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Bob Lacatena at 00:01 AM on 10 October 2012Climate time lag
360, Falkenherz, There are many solar reconstructions (through proxies), and many of them are at odds with each other. Be careful to avoid confirmation bias by choosing the reconstruction which best fits your hypothesis. You can find a discussion of two such reconstructions here. Separate from this... displacing a TSI graph would not be the right thing to do for three reasons. First, the displacement is only an estimate, and one with a broad range (25 to 50 years, a 25 year range). Second, and more importantly, to do so would imply that the sun's rays that struck the planet X years ago have a direct effect X years later. This is simply not the case. The imbalance at any point in time changes dramatically from day to day, month to month and year to year. It is impacted by multiple factors beyond TSI (albedo and GHGs being the two biggest). The change in global mean temperature at any one point in time is a function of the imbalance at that moment. The cumulative change over time is a function of the progressive imbalances, not a sum of the factors that caused the imbalances. Third, the system is just far too complex, and TSI is the least of the factors to be considered. Let's take Bob's water tank analogy and change it a bit. We have a tank of water with a hose (the sun) that is constantly filling it. The tank has holes so it is constantly emptying at, on average, the same rate as it is being filled. When the system is stable, the water level in the tank does not change. If we vary the flow of water into the tank over time so that on average it is the same as the amount exiting the tank through the holes, then on average the water level in the tank stays the same, although for short periods it will raise or lower. This will not be directly proportional to the changes in flow from the hose because, as has been explained, the increased pressure of a higher water level also causes the tank to drain more quickly. We can further complicate things by continually plugging some holes while other, new holes pop up, so that the amount of water leaving the tank changes. These are greenhouse gases. We'll also deflect some of the water coming from the hose so it splashes on the side of the tank instead of going in. These are anthropogenic dimming aerosols and volcanic eruptions. Now, out of all this, you want to take a graph of the water pressure in the hose for the past 12 hours, shift it 3 hours, and find some correlation with the height of the water in the tank... in a scenario where you know that the variation in the water pressure (flow) from the hose was in fact the smallest variable (i.e that the holes in the tank and the deflection of water away from the pool were larger factors in water level). Beyond this, you didn't even have a direct gauge on the hose until the last few hours, so you're guessing at the water pressure before then based on how loud the workmen thought it was, and you're not quite sure if you should be shifting it 2, 3 or 4 hours, and in fact you probably need to shift and distort the match-up by different amounts over time. You simply cannot naively take a graph of TSI, shift it X years, and say "ah-ha, now these should match up." It just doesn't work that way. The bottom line here that you do not seem to grasp is that things like this need to come from first principles. You need a coherent, logical reason as to why things would behave a certain way, make a quantifiable, mathematical prediction of what you expect to see, and then compare it to the result. You cannot take a thought process as simple as "hmmm, more or less sun should mean hotter or colder, and there must be a delay because it doesn't quite line up, so let's just shift these graphs left and right until we find a match." [h/t to Eric for pointing out not only that geometry reduces the W/m2 of TSI, but that albedo further reduces it. Also note that your 1880 choice is a cherry pick of a low, and one that egregiously ignores the "time lag" argument because it ignores the lag of the stronger TSI that preceded the low. The reality is that I still think you could claim at most 1 W/m2, divided by 4, times 0.7 for albedo giving 0.175 W/m2 or about .04˚C.] -
Eric (skeptic) at 22:58 PM on 9 October 2012Climate time lag
Falkenherz, it seems to me rather than a lag, the GAT response to a step TSI increase is an inverse exponential decay such as delta T = initial rise + rest of rise * (1 - exp( rate * time)). Of course TSI doesn't move in step functions. It's also been noted here that there is a modest 11 year signal in temperatures with no lag. My view is that there is a slight initial rise that produces the 11 year signal, but the rate of the exponential rise is slow due to ocean overturning. I'm not sure what you are talking about regarding 1880 and 1960, they differ by about 1.7W/m2 show here: http://colli239.fts.educ.msu.edu/2003/12/31/solar-activity-2003/ which translates to 0.3W/m2 after accounting for the spherical earth and 0.3 albedo. Using 0.75K/W/m2 sensitivity, that's about 0.2C. Dikran, I'm not sure if this is a radiation physics issue or an ocean response issue (not that simple either). That's because my presupposition is that secular CO2 forcing and secular TSI forcing lead to similar climate responses. -
Lionel A at 22:01 PM on 9 October 2012Update from Easton Glacier: Climate Crocks on Ice
I hope you don't mind me dropping in a post I made at Deltoid about a week ago, with slight edits. Of course when the 'usual suspects' of the world try to rubbish the scientific data they should consider going out on the ice like Dr. Mauri Pelto on Easton Glacier nr. Mt Baker in the Cascades – (video in a recent Climate Crocks post) and take Watts, Montford, Monckton, Bast, Bastardi, old uncle Tom Cobbly an’ all (that latter BTW idiom for the short list of high profile one-time scientists turned advocacy shills) with them. Think of the fun they would have howling at the moon that global warming is a hoax. Inhofe & co. could be dropped in by parachute – after all they could find a ready made igloo – in a crevasse. Those described above should pay attention to this bit, transcript as close as I could make out:This is just one measurement. Obviously the last two day we’ve marched around these glaciers, arggh, we’re going to cover about ten miles to get those two hundred measurements. Do that for thirty years on ten different glaciers and you get an idea of what it takes you to – just one little – you look at those graphs and you see a data series, a time series, even for an individual glacier or a series of glaciers in one range it gives you an idea of the kinda effort you need to put in.
That is what it is about, collecting the data for analysis to provide the information that informs us that global warming is for real. Anybody now continuing to obfuscate this basic fact should be sent for correction training to find out how science really works. Hey Watts & co., guess what, it isn’t sitting in a nice office somewhere comfortable confabulating over weather station photographs. You are behaving in a despicable deceiving manner by trying to deflect from the physical and mental effort of real scientists working in hostile and dangerous places. And yes I remember an acquittance of mine who disappeared, never to be seen again, into a crevasse on Greenland. -
Falkenherz at 21:02 PM on 9 October 2012Climate time lag
Dear co-commenters.... I think I found a big part of the answer, from Wang 2005 (which I had already read and quoted, but under a different article, so I forgot it; that's what I get from jumping from article to article with the same question...). Wang 2005 presents a model (ok, a model, but better than nothing), which goes back until 1700. It shows *only a small difference* in TSI levels in 1700, as compared to 1880 and 1960 (Fig. 15 on p. 535). Consequently, a trailing off of the global temperature (=response) from 1960 onwards can only correspond to a fraction of the difference between TSI levels in 1700 and 1960. Now I only need to see some corresponding observations, reconstructions, models of global temperature levels from 1700 onwards. This would help me to understand the possible scale of the long-term response linked to a dominant TSI forcing. Can someone point me to a source? Interim-conclusion: Even if we assume that a halting TSI level in 1960 still incurs some lagged/trailing-off raise of global temperature, the scale of this temperature lag could be too low to have any significant part of the response we saw since 1960, and it should have ended around 2012 (50 years since 1960). However, I am still puzzled that global temperature and TSI curve are directly compared instead of deplacing it on the timeline (x-axis), according to the lag time we know (25-50 years, say, 40 years). -
Dikran Marsupial at 20:59 PM on 9 October 2012Climate time lag
Falkenherz, you will find that contributors here are not likely to be impressed with you using the points they raise simply to try an create a contradiction where none actually exists ("But then, suddenly, Dikran #352...". Instead you would encourage better discussion if you were to actually engage with the points raised. Do you agree with the physics of my post, or not. If not, please explain why. At the end of the day, you need to understand the physics pretty well to know what you can logically conclude from the data. You would be better of learning the physics and attempting the data analysis later, when you have a better grounding (which is why I don't often comment on radiative physics issues). -
ajki at 19:27 PM on 9 October 20122012 SkS Weekly Digest #40
Side note unrelated to the topics of this digest: Early in 2012 german readers saw the phenomenal rise of a new bestseller on the german book market, still provided in piles in all book stores. Even my local public library has bought two books - so for the next five to ten years Vahrenholt/Lüning's 'Die kalte Sonne' will be available here for all citizens. Vahrenholt and his 'insights' on climate change have been noticed and to some extent covered on SkS here [dana1981] and here [Bart Verheggen]. But until now english speaking readers did not have the questionable pleasure to read about Vahrenholt's positions directly. But generously Prof Vahrenholt made available a lecture held on 06/13/2012 at the Royal Society in London with the title “Global Warming: Second Thoughts Of An Environmentalist” on his website [www.kaltesonne.de]. A pdf in english is downloadable from this page [direct link to pdf]. -
Falkenherz at 19:18 PM on 9 October 2012Climate time lag
Quoting from this article here: "How long does the climate take to return to equilibrium? The lag is a function of climate sensitivity. The more sensitive climate is, the longer the lag. Hansen 2005 estimates the climate lag time is between 25 to 50 years. How would climate have responded to the solar levels maxing out in the 50's? For the next few decades after the 50's, the radiative imbalance would've gradually decreased until the climate reached radiative equilibrium around the late 80's (give or take a decade)." Consequently from Bob #318: "If you see someone talking about time lags that mysteriously come and go (or change in duration) depending on whether they are "needed"or not, then chances are that the "time lag" doesn't have any physics behind it - just rhetoric." But then, suddenly, Dikran #352 "...Thus it seems to me that the response to TSI should be much more rapid than the adjustment to CO2..." ... and, gws #357 "The warming mechanism between increased atmospheric CO2 and increased TSI is not the same, hence you cannot infer that you would have to get the same lag times." And thanks for the honey, but the only thing I am doing is asking logical questions, and I expect logical/coherent answers. I do this here, I do this on sceptic pages. As you can see from the quotes, there seems to be a mismatch. This article should then explicitly explain, why TSI has much shorter "climate" lag (i.e. responses by global temperature) than a given alteration of the CO2-level. Bob, I totally recognize the point that we don't see a gradual decrease, a trailing off, YET!!! I simply question the time scale on which we should expect to see a decrease. So, again, my hypthesis is that 0,6 Degree are not caused by GHG/CO2 alone, that some part is still due to a TSI lag. You admit this yourself by reverting to the common statement that CO2 took over as a "dominant driver". By logic, for CO2 to take over from 1960, this means that CO2 (in the air in 1920 with a lagged response of 40 years, in 1960) should have more effect than TSI in 1920 (from 1920 with a lagged response of 40 years, in 1960). Again: Because this is the climate lag which this article states does exist! And this article explicitly takes the "solar energy" as an example for that lag! Also: As you all state repeatedly, TSI is just one factor, and GHG/CO2 adds on top; by logic, this should delay any visible lagged response to a stabilizing TSI from 1960. We can now argue that the TSI contribution from before 1960 to global warming since 1960 should be neclectably low, but again, this can only be stated coherently if you take a perspective since 1880. Because, there is only a very low upward-adjustment of the TSI level in 1960, compared to 1880. As I asked repeatedly, I would like this theory to be confirmed also on the basis of a long-term observation, since 1700. If we *should* observe a high upward-adjustment of the TSI level in 1960, compared to 1700, the process of trailing off *could* happen on a much larger scale, right? Why is this question so difficult to accept? -
EliRabett at 12:51 PM on 9 October 20122012 SkS Weekly News Round-Up #4
Not quite sure why anyone should be surprised by the aerosol aging paper -
Eric (skeptic) at 12:11 PM on 9 October 2012It's the sun
As Bob explained to me up thread there are various time constants for warming of lower layers of the ocean. There should thus be a roughly exponential rise in GAT (atmosphere) based on those time constants after the immediate GAT rise. The annual cycle of solar means it can only perturb the mixed layer before cycling back. A secular rise in solar would affect the deeper layers for which we would have to derive time constants. -
Riduna at 12:04 PM on 9 October 2012Sea Level Isn't Level: Ocean Siphoning, Levered Continents and the Holocene Sea Level Highstand
Rob - interesting. Can we assume that isostatic rebound and seafloor collapse occur at the same rate and if not, why? And what about the effects of gravity which the geoid shows are not evenly distributed? -
JasonB at 12:00 PM on 9 October 2012The Economic Damage of Climate Denial
I haven't gone through funglestrumpet's link in detail, but (apart from the general polemic tone of the writing) I did note that he makes a big deal about "energy density" as if this automatically is some sort of death blow to renewable energy. I've seen this kind of thinking elsewhere as well, ignoring the following facts: 1. While the area required for wind is large, that area doesn't need to be exclusively used for wind. In fact, every wind farm I've ever seen has been on land that was also being used for agriculture, and as far as I could tell (and from what I've read) the wind farm has little to no impact on the use of the land for its original purpose. 2. The area required for a coal-fired power station might be small, but it's ignoring the area required for mining that coal, which is incredibly large. See SourceWatch for one attempt to calculate some figures for the US. The bottom line is that the area that has been already disturbed by coal mining probably exceeds the total land area required to power the entire USA by solar thermal alone, and apparently nobody thought that was an obstacle to the use of coal. On top of that, coal tends to be found in forested and agricultural areas whereas the best sites for solar thermal tend to be deserts. I agree with KR that McKay's book is a good read. I also agree that it's important to put it into context -- the UK is unusually dense, small, and far from the equator. The idea that the UK should be able to take advantage of a switch to renewables to wean itself off energy imports seems fanciful -- it imports energy now, and it will need to continue doing so in future. Conclusions that apply to the UK hardly apply to the majority of the world. Another general tendency I've seen is for magic bullet thinking, and to rule out any technology that can't economically provide 100% of future needs. This is an unrealistic and unnecessary hurdle. After all, none of the current technologies are attractive if you scale them up to 100%. We use a mix of technologies right now precisely because of this. While we argue about whether wind or solar are viable at high levels of grid penetration, we miss out on the opportunity to bring them up to their optimal levels of grid penetration while giving us more time to solve those problems or find better alternatives. What are the optimal levels? Well, according to the NREL, at penetration rates of up to 6%, solar PV is actually beneficial because it allows less usage of peaking power generators. At higher rates, however, it’s generating so much power at peak times that it causes a problem because the existing baseload generators have difficulty scaling back output, and scaling them back to their minimum output, then adding in wind plus solar PV, actually results in generation greater than the load. However, replacing traditional plants with solar thermal plants with heat storage actually increases the penetration ability of PV because the solar thermal plants have higher ramp rates and lower minimum outputs than traditional large thermal plants. The solar thermal plants increase grid flexibility and its ability to accommodate wind and PV, to the extent that a total solar contribution in excess of 50% (PV + CSP) becomes viable. Adopting solar thermal, solar PV, and wind on a large scale while researching fusion and trying to make thorium reactors economically viable seems like a good strategy to me. Complaining about how wind farms and solar powerplants look while ignoring how coal mines look seems rather selective. Like KR, I'd much rather have the former nearby than the latter. -
AlanInAZ at 11:24 AM on 9 October 2012Nate Silver's Climate Chapter and What We Can Learn From It
I think this review is from a fan who would really not like to criticize someone he respects. I have read the chapter and the impression left with me is that climate scientists and acolytes like Gore tend to over state impacts. Silver leaves the impression that we can wait until predictions are more certain before pushing for difficult political decisions. Geo-engineering will come to the rescue if needed. He has the nerve to cite big Pharma and their patents as an example of our potential for technical innovation. The section on Nordhaus was only two sentences and lost in the considerable noise of the chapter. The book is good except for the climate chapter and that contrast increases my disappointment. -
Bernard J. at 09:05 AM on 9 October 2012It's the sun
The atmosphere, in particular the upper troposphere (RSS/UAH) responds quite quickly to changes in TSI. Overall effects (larger temperature swings) will occur over longer periods due to the thermal buffering of the oceans, but there is a fairly immediate and detectable atmosphere response.
Indeed - as the seasonal changes in response to annual hemispherical insolation changes suggest. -
CBDunkerson at 09:01 AM on 9 October 2012Climate's changed before
Peter A wrote: "...the fact that water vapour is a greenhouse gas is never mentioned in the mainstream media. That was my point there, and all I did was question why this is the case." It isn't the case. A simple Google News search proves that this 'fact' is fiction. So the real question is... why do you believe things which are plainly untrue? Did you never bother to check? -
gws at 08:01 AM on 9 October 2012New research from last week 40/2012
mike, the paper is open access, so you should be able to download it. yes, rice can be produced with lower methane emissions, but wetland rice production dominates (older paper here) The oil&gas production section does contain a combustion subsection (see Table 1 in paper) -
gws at 06:47 AM on 9 October 2012Climate time lag
Falkenherz @351 Your response shows you are a keen observer and have read through numerous papers, unlike your previous modesty about your knowledge. Your continued playing of devil's advocate starts to look strange to me. I asked about your understanding of the lag mechanism both verbally (again above by Bob) and graphically explained to you. It would help if we knew your answer. To repeat Daniel: The warming mechanism between increased atmospheric CO2 and increased TSI is not the same, hence you cannot infer that you would have to get the same lag times. -
Bob Loblaw at 06:03 AM on 9 October 2012Climate time lag
Falkenherz: I'm a bit busy, so I can only give you a few minutes at the moment. I may be able to follow over to the radiative transfer stuff a bit later, but for now I'm still on the "time lag" issue. Let's look at an analogy. You have a tall tank full of water. You put a small hole near the bottom. Water starts to drain out the hole. The final equilibrium water level is down where the hole is, but that won't happen instantaneously - it takes time. Let's assume the tank is large enough, and the hole is small enough that this will take 40 years. Thus, the time lag to equilibrium is 40 years. ...but water starts to leak out right at the beginning. What is the rate of leakage over time? Well, the leak rate depends on the pressure forcing water out the hole (plus the size of the hole), which is related to the height of the water above the hole (technically, the height difference). At the start, there will be a relatively rapid loss of water and a rapid decrease in the level in the tank, because the pressure is high (the full height of the tank). As water drains out, the height of the water decreases, the pressure decreases, and the flow rate decreases. Near the end, as we approach equilibrium, we only see a trickle of water, and the level in the tank is dropping very slowly. Note that we are committed to draining the tank as soon as we make the hole (unless we find a way to plug it). So someone coming in half way is going to be looking at a leak that is the result of an imbalance (hole) made 20 years ago, and the time lag in fully draining the tank means the leak will continue for another 20 years (time lag). The rest of the leakage is "in the pipeline" already (to make a bad pun, but using a term that is often used in climate change discussions). That person arriving at the 20 year point will be seeing a leak that was faster in the past, and gets slower in the future. What we don't expect to see is a pattern where nothing happens for 20 years after the hole is made, then the leak gradually gets faster and faster as the tank begins to drain. The physics just doesn't work that way. If you arrive at the tank after 20 years, and see the water level dropping at an increasingly faster rate, then you need to look for new leaks, not blame it on the hole that was made 20 years ago. To tie the analogy back to climate and radiation forcing, the pressure in the water tank is the radiative imbalance (sun pushing energy in minus the current IR loss to space). The flow out the hole is the increased loss of IR to space needed to eventually restore equilibrium. The level in the tank is temperature. For climate, the radiative imbalance is largest at the start and gets smaller over time, the temperature rises fastest at the start and slows over time, and the equilibrium temperature change is committed as soon as the radiative imbalance is created. It's kind of a backward analogy, because the water tank is losing water, while the earth is gaining energy (increased TSI, or CO2 reducing IR losses, leading to a net positive radiation balance), but hopefully you can easily visualize the water tank and how it responds, to understand how time and changing fluxes/levels factor in to restore equilibrium. Like all analogies, this one is full of holes (in addition to the one the water is leaking from), so first just try to make sure you understand the physics of the leaking tank, before trying to apply it to the global radiation balance. ...and the TSI increase vs. CO2 increase effects are, to a first approximation, not much different. -
mike roddy at 06:02 AM on 9 October 2012New research from last week 40/2012
That 2030 CH4 chart is very interesting. It tells us that livestock production must be slowed, and vegan diets encouraged. I had no idea that rice harvesting emitted so much methane. Three questions: Can you post current CH4 emissions for comparison? Are there ways to produce rice that do not include high CH4 emissions? Does the oil production section not include combustion? -
Climate time lag
Dikran, Falkenherz - I have responded on the appropriate thread here. -
It's the sun
(Continued from here) Dikran Marsupial, Falkenherz - Foster and Rahmstorf 2011 (discussed here) examined atmospheric responses to various forcings, namely aerosols, MEI/ENSO, and insolation, using multiple linear regression to examine their contributions. The steady increase in CO2 forcing was not associated with a time lag: as a near-linear trend, it doesn't have the necessary variations to be time-matched to temperature changes (no 'teeth' to match). For that component F&R 2011 just used a linear rising trend.
[Source]
The atmosphere, in particular the upper troposphere (RSS/UAH) responds quite quickly to changes in TSI. Overall effects (larger temperature swings) will occur over longer periods due to the thermal buffering of the oceans, but there is a fairly immediate and detectable atmosphere response.
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Daniel Bailey at 04:22 AM on 9 October 2012Climate time lag
Falkenherz, to make that substitution is inapplicable and demonstrates a lack of understanding on your part between forcings, feedbacks and the physical interconnections of our world. I suggest listening and reading more. I am not the only one doubting the existence of these "other skeptics" you paraphrase. -
Climate time lag
Falkenherz - CO2 did not magically appear as a forcing in the 1960's. Rather, it was around the 1960's when insolation took a downward turn, and when CO2 became the dominant forcing. And continued to rise in forcing strength as it has since the start of the industrial revolution. If you look at net forcings (as I showed here), they have been increasing roughly linearly for the last 40-50 years. Temperatures have also been rising roughly linearly over that time frame - not showing an exponential rate decay towards equilibrium, but rather following the forcings upwards. TSI has decreased over that interval, CO2 forcing has continued to increase. That temporal relationship clearly shows that recent warming (over the last half-century) is not due to the sun - and in fact, decreasing insolation has noticeably slowed the warming. If you wish to chase this TSI windmill any further, I would strongly suggest taking to the far more appropriate Solar activity & climate thread. -
Dikran Marsupial at 04:12 AM on 9 October 2012Climate time lag
Falkenherz, radiative physics isn't my strong suit, so hopefully my better informed colleagues can correct me if I am mistaken, but in this context I would have thought there is a difference between CO2 and TSI forcing. For CO2 forcing, increased CO2 raises the altitude in the atmosphere from which IR photons can escape into space. Due to the lapse rate, this higher layer will be colder, and hence the amount of IR radiated into space will be lower. As a result, the Earth will gain energy until the atmosphere warms sufficiently for the emitting layer to warm enough to radiate away as much energy as is coming in. For the atmosphere to warm, the oceans need to warm as well, and that causes a lag. TSI is rather different, imagine the height of the emitting layer remains constant. If TSI rises slightly, so that more energy comes in than is radiated away into space, there will be an energy imbalance, and the Earth will begin to warm. However if TSI then drops back to its equilibrium level, the energy imbalance disappears and the warming relatively quickly stops. Thus it seems to me that the response to TSI should be much more rapid than the adjustment to CO2, unless there is suddenly a way to scrub vast quantities of CO2 from the atmosphere and bring the height of the emitting layer back down again. -
Falkenherz at 03:28 AM on 9 October 2012Climate time lag
gws, if global temp follows [cause], but takes time to reach and stabilize at a higher energy level (corresponds to global temperature) as given by [cause], than this applies to both CO2 and TSI. In that case, on that graph above you should move the blue curve (=cause) to the right, or the red curve (=effect) to the left, in order to correlate that lag properly. This whole article here talks about a climate lag of roughly 25-50 years, because of the time for the system to get back into energy equilibrum (which corresponds to a certain level of global temperature). Even the link from Daniel tells of a lag of 40 years for CO2 and states explicitly "With 40 years between cause and effect, it means that average temperatures of the last decade are a result of what we were thoughtlessly putting into the air in the 1960’s." Now delete from "what we were thoughtlessly" onwards and replace with "the TSI increase which started somewhere around 1700 and lasted until the 1960s". BUT, by contrary, when TSI is concerned everybody just seems to state that, since TSI stopped increasing in 1960, then instantly, without any lag, any further rise of global temperature after 1960, the 0,6 Degrees since then, MUST be attributed to CO2. Apparently I am the only one who finds that odd. The only reason I can see as a logical argument is, if TSI rose only by minimal amount since *1700* (why do everybody here seem to assume they can ignore anything that happened with TSI and global temp before 1880?), because in that case, indeed there would be no physical possibility for a lagged increase of an amount of ~0,6 Degree. DSL, Forster and Rahmsdorff 2011 calculate the rate of rise of temperature ("the warming rate is steady over the whole time interval"). This. is. not. my. point. Side remark, the quoted essay of Krinova in the article speaks of going back to the maunder minimum, but the models they create go only back to 1868. That's not the maunder minimum. I can just assess the abstract, though. -
Dikran Marsupial at 03:03 AM on 9 October 2012Climate time lag
Falkenherz, my research interests lie in statistics, so I know from experience how dangerous it is to look for correllations first and explanations second. At the end of the day, if the correllation is real it is because of a physical reason, so if there is a correlation, but no physical explanation, assume that the correlation is spurious. -
Daniel Bailey at 01:53 AM on 9 October 2012Climate time lag
Falkenherz, rather than getting sucked into climastrology & curve-fitting, why not examine physical mechanisms potentially involved in lags between causes and effects? Try reading Climate Change: The 40 Year Delay Between Cause and Effect. As always, should you have any questions on that thread, please place them there. The regulars here will see them. -
gws at 01:50 AM on 9 October 2012Climate time lag
It appears to me, Falkenherz, you still have not understood the graph posted by Riccardo @324, and its implications verbally explained to you in detail, have you? -
Falkenherz at 01:42 AM on 9 October 2012Climate time lag
Dikran... now I give up, really. :( Can someone please point me towards a graph showing TSI (estimations) since 1700, and another graph showing global temperature (estimations) since 1700? Proxies, reconstructions, I don't care, I just want to know what we have for these two data since 1700 and I want to see how they correlate since the end of the maunder minimum around 1700. Then I can come back to you about "climate" lags. -
gws at 01:26 AM on 9 October 2012Climate time lag
Falkenherz: That would be moving the blue curve to the left, not right ... where does the presumption of a 40something TSI-climate time lag come from anyway? -
DSL at 01:21 AM on 9 October 2012Climate time lag
Excuse me, DK, I meant "DK" and not "KR." -
DSL at 01:20 AM on 9 October 2012Climate time lag
Agree, KR -- Falkenherz, why not a 140-year lag, or a 260-year lag. There are other similar periods of solar increase. Working back to physical principles from a graph of temperature is a bad idea. Surface temp is a very complex process. You've read Foster & Rahmstorf (2011), yes? -
Riccardo at 00:50 AM on 9 October 2012Modelling the permafrost carbon feedback
Lanfear english is not my first language either, so there is the concrete possibility that I was not very clear. :) Anyway, we should always be carefull when using the word "runaway" because, as you noticed, it may mean similar but different things. -
Dikran Marsupial at 00:22 AM on 9 October 2012Climate time lag
Falkenherz please can you specify a physically plausible mechanism that explains why there should be a 40 year lag of global temperature following TSI. The human eye is very good at detecting patterns in data that are not actually there and are merely artefacts of random/chaotic variability (which is why we have statistics). Requiring a plausible physical mechanism guards against jumping to conclusions based on spurious correlations. -
New research from last week 40/2012
Will there be a follow up article - The Influence of Ball Lightning on Climate Change? Or What Ball Lightning Tells us about Global Warming. I'm sure there's something. -
Alec Cowan at 23:35 PM on 8 October 2012Solar Hockey Stick
The last image in comment #75 is now at http://www.lsbu.ac.uk/water/vibrat.html under "The visible and UV spectra of liquid water". -
chriskoz at 23:09 PM on 8 October 2012Arctic Sea Ice Loss Has a Larger Impact than Antarctic Sea Ice Gains
Jim @3, Thanks for the pointers. Those are very useful posts by Tamino. Refered therein, I found this paper which answered my question in details. Great paper to learn the details of mid-Pleistocene revolution (MPR) when cycles switched from 41ka to 100ka. According to this and other newer studies, eccentricity just paces rather than drives the system while precession+tilt are the drivers. The ‘eccentricity myth’ (or simplified view of the relationship between glaciations and orbital forcings) an artefact of early spectral analysis of ice-core data. -
Falkenherz at 23:04 PM on 8 October 2012Climate time lag
Maybe even simpler: Just displace the blue curve in your graph 40 years to the right in order to represent a 40-year lag of global temperature following TSI (i.e. adapting to the new energy equilibrum, ceteri paribus). Does this illuminate what I mean with my speculative point a bit better? Again, all the arguments seem to be there, but for me it does not come together, yet. -
mspelto at 22:58 PM on 8 October 20122012 SkS Weekly News Round-Up #4
For next week's roundup take note of the change on Thwaites Glacier, Antarctica.Moderator Response: [JH] Thanks for the tip. -
Falkenherz at 19:57 PM on 8 October 2012Climate time lag
KR, the difficulty of non-scientist people like me is to understand the arguments I read about, and clarification is the tool. That's why it is great of you guys to offer a comment function and take the time to answer. Truth will answer to any question, and, in fact, it is only fully revealed by questions. I understand that I misunderstood the paragraph I quoted, and the uncertainity expressed cannot exceed the range of TSI given there. In that case, I was mislead by "...incomplete understanding of solar variability mechanisms over long time scales..." The key issue I was trying to clarify for me is in your No (5). And there, we seem not to understand each other's points, or my understanding is simply too limited. Maybe one last try: I am not talking about anything "hidden", concerning a temperature lag from long-term TSI. I simply believe that the matter of observing a decreasing temperature trend could be a matter of which timescale you are looking at. If you compare 1850 to 2010, and take 1960 as a "breakpoint" (and assuming that the data showing a declining TSI is indeed correct), imo no one can rally dispute your conclusion. But, would that counclusion be so clear if you looked at 1700 to 2010, with the same "breakpoint" at 1960? Relations might be different then, and what we perceive as "linear" (btw, I did not introduce this word and I don't see the relevance of it in our discussion, in fact, the "hockeystick" is far from linear) over the last 50 years might as well be read a slow trailing off if we wait a bit into the future. And CO2 on top might only be able to prolong ("hide"?) the process of trailing off, but not increase much beyond what TSI did on the long term. behold, a core argument of some sceptics. -
Lanfear at 18:43 PM on 8 October 2012Modelling the permafrost carbon feedback
Riccardo@19 "I was referring to the melting permafrost feedback." Ah, yes, then I do agree with you. Sorry for the confusion. With regards to Colose writing, this is largely my understanding too, as there is a whole spectrum of more probable outcomes between what we have now what constitutes a global 'runaway', which I tried to convey in my previous writing (english not being my primary language). wili@20 "Efforts to avoid panic have left us where we are" Again, this may be due to difference in what panic means, but I feel strongly that panic is the least helpful state that people should be in in this (or any) situation, and it seems that this is somewhat reflected in the writings of other people too. Panic IMHO means that individuals throw out their reasoning and goes into a short-circuit mode where the survival instinct rules, resulting in a quick and painful collapse of the society. Nothing can be accomplished in this mode. As a background reference, I am talking as an avid diver and aspiring cave diver where panic equals death. What I would solicit instead is a (rude) wake up call, not much unlike the Samuel L Jackson video 'Wake the f*ck up' backed up with numbers (like what Clinton did). The other part should be a (again rude) confrontation and stripping of any perceived validity of the denialosphere argumentation (maybe in the spirit of Christopher Hitchens). This is why I personally enjoy SkS, but it grieves me that the noise of the lukewarms as well as denialists are assumed by the public as 'equal'. A misanthropist would perhaps think that we deserve what is coming... -
Falkenherz at 18:37 PM on 8 October 2012Water vapor is the most powerful greenhouse gas
Ah, nevermind, I think I found a good source: http://www.sciencemag.org/content/327/5970/1219.full -
Falkenherz at 18:35 PM on 8 October 2012Water vapor is the most powerful greenhouse gas
I am sorry if that seems so much nonsense that it isn't even worth an explanation to you. I know that this article here starts with the assupmtion of water vapour being dominant, because a lot of sceptics say this. But I think you could discern and explain a bit more between the ratiative processes and the evaporation processes and the clouds caused by more water vapour, alll of which are very strong effects of water vapour. The sceptic I encountered refers to the radiative element, which is the only possible wv process for a positive forcing. My first quote is from Held 2000, p. 446 http://maths.ucd.ie/met/msc/ClimSyn/heldsode00.pdf who is trying to disprove this argument; sadly, I don't get it. The second quote is a translated argument I encountered from a sceptic who seems to know a lot about radiative physics, but then he suddenly comes with queer assumptions like this; and I found so far no source to directly disprove him with a scientific argument (Held 2000, p. 446, was a try, but I cannot quote things which I don't understand myself). As to temperature dominated by stratosphere, I believe this refers to the absorption length, which might not be long enough by just counting the troposphere. Thanks for the referral to Iacono and Clough, but it seem they do not adress this issue directly, but to follow up on it, as they are just "introducing an improved, LW radiative transfer model". I need an explanation why water vapour in the stratosphere is very much driving global temperature. With google I just found articles which report that a recent decrease of water vapour in the stratosphere was the cause of some cooling, but no explanation or experimental proof as to why. -
The Economic Damage of Climate Denial
funglestrumpet - While it's certainly a voluminous writeup on renewables, I would suggest considering that the writer (Leo Smith, MA) has some, shall we say, "skeptic" attitudes:...if you are not Concerned About Climate Change (and let's face it, a world with no electricity at all is a lot more terrifying than one a degree warmer) there's several hundred years of coal, which the Chinese will be burning anyway.
Curious capitalization... A fairly quick look on the InterWebs indicates that the author of this paper has a history of claiming that AGW is an incorrect theory. That doesn't bode well for his other work. I would suggest that you look at some of the SkS threads and references on renewable baseload power, such as here or here. Many of the opinions expressed in the Smith paper are discussed, and (IMO) shown to be mistaken. You might also look at a very interesting study by Archer & Jacobson 2007 - they found that connecting multiple wind plants (19) over a reasonably large geographic area (MidWestern US) would provide between 33-47% of the average output was reliable as baseload power by current availability standards. Add solar (with different availabilities) and that percentage will only rise. Power density? There's enough area to supply our electrical needs hundreds of times over with either solar or wind power. Widely separated power plants are actually easier to balance than large centralized ones. Intermittency/dispatch? See the Archer et al paper above - distributed sites across more than weather pattern can manage quite well. The McKay study (McKay book) he references is quite worth reading on its own - there he looks at area, power density, and the possibilities of sourcing all UK power from available UK renewable resources (hardly a global perspective). And I believe McKay is quite correct that the UK is too densely populated, too small, and rather too far north for that to be possible within UK borders. On the other hand, there's plenty of space in North Africa, and in Eastern Europe - and if the UK finds itself a net importer of energy, it will hardly be alone in the world in that respect. Note: The myth (which you repeat) that renewables require more fossil fuel use than the original fossil fuel plants they replace is complete nonsense, from (mis)analyzing single-site renewable sources, when a distributed grid is the correct system to evaluate. Finally: On a personal point of view, I would much prefer windmills and solar farms to coal strip-mines - eyesores that poison the local water table, and never ever recover to anything approaching the original land quality. I grew up in coal mining country - portions of it resemble a moonscape. Those mines (and oil fields, and fracking regions, and...) represent an unavoidable land area/power that has to be considered in balance to the area required by renewables. Outside my hometown there are a group of windmills on a ridge across the highway from a strip mine. IMO the choice is obvious. -
vrooomie at 15:24 PM on 8 October 2012Nate Silver's Climate Chapter and What We Can Learn From It
Two Commoner books that I read, as part of the requirements at Columbia's Earth Systems classes at Biosphere II, in 1997, were "Making Peace With The Planet," and "The Closing Circle." Those books, among many, were why I began my serious research into this issue, and Barry will be missed. He left a much-unappreciated legacy. -
vrooomie at 15:16 PM on 8 October 201293% of Fox News climate change coverage misleading
Andrew Mclaren@9: That would be "Ailes," not "Aimes." Roger Ailes has a looooooong history of being vehemently anti-liberal and aggressively right-leaning in his stewardship of Fox News. His is an ethic informed by the late Lee Atwater, the modern guru of attack politics, damned the cost. -
Doug Hutcheson at 12:59 PM on 8 October 2012The Economic Damage of Climate Denial
funglestrumpet@48, I have read the paper you linked and found it interesting, but the fact that the author quotes material produced by the Global Warming Policy Foundation makes me suspect the integrity of the research. The document is full of typos that would have been picked up by peer review, so it does not impress me with its reliability. Nonetheless, it discusses some genuine problems and provides insights into the thinking of the BAU brigade. -
vrooomie at 10:10 AM on 8 October 2012The Economic Damage of Climate Denial
funglestrumpet@48, I'll read your linked paper, BUT...this line makes me a bit suss, right off the bat. "...and let's face it, a world with no electricity at all is a lot more terrifying than one a degree warmer." That's opinion and sensationalism, not science. I'll get back to ya..... -
funglestrumpet at 09:17 AM on 8 October 2012The Economic Damage of Climate Denial
Liquid Fluoride Thorium Reactors surely have to be part of the mix. I know they need some development, but a Manhattan type effort would bring the time for that development down to a few years. (Surely, the problem deserves such an effort.) They are so much safer than the current fleet. Had Fukushima been of the LFTR type, it would have been a non-nuclear event - still awful, of course, but not from a nuclear standpoint. We cannot rely on solar and wind, so if we carry on as we are and still want a stable supply, we are going to have to have fossil fuel plants to follow the loading variations they automatically create, and upgrade the grid in the process to cope with it (not cheap). The more of those ugly wind turbines we have peppering our once beautiful landscape, the more variable will be the renewable input and so the more we will have to rely on fossil fuels. It is difficult to see how that is going to do much good as far as CO2 reduction is concerned. If we go with LFTRs they automatically are capable of load following. For an interesting paper on renewables, I recommend: http://www.templar.co.uk/downloads/Renewable%20Energy%20Limitations.pdf With small modular reactors, which LFTRs can easily be, we can distribute them so that they serve local communities. That way, we will hardly need much of a grid. They don't need the copious amounts of water that current nuclear reactor designs do, they are inherently safe (automatic shutdown), they cannot safely be used to make nuclear weapons, they use 99% of their fuel, which is ubiquitous anyway ... the list goes on. And as for being uninsurable, well, being automatically shutdown in an emergency surely goes a long way to solving that problem. All we need to do is get the Greens to shut up about nuclear for a while and we might, just might, save the planet. -
Philippe Chantreau at 06:58 AM on 8 October 2012Climate's changed before
Peter, on the other thread you suggested you had read the litterature. On comparing the radiative effects of water vapor and CO2, that would include Iacono and Clough (1995), the MODTRAN and LBLRTM works, numerous papers using the ERBE data, many more papers treating of absolute and relative humidity and why water vapor can't be considered a forcing. Statements that you made are considerably at odds with knowledge of all that litterature, hence the reactions you got. -
Old Mole at 06:18 AM on 8 October 2012Modelling the permafrost carbon feedback
wili @32 "Anyway, thanks for all the fish." I seem to remember that preliminary to that, there was some sort of guide that prominently said "Don't Panic" on it. To me, SkS is exactly that sort of guide. Best wishes, Mole
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