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Comments 101851 to 101900:
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dana1981 at 09:29 AM on 10 December 2010A Cloudy Outlook for Low Climate Sensitivity
Damn, I wish Dessler's paper had come out a week earlier! Maybe I'll have to do a new blog post as an addendum to this one... -
Marcus at 09:25 AM on 10 December 2010Ice data made cooler
Hi Tony, thanks for the reply. Yes, having done a fair bit of reading on Milankovitch Cycles, I can honestly agree that it is *extremely* robust-& fits extremely well into the climate cycles of at least the last 1 million years. My question was more seeking clarification of exactly how Milankovitch cycles work. Judging from John's reply, I was close, but not quite on the mark ;). Certainly the uniformity of recent warming events is yet more proof that Milankovitch cycles cannot be blamed this time around ;)! -
Alec Cowan at 09:21 AM on 10 December 2010Ice data made cooler
jp Excellent work! Don't worry about comment #3. I don't have the exact numbers at the moment but the same release from the oceans that makes CO2 raise from 250 to 400 ppmv as a product of the warming process makes oxygen, for instance, to rise from some 209,000 to 209,030 ppmv, so the conclusion is pretty obvious: much below other error margins. About eccentricity, Laskar et al have taken care of it, so the conclusion is: done. There are a few things that ""should"" be considered along the content of comment #3, but I'll better comment in your blog as many "eager skeptics" use to hang raw comments in sites like this just to have them corrected so they can publish them in other sites as arguments (the "throw everything at the wall and see what sticks" strategy described here by dana1981) -
Ice data made cooler
RSVP: Thank you for elaborating. I'm not qualified to give you an answer. I can only make a comparison. Forgive my not looking the name up, but there are a couple lakes in West Africa notorious for their sudden outgassing of CO2 that has sufficated nearby inhabitants. Somehow it was possible for thsese bodies of water to build up CO2 in ratios not typical of the atmosphere and then release it, also in ratios not typical. I have a few articles that describe the role of outgasing and the ocean's biological pump. One mentioned that a mechanism building up CO2 could be the reduction of ocean's biologoical pump. As I understand the biological pump, it's the growth of phytoplankton that take up CO2 die and sink to the bottom. A lot of recycling of nutrients happens in the 100 meters before the dead plankton sink, but the net sum of what gets through and buried can change, and this process is selective. In fact the scientific literature is full of processes that selectively operate on different chemicals and elements. Thank you for encouraging me to ponder this. jg -
Steven Sullivan at 08:34 AM on 10 December 2010A Cloudy Outlook for Low Climate Sensitivity
Camburn @64:"1. Statistically, and this is important unless you want to throw statistical analysis out with the wash, we have not warmed for the past 15 years." Leaving aside the disingenuousness of totally ignoring a *93%* level of significance for said warming: Start from when Phil Jones made that comment, and go back to 1995 -- *16* years instead of 15. Voila: warming, at or better than the 95% significance level. Or: Start from when Phil Jones made that comment. Go back to 1995 (15 years) Add the rest of 2010 since he made that comment. Voila: warming at or better than 95% significance level. Still feeling lucky, Camburn? Btw, I can see that at this point, having lost on the substance of Dana post, you're just robotically going down the same old well-worn list of 'skeptic' talking points. The Jones quote; the Trenberth quote; can 'hide the decline' be far behind? -
archiesteel at 08:32 AM on 10 December 2010Ice data made cooler
@RSVP: you seem to be ignoring the gigatons of anthropogenic CO2 being released in the atmosphere each year... -
archiesteel at 08:31 AM on 10 December 2010We're heading into an ice age
@NQoA: "That's pretty much what the "Climate Change Deniers" have been saying all along." Actually, that isn't true. There are still many deniers/politically-motivated skeptics who still dispute we are in a warming trend. Indeed, many of those who have been trying to prop up the failed manufactured Climategate scandal (which has now been thoroughly eclipsed by Cablegate) are saying just that. The fact that you seem to believe warming should be linear is also a sign you are gravely mistaken: complex systems do not react in linear fashion. Look at the Stock Market if you don't believe me... -
RSVP at 08:28 AM on 10 December 2010Ice data made cooler
jg #8 "The release of oxygen tempering the effect of CO2 releases is new to me." To me too, since I made it up on the fly. I am referring to the fact that all components of the atmosphere dissolve in water, so when CO2 is released as a function of warming so is everything else, thereby increasing partial pressures of all gases. If all partial pressures increase in unision, its not clear why the ppm of any one component should go up. In fact, you would expect the partial pressure of the more abundant gas to go up higher in proportion to its overall percentage, so that in fact ppm of CO2 being so small should go down. But I am no expert, so this is pure conjecture bases solely on skeptical logic. -
Ice data made cooler
Anyone wanting to exchange files can contact me at my blog. Go to http://www.brightstarswildomar.blogspot.com/. -
Ice data made cooler
paulm, Good suggestion. I'll add that feature to the list. There some enjoyable irony in that I built this program so that I wouldn't accidently mix up time periods. JK: The insolation values are for June (northern hemisphere) and December(southern hemisphere). So though both plots are of the same latitude, one is what you would measure at one point in Earth's orbit, and the other, six months later. So as long as there is some eccentricity, these values would be different, that is, except for times when the equinoxes are at right angles to the semi-major axis, e.g., at 135kyr (second diagram). When I first collected the data, I included plots that could compare +65 June to -65 June, and quickly decided this wasn't as valuble of a comparison as N. Summer (Jun) to S. Summer (Dec); However, I may add these graphs. Your request for a copy of the program--that was for Mike's global warming game, correct? jg -
jorgepeine at 07:50 AM on 10 December 2010Ice data made cooler
Hi Mike, this is a very interesting and fascinating program. Thank you. Can I get a copy of it? Just for teaching astronomy and climate physics. However I do not understand the following: When you - only - click insolation on 0º NH and simultaneously on 0º SH - I would expect equal plots. However they have a "phase shift" of - say it simple - 180º .. Could you explain that please? kind regards JK PS: I made a screenshot of this phenomenon - how could I provide that to you? -
cjshaker at 07:41 AM on 10 December 2010Models are unreliable
It appears that not quite half of the photosynthesis occurring on the earth is in the oceans. Search for 'Global' http://en.wikipedia.org/wiki/Primary_production "Using satellite-derived estimates of the Normalized Difference Vegetation Index (NDVI) for terrestrial habitats and sea-surface chlorophyll for the oceans, it is estimated that the total (photoautotrophic) primary production for the Earth was 104.9 Gt C yr−1.[12] Of this, 56.4 Gt C yr−1 (53.8%), was the product of terrestrial organisms, while the remaining 48.5 Gt C yr−1, was accounted for by oceanic production." So, I hope to read that these negative CO2 feedback effects are also being modeled for algae as well. Chris Shaker -
Joe Blog at 07:27 AM on 10 December 2010Stratospheric Cooling and Tropospheric Warming
Bob Guercio at 04:25 AM The ozone's thinning can and has been quantified, variable UV through the solar cycle, also effects stratospheric T's, UV is the most variable wave length through the cycle. But smarter people than me, have done studies on these things... there is that paper that by Johanna Haige, that a thread was done on here that may impact these. But the reason why raising co2, should cause the stratosphere to cool, is because it causes more energy to be lost from the stratosphere through radiation. VeryTallGuy - 212 Yes (-: -
cjshaker at 07:27 AM on 10 December 2010Models are unreliable
Older research on the topic, and it appears, more controversy http://www.sciencedaily.com/releases/2007/12/071211233441.htm "Interestingly, warming temperatures in response to rising carbon dioxide levels could make more nitrogen available, said Xiaojuan Yang, a doctoral student in Jain’s lab. This factor must also be weighed in any calculation of net carbon dioxide load, she said. “Previous modeling studies show that due to warming, the soil releases more carbon dioxide through increased decomposition,” she said. “But they are not considering the nitrogen effect. When the soil is releasing more CO2, at the same time more nitrogen is mineralized. This means that more nitrogen becomes available for plants to use.”" Chris Shaker -
cjshaker at 07:21 AM on 10 December 2010Models are unreliable
Found several articles lately about plant growth providing negative feedback against CO2 increases, including this recent NASA model update. I've also read a paper saying that rising temperatures will also make more nitrogen available for plant growth. These new models seem to make increased temperatures from a doubling of CO2 much more modest than previously claimed. Do these new models also include the negative feedback from the ocean equivalents of green plants, ie - photosynthetic creatures like algae, diatoms, coral, etc? The huge biomass in the oceans would seem to be more important than terrestrial plants? The Science Daily report on the NASA study http://www.sciencedaily.com/releases/2010/12/1012080 Here is the abstract from the paper http://europa.agu.org/?view=article&uri=/journals/gl/gl1023/2010GL045338/2010GL045338.xml&t=gl,bounoua "Several climate models indicate that in a 2 × CO2 environment, temperature and precipitation would increase and runoff would increase faster than precipitation. These models, however, did not allow the vegetation to increase its leaf density as a response to the physiological effects of increased CO2 and consequent changes in climate. Other assessments included these interactions but did not account for the vegetation down‐regulation to reduce plant's photosynthetic activity and as such resulted in a weak vegetation negative response. When we combine these interactions in climate simulations with 2 × CO2, the associated increase in precipitation contributes primarily to increase evapotranspiration rather than surface runoff, consistent with observations, and results in an additional cooling effect not fully accounted for in previous simulations with elevated CO2. By accelerating the water cycle, this feedback slows but does not alleviate the projected warming, reducing the land surface warming by 0.6°C. Compared to previous studies, these results imply that long term negative feedback from CO2‐induced increases in vegetation density could reduce temperature following a stabilization of CO2 concentration." Chris Shaker -
Joe Blog at 07:19 AM on 10 December 2010Stratospheric Cooling and Tropospheric Warming
mars at 19:39 PM on 9 December, 2010 says "The atmosphere at low levels is transparent to nearly all of the incoming radiation." I took that as a given, i was talking about LW. Mars says "The atmosphere is heated by contact with the surface. As a result a parcel of air close to the ground forms which is warmer than the surrounding air." The air is heated, by conduction and radiation, and as a result of the air being opaque to LW radiation in the lower troposphere, this energy is trapped, if it was transparent, it would simply pass through at the speed of light. There is nothing wrong with your description of convection, but the properties of the lower atmosphere are taken as a given, radiation is not considered, because the lower troposphere is opaque to the passing of LW, but at 6000m, radiation is the dominate means of energy transport(this is the average altitude of equilibrium with incoming and out going energy), not the sole, but dominate. As you rise further, the atmosphere becomes more and more transparent, and convection less and less important. -
syphax at 07:14 AM on 10 December 2010A Cloudy Outlook for Low Climate Sensitivity
Ha! And here's some additional commentary from Dessler, addressing Spencer directly. My cup runneth over. Especially this part:And as far as my interest in influencing the policy debate goes, I’ll just say that I’m in College Station this week, while Dr. Spencer is in Cancun. In fact, Dr. Spencer had a press conference in Cancun — about my paper. I didn’t have a press conference about my paper. Draw your own conclusion.
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Eric (skeptic) at 06:54 AM on 10 December 2010It's cosmic rays
muoncounter, the low frequency is a good point. I don't what the frequency history is, but likely it varies between zero and small. But it is not random since the galactic structure was not random over time and our transit through the galaxy does not take us into random amounts of leftover particles. It is quite unpredictable, although not completely unpredictable. They are modulated by solar activity and of course solar activity itself has other effects, so it is worth studying and using GCR as a proxy. But this thread is about cosmic rays and (my addition) the effect they could have on sensitivity. The fact of CO2 warming is not in question here (or at all), just sensitivity and I would greatly appreciate your opinion on my final sentence in #29. -
Albatross at 06:36 AM on 10 December 2010A Cloudy Outlook for Low Climate Sensitivity
Hot off the press: Dessler (2010) "Estimates of Earth's climate sensitivity are uncertain, largely because of uncertainty in the long-term cloud feedback. I estimated the magnitude of the cloud feedback in response to short-term climate variations by analyzing the top-of-atmosphere radiation budget from March 2000 to February 2010. Over this period, the short-term cloud feedback had a magnitude of 0.54 T 0.74 (2s) watts per square meter per kelvin, meaning that it is likely positive. A small negative feedback is possible,but one large enough to cancel the climate’s positive feedbacks is not supported by these observations. Both long- and short-wave components of short-term cloud feedback are also likely positive. Calculations of short-term cloud feedback in climate models yield a similar feedback. I find no correlation in the models between the short- and long-term cloud feedbacks." -
muoncounter at 06:29 AM on 10 December 2010We're heading into an ice age
#168: "Argentine glacier advances... " Missed this little tidbit from the lead paragraphs of the article: Argentina's Perito Moreno glacier is one of only a few ice fields worldwide that have withstood rising global temperatures. Nourished by Andean snowmelt, the glacier constantly grows even as it spawns icebergs the size of apartment buildings into a frigid lake, maintaining a nearly perfect equilibrium since measurements began more than a century ago. -- emphasis added So to say that a glacier "advances" when it is merely maintaining equilibrium is a tad disingenuous. However, since NQoA has such definite opinions in the context of this thread, it would be interesting to see how he lines up on the question of 'are we heading into a new ice age?' Especially interesting if he could provide some actual substantiation (beyond a mis-read of a news clip) for what must be very strongly-held opinions. Because that would provide him some credibility; without credibility, opinions are ... just opinions. -
muoncounter at 06:15 AM on 10 December 2010It's albedo
#16: "Dr Malcolm" And who wrote Jurassic Park? Same guy who did this bit of work. At last we see how those deniers work, moving so seamlessly that one cannot tell where their non-fiction ends and their fiction begins. -
syphax at 06:11 AM on 10 December 2010A Cloudy Outlook for Low Climate Sensitivity
It looks like Spencer is pounding the table again today that "hen cloud changes cause temperature changes, it gives the illusion of positive cloud feedback – even if strongly negative cloud feedback is really operating!" I think Spencer's all wet, but I haven't seen a thorough analysis of this line of argument. Spencer basically argues that climate scientists have cause and effect all mixed up. Unlikely, but an interesting line of thought. I have not seen a really good response to e.g. Spencer & Braswell- is there one? -
muoncounter at 06:08 AM on 10 December 2010It's cosmic rays
#29: "they keep going back to solar and use GCR proxies as a solar proxy." Because solar magnetic activity is what causes the observed variation in GCR frequency. Are you reading anything in this thread and following links that we provide? "Although GCR's are modulated by solar activity, they are their own animal." What animal? GCRs are infrequent and random; they come from times long ago and places far away. The only important feature of GCRs in this context is that they "are modulated by solar activity", which is what you questioned one sentence earlier in your comment #29! #26: "Events like SSW" OK, so I looked at the website you linked, which is pretty nice. It would be interesting if you would try to match up the dates of their SSW events with anything else. However, there are fewer than 30 events in their entire database, which runs back to 1958. How much warming are we supposed to be getting from fewer than one event per year? I suppose if you pile up enough of these disparate straws, you will indeed be able to put together a modest-sized strawman. But it is stunning that one can cling to 'this might' and 'that could', when the answer, my friend, is blowing in the increasingly CO2-enriched wind (apologies to Mr. B. Dylan). Unless it is some preconceived idea that it just can't be CO2. In which case, you should be reading more here at SkS. -
Tony Noerpel at 05:50 AM on 10 December 2010Ice data made cooler
Marcus The influence of Miankovic Orbital variations on Earth Climate are well understand and are robust. This was resolved with the publication of a paper in the 1970's by Hays and Imbrie. You can read about this in Imrie's book and in a book by William Ruddiman. I'm at work so can't provide details but this is enough if you hit amazon. Orbital variations do not change the solar radiation incident on the Earth over the year. They only change the distribution of that energy in time, depending on which season the Earth happens to be close to the sun (it is an eliptical orbit) and the tilt of the Earth relative the the plane of the Earth orbit. It turns out that when the solar insolation (look this word up) is weakest in the summer at about 65 degrees North Lat, then the winter snow accumulation will not melt very well and thus the ice sheet grows. Croll had the idea that orbital variations caused the ice ages but he thought that cold winters would do the trick. Milankovic's great insight was that it was cold summers which did the deed. All very fascinating and Imbrie has all the history of this discovery as well as being one of the discoverers Tony -
Eric (skeptic) at 05:30 AM on 10 December 2010It's cosmic rays
Riccardo, thanks for the link. That paper is broad, not deep, but I agree with their conclusion that it is inconclusive especially without good GCR proxy data earlier than the present and 130k interglacials. What is a little weird about the paper is that they keep going back to solar and use GCR proxies as a solar proxy. Although GCR's are modulated by solar activity, they are their own animal. My guess looking at fig 8 is that an interglacial requires both low GCR plus northern hemisphere sun (the other thread), it can't happen with just one or the other. -
Paul Magnus at 05:20 AM on 10 December 2010Ice data made cooler
Great stuff. How difficult would it be to ad two windows so you can inspect two period at the same scale.... -
archiesteel at 05:12 AM on 10 December 2010Renewable Baseload Energy
Just to be clear, even though Toshiba owns the majority of Westinghouse Electric Company, it is still based in the US. -
Steven Sullivan at 05:11 AM on 10 December 2010How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
re: Santer at ~min 35 of http://www.c-spanvideo.org/program/ChangePa Santer starts his rebuttal with: "Dr. Michaels' analysis is wrong; it's just completely incorrect." THAT is how it should be done. -
Steven Sullivan at 04:53 AM on 10 December 2010How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
archiessteel "If anything, professor Alley's responses were still too wordy (bald spot excepted). When the (very partial) congressmen started his nonsense about Mars experiencing the same climate change as we do, he should have simply said it isn't. When demagogues make statements which they can't prove, you can simply call them on it. This puts the burden of proof on them, and since they *can't* support that position (due to a lack of facts) they'll simply stop using it as an argument." +1 We scientists have to be able to parry the rhetorical tactics that troglodytes like Rohrbacher use. That means *short, declarative* statement first -- that's right/wrong, that's true/false -- FOLLOWED BY the explanation. Alley too often doesn't do this. He went right to the explanation, often obliquely. -
Ice data made cooler
Albatross, Thank you, and yes. I'll add the features you request. I'll probably have a new version released by the end of the holiday break. jg -
Albatross at 04:31 AM on 10 December 2010Ice data made cooler
John Garrett, A fantastic tool, a job well done. Thanks for this. If I might make one request at this time. Would it be possible to display horizontal scale lines and have the scale adjustable by the user? I realize the mouse-over function allows one to examine each data point-- but it would be nice to get an idea of the values without having to do that. Wish I had your skills John;) -
Bob Guercio at 04:25 AM on 10 December 2010Stratospheric Cooling and Tropospheric Warming
VeryTallGuy - 212 I didn't talk about the issue of ozone with regard to cooling of the stratosphere. Ozone brings heat into the stratosphere. However, with the thinning of the ozone layer that occured several decades ago, it is now bringing in less heat and this has caused some of the cooling. Bob -
VeryTallGuy at 03:55 AM on 10 December 2010Stratospheric Cooling and Tropospheric Warming
Oh, and meant to add whilst this is interesting, overall for the stratospheric cooling issue all that matters is that UV is absorbed, heating the stratosphere. CO2 enables the heat to be released; more CO2 means more IR radiance at a given temperature, hence increasing stratospheric CO2 reduces stratospheric temperature. I've almost convinced myself now... -
archiesteel at 03:54 AM on 10 December 2010Renewable Baseload Energy
Re: RSVP's last bunch of tro...I mean, comments, I'd be curious to hear how quokka would respond to the "argument" put forth. -
VeryTallGuy at 03:51 AM on 10 December 2010Stratospheric Cooling and Tropospheric Warming
Bob, Oxygen and ozone absorb in different regions of the UV. There's a good overview description of the process here: http://eospso.gsfc.nasa.gov/science_plan/Ch7.pdf "The formation of ozone by the photolysis of molecular oxygen removes most of the incident sunlight with wavelengths shorter than 200 nm. The wavelengths between 200 and 310 nm are removed by the photolysis of ozone itself." - bringing out the point that different wavelengths are involved in the different reactions. For detailed chemistry try here http://www-tonycox.ch.cam.ac.uk/Download/ERCA2_Stratosphere.ppt It's complicated but not conceptually difficult I think. -
archiesteel at 03:44 AM on 10 December 2010Renewable Baseload Energy
Looks like deniers are getting desperate. Is it because of recent wikileaked cables showing the US and China collaborated to make sure Copenhagen would be a failure? One thing's for sure: Cablegate has completely eclipsed Climategate, even as far as climate is concerned. To deniers and politically-motivated skeptics, I say: welcome to 2011. You've got your work cut out for you. :-) As far as nuclear goes, I can understand why some in the US would support China building more NPP. After all, that almost certainly means more money for Westinghouse. -
Rob Honeycutt at 03:34 AM on 10 December 2010How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
Daniel... That's fantastic. I love the very last comment that Alley makes. "The economic models say if you're really worried about uncertainties you put more money on the table." -
Ice data made cooler
Thank you for your comments. I have a full day ahead of me, and I'm doing an astronomy presentation for 5th graders tonight, so I have to be at my best. I'll respond now, and if necessary, I'll be more thorough 12 hours from now: Jeff: your question is my question too. I'm an amateur trying to figure this stuff out. When I built the viewer I was able to see for the first time that the correlation between northern hemisphere insolation and temperatures was visually striking for the Holocene and Eemian deglaciations, but not for the earlier two deglaciations in this data set. There are many areas to explore: e.g., see-saw effects that may delay warming in Antarctica? another Younger-Dryas like event? or perhaps there are errors in dating that magnify as you look at older ice. When I was studying the ice core data, I saw information on varying dating methods. I'll be exploring these. Mike: I'm eager to try out your program. I think it may be a great link to offer the kids I give astronomy presentations too. (I'm noticing an increase in kids asking what I think of global warming.) Mikemcc: thanks for the correction. I'll fix it. Marcus: I think the current theory is that orbital variations create differential heating of the high latitudes (north and south) that is more of a disturbance (rather than a change in over all heating) that can put more fresh water into the North Atlantic, changing ocean currents, which can release CO2 sequestered in the southern ocean (or reduce it's uptake of CO2); and then there are land changes such is deglaciation and lowered albedo, release of methane and carbon from northern tundra, permnafrost and bogs. One of my next steps is to get the average insolation values and see if they change much or if its mostly differential heating at work. RSVP: I will study your comment. My Earth, Orbit and Climate presentation includes mention of eccentricity affecting the time in season and that this was an earlier hypothesis superceded by Milankovitch. I think my reference for this is a Nature review article that I should cite as source. The release of oxygen tempering the effect of CO2 releases is new to me. I welcome more information on this. All: thanks for the time looking at my project and for your comments. jg -
Philippe Chantreau at 03:30 AM on 10 December 2010The Scientific Guide to Global Warming Skepticism
Great work John, thanks. -
Bob Guercio at 03:25 AM on 10 December 2010Stratospheric Cooling and Tropospheric Warming
VeryTallGuy - 209 Ditto on your remark on understanding. I think the problem is that in the study of Physics, you go into tremendous detail over single individual entities. For example, I remember going into mindboggling details over a mere water molecule. Atmospheric science involves everything which is why it is so complex. I could understand a water molecule but when combined with all the other chemistry of the atmosphere and other factors such as the spinning of the planet, it all becomes extremely difficult and very tricky. This is why I really will not feel comfortable about my blog until it is blessed by a professional. And that's the problem here. All we hear about is ozone but it is not just ozone that is generating heat. Oxygen is also and probably other chemicals that we have never heard of. So I guess the bottom line is that ozone is not primarily responsible for the generation of heat in the upper atmosphere. Oxygen is responsible for that! I think in the upper atmosphere, there is more of the process that you labeled "1". Bob -
VeryTallGuy at 02:56 AM on 10 December 2010Stratospheric Cooling and Tropospheric Warming
Bob @207 As I understand it (which is, painfully obviously, not all that well) there are several heat producing reactions with UV. 1) O2 is split: O2 = 2O (absorbing a photon of UV) 2) Ozone is created: 0+02=03 (releasing thermal energy) 3) Ozone is destroyed: O3 = 0 + O2 (absorbing a photon of UV) 4) Ozone is destroyed by other chemical reactions eg CFC catalysed At the top of the stratosphere you get more of (3) so despite absorbing quite a lot of UV, there isn't a very high Ozone conc. Each photon absorbed is a net energy & hence temp gain. Overall, there is more absorbed at top than bottom, hence the temp gradient. Lower down, the ratio changes hence the higher ozone concentration. -
RSVP at 02:24 AM on 10 December 2010Renewable Baseload Energy
CBDunkerson Sorry. I thought you understood the meaning of albedo. End of discussion. -
Riccardo at 02:11 AM on 10 December 2010It's cosmic rays
Eric (skeptic) scientists study all the reasonable hypothesis, it's their job afterall. Problem is when people take those hypothesis as valid alternative theories. Note that the paper, although submitted, didn't show up. Here you can find a nice review which includes the same data shown in the arxiv paper. -
CBDunkerson at 02:04 AM on 10 December 2010Renewable Baseload Energy
RSVP writes: "What is positive feedback?" Reality. As opposed to your law of conservation of energy violating claim of heating the planet with solar hot water. -
HumanityRules at 01:28 AM on 10 December 2010The human fingerprint in the seasons
I hate to bring this back to John's article but he's describing what a 'human fingerprint' would look like and comparing it to what a 'solar fingerprint' would look like. It's that comparison I'm trying to understand. I'm not saying "it's the sun" as Albatross says in #60, as I said before that's two steps forward. From what I can tell John's description of a solar fingerprint is essentially the direct effect from changes in TSI it ignores. 1) The GHG component, water vapour, of solar warming (non-contraversial but poorly constrained) 2) The top-down effect of UV (non-contraversial but poorly measured) 3) The role of CGR (contraversial) at the same time he seems to be ignoring the non-GHG component of a human fingerprint (albedo etc.). As i said before I think John is presenting this as an all or nothing scenario where 'human fingerprint' equals 'GHG fingerprint' and 'solar fingerprint' does not equal 'GHG fingerprint'. I put forward an alternative that solar has a 40-60% GHG component and the human fingerprint has a 66-100% component. I think his descriptions are too simplistic, in essence wrong. The question is whether the graph is as diagnostic as John seems to suggest when you factor in the feedbacks (and other stuff I mention). I'm asking the question and hoping for a reasonable explanation. I'm not putting forward any alternative theories for the warming. -
jmahr at 01:11 AM on 10 December 2010Ice data made cooler
Thanks, this is pretty cool, but this isn't my field so my questions might seem simplistic. I see the asymetry in insolation you are talking about (although I don't understand how you infer (or know?) that from 400,000 years ago); there is also an asymetry at ~350-400kya and I don't see that correlating with increased temperature or CO2 levels. Can you explain this? Not arguing against this, just trying to understand it. I teach Biology at a community college and am trying to cover this better in my classes. Jeff -
Bob Guercio at 00:39 AM on 10 December 2010Stratospheric Cooling and Tropospheric Warming
mars - 203 Great reference document! -
Bob Guercio at 00:38 AM on 10 December 2010Stratospheric Cooling and Tropospheric Warming
VeryTallGuy - 205 But this is exactly what my dilemma is. Heat is being released in the ozone layer that is about one third of the way up the stratosphere. Shouldn't this layer, therefore, be the warmest part of the stratosphere? But it's not. The top of the stratosphere is the warmest part. -
Mike_H at 00:13 AM on 10 December 2010Ice data made cooler
John Nice piece of flash programming. I offer to you and others a project I designed a few years ago, funded by NSF, an interactive Flash-based game on global warming. It, too, is a work in progress but it is available at no cost "as is" online. www.globalwarminginteractive.com Feel free to use and distribute. Mike Hillinger -
RSVP at 00:09 AM on 10 December 2010Renewable Baseload Energy
CBDunkerson What is positive feedback?
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