graph in the survey than I posted here. Second, show me where the data is false. -
apiratelooksat50 at 11:32 AM on 31 January 2011Ten temperature records in a single graphic
Marcus @ 102 How can any 100 year period tell you anything about climate and climate cycles? Pick and choose any 100 year period from that graph and we can "demonstrate" rapid rise, rapid decline, or stability. -
apiratelooksat50 at 11:28 AM on 31 January 2011Ten temperature records in a single graphic
DB @ 66, That top graph shows human civilization fluorishing as we came out of an Ice Age. We've done quite well over the last 10,000 years. Of course, nothing can be inferred from this graph about any positive or negative effects of a temperature rise when and if it happens. But, when and if it drops...Moderator Response: [Daniel Bailey] Short of Yellowstone going critical? Absent a negative feedback of considerable size, good luck with unphysical wishes. -
apiratelooksat50 at 11:24 AM on 31 January 2011Ten temperature records in a single graphic
DB @ 83, This line from the website you plucked the modified McShane & Wyner Graph says it all" "I've taken the liberty of (unscientifically) adding this onto the McShane and Wyner hockey stick graph..." Nuff said.Moderator Response: [Daniel Bailey] You failed to do your homework. The addition to the sqeptic's darling (McShane & Wyner's graph - thoroughly debunked in peer-review) is from a simple average of the IPCC's low-to-high estimates of expected temperature rises. As these estimates date from 2007, they are old and since been superceded by newer, and much higher, estimates. Both of which you might have noted had you done a bit more work. Simply dismissing the graph without attempting to understand why it differed from your expectations is a classic example of cognitive dissonance in action. If this were a graded exercise your score would not be very good. -
Riduna at 10:41 AM on 31 January 2011Latest GRACE data: record ice loss in 2010
24 Michael Sweet Thank you but the position of Ollier is in my view and that of his peers (http://www.geolsoc.org.uk/gsl/geoscientist/features/page7523/html) nonsense. In quoting him, I wanted to get a reaction from professionals to what he has to say on ice loss in Greenland. At present, my view is akin to that of Dr Hansen, though I think sea level rise due to WAIS and Greenland ice melt will result in sea level rise of around 1m. by 2050 and 2 – 2.5m. by 2100, about half the level he predicts. However, the article “Say goodbye to Greenland ice” (New Scientist, page 8, 8/1/11, does suggest that Dr Hansens views may be prescient. Either way, we are in trouble and what GRACE now tells us seems to confirm that view and a disturbing acceleration in Greenland ice loss. -
Tom Curtis at 10:01 AM on 31 January 20112010: A Year of Record Warmth and Weird Weather
johnd @48, I have already provided a perfectly good counter example to your claim. You have responded by definitional maneuvering. Therefore I see no point in providing more coutnerexamples unless you wish to make your claim explicit. By below average, do you mean less than the mean, or more than one standard deviation below the mean, or classified as average by the BOM? By similar period, do you mean of approximately the same duration as the period of below average rainfall. Are you in fact predicting, given the length of our recent drought, another eight years of above average rainfall? If you cannot specify the meaning of your claim with sufficient precision to make it falsifiable, given your responce to a clear falsifying instance, I am warranted to in concluding that you are playing word games, not reporting observations. -
Glenn Tamblyn at 10:01 AM on 31 January 2011Follow-Up Case Study in Skepticism
So sqeptic or squeptic hey! Thanks guys. Now I just can't get an image of Daffy Duck out of my head! But maybe that works. -
Follow-Up Case Study in Skepticism
RickG - My version of that sentiment was "You can lead someone to science, but you can't make them read the bibliography." The JoNova gang did not (ahem) like that line... -
John Hartz at 09:10 AM on 31 January 2011A retrospective of the Climategate retrospectives
The House of Commons report cited by JMurphy in #11 is the subject of a BBC article, “ClimateGate affair: 'Learn and move on', say MPs” written by Richard Black and posted on Jan 24, 2010. -
MarkR at 07:44 AM on 31 January 2011A Flanner in the Works for Snow and Ice calculations
That looks right to me! Be careful with sign conventions: to calculate total Y 'normal' is a positive sign for negative feedbacks that increase heat loss at the surface (blackbody, lapse rate, maybe clouds) and a negative sign for positive feedbacks that increase heat (water vapour, albedo, maybe clouds). This doesn't include slow feedbacks. Also, on my fifth equation down I introduce a minus sign so that positive feedbacks are now positive. People use a lot of different conventions (and sometimes the sensitivity parameter, λ = Y-1) so every time you read a paper you have to double check all this. So where I have: ΔQ = ΔF - YΔT that means that to restore equilibrium (i.e. ΔQ = 0), if Y is smaller then you need a bigger temperature change to restore equilibrium. -
muoncounter at 04:50 AM on 31 January 20112010: A Year of Record Warmth and Weird Weather
#42: "use measurements of effects instead of the "weird weather" notion." Oddly enough, the insurance industry has an index for that, although they've only been publishing the 'Climate Risk Index' since 2006. Here is a summary based on a wider variety of measurements. Graphs on pp 5-7 are particularly interesting, as are the summary points on p. 11. Wouldn't you know they'd figure out how to make a profit off climate change? -
Michael.M at 04:49 AM on 31 January 2011Follow-Up Case Study in Skepticism
"Pseudo-Sceptic" is also better for translations - I think it should work in most languages. (At least into german "Pseudo-Skeptiker") Deniers is of course also a possible name - but most deniers refer to themselves as "sceptics" and can more easily be shown to be (and rightfully named) pseudo-sceptics. Very often calling deniers denier leads into an off-topic hassle. -
muoncounter at 04:42 AM on 31 January 20112010: A Year of Record Warmth and Weird Weather
#45: "ENSO Index you linked to only goes back to 1949, insufficient to determine any trends" What are these long terms trends? Is there any published literature supporting their significance? "reconstructed El-Nino occurrences back to 1525" OK, what does that show? Instead of talking about 'providing insights,' show what those insights are. Take further discussion of specific ENSO issues to the appropriate thread. It is not the topic here. -
johnd at 04:33 AM on 31 January 20112010: A Year of Record Warmth and Weird Weather
Tom Curtis at 03:47 AM on 31 January, 2011, Tom, it is not a tautology, but a physical fact of life. Perhaps if you can list all the examples of droughts, extended periods of below average rain, and those that were NOT followed by a similar period of above average rains, then we can pass judgement as to whether my original statement stands or not. Aside from the above, declaring whether a drought has ended or not is not an easy exercise at the time, especially when so much rides on having to know whether the changes occurring are real or transient, and is not decided by rainfall alone. Droughts are not completely devoid of any rain over their duration, it's the timing as well as the volume that decides. -
Tom Curtis at 04:27 AM on 31 January 20112010: A Year of Record Warmth and Weird Weather
Eric, as a matter of interest, you may want to check out the graph of Brisbane River flood heights here (7th page, PDF). The graph is from a 1990 hydrological study and shows the probably flood heights of various historical floods with and without the effects of Somerset and Wivenhoe Dam. You will notice that if Somerset Dam had existed in 1893, the largest 1893 flood would have been lower than the 1974 flood; but if Somerset dam had not existed in 1974, the 1974 flood would still have been (just) lower than the 1893 flood. This is because of the different rainfall patterns, with the heaviest rain in 1893 falling in the Somerset catchment, while the heaviest rain in 1974 was over the city. It is not possible to compare directly the size the 2011 flood would have been without any dams because of this variability. But we can compare its actual size to the modeled sizes of the historical floods given the presence of both Somerset and Wivenhoe. If you do, you find that the first 1893 flood (and Brisbane's second highest since settlement) would have been 0.12 meters shallower than the 1974 flood, which in turn would have 0.98 meters shallower than the 2011 flood. No major flood would have surpassed the 3.5 meter threshold to be considered a major flood. An educated guess as to the size of 2011 flood without dams is that it would have been over 9 meters. This is still less than the highest known flood (from geological evidence) in Brisbane, which was 11 meters deep, but still far surpasses any flood since settlement (ie, for nearly 200 years). I refered to this information in my post 24. I bring it up in more detail because I notice a number of people play the silly game of saying the 2011 flood was smaller than the 1893 or 1974 flood at the gauge, therefore it was not a big flood. That is a very silly game, IMO, indeed a dishonest game, because it assumes that the dams on the Brisbane River have absolutely no effect in terms of flood mitigation. It's like comparing athlete's top speed to see who is the best, while ignoring the fact that some of them are on bikes. -
Tom Curtis at 03:47 AM on 31 January 20112010: A Year of Record Warmth and Weird Weather
John D, 2008/9 rains restored Wivenhoe dam levels from near 15% to 80%. That's more than enough rain for agriculture to procede without problems. The drought was broken at the latest by April/May of 2009 when there was sufficient rain to raise Wivenhoe's level by over 30% over the two months. I would say it was broken in February 2008, when rain started refilling the dam, and more rain always came to fill it further before it got back down to the previous low level. Further, using your definition of "ending a drought" reduces your claim to a tautology. If you do not accept a drought as being ended by average rain, even if farmers are getting their crops in and dam levels are rising, well then of course the "drought" only ends when the rain is above average - but that is simply because you have chosen to call nothing but above average rain the end of a drought. -
johnd at 03:37 AM on 31 January 20112010: A Year of Record Warmth and Weird Weather
muoncounter at 00:46 AM on 31 January, 2011, the ENSO Index you linked to only goes back to 1949, insufficient to determine any trends given the length of time it takes for those longer termed ocean based indexes to cycle through both their positive and negative phases. Example, the IPO only entered a new negative phase in 1945, changing to a positive phase in 1978, it requires a big leap of faith to see any longer term trend there. Quinn reconstructed El-Nino occurrences back to 1525, it is those time frames that provide real insights into longer term trends. In relation to the discussion about the Brisbane floods, it would thus be appropriate to provide the ENSO index that covers the period back to the earliest floods, then perhaps some serious comparisons can be made. -
Tom Curtis at 03:36 AM on 31 January 20112010: A Year of Record Warmth and Weird Weather
Eric @42, unfortunately gauge information kept by the Bureau of Meteorology is only make available to the public for 2 days after the record is tracked, while those maintained by the Queensland Department of Environment and Resource Management are only made available for 14 days. However, it is known is that the Bremer River peaked at about 1 meter below the 1974 level. That makes 2011 the third largest flood in the Bremer River since settlement (1824), behind 1893 and 1974. However, in 1974 the Bremer River had a discharge of only 220 cumsecs (cubic meters per second)(DERM Walloon gauge), which is significantly less than its peak recorded discharge of 900 cumsecs. That indicates that a large part of the height of the Bremer River was from back flow from the Brisbane River. Further, it is known that Lockyer Creek peaked 60 cm higher than in 1974. In 1974 Lockyer Creek had a flow rate of 2,320 cumsecs, its highest recorded (DERM Rifle Range Road gauge). It is probable given events at Murphy's Creek and Grantham, that the peak flow was higher in 2011, but I cannot say by how much. At Wivenhoe on the Brisbane River it is difficult to say what the effective natural flows were because of the effect of the dam. However, at the dam's peak discharge rate, it was discharging 7500 cumsecs while still retaining water. For comapison, the peak flow at Savages Crossing on the Brisbane River below the confluence of Lockyer Creek in 1974 was 7400 cumsecs, and that would have included a sizable flow (ie, over 2000 cumsecs) from Lockyer Creek. Over 48 hour period of Tuesday and Wednesday, Wivenhoe Dam averaged inflows of around 8,500 cumsecs. Its peak inflow would have been significantly higher than that, but I do not know what it was. The entire flow at the port office (city center) in 1974 9,000 cumsecs, so over the 48 hour period, Wivenhoe swallowed two 1974 floods. Over the weekend prior (Saturday, Sunday and Monday) it swallowed enough water for a third 1974 flood, although, dispersed as it was the water would not have reached 1974 peaks over those days. Having taken on so herculean a task, it is no surprise the dam had to surrender enough water so that we are talking about Brisbane's 2011 flood. Without the dam, we would have been talking about the floods of 2010 long before this. Wivenhoe swallowed a 1974 style flood without any disruption in October of 2010, and a near 1974 level flood in the last week of December 2010, and a fortnight before the flood of 2011. It also swallowed a smaller flood the week before that with minor disruption because of concurrent king tides. Information about 1974 river flows from http://www.derm.qld.gov.au/water/monitoring/current_data/map_details.php?group=brisbane Information about Wivenhoe dam levels from http://www.seqwater.com.au/public/catch-store-treat/dams/wivenhoe-dam -
johnd at 03:10 AM on 31 January 20112010: A Year of Record Warmth and Weird Weather
Tom Curtis at 23:36 PM on 30 January, 2011, Tom, how long lasting was the recent drought in South East Queensland? Certainly longer than one year. A long lasting drought is not broken by one year of near average rain, instead only considered broken when rain replenishes the depleted soil moisture reservoir, returning it to "normal". -
John Hartz at 03:07 AM on 31 January 2011Animated powerpoint of the Indicators of Warming
General question: How do the "indicators" shown on the graphic and suggested in the comment thread relate to the "multiple lines of evidence" documented by the IPCC? -
John Hartz at 03:03 AM on 31 January 2011Animated powerpoint of the Indicators of Warming
@ John Cook: Addition to the list I started in #18: 5. Where are "Wildfires"? -
RickG at 02:55 AM on 31 January 2011Follow-Up Case Study in Skepticism
I like the comment made by Gavin over at Real Climate. "You can take a source to science, but you cannot make him think." -
Eric (skeptic) at 02:01 AM on 31 January 20112010: A Year of Record Warmth and Weird Weather
#35 muoncounter said "There's the same refrain: high temperatures (here, sea surface), higher probability of extreme weather events follow." That may be true in general but the "extreme weather events" needs to be better defined to include the protracted pattern of flow, excessive rain over time, rain on saturation ground, and everything else can be measured and trended. IOW, use measurements of effects instead of the "weird weather" notion. #37 (the Yeh paper) the nonzero elements being flattening of the thermocline depth with longitude and the weakening of the Walker. That's a change that doesn't average out like you said, but we need to see what the long and short term trends are ftp://ftp.gfdl.gov/pub/gav/PAPERS/VSWHLH_06.final.pdf because some of the long term trend in the flattening of the thermocline depth (fig 4 lower left block) looks to me to be natural. Looking at the lower right block, I should add some discussion to the natural cycles thread. #39 Tom Curtis, the more I look at 1974 and 2011, the more I see apples and oranges, especially in the rainfall distribution maps. The two events are hard to compare in those maps. But an easier way to gain historical perspective may be the river gauges (thus defining "weird" as the broadest effect on land). Some historical events are listed here http://www.bom.gov.au/hydro/flood/qld/brochures/brisbane_lower/brisbane_lower.shtml (the table with flood gauge heights). So far I have only found the Gatton gauge on a blog at 18.92, higher than all prior events in the table. It would be very interesting to add a column in that table for the 2011 event and then figure out the geographical impact of the flood both in terms of where the water came from and where it piled up the most. I know next to nothing about Australian geography but I am very familiar with the Potomac basin. Essentially, rainfall or meltwater on the Blue Ridge feeds the Shenandoah and the same on the Potomac highlands feeds the Potomac directly both ending up at Harper's Ferry but with different delays. It is easy to look at the flood gauges and see where the water came from. -
arch stanton at 02:00 AM on 31 January 2011Follow-Up Case Study in Skepticism
I like pseudo-skeptic. It is more accurate and don’t think the “q” spellings will impress folks afflicted with Dunning-Kruger or anyone else who is influenced by them. Of course it is hard to pass up the utility of “denier” for those that refuse to admit it when they are wrong. For those that make a true art continually twisting the story 180 degrees I reserve the title of “denialist”. -
muoncounter at 01:28 AM on 31 January 2011Tree-rings diverge from temperature after 1960
#15: "any causal link between reduced solar (or cosmic) radiation and reduced tree ring growth." This was suggested by Suess 1980, who was the author of one of the greatest one-liners in all of science: "The line was not drawn by computer - I drew the line by `cosmic schwung'. More recently, Kulmala et al 2009 and Dengel et al 2009 provided some fuel for an uptick of chatter in the deniersphere. The usual crowd made the usual misrepresentations of an otherwise valid study (you can find this by googling 'cosmic rays tree ring growth'; I don't link to sources of disinformation). The basis of the argument is that increased cosmic ray flux stimulates cloud formation (that's not proven) and clouds control tree growth rates (somewhat), so that cosmic ray flux helps explain tree ring anomalies (indirect, uncertain, unsettled). There are some vague resemblances of tree ring cycles to the solar cycle (see Dengel), but that's hardly a smoking gun for cosmic rays as a cause. But with evidence like the figure shown below (Kulmala), it will take more than cosmic schwung to draw a line.The larger subject of cosmic ray flux is discussed in the thread It's cosmic rays.
Moderator Response: [Daniel Bailey] Fixed broken linked image URL. -
Daniel Bailey at 01:19 AM on 31 January 2011Tree-rings diverge from temperature after 1960
@ Philip Shehan @ 15 Tree rings are not my area of expertise, but a re-read of the post above makes it clear there is still significant uncertainty (see the linked summary above for details). I suspect the cause is indeed multi-factorial (with the other factors mentioned in play, tree growth response to the rising temps [we are now at temps equal to that of the Holocene Maximum of 8,000 years ago] of the latter half of the 20th Century may be discontinuous to established response). Certainly the experts in this field are continuing to look at all possible factors (a scientific "race to glory" for bragging rights). My two cents. The Yooper -
muoncounter at 00:46 AM on 31 January 20112010: A Year of Record Warmth and Weird Weather
#38: "perhaps it is the El-Nino/ La Nina occurrence ratio that must also be considered" Those data are available; have at it. Evidence that long term changes are underway continues to mount. Where is the published science that counters observations such as those of Allan and Soden 2008? ... observations reveal a distinct link between rainfall extremes and temperature, with heavy rain events increasing during warm periods and decreasing during cold periods. Furthermore, the observed amplification of rainfall extremes is found to be larger than predicted by models, implying that projections of future changes in rainfall extremes due to anthropogenic global warming may be underestimated. It's high time to hold any claim that these extreme events are just part of the 'natural cycle' to a higher standard. That sort of thinking breeds popular complacency, which in turns leads to inaction in the face of danger. The water rises, people die. After the flood, out come theliesexcuses: 'no one could have predicted this' and 'why didn't you warn us?', etc. -
Tom Curtis at 23:36 PM on 30 January 20112010: A Year of Record Warmth and Weird Weather
John D, @36, you have twice stated that, "a period of below average rain always ends with a period of above average rain". That is simply not true, and would not be an explanation even if it were. In fact, the recent drought in South East Queensland was broken in 2008, and was followed with a year of near average rain. Of course, the following year (2010) had far above average rain, but that is neither explained by the preceding drought, nor followed directly after it. -
Dikran Marsupial at 22:44 PM on 30 January 2011It's not us
Julian@Flood@22 wrote "How does the process know to only sequester 45% of the extra, and how does it distinguish that 45% blip from all the other processes which are not steady state but which vary with the season, run-off etc. What, in other words, is the _mechanism_?" It stems from the fluxes of carbon between reservoirs being proportional to the atmospheric concentration and the fact that emissions are rising approximately exponential. The carbon cycle is a dynamical system, which can be described by linear differential equations. If you apply exponential forcing to such linear D.E.s you get an exponential result (with the same rate constant). As both exponentials have the same rate constant, their ratio is constant. I did the D.E.s myself last year to satisfy myself that a constant airborne fraction is what you would expect for an anthropogenic origin, and indeed it is. -
Dikran Marsupial at 22:36 PM on 30 January 2011It's not us
Julian@Flood@22 The mass balance argument does not need to make any assumption about the carbon cycle other than conservation of mass (of carbon), neither does it depend on any knowledge of the individual fluxes into and out of the atmosphere. The diagram below shows annual anthropogenic emissions (for which we have good records), the annual increase in atmospheric CO2 (for which we have accurate records, in this case Mauna Loa), and the difference between total natural emissions and total natural uptake, which can be inferred from anthropogenic emissions and atmospheric increase assuming conservation of mass.For conservation of mass, we know that dC = E_a + E_n - U_n where dC is the annual change in atmospheric CO2, E_a is anthropogenic emissions, E_n is "natural" emissions and U_n is "natural" uptake. Of these, we can directly measure dC and E_a, so rearranging, we have E_n - U_n = dC - E_a This is the green line, which gives total net emissions into the atmosphere from all natural sources (including soil respiration). As you can see, it is always negative, demonstrating that the natural environment is a net sink, and is hence opposing the atmospheric rise, not causing it. The data is shown here it can all be downloaded from the Carbon Dioxide Information Analysis Center CDIAC, the specific datasets you need are: anthropogenic emissionshere and Mauna Loa data here. Note that the error bars on the inferred natural net sink depends on the uncertainty in anthropogenic emissions and measurements of atmoispheric CO2, both of which are small. The bottom line is that the annual rise in atmospheric carbon is the sum of anthropogenic emissions, natural emissions (whatever the mechanism) minus natural uptake (whatever the mechanism). If the annual rise is less that anthropogenic emissions, then the only way that can happen is for natural uptake to excede natural emissions.
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Tom Curtis at 22:20 PM on 30 January 20112010: A Year of Record Warmth and Weird Weather
Eric @33, you also left out the interesting comment that: "However, in 1974 the heaviest rains were close to the coast, whereas in 2011 heavy falls spread further inland, and on the western fringe of the Brisbane River catchment and on the Great Dividing Range 2011 was the wetter of the two events (Figure 5, right)." That western fringe is, of course, the catchment of the Wivenhoe Dam. I am uncertain how to interpret BOM's comment about the four major subcatchments as the Brisbane River has six major subcatchments (Upper Middle and Metropolitan Brisbane, Bremer, Lockyer and Stanley). It his, however, clear from BOM's statement that what made 2011 unusual was the very high run off rather than the very high rainfall per se. As land use is essentially unchanged in the relevant areas, that is not a significant factor. There are probably two significant factors. First is the generally wetter preceding period. Second is the very high intensity of rainfall on Monday the 10th. Higher rainfalls were recorded in coastal areas in 1974, but the much of that fell out of the Brisbane River catchment, or onto short catchments that joined the Brisbane only in its lower reachs (Ennogra and Breakfast Creeks). I have been struggling to get data on the relative intensity in the Wivenhoe catchment of the rainfall on Monday 10th. I know it was higher in the Wivenhoe catchment than in Toowoomba or the Lockyer valley, but how much higher I cannot say. As rainfall on Tuesday was heavy, but not unusually so, and relatively light on Wednesday (ceasing altogether by evening) I am not sure the three day comparison is the best way to look at the data. You have raised reasonable doubts about my claims about the rainfall. But I do not think you have raised any doubt about the unusual nature of the flood. The fact remains that total river flows were of the scale compared to previous floods since European settlement, with the 2011 flood likely to have been a meter higher than the 1893 flood were it not for the flood mitigation provided by Somerset and Wivenhoe Dams. River flows were still greater than 1974, but with a lower peak due to improved storm drainage, and the absence of a storm surge. Whatever the contributors to that mass of water, whether exceptionally wet soil, or freak storms at the wrong locations, the net result is still an exceptional flood. -
Julian Flood at 22:00 PM on 30 January 2011It's not us
Dikran Marsupial at 06:52 AM on 30 January, 2011 wrote quote Julian Flood@20 Are you questioning the attribution of the observed rise in atmospheric CO2 to anthropogenic emissions? If so, you don't need isotopic arguments to establish that the attribution is correct. The principle of conservation of mass requires that if both man and the natural environment are carbon sources (i.e. emissions exceed uptake) then the annual increase in atmospheric CO2 must be greater than anthropogenic emissions (our uptake is negligible), as it is the sum of the net anthropogenic and natural contributions. This is observed not to be the case, atmospheric CO2 is rising at a rate about 45% of anthropogenic emissions, so the natural environment must be a net sink, and hence is not causing the observed rise. That particular piece of attribution is rock solid. unquote I'm afraid you'll have to go through the logic of your case in baby steps, as to me they don't make sense. If the world had only two agents working on CO2 production and sequestration then perhaps you would have a point. However, this is not the case. Just take, for example, the biology of the oceans: numbers of phytoplankton vary as nutrient flows (run-off from land, deep current upwelling, wind-mediated stirring of the top few hundred feet of the oceans, volcanic rain-down, seasonal changes etc etc) and this will change the amount of CO2 pulled down and/or the amount of CO2 given off. So to do your calculation of 'mass balance' you need to know the figures for all of these. Further, and more importantly, you need to know the amount going into and coming out of the biggest reservoir of CO2, the deep ocean. I think the figures you are using for your mass balance are dwarfed by the uncertainties in the figures for all of the above. To illustrate: human emissions go up by X, deep ocean export swings up by 99X, sequestration by phytoplankton goes up by 99.55X. Net increase, .45X. Now add error bars to those figures -- plus or minus 70 Gt. 70! So you don't know the numbers within something like 10X and you're calculating to decimal places. And from this you can claim that it's all the fault of the little boy piddling in the reservoir? I must be misunderstanding something basic. Please explain again a different way and I'll try and follow the logic better. quote The fact that the long term rise in atmospheric CO2 has been steady at 45% of anthropogenic emissions would be a bit of a coincidence if the observed rise were natural and nothing to do with us! unquote So Zog, when he picked up his first bit of seacoal and threw on his fire, altered the CO2 content of the atmosphere by 45% of the C in that coal? You know that bit in Borat where he looks at someone with disbelief? Picture me like that. How does the process know to only sequester 45% of the extra, and how does it distinguish that 45% blip from all the other processes which are not steady state but which vary with the season, run-off etc. What, in other words, is the _mechanism_? TIA JF (thanks for isotope data. I think the same error is being made here as in the mass balance argument, that there is a steady state in the isotopic composition of the pull down -- just adding a little dissolved silica to the oceans will invalidate that assumption.) -
michael sweet at 21:58 PM on 30 January 2011Latest GRACE data: record ice loss in 2010
John@23: It is not yet known how to extrapolate melt rates into the future. Will melt increase 100 Gt per year or will melt continue to double every 8 years? That is the difference between 0.5 meters of melt by 2100 and 5 meters of melt. There is no consensus of what will happen. Some scientists believe that there is a maximium rate of melt (about 2 meters/century) while others think the ice could disintegrate by a rapid wet process (5-10 meters/century). That is why this data is so important. The West Antarctic ice sheet is especially vulnerable to rapid disintegration. Stay tuned for updates! -
michael sweet at 21:38 PM on 30 January 2011Latest GRACE data: record ice loss in 2010
Agnostic: Cliff Ollier is a geologist, not a climate scientist. Linking to an opinion piece by a geologist is not a scientific way to support your position. Try to find a peer reviewed paper, I suggest you look at material that is at least 10 years old. The IPCC AR3 might support that position. It is wrong. Scientists used to think that it would take centuries for the ice to respond to increasing temperatures, but that has been proven incorrect in the past 5 years. The ice has responded much faster than expected. That is the point of this post. See my link at #19. Fydijkstra's link at 7 shows substantial surface melt above 1500 meters, which was not expected yet. At 1500 meters they lost 50 cm of ice last year. It is now known that the ice responds rapidly to hot ocean water around the pheriphery of the ice sheet. Scientists are trying to determine how strong the response will be. There is more CO2 in the air than at any time in the past several million years. Why would you expect the ice to respond the same? Only 100,000 years ago, within your 750,000, sea level was 6-9 meters higher. Good bye Bangladesh and Florida. We are hotter now so we expect the sea to rise higher. How much and how fast is still to be determined. Pray James Hansen (who IS a climate scientist whose work is peer reviewed) is wrong this time and the rise is not 5 meters by 2100. -
johnhprice44 at 21:25 PM on 30 January 2011Latest GRACE data: record ice loss in 2010
John, thanks for this update. In a sketch, extrapolating this trend to 2015, I found the net annual mass loss rises to something like 700Gt - equivalent to about 2mm of sea level. Would it be possible to invite your informants to perform the calculations to show what this trend would produce over another couple of decades? I don't really know, but I'd guess there are no known processes capable of retarding the trend, but several conceivable ones which might accelerate it. I'd be interested to know if the GRACE data is indeed disclosing a lower bound for estimates of Greenland's contribution to sea level rise up to 2030 or so. Thanks again for your good work. John Price -
Philip Shehan at 21:07 PM on 30 January 2011Tree-rings diverge from temperature after 1960
Thank you Daniel for the welcome. My original post may have been ambiguous. I was specifically wondering if ther was any causal link between reduced solar (or cosmic) radiation and reduced tree ring growth. -
michael sweet at 21:02 PM on 30 January 2011Ten temperature records in a single graphic
Students produce work as they are guided. Pirate claims this is student work, but the survey reflects directly the points that he has emphasized in his postings at his first post here. The graph they used is the same one he first posted!! If Pirate emphasizes in class 400,000 year old data that shows natural changes and then asks is current change natural his students will follow the same pattern. Then the students will show up here and say "My high school environmental teacher said" and they will have to unlearn what they were taught. It is hard to unlearn false data. -
Bern at 20:10 PM on 30 January 2011Follow-Up Case Study in Skepticism
So what you're saying is that the deniers (no, really, that's what they are, as per BillyJoe's post) are taking the "say it loud, say it often" approach todebateargumentation? -
Riduna at 18:46 PM on 30 January 2011Latest GRACE data: record ice loss in 2010
fydijkstra @ 7 I think Professor Cliff Ollier might support your view. In a recent article (http://www.onlineopinion.com.au/view.asp?article=11212&page=2) he states that “There is no melting in the interior of ice sheets - it is far too cold. The centres of the ice sheets, occupying basins, flow only at the base, warmed by geothermal heat and driven by the weight of the overlying ice. There is no direct flow of the near-surface ice in the centre of an ice sheet to the outflow glaciers. It is fanciful to conclude kilometres of ice can suddenly melt when the records show no melting whatsoever in the ice sheet accumulation areas. After considering the evidence of three quarters of a million years of documented continuous accumulation, how can we rationally accept that right now the world's ice sheets are collapsing? Johannessen and colleagues analysed satellite data on the Greenland Ice Sheet from 1992 to 2003. They found an increase of 6.4 ± 0.2 centimetres per year in the vast interior areas above 1500 metres, in contrast to previous reports of high-elevation balance.” So, are we to believe that peripheral ice melt has any effect on the Greenland ice sheet and if so, what? Does an accelerating rate of loss presently 200-300 Gt per annum matter and if so why? -
gpwayne at 18:26 PM on 30 January 2011Follow-Up Case Study in Skepticism
MattJ asks: "It would have been real interesting to see how many of the deleted comments came from the 'skeptics'. Judging from the comment initially quoted above it sounds likely that most of them were, but the above statistics neither confirm nor deny that conclusion" The answer is as follows. The total number of visible deletions when the thread closed was 55. (Well-intented rebuttals to moderated posts are made to 'disappear' rather than be left as what we call 'tombstones' so as not to give the impression that the rebutter had also transgressed). Of that 55 posts, 44 were from deniers. The remaining 11 were all from warmists, including 3 from me and 1 from Dana. More telling perhaps is this: 44 denialist posts removed were written by 17 people, the remaining 11 were written by 6 warmists. -
Glenn Tamblyn at 17:54 PM on 30 January 2011Ten temperature records in a single graphic
Just to jump in here in defence of 'pirate' and the survey. It looks to me like several people here may have taken the wrong impression from what he said about the survey. My reading of what he said and the content of the survey is that this was a survey 'created by' his students, not just simply responded to by them. So yes, there are 'problems' with the survey. Qyestion 1 has 3 options for example without the obvious 4th option - 'all of the above'. But is this something foisted on the students, or a fault with what they produced? Perhaps pirate can clarify this. -
BillyJoe at 15:45 PM on 30 January 2011Follow-Up Case Study in Skepticism
Stephen Leahy #24 "I generally use the term denier for those who are ideologically, politically or financially motivated to deny. " I generally use the term "denier" when - a person makes a claim - that claim is effectively rebutted - the person making the claim ignores the rebuttal - that person continues to make the claim - that person continues to ignore the rebuttal -
johnd at 14:42 PM on 30 January 20112010: A Year of Record Warmth and Weird Weather
muoncounter at 13:35 PM on 30 January, 2011, whilst the study referenced, Yeh et al, may help better understand the shorter term events relevant to 2010, for 2010 itself to understood in a longer time frame, then perhaps it is the El-Nino/ La Nina occurrence ratio that must also be considered when new records are compared to past record events, and whether or not that ratio averages out, especially given the connection of the various record Brisbane floodings and La-Nina events. -
muoncounter at 13:35 PM on 30 January 20112010: A Year of Record Warmth and Weird Weather
#36: "it should be the nett effect of what occurred on BOTH sides of the system" Yes, I think that's an excellent point. Not only do oscillations average temporally to zero, but as you suggest, they average spatially to zero as well. That reinforces the point that these cyclic events can only be insignificant factors in the long term trend. The thread Global warming and the El Niño Southern Oscillation is an excellent place for discussion of this topic. To look at long term changes to the character of el Niño from its Eastern Pacific (EP) to Central Pacific (CP) phases, see Yeh et al 2009: Using calculations based on historical El Niño indices, we find that projections of anthropogenic climate change are associated with an increased frequency of the CP-El Niño compared to the EP-El Niño. When restricted to the six climate models with the best representation of the twentieth-century ratio of CP-El Niño to EP-El Niño, the occurrence ratio of CP-El Niño/EP-El Niño is projected to increase as much as five times under global warming. -- emphasis added Now that's a change that does not average out. -
johnd at 13:02 PM on 30 January 20112010: A Year of Record Warmth and Weird Weather
muoncounter at 10:18 AM on 30 January, 2011, whilst the article referenced from "The Australian" focuses in on how the events leading to the flooding developed in the more recent months, perhaps the stage was being set even further back, back during the preceding El-Nino which was identified by some as a variation of the normal El-Nino pattern, and labeled an El-Nino Modoki. A few accepted truths are perhaps relevant here, one being that a period of below average rain always ends with a period of above average rain. Another is that generally in Australia, by virtue of the regions it covers, there is nearly always a drought somewhere, even when there are may be floods elsewhere. One other is that what a La-Nina means to Australia, is what an El-Nino means to those on the other side of the system and vice versa, so when any analysis is being done on the effects on any such event, before it can be evaluated with reference to longer term climate trends, the bigger picture,it should be the nett effect of what occurred on BOTH sides of the system that are relevant rather than what may have been experienced on just one side. For me the big picture is not complete yet merely by looking at both sides of such events, but also looking at many such events over a longer time frame. With systems that operate in the various oceans and oscillate through identified positive and negative phases that perhaps seem to be 6 decades, more or less, then I am more interested in what can be observed over multiple such cycles, only then can any analysis have any real value above what essentially relies a lot on the making of assumptions and guess work. -
David Horton at 12:38 PM on 30 January 2011Follow-Up Case Study in Skepticism
Stephen and Dana thanks for that, Stephen's link is a useful addition to the Real Climate account of the affair. I'm happy with all that - climate science should be left to climate scientists, or at least referred to them! The only, minor query I had is that the graph Real Climate shows in explanation begins in 1900. There is, if my ageing memory hasn't failed me, some additional warming before 1900 which would make the FEU "2.4 above" "pre-industrial", although still an exaggeration, slightly less of an exaggeration. Or have I misunderstood?
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