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Cornelius Breadbasket at 19:17 PM on 11 October 2012Nuccitelli et al. (2012) Show that Global Warming Continues
You have worked so hard on this. Very well done. -
bill4344 at 15:33 PM on 11 October 2012Nuccitelli et al. (2012) Show that Global Warming Continues
Well done indeed, team! -
Stevo at 15:16 PM on 11 October 2012Nuccitelli et al. (2012) Show that Global Warming Continues
A milestone if ever there was one. Congratulations! Now keep 'em coming. -
Rob Honeycutt at 14:17 PM on 11 October 2012Nuccitelli et al. (2012) Show that Global Warming Continues
Excellent work as always, Dana! You rock!! -
DSL at 13:37 PM on 11 October 2012Nuccitelli et al. (2012) Show that Global Warming Continues
Hey, what's up with you people? You didn't trumpet it. You didn't wind up the press. You didn't get your minions to start babbling questionable assumptions. You let actual working climate scientists get involved. What's up with that? Congrats, all. Not surprising, so I won't add any exclamation marks. -
Albatross at 13:32 PM on 11 October 2012Nuccitelli et al. (2012) Show that Global Warming Continues
Congratulations to the authors! This is not going to be the first peer-reviewed paper that the SkS team produces... It is going to be interesting to see what excuses the fake skeptics are going to contrive to try and dismiss or downplay this solid refutation of DK12. It would not surprise me if at the same time, the fake skeptics fail to recognize or cede the serious problems with DK12 that undermine its entire premise.Response: [JC] "This is not going to be the first peer-reviewed paper that the SkS team produces"
Well, it is the first. Whether it's the last peer-reviewed paper that SkS produces is another matter :-) -
Daniel J. Andrews at 13:24 PM on 11 October 2012Nuccitelli et al. (2012) Show that Global Warming Continues
I saw this via twitter, and wanted to say congratulations there, but figured it would appear here where I could say it. So "Congratulations!" for getting published and for the work itself. Very nicely done indeed. Hope you all are still flying high on this. -
chriskoz at 09:33 AM on 11 October 2012Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
jyyh@12, Jerry explains that in great details starting from 25:00. Re-watch it. -
Jeffrey Davis at 07:50 AM on 11 October 2012Update from Easton Glacier: Climate Crocks on Ice
We saw a glacier in Alaska this summer that had retreated ~500 ft. In a year. -
Same Ordinary Fool at 04:33 AM on 11 October 2012Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
Icarus @9 "He [Mitrovica] and others working on the same problem start with the equivalent of four "fingerprints" all laid down atop each other: they know how much sea levels have risen during the past century - or in some cases, several centuries - at various inhabited locations. From these observed changes, their work is to isolate the distinct impact - of the melting of the West Antarctic Ice Sheet; the Greenland Ice Sheet; other glacier systems including that in Alaska; and thermal expansion...In this way they are able to make an indirect observation of precisely how much volume and mass each ice sheet has lost." (Harvard Magazine) "Localization" effects can be determined from the difference between the video's Greenland effects map based on a uniform 1mm equivalent (of meltwater to cover the world's oceans) and another Greenland effects map with the same amount of meltwater located where the melting actually took place, based on best estimates. (Oceanography, pp32-34, Figure 4) Conceivably this might also be done with separate oceans. I bet Jerry Mitrovica could solve it, if he had enough grad students.Moderator Response: [DB] Fixed Link. -
John Hartz at 03:46 AM on 11 October 2012Climate time lag
Seems to me that the OP would benefit from an update that incorporates the some of the detailed comments being made in response to Falkenherz. -
gws at 02:47 AM on 11 October 2012Climate time lag
KR, indeed. That is why I commented that this is Falkenherz's "thought experiment". As the long time lag dominates, the picture is not too far off, but as was commented here before, the shorter air-T time lag has additional effects that make it more realistic. -
Climate time lag
A single lag time is insufficient to describe the observed climate response (as in Bob Loblaw's post, the model shouldn't be too simple). Tamino has an excellent post on this, Fake Forcing, where he examines attempts to use single lags - attempts that require ad hoc, physically unsupported tweaks to come even close; the "fake forcings". On the other hand, if you consider a two-box model, two time lags, roughly corresponding to the responses of atmosphere and oceans, you can replicate climate behavior quite well. That model (lags in Taminos example of 2 and 45 years, respectively) fits observations quite well without modifications, and has the added benefit of being based on physics. It also directly provides an estimate of climate sensitivity using purely instrumental data, of 2.4C/doubling of CO2, well within IPCC estimates. Sliding time-lines back and forth for visual matching (which also neglects the fact that the climate responds to all forcings, not just one, and that analysis should be measured by statistics, not the "eyecrometer") is equivalent to using a single-box model - that's just too simple to describe observed climate behavior. -
gws at 02:19 AM on 11 October 2012Climate time lag
continued Multiply the above picture with the actual TSI impact (aka smaller 1 W/m2) and you understand why the TSI impact is so small. What about CO2? I created a simple model of atmopheric CO2 concentrations (from 280 to roughly 395 ppm) following an exponential increase with constantly increasing growth rate (see, e.g., Tans et al., Atmos. Environ. 43(12), 2009); not exact, but an ok first guess. I then used the Myhre formula (forcing = 5.35*ln(C/C0), which gives a 3 K climate sensitivity for doubling CO2, and a 1.7 W/m2 value for the 395 ppm end point) to calculate the changes in forcing over time, then repeated the incremental integration as above. For comparison purposes to TSI, I further assumed that the atmospheric CO2 increase suddenly stopped at 400 ppm. The resulting graph looks like this:
Note, again, that the T increase is in lock-step with the driver increase (here: [CO2]) as long as the increase is maintained, thus a close correlation between CO2 and T is expected as long as only CO2 is driving the system. But note that in this case, much more warming is in the system, with "only" 0.7 K realized by the time the CO2 forcing stops, with another 0.5-0.6 K in the "pipeline".
Not bad for a simple box model I would say. I was suprised myself. I will supply the R code for this to the moderator, or post it here if desired.
One other thing:
The difference in physical forcing between TSI and CO2 is one of wavelength: In the case of TSI increase, most of the extra incoming energy is in the form of shortwave radiation. In the case of GHGs, it is in the form of long-wave radiation (infrared). So while GHGs "dump heat" efficiently into the system, TSI increases drive a number of other things as well, e.g. chemistry.
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gws at 01:59 AM on 11 October 2012Climate time lag
Falkenherz Hmmh, you are smart but you decline to look into the math ... so ok, I did the math for you, or better say, for your thought experiment: We start with the assumption that the system does have a lagged response between 25 and 50 years. If a perturbation (energy imbalance, I, in energy per time) to it occurs, the response is converted with a rate k (=1/tau) into a temperature, T, increase proportional to the difference in T between the equilibrium response and the current temperature, aka dT/dt = k*(I*cs - T(t)) (eq. 1) with cs = climate sensitivity in K per energy (assumed to be ~0.7 K per W/m2 as in Hansen et al., 2005), and k in per time (so that tau is in time units, say yr^-1) The solution to this (separable) differential equation is T(t) = I*cs *(1-exp(-t/tau)) Let's assume first that we have an instantaneous input of I to the system, a step change so to say. This was explained hetre before in numerous words, and by Riccardo with a graph. The first graph I produced here is the same basically:
It shows the response to the step change for various lag times from 25 to 50 years (in 5 year steps plotted in black to cyan).
Note that I alinged the year axis roughly in assumption that the increase occurred in 1750. Let's say this is the hypothetical TSI increase of 1 W/m2, so I am actually strongly overestimating its potential effect on Earth's T.
So this is for illustration on how the lag works.
Next, let's make it a bit more realistic:
The TSI increase could be assumed to be linear (based on your comments) instead of step-change like. So I had it linearly increase from 0 to 1 and then stop (as per your comment again).
The differential of that curve gives me the yearly increase in TSI, each year inputing a bit of energy to the system, which can be modelled exactly teh same way as for teh step change illustrated in the above graph. One then needs to simply add up all those changes (integration). The resulting change in T looks like this:
Note that (a) during much of the linear TSI increase, T also increases linearly, hence the close, near linear correlation between TSI and T during the phase of change, and (b) once the forcing is shut off, an exponential decay of the remaining T-increase results. As you can see though, much of the increase had already happened at the time the forcing was shut off (0.5-0.6 of the equilibrium 0.7 K, depending on lag).
(more to come)
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Bob Loblaw at 01:55 AM on 11 October 2012Climate time lag
Falkenherz: ""climate lag is the same for all forcings but it is not the same for all forcings" (hi, bob) " What I specifically said above in #356 was "and the TSI increase vs. CO2 increase effects are, to a first approximation, not much different", and I followed that in #369 with "different radiative forcings can have different effects, although many of the differences are subtle." Note the "first approximation", and "not much different" in the first quote, and the "many of the differences are subtle" in the second. If you seem to think that I claimed that "climate lag is the same for all forcings", then you you aren't reading well (or aren't understanding well). If you seem to think that my two statements are in disagreement, then please be explicit is saying how. I'm going to try to rephrase what I (and others have) said earlier. Concepts such as "time lag" are very simple ways of trying to understand one aspect of a system. Although such simple constructs may provide a useful way of visualizing one or a few characteristics, the simple constructs will fail to catch many of the details. Trying to force the details into that simple construct will undoubtedly fail. "It is still not clear to me why an existing climate lag cannot be visualized by displacing cause (TSI) and effect (global temp) accordingly on the time axis." For starters, there isn't a single "existing climate lag". Secondly, what are you trying to show by doing this? The appearance is that you are trying to force observations of the real world to fit a simple model - one that is too simple. As DSL points out, to do it well, you have to start out including other factors. I gave a list in #369 of all (or close to all) of the things that would need to be considered to get a full understanding of the climate system. Depending on the purpose, models can leave some of those things out - but still be useful. Leave the wrong ones out (for a specific purpose), and you'll end up with a bad model. Remember the old saying "as simple as possible, but no simpler". By focusing on a single time lag concept, you are going too far past the "no simpler" point. -
Composer99 at 01:42 AM on 11 October 20122012 SkS Weekly Digest #40
With regards to the 'What Say You?' portion of this post: What spoonfuls of sugar do we have in our arsenal that might enable the average person to swallow the "medicine" of climate change mitigation and adaption? I might suggest that babies are a particuarly poignant spoonful. From the evidence, we can be reasonably confident that climate change and ocean acidification is already disrupting present-day food production and will eventually cause severe disruptions in global food production. I personally would go so far as to say that we are at, or near, the point of choosing between the mutually exclusive options of a carbon-based society today or reliable global food production tomorrow (metaphorically speaking). Suffice it to say, small children across the world alive today are the ones who are, at present, going to feel the worst of the climate disruptions to come (to say nothing of their descendents). I have a one-year old son, and the thought of him not having the opportunities afforded to me and my generation due to ongoing climate disruption is not a pleasant one. Suffice to say I do not find appeals to emotion, or appeals to consider the interests of future generations, illegitimate, as long as they are based on a solid foundation of evidence & logic. -
DSL at 01:21 AM on 11 October 2012Climate time lag
Falkenherz: "It is still not clear to me why an existing climate lag cannot be visualized by displacing cause (TSI) and effect (global temp) accordingly on the time axis." Who says it can't? However, if you're going to do it well, then you need to isolate the solar signal in the temp series. You need to strip out GHG forcing, aerosols, ENSO, etc., to reveal the solar effect on temp as purely as possible, and then you can go lag hunting. Even then, it's going to be tough, because the effect isn't going to return 100% at one point in time. General circulation is going to spread out the return. The spread may be consistent, but it still confuses the issue. -
Falkenherz at 01:02 AM on 11 October 2012Climate time lag
Dear all, thanks for your last comments, but I think most are by now besides my point. I have the impression you sometimes read only half of my arguments and jump on some red flags; answers range from "you have no idea so shut up and read" to "climate lag is the same for all forcings but it is not the same for all forcings" (hi, bob) to "it is too complicated to give a simple answer" to "you cannot do this". (-snip-) I need to be able to understand answers with my limited non-scientific perspective. Especially the link to the discussion of Shapiro et al. offers interesting insight for me. It is still not clear to me why an existing climate lag cannot be visualized by displacing cause (TSI) and effect (global temp) accordingly on the time axis. If I roughly understand the results and the discussion under the "Shapiro article", I should confirm nothing else than what we found out here, anyways: The current rise of global temp is simply too much to be even a concealed trailing off from a raised TSI-end-level from 1960.Moderator Response: [DB] Tone-trolling snipped. -
jyyh at 23:59 PM on 10 October 2012Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
the gravitational pull effect occurs likely with Antarctica too, so what does that do for sea levels in NH? -
chriskoz at 23:31 PM on 10 October 2012Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
Rob@4, Yeah, let's say that: Jerry did not draw the complete picture of SL in last 10ka but suggested it would be a hockey stick shape with a blade angle 1.5-2mm/y in XX century and accellerating to 3.5mm/y in satelite era. So there is no doubt which paleo guy from PSU you are talking about. It's so obvious that I don't even think about it, and I'm not even sure if SLR hockey stick can be technically compared with the original from tree rings but the PSU guy deserves every piece of credit, so let's add SLR hockey stick to his "league". -
chriskoz at 23:11 PM on 10 October 2012Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
Jerry does explain the SLR variability maily with icesheet gravitational pull. He shows the map (at 16:10) of modelled GIA melt that explain the "European problem". He mentions the isostatic rebound be also a part of that map, but does not explain the relative impact of ISR vs. gravitational pull. We know that i.e. Scandinavian Peninsula is affected by ISR. Further, I don't see ISA from Laurentide Sheet on Jerry's map. In particular the sinking of the East US coast is not visible at all. I would like to know at least the ballpark figure how those two effects relate: which one is larger at the current SLR rate. Anyone knows? -
Icarus at 22:39 PM on 10 October 2012Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
Very interesting lecture - thanks for the link. I thought: Maybe they can use the geographical fingerprint to add useful data to our understanding of ice mass melt over time (e.g. maybe the tide gauge data would show that Greenland started to melt before the WAIS)... but wouldn't that be confounded if there was also non-uniform warming of the oceans? Given that a component of sea level rise is thermosteric (I hope that's the right word), presumably some parts of the world's oceans are warming faster than others and therefore contributing more to sea level rise in those regions. If the portion due to ice melt was not geographically uniform then that would be another complication to have to take into account, and might limit the usefulness of the 'fingerprints'. -
Daniel Bailey at 22:37 PM on 10 October 2012Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
anja247, isostatic rebound is a slow process. Here in North America crustal rocks are still rebounding from the demise of the Laurentide Ice Sheet and its associated overburden more than 10,0000 years ago. Expect SLR on the decadal-to-millennial timescale with crustal rebound lasting for many, many millennia more until a new equilibria is reached. -
anja247 at 22:28 PM on 10 October 2012Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
that was a truly fascinating lecture! i was left wondering about the duration of the 'european problem': when the ice on greenland melts the gravitational pull diminishes, and adjacent sea levels drop... i understand that mechanism, it makes perfect sense. but, once the weight of the ice sheet on greenland disappears, wouldn't this cause greenland to rise, and won't the gravitational pull then be re-established? and would that not affect sea level in the northern hemisphere (increase)? -
Kevin C at 21:05 PM on 10 October 2012Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
batsvensson@1: If I understand correctly you are right. Using tide gauges we need to track local sea levels, because only by tracking local changes and the reconstructing the global change from the fingerprints can you get an accurate picture of the volume of water in the oceans (which is what changes when ice melts). I presume satellites give a more direct indication of volume. For any future ice melt, you need to project where the ice will melt and then apply the corresponding fingerprints to gain an estimate of local sea level rise. Global sea level rise is a useful metric to give a big picture, but doesn't tell you what will happen locally. Rob's excellent 'Sea level Isn't Level' series goes into more detail on this. -
skymccain at 20:43 PM on 10 October 2012New research from last week 40/2012
Thanks Ari for pulling all this together in one place. I really value this one-stop source as it obviously allows me more time to read, copy and file those studies on topics that I try to follow and seek to better understand. -
AndrewDoddsUk at 19:33 PM on 10 October 2012Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
Global sea level is very much of interest.. From geological records, sea level rises of meters per century (max between 3 and 10m) are established; however these were in response to considerably slower warming. My impression is that both the WAIS and southern portion of the GIS are effectively unstable right now - as in, if we stablised CO2 concentrations at current values they would probably vanish over time. The only real question is how fast this can happen. So far the answer seems to be 'not catastrophic', but there again that's what we thought about the sea ice last decade.. -
skywatcher at 18:06 PM on 10 October 2012Update from Easton Glacier: Climate Crocks on Ice
Rob #4 (and #3 William) glad you mentioned that, was at Franz and Fox last year and it seemed pretty clear to this geomorphologist that they were both decidedly retreating. The information board at Sentinel Rock was IMHO out of date. Very soon, Franz won't actually be visible from the famous Peter's Pool too. Lionel A, well said indeed. Most of the clowns that claim various egregiously wrong things about the climate have no concept whatsoever about the efforts, hazards and challenges involved in collecting field data from remote and often hostile environments. -
Rob Painting at 17:35 PM on 10 October 2012Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
"So what do we conclude from this?" Actually, I'm very surprised that no commenter has noticed that these observations scuttle a well-worn contrarian myth. They very broadly support the conclusions of a very well-known paleoclimatologist from Penn State University. -
John Brookes at 16:01 PM on 10 October 2012Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
Nice video, thanks! -
batsvensson at 13:51 PM on 10 October 2012Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
Interestingly enough according to the presentation0 there is a positive 2nd derivative in the past two decades for sea level rise and that make me wonder what the explanation for this is? -
batsvensson at 13:39 PM on 10 October 2012Jerry Mitrovica: Current Sea Level Rise is Anomalous. We've Seen Nothing Like it for the Last 10,000 Years
So what do we conclude from this? Is global see level of less interest and what we instead should keep track of is the local sea levels? -
Climate time lag
Falkenherz - "...TSI changes will affect all other forcings, but no other forcing will affect TSI..." To clarify my previous comment: GHG's, volcanic aerosols, and ENSO are not driven by TSI changes. Anthropogenic GHG's are driven by our economic decisions, volcanism by geology, and ENSO by it's own aperiodic variations. The baseline TSI is quite stable; changes in TSI are only a fraction of a percent in value. And those TSI forcing changes are very small in comparison to GHG forcing changes - an order of magnitude smaller:
[Source]
I suggest you follow the evidence.
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Daniel Bailey at 10:26 AM on 10 October 2012Update from Easton Glacier: Climate Crocks on Ice
Phil, you doing a Dr. Evil thing? Monocle too? And here I thought that I was the only one who did that... -
scaddenp at 10:16 AM on 10 October 2012Update from Easton Glacier: Climate Crocks on Ice
"he is a Viscount, no less, so he should know." splorff! Now I have coffee in my keyboard and scratches from the cat. -
noelfuller at 09:49 AM on 10 October 2012New research from last week 40/2012
mike There are vaious forms of dry rice farming that overcome issues of CH4, water availability and high labour input at the expense of increased risk from weeds and pests but there is organic dry rice farming too. Rice is grown from seed directly instead of planting out seedlings. Also check out aeroponic rice farming. You have to give google a nudge here as it defaults to hydroponics. Noel -
vrooomie at 09:28 AM on 10 October 2012Update from Easton Glacier: Climate Crocks on Ice
"...this video...conflicts with what Lord Monckton says..." Yes; reality and facts are often at odds with the good Viscount. Fortunately, it's easy to figure out where reality ends and Monckton's Myths begin... The deniers really are going to look (even more) *really* idiotic, and sooner rather than later will be fine by me. One can only argue against empirical data for so long. -
Bob Loblaw at 08:06 AM on 10 October 2012Climate time lag
Falkenherz: To update: different radiative forcings can have different effects, although many of the differences are subtle. Different parts of the system have different response times. Different parts of the system have different energy flows and circulations that must be accounted for. You seem to be in search of simple explanations for components of the system, and then when you get them you seem to want to mix and match those simple explanations while keeping them simple. This is not working, because the simple illustrations all leave something out - so that they can be simple. Here is what you need to do: - look at incoming solar radiation at the top of the atmosphere, including daily, seasonal, and decadal variation. Don't forget to include spatial distribution ("geography"). - look at the changes in solar radiation as it passes through the atmosphere. Don't forget to include the effects of normal air molecules, trace gases, particulates, aerosols, absorption, and scattering. Don't forget to include daily, seasonal, and decade variation, and spatial distribution. - look at IR radiation in the atmosphere - both emission and absorption. Don't forget to include daily, seasonal, and decade variation, and spatial distribution. - look at surface absorption and emission of radiation. Don't forget to include daily, seasonal, and decade variation, and spatial distribution. - look at other energy flows: thermal energy, evaporation, condensation ("latent heat"), etc. Include the atmosphere, earth, and oceans. Don't forget to include daily, seasonal, and decade variation, and spatial distribution. - look at stores of energy - oceans, earth, atmosphere, and the exchanges between them. Don't forget to include daily, seasonal, and decade variation, and spatial distribution. - look at the physical circulation patterns of the atmosphere and oceans,and how the pressure distributions and circulation are linked to the energy flows. Don't forget to include daily, seasonal, and decade variation, and spatial distribution. If you search carefully, you may find that someone else has already done this. They will have taken a description of the earth/atmosphere/ocean system with realistic geography, included circulation mechanisms and energy transfers and storage, solar input, IR loss to space, etc., and put it all into one package. They may have expressed all this in a series of equations and put it into a computer, and done some calculations to see what happens over time. Try searching for "general circulation model", along with "climate". If you are really, really lucky, someone will have brought together a group of scientists to review the work that has been done as described in the preceeding paragraph, and put it together in a summary of the state-of-the-art knowledge of our climate. You can start your search here. What you will find is that when science's best understanding of the complex systems involved is used, the current warming rates cannot be explained by TSI and time lags. -
DSL at 07:39 AM on 10 October 2012Climate time lag
Falkenherz - "My reasoning is that TSI is the primary cause for all other effects, which build upon and react to it. TSI changes will affect all other forcings, but no other forcing will affect TSI, but is dependend on TSI instead." That's precisely why I brought up energy exchange at the ocean surface. GHG forcing can directly affect how much solar energy is stored in the oceans (and thus made subject to oceanic circulation). If you want to understand AGW, you can't start with the surface temp record. You have to start with the physical mechanism--absorption/emission of thermal infrared radiation. Once you understand that that physical mechanism exists with a very high degree of certainty, it must then be accounted for. Solar's going to do what solar does. GHG forcing is going to do what it does. The relative strengths of both have not been determined by the surface temp record. Downwelling radiative flux has been directly, instrumentally measured at both surface and TOA. That energy must be accounted for. Must be. In every calculation. In every curve fitting exercise. It can't be disappeared by an alternative theory, unless that theory includes a way for multiple instruments to be precisely wrong hundreds of times and for applications that rely on known physics to suddenly stop working. If you ultimately find that scientists have made a mistake, that solar actually is responsible for the current trend, then we're in deep doo doo, because that energy stored via GHGs is building up somewhere. -
funglestrumpet at 07:15 AM on 10 October 2012Update from Easton Glacier: Climate Crocks on Ice
I really would like to think that this video is real, but it conflicts with what Lord Monckton says, and he is a Viscount, no less, so he should know. -
wili at 07:00 AM on 10 October 2012Modelling the permafrost carbon feedback
Thanks to all who posted here and to Andy S for bringing this to our attention. I don't want to get off topic on the "panic" thing, but the image you have to have of the American public and of our decision makers is one of what is known as a "couch potato"--someone who spends all day on the couch drinking beer and watching TV. The only think likely to wedge such a creature from its perch is the perception/understanding that his house is on fire. Anything short of that will just be passed off as something he can get to later. Once panic gets him up and moving, that will be the time for him to come to some coherent plan. But voices telling him "the smoke coming from the next room probably isn't going to threaten you any time soon" are not going to motivate any action. Again, the reality of how policy responds (according to Schlessinger who spent his life working in these areas at top levels) is that the only actual alternative to at least a bit of motivational panic is complacency, which is pretty much what we've had. If proof (or at least strong evidence) that we have passed into a runaway greenhouse world--which I take this article to be, and I have not so far seen anyone argue convincingly otherwise--isn't cause for some strongly motivational panic to get us and our leaders off of our collective couches, I don't know what will be, besides utter collapse, at which point it will really really be too late. Best, and thank again to all. wili -
Daniel Bailey at 06:44 AM on 10 October 2012Climate time lag
@ Falkenherz: Lacking the understanding of the physics and the physical mechanisms themselves, you could choose: 1. To study those things, including the differences between the various feedbacks and forcings 2. To ignore number 1 above and continue to practice climastrology and curve-fitting; the modern equivalent of eye of newt and toe of frog Your comment above makes it clear you choose option number 2, so I'm bowing out of this discussion. -
Rob Painting at 05:23 AM on 10 October 2012Update from Easton Glacier: Climate Crocks on Ice
The Franz Josef glacier has undergone spectacular retreat in the last few years. See the images here. -
william5331 at 04:28 AM on 10 October 2012Update from Easton Glacier: Climate Crocks on Ice
The only reason the Fox and the Frans Yosef glaciers in New Zealand are advancing is because of the unbelievable amounts of precipitation falling in the snow fields where they start and these short periods of advance are in the middle of a long term retreat. The mountains are very very steep on the west coast of South Island where they occur and the glaciers poke right down into a temperate rain forest. If you walk up from the bottom of the valley you see a wonderful sequence of land reclamation by nature with forests at the bottom and only lichens and mosses right up beside the toe of the glacier. All this has happened within the past couple of hundred years. In no meaningful way can we say that these glaciers are advancing. -
Climate time lag
Falkenherz - "My reasoning is that TSI is the primary cause for all other effects, which build upon and react to it. TSI changes will affect all other forcings, but no other forcing will affect TSI, but is dependend on TSI instead." Actually, that is entirely incorrect. Anthropogenic greenhouse gases and volcanic aerosols are not dependent upon TSI - they are separate influences. Neither is (at least, not directly) the quasi-periodic ENSO variation. None of these are dependent on TSI, none are driven by TSI temporal patterns. If you treat TSI as the only driver, the "first cause", you will be starting from an erroneous premise - and will therefore come to erroneous conclusions. TSI certainly needs attention - but that is no reason to ignore GHG forcings, which on a purely physics basis are much more relevant to recent climate change. You seem quite strongly motivated to find a TSI explanation for recent climate change - I would suggest instead looking at the evidence and seeing where that leads. Motivated reasoning leads to confirmation bias, which (IMO) is what you are exhibiting - asking for stronger and stronger evidence for points you disagree with, while having an extremely low bar regarding evidence supporting your position(s) (proposing multiple century TSI lag is but one example). The evidence, from multiple lines of investigation and 150 years of physics, shows that our emissions are strongly affecting the climate, that they are the dominant influence right now. That is really the only answer a true skeptic should need. -
Falkenherz at 03:34 AM on 10 October 2012Climate time lag
KR, thanks, your comment corresponds to my interim-conclusion. However, I have to explore the sceptical further, because I still do not know sufficiently how strong TSI affects that sum of all forcings. My reasoning is that TSI is the primary cause for all other effects, which build upon and react to it. TSI changes will affect all other forcings, but no other forcing will affect TSI, but is dependend on TSI instead. That is why I believe TSI needs at least as much scrutinity as GHG, albedo and everything else. Spaerica, thank you very much for the link to reconstruction models. Scepticalscience indeed seems to offer a whole virtual library. Just a short comment on your three points: First, the displacement is only an estimate, so what, we don't seem to have anything better. Second, the "climate" lag should be the same for all kinds of radiative forcings. We know about lag, so we can as well try visualize it. Third, the system is indeed very complex but TSI is, by logic, not the least but the main factor, see my comment above. The impact, based on the known observations, might as well be small, though. Eric, I must admit you talk too scientifically abstract for me to understand. But I have the impression that your thoughts follows along similar lines which I tried to discuss here so far. But see also to Spaericas objections. Imo, key is, how much difference of TSI level can we establish and how is global temperature affected on the long term, including the "lag argument" which this article here is about. I will take some time to study the article about Saphiro et al.; on first glance, it seems the data I asked for is represented there, thanks again for that. -
Climate time lag
Falkenherz - Something important that I don't think is being emphasized enough in this discussion: the climate isn't responding to just TSI, to just, but rather to the sum of all forcings. And any lag in the transient or equilibrium climate response is to that sum of forcings. While there are some fingerprint particulars (faster response to TSI in the upper troposphere, for example), the overall efficacy of various forcings is close to identical, and what you need to look at is the sum forcing to see where the climate is going to go next. That total forcing is rising, and has been rising roughly linearly for half a century. The TSI component of that forcing has been declining over that period (and rather redundantly is therefore not responsible for the rise in total forcings), but at nowhere near the rate that GHG forcings have increased. In causal terms, GHG increases are responsible for warming, while TSI decreases are in turn responsible for limiting that warming somewhat. Given the (supported by the physics) climate lag response of 25-50 years, what happened in 1700 simply isn't relevant to this past century. It's not the sun. "Eyecrometer" time displacements simply won't make it so... -
Lambda 3.0 at 02:23 AM on 10 October 2012Update from Easton Glacier: Climate Crocks on Ice
When I tell people about the glacier melting or the arctic melting, I sometimes get asked, "why does it matter?" These glaciers make up a large part of the water supply for major cities and agriculture in many parts of the world. Without them, a lot of Great Plains agriculture would be impossible. A lot of western cities would be impossible as well. Not to mention a lot of the south Asian population would be put under severe distress. We're talking about potential upheavals of millions of people having no water to drink and less food to eat. Yes, it is a serious problem. -
DSL at 01:44 AM on 10 October 2012Climate time lag
On small improvement to the water tank analogy: instead of plugging up holes, we're placing screens over the holes, and as GHG concentration rises, the screen mesh gets tighter. There's something else, though, that I recall having been brought up at SoD. Does down-welling longwave radiation decrease the cooling efficiency of the mixed ocean layer (1-2m). In other words, as the skin receives more thermal IR, does it in turn prevent the mixed layer from getting rid of its energy -- to some degree, of course? This is an area where I'm still in the dark. The SoD discussions seem to be inconclusive on the incorporation of DLR into the general ocean heating mechanism. SkS doesn't have a post on it that I'm aware of.Moderator Response:[DB] I think you'll find your answer here:
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