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Lou Grinzo at 08:45 AM on 5 September 2010Is climate science settled? Especially the important parts?
One interesting resource on the "when did we know CO2 was bad" topic is the 1965 report to US President Johnson. The appendix that refers to CO2 is: http://bit.ly/dvbtRN (That's a link to a PDF in a public folder in my DropBox account.) -
Anne-Marie Blackburn at 08:22 AM on 5 September 2010How we know an ice age isn't just around the corner
johnd, I said that greenhouse gases were overwhelming the impact of other factors, which in context meant that their warming impact was greater than the cooling impact expected from other, natural factors. With regards to natural processes, I don't agree with you. If natural processes were overwhelming CO2 emissions, we'd see no increase or even a decrease in CO2 levels. But CO2 levels are rising, which means CO2 emissions from human activities are overwhelming the ability of natural processes to remove this additional CO2. -
johnd at 08:14 AM on 5 September 2010How we know an ice age isn't just around the corner
Anne-Marie Blackburn at 07:55 AM, yes, the alternative scenario is no anthropogenic emissions. Only then could a baseline be established for where natural processes would be heading. At the moment natural processes sequester about half of anthropogenic emissions so it is not valid to claim that the emissions are overwhelming the natural processes, as they, the natural processes are equally overwhelming the anthropogenic emissions. -
Anne-Marie Blackburn at 07:55 AM on 5 September 2010How we know an ice age isn't just around the corner
johnd, I'm not sure I understand your point - what is the alternative scenario in this case? I have pointed out in my original post that natural factors would in all likelihood have led to global cooling, though the overall forcing would probably not have been strong enough to cause a new glacial period. Isn't this the alternative scenario you mention? Also I should mention that this is the basic explanation for this rebuttal - you can read a more detailed explanation here. -
Chris Colose at 07:39 AM on 5 September 2010Empirically observed fingerprints of anthropogenic global warming
Dana, Good job. This is a nice and useful post in general, though I would be careful (for this and future posts that Skeptical Science does) not to oversell some of these points and equate ‘consistency’ with a ‘fingerprint.’ Consistencies do not always lead to any explanatory or predictive power, and this could very well be the case with the simulations of the time evolution of global mean temperature anomalies. The solid agreement between model simulations of temperature change (e.g., the Meehl graph) and observations is curious given the strong uncertainties in radiative forcing which ranges from ~0.6 to 2.4 W/m2) (see AR4 Figure 2.20), feedbacks, ocean heat content uptake, and the model ensemble members themselves (e.g., Schwartz et al 2007 Nature commentary; Knutti 2008, GRL). Indeed, the models probably do not sample the full range of uncertainty which is in part owing to the neglect of aerosol indirect effects or possible anti-correlations across the models between forcing and sensitivity, and more detailed inclusion of aerosol physics could very well lead to inconsistencies in model-observations. This should not be surprising or problematic, since formal attribution is about spatio-temporal patterns rather than the agreement in model-observation time series of temperature change. This can be done even after subtracting off the global mean temperature anomaly or ‘tuning’ the amplitudes of a perturbation (since we don’t know the sensitivity). For instance, we would generally expect the response to a volcanic eruption to occur after the eruption. In space, we might expect the response to short-lived aerosols to be focused over areas with large changes in sulphate emissions. These patterns should be pretty robust because they are very strongly constrained by the basic characteristics of the forcings and the climate system. As another example, the increase in downward infrared radiation to the surface is not necessarily unique to increased greenhouse gases, nor is it necessarily inevitable that more CO2 should directly make the atmosphere a better emitter to the surface. This would be the case if the boundary layer was moist enough to already radiate close to a black body at its temperature, which is nearly the case in the tropics. The CO2 still makes it warmer by reducing the outgoing flow of radiation and the increased temperature of the troposphere increases all the energy fluxes into the surface (the sun could do this too), not just the radiative fluxes. Water vapor really complicates getting a clean CO2 spectrum of downwelling radiation, and the best place to do this would probably be a clear night in the Antarctic winter, but this is not too relevant to the enhanced greenhouse effect anyway. I don’t see how Philipona et al (2004) really understood this at the time. Chris -
Peter Hogarth at 07:27 AM on 5 September 2010Is climate science settled? Especially the important parts?
Colorado Bob at 00:23 AM on 5 September, 2010 Thanks for that link. The various GRACE estimates of mass loss are known to disagree (sometimes by significant factors) due to the relatively short time series, and this paper looking at GIA correction is actually in line with other recent GPS based work. However all trend estimates show unquestionable significant mass loss and acceleration of loss. Better absolute estimates of this loss are important for the sea level budget, but do not change the mean sea level rise measurements. -
johnd at 07:20 AM on 5 September 2010Carbon dioxide equivalents
Daniel Bailey at 06:27 AM, I also appeal to the moderators to allow reply to posts that have previously introduced a line of discussion and have been allowed to remain. I made a general response regarding how logging permanently removes large amounts of essential nutrients thereby depleting the nutrient reservoir within the soil. You made mention of the "remnants of the once mighty forests that stood here (the stumps of which measure up to 8 feet across)" which you indicated as being having been logged out. Mighty forests cannot grow without the nutrients firstly being available in the soil, there is only so much that can be absorbed out of thin air. If you could estimate the quality and quantity of timber that was removed from the forests, it would be easy to arrive at a reasonable estimate of what amount of nutrients the soil had available originally, but not once the timber was removed, thereby allowing some comparison of soil nutritional levels before and after.Moderator Response: Please instead post your comment on a relevant thread, and on this thread post a comment saying you have replied over there, with a link to your specific comment. You can get the link to your comment by right clicking on its date-time stamp and choosing the resulting menu item Copy Link Location. -
johnd at 06:45 AM on 5 September 2010How we know an ice age isn't just around the corner
Anne-Marie Blackburn at 20:32 PM, given that about half the anthropogenic carbon emitted is sequestered by natural means it can also be claimed natural processes are as equally influential in determining the nett result. As to which is prevailing can only be judged by considering what the situation would be without the anthropogenic emissions. Would natural processes have continued to reduce CO2 levels leading to global cooling? Making an case supporting one scenario is biased unless the alternative is recognised and quantified. -
sun tzu at 06:31 AM on 5 September 2010It's the sun
thanks, after reading up on it and starting to understand the basics im pretty much sold on the CO2 and greenhouse gas as the prime candidates.. only problem is, it seems so many people want to blame it on something that wont hit their profit margins, not to mention all the media and blog sensationalism pushing the general consensun to the point of denial. Anyhow, thank you very much for taking the time to reply to my posts. I also found this link to be a source of great information : http://www.metoffice.gov.uk/climatechange/ However I cant help but feel that a very real problem is being used as an excuse to keep energy company shareholders happy - charge more for less - after all... its saving the world lol -
Elderbear at 06:28 AM on 5 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
@Berényi Péter: Why are you drawing a linear trend line on your graphs? They clearly do not represent linear processes. One could argue for a multi-decadal signal in your 25-year averaging, and probably in your 10-year averaging. On what basis did you choose your averaging periods? If you want to do something interesting, integrate your data over each solar cycle and express the results in terms of energy released. BTW, what does "Annual Sum of Saffir-Simpson Category" mean? For 2004 there were 9 hurricanes in the Atlantic giving an annual sum of Saffir-Simpson categories of 27, well above the range of your scale. -
Daniel Bailey at 06:27 AM on 5 September 2010Carbon dioxide equivalents
A plea to our moderator and John Cook for forbearance, in that we are straying perilously off-topic on this thread. But a claim was made that I feel needs to be justified with a source: Re: johnd (19)"The soils would not always have been poor, especially if it could grow giant trees... good soil can suddenly become poor soil."
What source do you reference that shows the soils in Northern Michigan and Wisconsin were ever good? Soils in this area not under cultivation already tend to have 1-12" of acidic loess overlaying either sand dunes or bedrock. Shorter growing seasons relative to warmer, more southerly climes have meant narrow, more densely packed tree growth rings than is typically found. As a result, the forests here take a long time to achieve maximal height and spread of canopy. Compare this to soils farther south in Ohio, Indiana and Illinois, where loessal drift is often measured in thousands of feet. Coupled with a warmer, longer growing season, forests there achieve greater heights and canopy spreads yielding much greater boardfeet yields when harvested. Even hardwoods. Unless you have more direct experience in the soil types and forests of this area than I, please cite your sources which offer testimony different from what my own direct, personal lifelong experience shows? Michigan background info the same for Wisconsin Not trying to be argumentative here. But this is really not a subject I'm willing to debate, nor is this a proper venue for anything other than science-based discussions and sharing of learnings. So please, share the learnings. The YooperModerator Response: It's better to post a comment on a relevant thread and then on this thread post a link to that comment. -
johnd at 06:21 AM on 5 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
I don't know if it has been raised before or not in other threads, but it should be considered as part of the discussion how such events rather than being considered indicators instead form part of a negative feedback system. -
actually thoughtful at 06:19 AM on 5 September 2010Climate change: Water vapor makes for a wet argument
AdrianSmits - can you provide a source for your statement that humidity is reduced (Please realize that "Watts up with that" is not a source)? Can you possibly restate your first point - I don't understand it as written. Thanks. -
cynicus at 06:02 AM on 5 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Ned, that's an interesting quote. If true would it mean that the whole discussion (about evidence on stronger or more frequent cyclones already being visible in the records) is a straw man because noticeable changes would only appear in the second half of this century? -
J Bowers at 05:42 AM on 5 September 2010Is climate science settled? Especially the important parts?
Re. 6 MattJ. I thoroughly agree. -
miekol at 05:24 AM on 5 September 2010Is climate science settled? Especially the important parts?
Global warming is settled, the why is not. -
J Bowers at 05:23 AM on 5 September 2010Is climate science settled? Especially the important parts?
But, but... "...And I’m going to show you the latest science, which now doesn’t leave the question unsettled anymore this is now settled science, it is now settled science that there is not a problem with our influence over Climate. The science is in, the truth is out and the scare is over.” -- Christopher Monckton. 10/14/9 Minnesota Free Market Institute presentation H/T to Citizen's Challenge -
chris1204 at 00:31 AM on 5 September 2010The surprising result when you compare bad weather stations to good stations
At 52 years of age and happily married, I've grown immune to foxy nurses - they're nothing but trouble! :-) From what little I know of population behaviour, I find straight lines with identical or near identical slopes rather different from what I'm used to seeing in the real world (even if we're dealing with anomalies rather than raw data). I note the Menne 2010 paper contains graphics for adjusted and unadjusted data - this post shows unadjusted data only. At the risk of demonstrating my ignorance, I'd expect to see at least some error bars or other evidence of scatter in the comparisons of well sited and poorly sited stations. As the current post stands, it really does look as if the maximum and minimum anomalies were extraordinarily small. Consequently, while I didn't 'imply that the USHCN has shown the exact same increase in temperature, for each station, over the period in question,' I did find the uniformity between the two sets of data disconcerting. I believe Menne at al (2010) pretty well said as much if I understood them correctly. -
Colorado Bob at 00:23 AM on 5 September 2010Is climate science settled? Especially the important parts?
Heads up - Ice caps in Greenland and West Antarctica melt is not as hard as thought 02 september 2010 door M&C September 2, 2010 by M & C http://translate.google.com/translate?js=n&prev=_t&hl=nl&ie=UTF-8&layout=2&eotf=1&sl=nl&tl=en&u=http%3A%2F%2Fwww.tudelft.nl%2Flive%2Fpagina.jsp%3Fid%3D7a6c3d15-1c1e-4869-b378-840a000c6803%26lang%3Dnl -
Argus at 00:21 AM on 5 September 2010IPCC is alarmist
citizenschallenge, Maybe the IPCC itself, has helped to diminish 'its public moral authority', by, among other things, purposely publishing outrageous predictions, even though two expert reviewers and the Indian government adviced them to withdraw the erroneous claim (e.g. the Himalayan glaciers). Recent news: The world's leading climate science body must "fundamentally reform" its organisation and how it operates if it is to regain the public's trust, according to a major review. -
dana1981 at 00:17 AM on 5 September 2010Empirically observed fingerprints of anthropogenic global warming
If by 'greenhouse theory' you mean anthropogenic global warming, that was the entire point of this post. The empirical observational data is matching what's predicted by the models. That's experimental evidence. -
jdsykes at 23:58 PM on 4 September 2010Is climate science settled? Especially the important parts?
Given the lives in the balance, it would seem to me that the deniers should be required to prove their allegations that AGW is false, and that their "proof" should be beyond a shadow of a doubt. After all, it is their premeditated obstructionism that will contribute to the suffering of millions. -
lciattaglia at 23:20 PM on 4 September 2010Weather vs Climate: Watch the waves, miss the turning of the tides
Adelady,I wanted simply to suggest that our lifespan ( or what we remember of the past) is not the correct meter for interpreting the meteorological episodes as a proof of the climate change…. My post had the intention to support the previous one (posted by keepingitreal) on waves and tides. -
Ned at 21:08 PM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
My understanding is that much of the uncertainty about whether AGW will lead to more frequent tropical storms is due to the competing effects of SST and wind shear, both of which will presumably be increased in a warmer world. Higher SSTs tend to promote TS development but higher wind shear tends to hinder it. Thus, different models that emphasize one parameter or the other will give very different results in terms of future TS frequency. See, for example: Knutson et al., 2008. Simulated reduction in Atlantic hurricane frequency under twenty-first-century warming conditions. Nature Geoscience 1: 359-364. Zhao et al., 2008. Simulations of Global Hurricane Climatology, Interannual Variability, and Response to Global Warming Using a 50-km Resolution GCM. J. Climate, 22, 6653–6678. Knutson et al., 2010. Tropical cyclones and climate change. Nature Geoscience, 3, 157 - 163. The latter is somewhat interesting -- it's a review article, with a list of authors covering the gamut from Chris Landsea to Kerry Emanuel. It also nicely illustrates that some parts of this picture seem clear, while others are still very uncertain:Whether the characteristics of tropical cyclones have changed or will change in a warming climate — and if so, how — has been the subject of considerable investigation, often with conflicting results. Large amplitude fluctuations in the frequency and intensity of tropical cyclones greatly complicate both the detection of long-term trends and their attribution to rising levels of atmospheric greenhouse gases. Trend detection is further impeded by substantial limitations in the availability and quality of global historical records of tropical cyclones. Therefore, it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes. However, future projections based on theory and high-resolution dynamical models consistently indicate that greenhouse warming will cause the globally averaged intensity of tropical cyclones to shift towards stronger storms, with intensity increases of 2–11% by 2100. Existing modelling studies also consistently project decreases in the globally averaged frequency of tropical cyclones, by 6–34%. Balanced against this, higher resolution modelling studies typically project substantial increases in the frequency of the most intense cyclones, and increases of the order of 20% in the precipitation rate within 100 km of the storm centre. For all cyclone parameters, projected changes for individual basins show large variations between different modelling studies.
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Rob Painting at 20:33 PM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
BP, you have successfully demonstrated that really bad hurricanes/cyclones have a tendency not to travel to the United States, but given that they're not actually born there, not really enlightening. There's actually peer reviewed studies (see @34) that there are more intense hurricanes/cyclones being generated in the last few decades in the tropical regions. So it appears they have a hunkering for more international travel. The PDI kinda looks like a hockey stick too. -
Anne-Marie Blackburn at 20:32 PM on 4 September 2010How we know an ice age isn't just around the corner
gallopingcamel #38 Interglacials can last up to 30,000 years. Another glacial is unlikely to happen any time soon because orbital factors are currently too weak to trigger one. On top of that, we're seeing a rise in global temperatures when natural factors should be leading to a slight cooling. This strongly suggests that greenhouse gases are overwhelming the impact of other factors. -
Rob Painting at 20:12 PM on 4 September 2010The surprising result when you compare bad weather stations to good stations
Chriscanaris @ 63 -"Actually, if you knew anything much about sphygmomanometers and blood pressure measurements, you'd know that there's very considerable variability in readings depending on type of sphygmomanometer" So why the spurious analogy?. @58 your scenario was this: "However, if every sphygmomanometer showed an almost identical rise in blood pressure of, say, 20 mm-Hg +/- 0.5 mm-Hg, you'd be wondering about the validity of the data set." You imply that the USHCN has shown the exact same increase in temperature, for each station, over the period in question. It hasn't. If it had then sure, that would indeed cause the clattering of alarm bells. As to your amended scenario it still misses the mark, for instance:- What was the average of the 100 readings?. Has some form of calibration been carried out on the sphygmomanometers?. What was the mean of the anomaly in the 2nd check up compared to the baseline 1st reading?. But even then it's not valid, Your sphygmomanometers would be in constant use between your visits & therefore would require the same protocols for every use. But even then............. How's this for expanding on your analogy? - suppose you expect having a super hot babe nurse taking the readings will bias blood pressure too high for you (micro site influences). So you compare the small number of readings taken by foxy nurses, and the large number taken by the butt ugly doctors (good/bad stations). Your expectation is not borne out by the results, you're a couch potato, smoke and have poor eating habits, and in the 2nd check up the blood pressure trend is upwards with a virtually no discernible difference between the anomaly trend of readings taken by the foxy nurses and butt ugly doctors (Menne 2010). This is where sphygmomanometersorg. weighs in - they have enlisted volunteers who have photographed the foxy nurses. The photos look compelling, any red blooded male couldn't help but see his blood pressure skyrocket one assumes (me too) but that's not what the data shows. You say it seems a tad too uniform, I say well I'd expect your blood pressure to go up with that kind of lifestyle, but let's wait and see if science can resolve why the foxy nurses didn't bias your readings higher. -
johnd at 20:03 PM on 4 September 2010Carbon dioxide equivalents
Daniel Bailey at 08:09 AM, re "Those giants took many centuries to reach maturity in these poor soils." The soils would not always have been poor, especially if it could grow giant trees. Trees drag a huge amount of essential nutrients out of the soil. In a permanent forestry situation, the foliage, branches and trees that die and fall to the forest floor allow those nutrients to be recycled. However if logging occurs all those nutrients that have been taken from the soil over the life of the tree are permanently removed from the system depleting the natural reservoir of nutrients and thus degrading the soil. Irrespective of what is grown from the soil, unless those nutrients that disappear down the road on a back of a truck are replaced, the system is not sustainable. In farming, the nutrients are generally regularly replaced, and sometimes in plantations, but rarely when natural forests are logged, hence formerly good soil can suddenly become poor soil. -
johnd at 19:10 PM on 4 September 2010Carbon dioxide equivalents
RSVP at 16:06 PM, well managed improved pasture systems are a more efficient form of CO2 sequestration than forestry and will build up the amount of carbon stored in the soil, and keep it there as long as it remains well managed. Governments are looking at providing incentives to allow primary producers to profit from such capturing and storing. -
Rob Painting at 18:32 PM on 4 September 2010Empirically observed fingerprints of anthropogenic global warming
Gnbatt @ 6 - How do we know more CO2 is causing warming? and On the Absorption and Radiation of Heat by Gases and Vapours, and on the Physical Connection of Radiation, Absorption, and Conduction -
MichaelM at 17:57 PM on 4 September 2010Carbon dioxide equivalents
It would only be sequestration if nothing ever consumed the farm products eg wheat was stored in a mine and never used. Once we consume it we convert it back to CO2. -
gnbatt at 16:58 PM on 4 September 2010Empirically observed fingerprints of anthropogenic global warming
forget the model simulations... are there any direct experimental evidence for 'greenhouse theory'?Response: There are several independent lines of direct experimental evidence for greenhouse theory (in fact, there was a detailed blog post on this yesterday). -
johnd at 16:53 PM on 4 September 2010Climate change: Water vapor makes for a wet argument
scaddenp at 12:19 PM, read more carefully, you have not grasped what has been written. Solar shortwave radiation provides the energy required for evaporation to occur. IR radiation, heat, can only be emitted after the solar energy has been absorbed by any matter on the surface, transforming the energy from light to heat, the air is then warmed from below by contact with such matter. Without solar radiation first transferring it's energy to any form of matter, such matter cannot emit IR radiation, heat, nor would water have the energy it requires to evaporate. -
johnd at 16:30 PM on 4 September 2010Climate change: Water vapor makes for a wet argument
Ann at 19:56 PM , what do you mean "more or less" in equilibrium? Seeking equilibrium is totally different to being at equilibrium. An active person seeking to match food intake with energy output is more or less seeking some form of equilibrium. A dead person may be at equilibrium in terms of the same energy input and output, but if not, then certainly at rest. -
johnd at 16:21 PM on 4 September 2010Climate change: Water vapor makes for a wet argument
Phil at 19:44 PM, rate and equilibrium are closely related. With two opposing forces, in this case incoming energy and outgoing energy, equilibrium will only be found at the point where the energy gained balances the energy being lost. But is equilibrium ever found? In the case of a single location where the length of days and nights vary, and so too the rate at which energy is gained or lost, at what point of any day, or at what day of any annual cycle can the system be said to be at equilibrium? -
RSVP at 16:06 PM on 4 September 2010Carbon dioxide equivalents
TOP said "States like Wisconsin that once were huge forests and now have a lot of worn out farm land " I was driving through farm land yesterday (not Wisconsin) seeing all that is grown... is the use of land for farming also not a form of carbon secuestration? -
chris1204 at 15:32 PM on 4 September 2010The surprising result when you compare bad weather stations to good stations
Dappledwater @ 59: Actually, if you knew anything much about sphygmomanometers and blood pressure measurements, you'd know that there's very considerable variability in readings depending on type of sphygmomanometer, the size of the cuff, the size of the patient's arms, and in the case of the old fashioned mercury sphygmomanometers, the sensitivity of the doctor's ears as s/he listens via a stethoscope for the sound of turbulent blood flowing through the brachial artery. There's even a direct effect caused by the doctor - some patients get nervous when they see a doctor and their blood pressures come back as high (but show normal range readings with ambulatory blood pressure monitoring). However, it was not I who introduced the blood pressure analogy. The analogy was introduced by omnologos @ 19. I responded to his or her analogy. I note you've raised the issue with omnologos @ 62. I do know the difference between absolute measurements and anomalies. What puzzles me is not the presence of a warming trend regardless of station siting but rather the extraordinary lack of divergence between poorly sited and well sited stations - indeed, in many instances it would seem absolutely no divergence over a number of years particularly in minimum temperatures. To return to the blood pressure analogy (and attempt to make it more valid), let's say I visit 100 doctors on the one day and get my blood pressure checked. I revisit the same doctors a year later and have my blood pressure checked again. If my blood pressure has gone up significantly, I'd expect most of the doctors to come up with a higher reading. However, I'd be very surprised if, say, 97 out of 100 doctors came back with blood pressure readings exactly 15 mm-Hg higher than my initial reading. I'd expect some of the doctors to come back with readings 10 mm-Hg higher, others 12 mm-Hg higher, others 20 mm-Hg, and so forth. I'd expect the anomaly (ie, the rise over the course of the year) to vary from doctor to doctor. However, I'd probably still end up concluding I needed to have treatment for elevated blood pressure. Similarly, I would argue from the data presented that the temperature record argues for a warming trend in the US because of the consistent direction of the anomaly. However, the sheer uniformity of the anomaly seems counterintuitive - hence my reservations about the paper. -
gallopingcamel at 15:32 PM on 4 September 2010How we know an ice age isn't just around the corner
Joe Blog (#30), I don't doubt what you say about the importance of continental drift when it comes to the "big picture" of climate over hundreds of millions of years. However, global temperatures were high in the Ordovician but fell sharply toward the end of that era and then rose again in the Silurian. The time scale is too short for continental drift to be a factor and CO2 concentrations remained high throughout that period. So what caused that Ice Age? Shariv postulates that the Earth's movement into a region in one of our galaxy's spiral arms with a high stellar density could be responsible for the late Ordovician Ice Age. Do any of you have a better hypothesis? -
gallopingcamel at 15:09 PM on 4 September 2010How we know an ice age isn't just around the corner
Ned (#32) Thanks for the RSS graph. It clearly shows that there is no temperature rise in the last decade in spite of the recent peak due to the summer of 2010. This thread was about the possibility of a plunge in temperature leading into a new Ice age. Let's stop drifting "Off Topic". The current era (Holocene) is technically an Ice Age but we live in a fool's paradise called an inter-glacial period. The Vostok ice cores show that inter-glacials are relatively short, so enjoy it while it lasts. -
David Horton at 14:02 PM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Nice work Graham. As with so much else in climate change the burden of proof argument has come to fall the wrong way. If deniers are really going to argue that frequency and/or strength of hurricanes is NOT going to increase with rising temperatures, it should be up to them to explain why this would be the case. I can see no good reason why both intensity and frequency would not increase. Given that hurricanes always occurred with lower temperatures, it is nonsense to suggest that, once given the conditions to start, greater warmth wouldn't, on average, leader to a greater intensity. It also seems to me intuitively obvious that warmer moister air columns are going to be more frequently available to trigger initial hurricane formation. The graphs that Graham and Dappled Water show exactly coincides with others showing the rise in CO2 levels and the resultant effects, beginning around the mid 1970s. Either we are faced with the most astonishing and inexplicable series of coincidences or all of these graphs show the consequences of climate change. And l we also have in this thread, yet agin, the use of figures from the US to try to disprove some obvious outcome of global warming. And even then, whatever else BPs graph shows, it concurs in the recent increase in activity. In thread after thread we are it seems to keep forever being asked to prove that one plus one equals two. -
dana1981 at 13:00 PM on 4 September 2010Empirically observed fingerprints of anthropogenic global warming
Thanks Rick. That's covered in the human CO2 emissions rebuttal. It's a cause of the anthropogenic warming as opposed to a consequence of it. -
Rob Painting at 12:28 PM on 4 September 2010The surprising result when you compare bad weather stations to good stations
Omnologos, sorry you've not improved on the analogy at all. Sphygmomanometers or EKG's still aren't appropriate analogues, the surface temperature record deals with anomalies, not absolute temperature. -
scaddenp at 12:19 PM on 4 September 2010Climate change: Water vapor makes for a wet argument
Whoops should read: On the other hand you seem perfectly content to dismiss the logical, obvious way of increasing evaporation - more radiation warming the surface. -
Rob Painting at 12:18 PM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
Whilst hurricane intensity in the US may be of interest to Americans, the US is only some 2% of the Earth's surface, and most of us aren't Americans. What happens if we look at the tropics?, an area making up roughly 25% of the Earth's surface and inhabited by some 40% of the world's population?. It is the region where hurricanes/cyclones form after all.Increasing destructiveness of tropical cyclones over the past 30 years Emanuel 2005 "Whatever the cause, the near doubling of power dissipation over the period of record should be a matter of some concern, as it is a measure of the destructive potential of tropical cyclones.Moreover, if upper ocean mixing by tropical cyclones is an important contributor to the thermohaline circulation, as hypothesized by the author, then global warming should result in an increase in the circulation and therefore an increase in oceanic enthalpy transport from the tropics to higher latitudes."
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Daved Green at 11:43 AM on 4 September 2010Hurricanes And Climate Change: Boy Is This Science Not Settled!
ProfMandia , Thanks for the link to the paper I can see their reasoning now and it seems sound . It surprises me that results of papers like these are not discussed more in the general media as they are quite dire examples of what could be in store for the world . -
Daniel Bailey at 11:40 AM on 4 September 2010Climate change: Water vapor makes for a wet argument
Re: davidwwalters (37)I guess my question now is why CO2 trumps water vapor as the prime greenhouse gas even though there is so much more water vapor in the atmosphere relative to CO2 and other greenhouse gases.
Short answer? The concentrations of water vapor in the atmosphere are pretty stable. Variations from background concentration levels normalize within a 9-day period (the residence time of water vapor in the atmosphere). Thus, while there is vastly more water vapor in the atmosphere than CO2, the greenhouse gas effects of that water vapor change little. Also, those effects are played out in the lower troposphere (because temps decline with increasing altitude, extra water vapor precipitates out...and when the freezing point of water is passed, the air gets pretty dry indeed). CO2 concentrations, on the other hand, are rising (about 40% above the interglacial range). And much of their effects occur in the upper troposphere, above the point where water vapor plays much of its King Lear role. Must-see video: Richard Alley AGU talk: CO2 Biggest Control Knob. For more in-depth background on greenhouse gases, global warming & climate science in general, go here. A little bit of CO2 goes a long ways. Hope this helps, the Yooper -
scaddenp at 11:06 AM on 4 September 2010Climate change: Water vapor makes for a wet argument
Johnd - still not making sense. I think the drivers for evaporation for warm water is perfectly well understood. I cannot understand what model for warming you are proposing - the some supposed interaction between clouds and wind can change the overall energy balance?? Seriously? On the other hand you seem perfectly content the logical, obvious way of increasing evaporation - more radiation warming the surface. Do accept the more radiation globally warming the ocean will increase water vaour? If not, what is postulated way of saving First law if the increased radiation is not warming the waters. If you are trying to make any sense at all, then please give us physically reasonable model so we can examine, make predictions and compare with reality. -
adrian smits at 11:02 AM on 4 September 2010Climate change: Water vapor makes for a wet argument
It seems to me I was reading just last week that an increase in co2 causes a corresponding decrease in air saturation by co2 and therefore removes the warming effect of co2.average humidity has decreased worldwide since the 1940's ,so there might be some truth in that theory.whats up with that? -
RickG at 10:29 AM on 4 September 2010Empirically observed fingerprints of anthropogenic global warming
Great post, thanks! How about carbon isotope ratios showing that the increased carbon is anthropogenic? -
scaddenp at 10:01 AM on 4 September 2010New presentation debunking Monckton's critique of IPCC predictions
"fact" finder - your comment about "fairy tales" is somewhat ironic. However, to have any sensible discussion here, perhaps you would outline what you think is a reasonable process for you to distinguish "fact" from "lie"? Then we might be able to help you sort out a few fictions.
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