Recent Comments
Prev 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 Next
Comments 94851 to 94900:
-
ChristianP at 20:09 PM on 22 February 2011It warmed just as fast in 1860-1880 and 1910-1940
Sorry for my bad English, I am french. Thank you for your very good blog. In your case, without the confidence intervals for the trends, it is difficult to say if all the trends are really statistically significant different. For example, in this graph of Tamino, http://tamino.files.wordpress.com/2010/08/rates.jpg, for those trends, http://tamino.files.wordpress.com/2010/08/annual.jpg, there is not statistically significant difference between the trend 2 and 4 (so, no difference significant between the trend 1 and 3) Other example in my graphs with the GISS data for the lands only, all the differences between the trends are statistically significant : http://meteo.besse83.free.fr/imfix/signifianoterrestrendgiss.png http://meteo.besse83.free.fr/imfix/anoterrestrendgiss.png Could you give us the confidence intervals ? Thank you. -
jyyh at 17:55 PM on 22 February 2011The Global Carbon Cycle by David Archer—a review
"We’ll have to wait and see.", like "youll see what happens when youre dead." -
Ari Jokimäki at 17:29 PM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
The iris hypothesis has been studied long ago and the observations were found to be against it. It's amazing that in this situation somebody would claim that this hypothesis is well established. -
owl905 at 17:06 PM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
Aerosols get a big vote for variable concentrations and contributions to global weather-system effects. Mid-century suppressed warming has a decent correlation. But this distraction on cloud cover has a big dead end sign on it - it shows little significant change, over decades and half-century measurements, that would indicate it will be a player in reshaping trends. As a forcing or feedback, it's insensitive. From AGWObserver's Collection: http://agwobserver.wordpress.com/2009/09/10/papers-on-global-cloud-cover-trends/ “The global average trend of total cloud cover over land is small, -0.7% decade-1, offsetting the small positive trend that had been found for the ocean, and resulting in no significant trend for the land–ocean average.” "Global mean total cloud cover over the ocean is observed to increase by 1.9% (sky cover) between 1952 and 1995. Global mean low cloud cover over the ocean is observed to increase by 3.6% between 1952 and 1995. … On the other hand, the fact that ships with a common observing practice travel over most of the global ocean suggests a possible observational artifact may be largely responsible for the upward trends observed at all latitudes." -
RW1 at 16:57 PM on 22 February 2011Climate sensitivity is low
KR, "To put it more clearly: If it's not an anisotropic emission, it won't show up. Isotropic emissions, absorptions, and re-emissions are part of the model, not part of the output spectra. Total power emitted from the atmosphere given the model conditions is the output - not a sub-portion of internal isotropic emissions that will then get bounced around." OK, where is this documented? Point me to the paragraphs or pages that state this is what the output spectra represent. -
RW1 at 16:51 PM on 22 February 2011Climate sensitivity is low
I'm willing to be shown incorrect on this issue (and I believe George is too), but you're talking around the crux of the issue. Words like "should" and "everyone else" isn't evidence to the contrary, and more importantly doesn't answer the fundamental question. In another thread, you said the total additional absorbed infrared from models/simulations from 2xCO2 was 7.4 W/m^2. And why haven't you said all this to George on his article and post on the issue at joannenova that you linked? -
Bern at 16:44 PM on 22 February 2011Models are unreliable
As I posted in the other thread: I think the selection of sites in that paper is suspect. In Australia (the only one I commented on), 3/4 of the sites selected for comparison with GCMs are in the rather arid central part of Australia, an area that naturally gets rather extreme weather (either very hot & very dry, or merely quite hot & very wet). To compare data from such stations with a regionally-averaged GCM seems disingenuous, to say the least. You don't have to go all that far from those sites to get others with completely different weather conditions. (It'd be like picking three weather stations in the Namib & Kalahari Deserts, and saying "hey, these measurements don't agree with climate model predictions for southern Africa!" - or, for north american folks, like picking a few stations in Nevada, Arizona, and New Mexico and comparing the results to predictions for all of North America.) -
Climate sensitivity is low
RW1 - To put it more clearly: If it's not an anisotropic emission, it won't show up. Isotropic emissions, absorptions, and re-emissions are part of the model, not part of the output spectra. Total power emitted from the atmosphere given the model conditions is the output - not a sub-portion of internal isotropic emissions that will then get bounced around. -
Climate sensitivity is low
RW1 - Assuming that GW is using the HITRAN spectral database and something like JavaHAWKS for full atmospheric simulations, the spectral database includes absorption/emission spectra for a large number of IR interactive molecules. Full atmospheric emission modeling means looking at absorption, emission, and transmission across the full black body spectra of the Earth emission, over the depth of the atmosphere. Some IR gets radiated back to the surface, some gets radiated around and re-absorbed in the atmosphere, a certain percentage in the 'IR window' goes straight to space, etc. The output from JavaHAWKS is the amount of radiation that actually leaves the atmosphere. Now, I cannot speak for GW, but "imbalance" should be a difference between the outgoing radiation from JavaHAWKS and incoming from the sun (a reasonably known value). Not the amount isotropically radiated from some level of the atmosphere, but the amount finally leaving the atmosphere (one directional) at the end of the modeling. And that's because the model includes the isotropic (omnidirectional, spherical) radiation as part of the calculation, summing up the anisotropic portion as output. That's certainly what everyone else running these models gets; 3.6-3.7 W/m^2 anisotropic radiation going to space for a doubling of CO2. An imbalance (difference!) between incoming and outgoing, an amount going in one direction not balanced by an amount going the other. I hate to say it, but GW does not understand the model he's running... -
RW1 at 15:59 PM on 22 February 2011Climate sensitivity is low
KR, "The line-by-line calculations include photons going up and down by absorption and re-emission, for every level of the atmosphere covered by the model. The imbalance is the end difference between incoming and outgoing, the leftover quantity. Not emitted in all directions from some level of the atmosphere, but just the value emitted to space." OK, show me where this is documented. -
Bern at 15:55 PM on 22 February 2011Prudent Path Week
Moderator: it seems the wrong link was posted in the moderator comment at #36. While off-topic, it seems an "edit post" feature for commenters would be extremely handy...Moderator Response: [Daniel Bailey] Fixed link, thanks! -
Climate sensitivity is low
RW1 - When the HITRAN model (and others) indicate a 3.6/3.7 W/m^2 imbalance, they are indicating photons going outward. The line-by-line calculations include photons going up and down by absorption and re-emission, for every level of the atmosphere covered by the model. The imbalance is the end difference between incoming and outgoing, the leftover quantity. Not emitted in all directions from some level of the atmosphere, but just the value emitted to space. That's what you get when you model the absorption/re-emission over the entire atmosphere. What's going back down to lower levels of the atmosphere or to the surface is part and parcel of the model - the imbalance is only the portion going in one direction, whether that's positive or negative depending on conditions. I'm afraid that George White's misunderstanding of this (and subsequent "halving" of the imbalance) indicates his overall poor understanding of the models he's been running. -
RW1 at 15:34 PM on 22 February 2011Climate sensitivity is low
It was and remains a simple question unanswered. If it's so obviously wrong as being claimed here, it should be easy to point to the documentation that the "halving" is already applied to the 3.7 W/m^2 forcing. I have search around too. I couldn't find anything. -
SoundOff at 15:26 PM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
rhjames, It’s not quite right to judge clouds’ cooling effects by how you feel as a cloud passes over your head. Clouds aren’t outside the climate system. The SW energy that did not reach your skin was partially absorbed by the cloud top and partially reflected to somewhere else, some of it outside the climate system. The warmer cloud warms the surrounding atmosphere. At the same time, some of the LW energy emitted by the Earth around you is intercepted by the water vapor held by that same cloud and again used to warm the surrounding atmosphere. A warmer atmosphere won’t let the Earth’s surface radiate as effectively so the surface will warm, though not as much as it cooled in the shady spot where you are standing. Some complicated measurements and accounting are needed to assess the overall effect and we aren’t there yet. -
Marcus at 13:48 PM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
@ KR. Yep, as I recall the CERES satellites showed that, even if warming were to result in fewer tropical clouds, that the amount of energy getting *in* through those clouds would be greater than the amount of energy getting out. At least, that's how I understood it. -
Rob Honeycutt at 13:36 PM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
I seem to remember reading somewhere that Lindzen even gets annoyed if people ask him about the iris effect. -
Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
Chemist1 - The "iris effect" turned out not to fit the facts, and Lindzen dropped that years ago. I believe others are adequately answering your points - most of your comments belong on either the Hansen was wrong or Models are unreliable threads, where they have been more than debunked. -
scaddenp at 11:19 AM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
"but the Iris effect is well established". Sorry? My reading is that extensive search failed to find it so the hypothesis has vanished. Got some papers which "establish" this hypothesis? -
scaddenp at 11:07 AM on 22 February 2011Climate sensitivity is low
Yes, precisely what I mean. -
dana1981 at 11:07 AM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
Chemist -"Having 3 scenarios of 3 different magnitudes and picking the closest value to published reports does not equate accuracy."
And that's not what was done, either. I suggest you actually read the link I provided."I get it, there is a statistical clustering at around.3 degrees. In reality there is no empirical or physical reason to believe so."
No, again, I suggest you actually read the link I provided. You keep making these factually incorrect statements and then ignoring the references provided which refute your errors. Please, take the time to understand what research has been done rather than simply making erroneous misinformed statements about it. -
scaddenp at 10:54 AM on 22 February 2011A broader view of sea level rise
"Could cutting down forests for agriculture have anything to do with it? " Depends what you mean. Land use change is another (on balance negative) forcing considered in climate theory but as to the CO2 in atmosphere, the isotopic composition shows the increase in CO2 is from fossil sources not biosphere.Moderator Response: [DB] As it turns out, pekka's last post here at SkS was also on 15 October 2009. Kudo's for being thorough, Phil. Hopefully pekka's still around to read your response. :) -
Rob Honeycutt at 10:47 AM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
Chemist1... "Having 3 scenarios of 3 different magnitudes and picking the closest value to published reports does not equate accuracy." That would be interesting if it were the case. Problem is, what you're saying is wrong. The accuracy of Hansen's early work is said to be off due only to his estimate of climate sensitivity at 4.2C It's when you adjust the sensitivity figures in his work to 3C you get an almost uncanny match to reality. And, to back that up even further, that happens to be the number that's coming out of many other studies into climate sensitivity. About 3C. In this we have multiple lines of evidence and research zeroing in on exactly the same figure. I don't understand why you would throw your eggs into the Lindzen basket when his work is clearly an outlier. You would be as justified in suggesting that the extreme high sensitivity figures of 10C-12C are correct, which several studies do show. If I were here claiming 10C for climate sensitivity what would you think of my argument? You'd think I was fruitcake! But here you guys repeatedly do exactly the same thing on the low side of climate sensitivity.Moderator Response: Also, scenario B was not picked as the most representative of the temperatures, but as the most representative of CO2 emissions, volcanoes, and so on--the conditions that were used to make the predictions. -
Alexandre at 10:41 AM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
I bet the "skeptic" crowd agrees with both Lindzen and the NIPCC. -
muoncounter at 10:21 AM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
Chemist1, "Hansen has made numerous projection errors ... Even Real Climate states so" Or not. Since you mentioned RC, here's their latest update of models vs. world: There are other threads which validate Hansen's various 'projections.' See the one dana points to for starters. Once again, these declarative statements hold little weight here. -
Chemist1 at 10:20 AM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
Having 3 scenarios of 3 different magnitudes and picking the closest value to published reports does not equate accuracy. It barely indicates precision. Lindzen is not infallible, but the Iris effect is well established. The projected high probability of a 3 degree at doubling is too high I get it, there is a statistical clustering at around.3 degrees. In reality there is no empirical or physical reason to believe so. -
dana1981 at 10:10 AM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
rhjames, please see the 'climate sensitivity is low' rebuttal. Chemist, please see the Lindzen Case Study post and Hansen 1988 was wrong rebuttal. -
Chemist1 at 10:03 AM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
Michael, Hansen has made numerous projection errors. He relies on partial data and GCM, high end estimates Even Real Climate states so when praising his scenarios Cloud formation is still highly uncertain. Knowing that,my calculated estimate will most likely need worlk -
ahaynes at 09:59 AM on 22 February 2011Link to skeptic rebuttals with short URLs
- "It's not a bug, it's a feature" (at least that's the gist of the initial response), but "Meanwhile you can select text [e.g., that short URL] in the card list off the edit menu." -
Chemist1 at 09:58 AM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
Well if aerosols partially warm but in fact provide a net cooling it will be reduced by black carbon IFR absorption and indirect warming of the Artic by aerosols in the absence of plentiful aerosols. The net warming effect is reduced by IFR scattered to space, partially through horizontal transfer to cloud formation, latent heat processes, forming thunderstorms from cirrus clouds and variable ice sizes. Roughly, estimated, taking UHI, thermometer siting issues, and calculating a median sensitivity with more parameters than Charny, I get a current 0.435 degree C warming, now maximum from all green house gases and only 0.375 maximum with all sulfates input. For a doubling of CO2 the Iris effect effect seems to increase in relative terms in accordance with the known physics, and the total warming is between .85 and 1.06 degrees C which is not significant. This assumes the GCM's are somewhat correct as well as available data -
Phil at 09:55 AM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
I think rhjames should actually read the post he was ostensibly responding to. -
michael sweet at 09:51 AM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
Rhjames, You need to read some of James Hansens' papers. He also does not like to rely on models and theory so he used data from the past to estimate how the climate will change in the future. There is a lot of data on paleoclimate that shows future climate will be hard to handle. If you were more informed on the facts of Climate Science you might feel less uncertainty. -
rhjames at 09:38 AM on 22 February 2011Radiative forcing by aerosol used as a wild card: NIPCC vs Lindzen
The IPCC has admitted that cloud formation and influence is poorly understood. The CERN CLOUD experiment will hopefully contribute some useful data. Just standing outside on a sunny day, and feeling the difference when a cloud blocks the sun, indicates that cloud area and density must have a significance influence on climate. It seems that the effects of aerosols is also very much still based on theory and models. While it's fair to claim that a lot is understood about climate science, it seems to me that there are still far to many variables which aren't understood. Will positive or negative feedback dominate? Other than models, and can't find any data to conclusively show a direction. I consider that any predictions for future climate must be treated with a high degree of uncertainty. -
Tom Curtis at 09:03 AM on 22 February 2011Climate sensitivity is low
saddenp @91, you mean that if the models where wrong, you would not get results like this: Note: the spectral lines have been deliberately offset so they can be seen clearly. Without the offset, it looks like this: -
John Hartz at 08:44 AM on 22 February 2011We're heading into cooling
The origin of the myth rebutted by this article may be: Dutch Professor Cees de Jager, a prominent astronomer and solar expert, forcefully asserts that we the world is indeed entering for a long period of very low solar activity. The professor and his colleagues are certain Earth is heading for a "long Grand Minimum" - defined as either a Solar Wolf-Gleissberg or a Maunder Minimum - "not shorter than a century." His 2010 paper, "The forthcoming Grand Minimum of solar activity," outlined the extended period of time that the diminished solar radiation would affect the Earth. The above paragraph is from the article, "Scientists: Sun's approaching 'Grand Cooling" assures new Ice Age" which is spreading like wildfire throughout Climate Denial land. It was posted Feb 18, 2011 on: http://www.sott.net/articles/show/224557-Scientists-Sun-s-Approaching-Grand-Cooling-Assures-New-Ice-AgeModerator Response: See also "What would happen if the sun fell to Maunder Minimum levels?" -
scaddenp at 07:31 AM on 22 February 2011Meet The Denominator
I know I shouldn't but I came across this very funny analysis (thanks Tamino)of an E&E paper which gives some insight into the quality of E&E's editorial work, as well as the "peer-review". I know PT is completely indifferent to such considerations but just so anyone else doesnt confuse E&E with a science journal. -
Chemist1 at 07:22 AM on 22 February 2011Prudent Path Week
Regarding aerosols, that is -
Chemist1 at 07:21 AM on 22 February 2011Prudent Path Week
Moderator, it is well established in physical geography and climate/meteological textbooks and is easily searchable on google books and scholar. I was responding to a post in this thread . -
Chemist1 at 06:25 AM on 22 February 2011Prudent Path Week
I will continue my discussion on models in the appropriate thread. I will say this though: the journal in question is not so small and there is support of the work in science and climate science. More on that in the models are unreliable thread. -
Chemist1 at 06:21 AM on 22 February 2011Prudent Path Week
Aerosols warm and cool.Moderator Response: [muoncounter] See It's aerosols It's helpful if you avoid declaratory statements like this one; please provide some substantiation or citation when commenting on the correct thread. -
scaddenp at 06:19 AM on 22 February 2011Climate sensitivity is low
And also, in scientific arguments, nature is the arbiter. The codes can used to calculate what experiments should observe. If George was right, then the experiments should be giving results half what they in fact do so. -
Ron Crouch at 04:51 AM on 22 February 2011The Dai After Tomorrow
#35 Daniel It's definitely going to be interesting. I think we'll really start to see things going haywire in the next 10-15 years. Should make '29 look like sanity. Yes go to bed and if your like most of us you'll dream that you wake to find it was all just a bad dream in the first place. I sit back and laugh at the irony though. I mean -- what else can one do in this situation. I've got enough grey as it is and I'll be darned if I'm going to ruin my health over the world's problems. Like they say talk is cheap and all I ever hear is talk. How much longer must I or anyone wait for affirmative action? People need to wake up and realize that they are in the biggest war of their lives, a war for their future survival and that of their children. -
RickG at 04:33 AM on 22 February 2011Models are unreliable
293 muoncounter, I noticed also out of the 26 references cited in the paper that the authors cited themselves 10 times and NASA was only mentioned once in the entire paper. I also find it rather less than scholarly to have a blog cited as one of the references, albeit Gavin Schmidt at realclimate.org., of which you have already described. -
ahaynes at 04:16 AM on 22 February 2011Link to skeptic rebuttals with short URLs
...but there's a bug there, you can't copy-paste the URLs. I'll point this out to the proprietors. -
ahaynes at 04:04 AM on 22 February 2011Link to skeptic rebuttals with short URLs
I've updated the flashcards (link) to use the short URLs - or rather, I created a new set, since new myths&rebuttals have been added since I put up the original set. The new improved set is at: Skeptical Science climate flashcards - short URLs http://www.flashcardexchange.com/flashcards/view/1669772 -
michael sweet at 03:58 AM on 22 February 2011Prudent Path Week
Chemist1, I read your reference. The authors do not like global climate models. It is published in a relatively small journal and has not received much support from other scientists. Gavin Schmidt(who is published in high visibility journals) here comments on their methodology from their previous paper. The results you cited are certainly not the consensus of the field. I find it difficult to determine what your objections are. If you specify what your objections are perhaps we can address those issues. Do you claim that all models are unreliable? Comparing for example Dr Hansens 1989 projections to what has been observed the projections are close to reality see models are unreliable. -
Dikran Marsupial at 03:55 AM on 22 February 2011Models are unreliable
I thought it was well-known that GCMs only give reliable projections on global or regional scales, which is why regional climate models or statistical downscaling are used to get projections of local climate. I don't recall ever hearing a modeller claim that the models were accurate at station level resolution. -
muoncounter at 03:44 AM on 22 February 2011Models are unreliable
Continuing from comment here: "What is an issue is the projected warming at NASA." and here: "comparing results of global climate models to records for individual stations is missing the point, and shows a fundamental misunderstanding of what those models tells us." The paper in question compares GCM output to data at selected stations using point-by-point, year-by-year observation to computed model output. The authors note the following regarding their prior work: criticism appeared in science blogs (e.g. Schmidt, 2008). Similar criticism has been received by two reviewers of the first draft of this paper, hereinafter referred to as critics. In both cases, it was only our methodology that was challenged and not our results. It would seem that if the methodology is challenged, the results are implicitly challenged. The comparison of yearly data to model output is clearly one of apples and oranges: It is little more than comparison of weather to climate. In addition, there's a deeper flaw in the methods used to process individual station data: In order to produce an areal time series we used the method of Thiessen polygons (also known as Voronoi cells), which assigns weights to each point measurement that are proportional to the area of influence This was an issue in the early days of computer-aided mapping. Rather than spatially average a local cluster of stations first, this process allows any error or anomaly at a single station to propagate into the database. Why not filter for a noisy (or bad) datapoint before gridding? So it's not at all clear the original criticisms were answered by the newer paper. -
dana1981 at 03:32 AM on 22 February 2011Prudent Path Week
bart - true, aerosol emissions may be cleaned up before GHG emissions are reduced, which would lead to even further warming. A valid point. Gianfranco - yes, I essentially mean compared to what's to come. The consequences thus far have been bad, but they haven't had particularly horrific consequences yet. -
Gianfranco at 03:13 AM on 22 February 2011Prudent Path Week
By "the consequences of anthropogenic climate change so far have been manageable" I presume you mean relatively in comparison to what will happen. Alpine glaciers have melted dramatically for over a century now. Sea water's acidity increased and several species alredy experience difficulties forming their shells and skeletons, and these species happen to be right at the beginning of the marine food chain. -
Chemist1 at 02:42 AM on 22 February 2011Prudent Path Week
Bern, the station picks are not an issue. What is an issue is the projected warming at NASA. Try reading the paper first please.Moderator Response: [muoncounter] This is a discussion better taken to Models are unreliable.
Prev 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 Next