The other question is how does this show up in the 11 year solar cycle?
I’m not aware that there is any correlation with troposperic or stratospheric temperature change.
3 years of data doesn’t seem very conclusive in establishing the hypothesis, but I’ve noticed that the newspapers that are most associated with denying anthropogenic Global warming are already exploiting this study contrary to the stated views of its authors.
This is the most recent study on the 11 year solar cycle that I’ve been able to find:-
Title: “Surface warming by the solar cycle as revealed by the composite mean difference projection”
Authors: Charles D. Camp and Ka Kit Tung: Department of Applied Mathematics, University of Washington, Seattle, Washington, U.S.A.
Source: Geophysical Research Letters (GRL) paper 10.1029/2007GL030207, 2007
It reports a global temperatures increase 0.18°C due to an increase in Total Solar Irradiance (TSI).
(This 11 year cycle is superimposed over the long term global warming trend.)
Thanks for this. With my limited ability to digest scientific information, this provides just the level of skepticism about this issue needed. It is so easy to read vast reams of irrelevant opinion into factual material like this.
I also looked at the BBC Open University site, and while the page from Dr. Haigh is good, the overall tone of the grouping gives far too much weight to the supposedly skeptical view. Unfortunately, real skepticism is all too rare – the kind that looks at all the available information and does not overweight information it wishes to believe. The proliferation of think tanks and expertise supported by wealthy interests lends plausibility to the assumption that there is a large cadre of credible scientists in relevant fields with views that contradict the real state of scientific understanding.
Confusion, unfortunately, is all too easily conflated with uncertainty.
For people upset about the implications for the impact during the Maunder Minimum, I’d suggest that this observation, if confirmed, can only be said to apply to the current, active level of 11 year cycles. It would I think be erroneous to jump to the conclusion that during an extended quiet period, visible radiation must also remain continuously increased throughout that period.
In particular, the visible increase may be the result of some “rebound” mechanism resulting from the previous TSI high. If there were no previous TSI high, there might be no subsequent increase in the visible radiation. This would be particularly true if the duration of the visible radiation increase is in fact short (“only lasts for the first few years”).
Until the reason/mechanism is hypothesized/understood, or until we encounter another Maunder Minimum period of solar behavior during which we can directly observe the behavior, it’s impossible to say what’s what.
Since absolutely positive statements have previously been made that the solar variations can’t possibly cause significant temperature changes, and since we seem to be learning new things about solar activity all the time, statements like “Conceivably, there might be another missing element (such as a cosmic-ray/cloud connection) that would counteract this physics and restore the expected sign of the change, but no-one has succeeded in finding any mechanism that would quantitatively give anything close the size of effect that would now be required (see our previous posts on the subject).
So is this result likely to be true? In my opinion, no.” shows the ignorance of the author. WE DON’T KNOW is the fact here. No one has found a mechanism, but you just stated a new and previously unknown mechanism. There is no reason to think we have found all there is to know yet. Be a bit more open minded.
[Response: If you are not interested in my opinion, then don't read the blog. ;) But if you are interested in what people that have looked at this issue in detail, then you might want to pay attention. When you get results that purport to overturn decades of understanding, the most likely outcome is that there is an error some down the line. In this case, my guess is that there is still an unidentified issue with the early years of the satellite. If new data comes in that confirms this result (i.e. SMI in the visible goes down as we go to solar max), then I will update my expectation, but in the meantime, great caution is warranted. Being open-minded is all well and good, but the whole point about actual expertise is that it allows you to weight new information in a more efficient manner. My advice to you is to wait-and-see, rather than jumping to any conclusions. - gavin]
Comment by Leonard Weinstein — 7 Oct 2010 @ 9:44 AM
Are there data for other stars? Do they show individual changes in stellar output? Any pattern suggesting local dust might be affecting what reaches us?
(I expect this has an obvious answer to the astronomers, not likely to take up space in paper publications, it’s a ‘peanut gallery’ question.)
So my take away was.. what if it means that the radition during a maximum reacts more with the greenhouse effect, than during a minimum. Changing the balance of the causes of warming. None greenhouse solar warming is more during minimum, but greenhouse warming is reduced. So during a maximum, direct solar warming is less, but there’s more greenhouse warming.
I’m finding it very amusing how the contrarians are reacting to this paper – the most incoherent example is illustrated by the UK’s Daily Express story. First off the whole story is predicated not on the actual results, but on what the ‘skeptics’ think of the results, and the quotes they use indicate without a shadow of a doubt that Monckton, an MEP (of unknown origin) and Montford do not have a clue.
The MEP (Godfrey Bloom) goes into a knee-jerk ‘the sun did it response’ without noting that the results of this study would completely contradict earlier associations of the medieval warming to increased solar activity. He even claims to be using logic! Monckton plays it safe saying there is a ‘close association’ between temperatures and the sun, without actually noting that the association is reversed in this study from anything he has previously insisted on. And Montford uses the absolutely lowest level generic response in the contrarian playbook “[insert any new paper here] implies the science isn’t settled” – as if that meant anything. (Note that no scientists would publish any papers if all questions were settled!).
One doesn’t expect much from the Express (or the contrarians), but this is embarrassing.
But if TSI and UV behave indicate opposite sign, since both have warming gases, it means “total warming power of sun” is stable than expected by TSI’s variation. If increased UV caused the recent warming, what happend the strong positive correlation between TSI and atmospheric temperature record before 1975? Is there any reason that the UV is stronger only recently than in the past cycle?
What’s shocking to me about that article is that I don’t see how this discredits AGW theory in any way. Silliness aside (like the claim of no warming for 12 years as a given fact, or the argument that other planets in the solar system are warming), how does this relatively meager discovery explain warming to date? There’s no evidence that this is a phenomenon that only began when recent warming began, or that it’s in any way different from the sun’s usual behavior. It’s unexpected, and will impact all sorts of models and expectations, but it’s hardly either an explanation for current climate change, or in any way a lever to explain why AGW should not and would not happen.
The denier’s (excuse me, “contrarian’s”) bottom lines? (A) This is firm proof that we don’t know everything (duh!) and (B) the sun must be involved, so any new evidence that has the word “sun” used in a sentence completely obviates anything else being said or considered.
- ‘hot of’ => ‘hot off’
- ‘attributions of solar variability to temperature changes in the lower atmosphere and surface ocean’ => the other way around (or a lot more models and theories will have to be overturned…)
Answering (in an amateur way) my question above, astronomers would have noticed if the interstellar medium were varying to this degree; it’s not. http://arxiv.org/abs/astro-ph/0601359
“Optical or UV data are now available for ∼100 stars sampling nearby ISM [interstellar medium] … Very high-resolution optical data … for ∼40 nearby stars, and high resolution UV data … for an additional ∼65 stars.”
Not likely anyone knowledgeable in the field would have missed
Also great stuff. This is how science works people. Congrats to Haigh et al. even if the results turn out to be wrong!
[Response: That's a very good point. There is no problem in scientists exploring the 'what if's' of the data that comes in. Sometimes they are going to be ahead of the curve, sometimes it's going to be wrong, but it is the quantification of the consequences of new information that allows everyone else to look for those signals and help support (or not) the original idea. This is people seeing where the data takes them with an open mind. - gavin]
The key phrase in this post is “instrumental drift.” I love the solid state stuff they put in the sky because it does not drift – much! Then, they put everything through a fairly complex model. It is very interesting, but it is not data of known quality and it has limited utility in risk management.
It is time for climate science to grow up and establish standards of data quality; and procedures for data validation as was done under CERCLA for Human Health Risk Assement from hazardous waste.
Data of known quality did much to get the paid data slingers out of the (CERCLA) spotlight. We need to turn the spotlight of climate science away from the data, and toward policy and action.
[Response: You greatly overestimate how easy it is to control instruments once they are launched into orbit. Space is a pretty hostile environment, and with the single exception of the Hubble Space Telescope, once an instrument is launched there is no way of getting hold of it again. Since we generally only have single examples of new data, cross-checking is hard. If you would like to suggest doubling the budget so we could get two instruments every time, that would be great, but for the time being, we are stuck with the data we have, not the data we'd like. - gavin]
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New data indicates that changes in the Sun’s output of energy were a major factor in the global temperature increases seen in recent years. The research will be unwelcome among hardcore green activists, as it downplays the influence of human-driven carbon emissions.
Some idle speculation: The photosphere of the sun is often assumed to radiate like a black body, which implies that a reduction in total emitted radiation would be accompanied by a reduction at all wavelengths, even though the ratio of visible to UV would increase. For the absolute level of visible radiation to increase would seem to imply either a “non-black body” increase at the source that heats while the photosphere as a whole is cooling, some change in the transmission to the TOA (e.g., via an unmasking effect in the interstellar medium or the higher reaches of the atmosphere), some mechanism that shifts the frequency of radiation from shorter to longer wavelengths (e.g., by absorption and re-emission), or some combination of the above. Is there evidence for any of these phenomena, or any other mechanism that would explain the observations?
In any case, whatever mechanism is operating would be unlikely to maintain an increase in visible radiation if TSI fell by more than a small decrement, and would therefore probably not invalidate conclusions relating major changes in TSI to changes in solar forcing and temperature of the kind that have generally been considered likely – changes that are small compared with greenhouse gas forcing but nevertheless in the same direction as changes in TSI.
Fred Moolten (23), it is very curious. If I had to bet I’d put my money on variable emissivity. Though it’s hard to picture an essentially homogeneous surface varying its emissivity per wavelength much. I’d want some odds.
My suspicion is that their “relatively complex chemistry/radiation model” overestimates the 200-295 nm UV, and uses that to (mis) correct the 450-550 nm VIS to create a dip artifact in the VIS where the UV is high and rapidly changing, around 2004-2005.
[Response: It's not the model, it is the input data. - gavin]
1. To argue the human-caused global warming is minimal and/or not a problem
2. To spread confusion
The study does nothing to support #1, and if anything, is evidence against it. It tentatively argues that solar effects on climate (past and present) are smaller than previous estimates.
“Overall solar activity has been increasing over the past century, so the researchers believe it is possible that during this period, the Sun has been contributing a small cooling effect, rather than a small warming effect as had previously been thought.”
“We cannot jump to any conclusions based on what we have found during this comparatively short period and we need to carry out further studies to explore the Sun’s activity, and the patterns that we have uncovered, on longer timescales. However, if further studies find the same pattern over a longer period of time, this could suggest that we may have overestimated the Sun’s role in warming the planet, rather than underestimating it.”"
Puzzling results indeed. The integrated spectra generate a TSI versus time plot which is pretty close to other TSI versus time plots, so if the spectral changes they are talking about are artifacts, then there would have to be offsetting errors at different wavelengths. The other interesting thing is that wavelengths which are reasonably close together show substantial divergence over time. This is looks difficult to explain with calibration problems. The dual identical spectrometer design, with one used only once per month the check radiation induced loss of transmission on the other, and other on-board calibration methods, look reasonably robust.
All of which is not to say there could not be a problem with calibration, but if this turns out to be the case, it will probably have to be something that the design group completely missed. Unfortunately, the satellite is expected to die long before a replacement is launched, which will leave a gap of a few years in the spectral data.
Comment by Steve Fitzpatrick — 7 Oct 2010 @ 1:54 PM
Panel 3 appears to be double valued in 2005. It looks like something evaporated from the window of the SORCE instrument, allowing clear vision by 2010.
Cyclical changes in solar output — regardless of the sign on them — don’t appear to have had much impact on the steadily ramping global average temperature. It’s not the variability of the changes associated with AGW that are worrisome — it is the overall direction — and the overall direction seems driven by something outside of solar cycles. If it were otherwise none of this discussion would have ever taken place.
“this anti-phase behaviour only lasts for the first few years”
Help, please. If there is no instrumental drift, wouldn’t those first few years show the same behaviour in the maps of the ozone holes? And possibly during previous solar cycles as well? Joanna Haig’s paper mentions tropical ozone, so I must be missing something.
Spend a few minutes looking at the SORCE data (Gavin conveniently linked it.)
There’s a surprising (to this naive layperson at least, but also probably Fred and Rod, too, at least) amount of variability over shifts of just a few tens of nanometers of wavelength. Quite different irradiance levels, different curves over time. Check it out.
Gavin great post. I wholeheartedly agree with your responses reminding people what science is and is not. Whether this paper is correct or not, it is the subsequent searching and looking at data and calculations that will better help us understand such complex issues. Global warming for example is well evidenced too so one claim to the contrary does not negate it either but as instruments and models are fine tuned and we have more data in hindsight better projections can be made. It can be tricky working out all the physics of these complex processes but I do feel as if this entry is more fair and balanced than many others will give it credit for.
There is nothing wrong with a scientist giving an opinion. I have opinions based on how I view the data about future warming. I may be correct or I may be wrong. Uncertainty does not bar exploration. What I like is the opinion and the facts are separated very well by the author of the paper and by Gavin.
Yes, but it is the BBC on the web*. As usual the radio was quite different.
I have been told that Radio 4 at about 7AM was very confused, and that John Humphreys provided the news about it by reading out listeners emails. Later in the day, the item disappeared.
* There is pressure to cut or chop this arm of the BBC
[Response: It's not the model, it is the input data. - gavin. That's a pretty big call. Many years ago, the stratospheric ozone models that included only gas phase were considered to be pretty solid too.
Sounds like there’s a lot of love going around, however, I couldn’t help noticing the sarcasm. Would be slightly more interesting if it somehow jeopardized AGW alarm, although somehow I feel that wouldn’t get as much “love”.
MarkB (26), Skeptics are not Contrarians, which saves me a ton of words rebutting some of your post.
[Response: Many of the so-called 'climate skeptics' are indeed contrarians, despite the fact they don't have a skeptical bone in their body when it comes to anything that aligns with their preconceived notions. The true and honorable sense of the word has been corrupted though association with them. All scientists need to be (and are) skeptics (in the true sense). But let us not waste time on arguing about who is or is not skeptical in any of the thousands of ways the term is used. - gavin]
#41 The climate did cool from the 1940′s to the 1970′s. A big part of that were sulfates as Weart and other point out but who can say yet that solar activity did not also contribute? (Some also blame after effects of nuclear weapons) Perhaps there is more inertia than discussed prior to a cooling (or warming) effect. I am not stating it is the case but since some preliminary warming (a small comparitive %) in the paleoclimate record began prior to a C02 increase and then C02 acted as a forcing of said warming, why cannot it also be true of cooling? A lot of counter intuitive things could turn out to be true while C02 still remains a greenhouse gas. Nothing changes the fact GHG exert a greenhouse effect, but warming and cooling may be more complex than we ever imagined:)
A 1997 paper by Gray and Livingston in The Astrophysical Journal is of interest, at Solar Temperature
Although I’m not qualified to judge the methodology, I found Figure 9 of particular interest. It shows solar irradiance and solar temperature generally to vary in phase during the solar cycle, but not completely. In particular, in 1983 and again in 1992, temperature exhibited a slight temporary rise during a descending phase of the irradiance cycle. One implication is the existence of multiple sources of radiation that vary semi-independently, such that an irradiance decline could be accompanied by a transient increase in solar temperature, and therefore, radiation in visible wavelengths, even while an independent UV source was declining. I’d be interested in the interpretation of others who are conversant with astrophysics.
That TSI and UV are not well coupled, or not coupled with the same sign shouldn’t be that surprising. There are two reasons the sun does not radiate as a black body. The most obvious is that the opacity of the solar atmosphere varies widely across the spectrum, so the average depth within the solar atmosphere that a given frequency comes from varies greatly. More importantly the upper parts of the solar atmosphere are superheated by turbulent hydromagnetic effects. The later effects vary strongly with the solar magnetic cycle. TSI, varying probably would imply energy storage within the outer layers of the sun itself, presumably by contracting and expanding its outer layers slightly. That the phases of the two effects are not the same probably says something about the interaction. But we shouldn’t be surprised that they TSI and UV might not vary in the same way. The crudest handwaving theory would be that periods of high magnetic activity slightly inhibit convective heat transfer with the sun (thats why sunspots are dark), and if so during periods of high solar activity some of the heat flux may be diverted to the energy storage (thermal and gravitational).
In any case, some of these effects are likely transient behavior, and disentangling transient effects from secular effects may not be easy (if say solar activity is changing on century or longer timescales). The correlations of the different wavelengths may be different on short and long timescales.
Also we have to remember, that the current solar minimum is anomalous, so we don’t know how the current data (if verified) relates to an average solar cycle.
Um, sunspots? Speaking from a cosmological point of view, the sunspot cycle would seem to correspond closely to the data shown above. Visible light is reduced when sunspots are at maximum and, as sunspots are hotter than the rest of the sun’s surface, infra-red radiation increases. Obviously, the reverse is also true.
The study doesn’t seem to be saying anything new at all, as far as I can see.
[Response: Total irradiance increases with sunspots because they are accompanied by bright 'faculae' that more than compensate for the spots. So people expect increased warming as solar activity increases. - gavin]
Does anyone have a time series of solar UV intensity? Where can I find one?
[Response: The raw satellite data are available at the SORCE site linked above, while the solar irradiance models produce time series at all frequencies (see Wang Lean and Sheely for instance). - gavin]
Papers like the one by Gray and Livingston show the solar contribution of the recent temperature increase to be significant. According to their report, the sun may have contributed 0.28C to the observed 0.6C of warming from 1979-1998. Reports of reduced solar activity since may help to explain the more recent decrease.
All in all, too many people (alarmists and deniers) are using single reports of solar activity to (dis)prove global warming. The way this report was presented in two of the articles listed above shows that. The role of the sun needs to be fully understood in order to place it role in the entire climate debate.
[Response: Sure, but the numbers you quote are much larger than can be justified - do you have a proper cite? - gavin]
Dan – The “secular trend” of 0.014 K/year you mention refers to the temperature of the sun (at an average temperature of about 5800 K), not the temperature of the earth, and the authors point out that the “trend” is not necessarily long term. It would be unlikely to dramatically affect temperatures on Earth at an average of 288 K.
Thomas – I agree that TSI can’t be explained as the simple result of black body emission by a homogeneous entity. Regarding UV and TSI, they do seem to be more or less in phase (i.e., they change with the same sign), but the UV variance exceeds that of TSI. The real challenge of the recent results, however, if they are interpreted as more than transient effects, would be to explain a phenomenon that appears to imply that some major source of solar radiation may be hotter at solar minimum than at solar maximum, thereby causing an increase in irradiance at visible frequencies. This would be a revolutionary finding indeed, but the Gray and Livinston paper (see my link in #45) indicates that phase discordances between TSI and visible irradiance (if the latter is a reflection of solar temperature) are probably transient phenomena, while over the entire cycle, the two are correlated. In that case, the newly reported findings would not greatly alter our current thinking about the relationships between solar activity and our climate over the course of multiple solar cycles or even over the entire course of a single cycle.
“Upper parts of the solar atmosphere”: The UV from the Corona varies by 5 orders of magnitude. This gives us sunburns, but I thought that the energy was rather small compared to total solar output. The corona also makes X-rays. Are we talking photosphere vs corona? Isn’t the corona powered by magnetic storms? Do we need to talk about what the sun is doing in more detail to figure out where the UV we are talking about comes from?
Re Gavin’s inline comment on 21
At first, we just had experts in data quality grade our data (i.e., we had (third party) senior chemists go back and check all of the work line by line, and flag problems with analytical results.) Then, as we moved to solid state analysis was more checking proper sampling, calibration, maintenance, and database operation. (Gavin, When was the last time you had data that had been carefully reviewed, line by line by a third party expert with access to ALL lab logs?)
Eventually we got to DQO (http://www.epa.gov/quality/qs-docs/g4-final.pdf) where the entire data collection process was planned to support a decision and risk management process, such that critical decisions were allocated the resources to get the better data that such important decisions required.
Yes, we have important decisions to make and we need data of appropriate quality to base those decisions on – whatever it takes.
A few space rockets are no more expensive than the environmental sampling at US DOE sites Hanford and Savannah River. And, a couple of contaminated nuclear production sites are not as critical to our future as global climate change.
A good decision on climate change is worth the cost of good data.
Aaron Lewis would do well to hi his-self over to NASA’s IVV for an education on mission software verification. As to Savannah River, Eli knows a bit more than a bit about the chemistry of the clean up program, and to call it a very far behind schedule mess with questionable chemical process design is to be very charitable.
Gavin, excuse me if I refuse the stereotype people on both sides of the question want me to accept. I am neither a denier nor a contrarian. The fact that many have hijacked those terms so they can be applied much more broadly to anyone they don’t particularly like is nothing more than name calling. I’ll stick with the accepted meaning of the terms, not the bastardized terms.
Aaron Lewis says: “A few space rockets are no more expensive than the environmental sampling at US DOE sites Hanford and Savannah River.”,
OK, you owe me a new keyboard due to coffee damage. Dude, do you realize it costs $10000 to launch a can of Coke into space! I’m sorry, Aaron, but doing things in space has always been expensive, it is still expensive, and it will always remain expensive.
I believe you have succumbed to the fallacy that everything you don’t understand must be simple. The cure: Understand spaceflight. I’d be happy to explain things to you.
Nick @56: The current solar minima, that we are jut coming out of is unprecedented in the modern record, this minima is deeper and longer than has been seen for several decades. How, TSI versus sunspot numbers vary on time scales longer than a solar cycle, I think is still not known.
Should be easy to accomplish. Let’s see, we first need an informed public on the issues = no spin in the media = so politicians will be properly motivated to act = no special interest influence in campaigns and governance = overturning Supreme Court decisions: Citizens United vs. FEC (2010); Buckley vs. Valeo (1976); Santa Clara vs. Southern Pacific Railroad (1986) = politicians do the right thing because it gets them votes + meaningful market transparency regulation imposed + antitrust laws increased for effect and enforced = greater transparency in markets + stronger fair competition = eliminating derivative market systems + stronger shareholder rights = less artificial inflation = more money can go to science = potential for mil spec sat systems.
\Thomas, The last solar minimum was hardly unique. You only have to go back about a century to find minima as deep or as long. Yes, it was an odd cycle, but not that odd.\
Ray the solar activity in the last 40 years of the 20th century was the highest in roughly 10,000 years. What is unusual about cycle 24 is the abrupt change from a very high activity to low activity. (My point there is more to the scientific problem than the number of sunspots. For example what creates the sunspots and why has that mechanism suddenly changed.)
There are two related scientific questions. Why and how can the sun change and how can the solar changes affect the planet.
When sunspots intensify, less energy is lost from the Sun > a ‘solar greenhouse’ slightly analagous to ours except that it would be at visible wavelengths.
Of course you do not have to have energy balance on the Sun , but it still seems to me that a reduction of outgoing radiaton at one point might imply a rise in temperature somewehere else in the surface region. Could that be a way of thinking about the faculae? It would not necessarily change the numbers.
Has it ever occurred to anyone here that there could be another critical factor that influences average global temperatures?
Charles Keeling and Timothy Whorf (2000) [PNAS, Vol. 1910, No. 8, pp. 3814 - 3819], found that changes in the Earth’s global temperature record for the last 120 years showed spectral properties that matched those seen in the peak Lunar tides.
What if the properties of the lunar orbit that were responsible for the timing of the peak lunar tides (i.e. changes in the shape and orientation of the Lunar orbit) were some how synchronized with long-term changes in the level of solar activity.
It has long been argued that the changes in solar activity that could effect global temperatures (e.g. TSI) are too small to be of any significance unless they are “amplified” by some, as yet, unknown mechanism. Some people have proposed that it is large variations in the UV over the course of the solar cycle that are responsible. However, if changes in the shape and orientation of the Lunar orbit are synchronized with long-term changes in solar activity, this would naturally produce an apparent “amplification” of the Sun’s effect on global temperatures without
any [direct] need to invoke changes in the TSI of the Sun.
Geoff: If solar activity does effective the net radiation from the solar surface, then the delta in energy must go inot/from some energy store, magnetic, or thermal/gravitational. Of course if you warm up a layer of the sun, it expands against gravity, and paradoxically it can cool enough that net radiation could decrease. So we could have two effects from a sunspot, which is dark mainly because it supresses thermal convection (effectively magnetic damping of conductive fluid motion (magnetohydrodynaimcs). The most obvious is that perhaps the heat is simply deflected horizontally, and comes out nearby. But if it causes the outer layers to either expand (store energy) or contract, it would be possible for the net solar output to be temprarily modulated by the activity. Of course the magnetic energy, which is taken from the fluid motion of convection heats the Chromosphere and corona, and drives things like the solar wind, and transitory things like flares and coronal mass ejections etc. So what is actually happening gets pretty complicated pretty quickly. Any layer of the sun that is not in energy balance (flux coming up from above balancing flux lost upwards) will be heating/cooling because of the imbalance.
Playing a contrarian premise, in this case, extra UV in solar minimas give somehow more surface heat.. -As it should since solar cycle 24 coincides with extreme warming temperatures- except during darkness, the long night and or low sun elevations deny this utterly:
Hello, I live in rural New Zealand in the central North Island in a farming area. I have been noticing for two or three years the evidence of severe burn in spring, summer and autumn, on plants and on people who are outside a lot. In the farming newspapers you will often see photos of farmers whose faces are extremely reddened. In my area in the summer you see the same extremely reddened faces amongst outdoor workers even after one sunny day . I asked Niwa to put a spectrometer at my place to check it out the UV levels, which they did but the person doing the work left before the results were analysed and I have heard nothing further. I am sure UV levels here, with clear air, and an altitude of 300m are actually very very high. It concerns me. To me something seems very different to three years ago, when none of the facial burning was noticeable.
Comment by Robin Rutherford — 10 Oct 2010 @ 3:08 PM
Some good data can be got out of an instrument if the drift is constant
even down down to near death
The satellite record is not really long enough to use it as gospel ,
it’s more indications than boiler plate solid ,
As for the Sun physic , if one take predictions as the standard for good science , astronomers can make prediction on the planets position a couple of decades in advance and be right 100%
Solar physicists at the Marshall center have just had eggs on their faces predicting the current cycle ,they keep adjusting their predictions to fit the graph of C24
Solar physic is explorator territory still
I would take all solar sciences as brave educated guesses for the while .
but , I’m of a skeptical nature ,
if it doesn’t predict well ,it is not much good and back to the blackboard
UV getting through has something to do with Total Atmospheric Ozone depletions, which is keenly related to temperature of the stratosphere, in the past, always very cold, but now coupled with the presences of CFC photo-chemicals. You live not far away from a region not rich in stratospheric ozone.
Suggest looking at “Toast” http://www.osdpd.noaa.gov/ml/air/toast.html , on a regular basis, and or use the archives to see if you can explain past severe sunburns.
I envy you your location. My wife and I both loved New Zealand. I would imagine your UV flux is affected by the ozone hole more than solar variability. However, we’d be very interested in the results you hear. Do protect yourself from the UV, please.
Re 81 Hank Roberts – a bit OT but that’s interesting stuff; I wish I could find somewhere where the relative strength of the tides is given – say as a % change from average (or from average spring tides specifically). I wouldn’t think that the variance is all that big, outside of half a lunar month (where it should be a ~ +/- 50 % change from average) (and before going into geologic time, of course). Also I don’t recall seeing anything about variations in the lunar orbit’s eccentricity in those papers. Also, the diurnal and semidiurnal tides could be expected to respond somewhat differently to the moon’s inclination to the ecliptic at times of syzygy (PS if the tides followed equilibrium, the diurnal tides would be largest in midlatitudes and the semidiurnal tides would be largest in the tropics; of course, if the tides followed equilibrium, we wouldn’t have noticed them without scientific instruments! (the ocean and crust would move together).) I recall once reading of a glacier at sea level with a tide-dependent flow rate; I can imagine a potential threshold behavior for that sort of thing, but don’t expect longer-period tidal cycles acting through that or the following paranthetically-stated mechanism it would affect global climate much (PS thinking of tidal currents through islands breaking up sea ice…).
Jeannick #85 – I don’t agree with your statement that “predictions are the standard for good science”. Some physical systems simply can’t be predicted with any accuracy beyond fairly short timescales – this is the main point of chaos theory. It doesn’t mean there’s anything wrong (per se) with the model.
If sunburn incidence is rising it should show up in hospital records. You might check with local hospitals who probably keep records of that sort of stuff.
Comment by John E. Pearson — 11 Oct 2010 @ 7:56 AM
Dean, that’s to low earth orbit. Geosynchronous costs more, and getting to L2 is even more expensive.
But the biggest launch cost is probably insurance. When you are launching something like Envisat, the result of a 2.3 billion EUR project, the 120 million EUR for the launch is almost trivial. That was a polar orbit (out of reach for a Dnepr vehicle) and it’s too heavy for nearly everything except Ariane 5. The cheap options just melt away like morning dew.
Excerpt from above paper.
“In Sects. 5 and 6, we show that inadequate account of the number of degrees of freedom leads to a large underestimate of the confidence interval found in LMKC, and that the remaining significance is only due to coincidence of high solar activity with anthropogenic forcing over the last 50 years.”
There does seem to be agreement that the solar magnetic cycle was very activity in the last part of the 20th century. The papers that allege to disprove the solar modulation of climate (including the paper linked to above) do not consider other solar mechanisms and changes, such as solar wind bursts. TSI is one of five different solar physical parameters that could modulate climate. Heliosphere strength (which modulates GCR), Solar wind bursts (that removes GCR via modulation of the global electric circuit), TSI, UV level, and what ever is causing the ionosphere to change in height (assuming that change is caused by a solar change). My point is that if one does understand how the sun has changed in the past and how the solar changes affect climate one cannot prove or disprove its affect on climate in the later part of the 20th century.
An example would be Tinsley and Yu’s assertion that an increase in GCR can cause an increase in winter storm severity. If solar wind bursts remove GCR, they could mitigate and mask the effect, making it appear that GCR levels do not affect planetary climate. There is a comment in this thread that there is no correlation of GCR levels and planetary temperature in the later part of the 20th century (i.e. Planet warmed during some periods when GCR levels high.) Solar wind bursts were also high during the periods when there was a lack of correlation.
In the past there is alleged to be correlation of cosmogenic isotopes C14 and Be10 changes with climate change. There is not however agreement as to what solar mechanism could cause changes to the climate in the past or even what was the magnitude of the changes in the climate the past.
Cycle 24 seems to be anomalous for a number of reasons. There is an observed abrupt change from a very high level of magnetic cycle activity to low or possible to an interruption in the solar magnetic cycle. It is not clear from a solar physics standpoint why there is a linear reduction in the magnetic field strength of individual sunspots hence there is push back whether Livingstone and Penn’s observation is correct. There is not agreement why the 2000 gauss to 3000 gauss concentrated magnetic areas “sunspots” form, where they form, so one cannot predict what will happen next. The comment that the visible portion of the solar magnetic cycle has increased would imply that the sun is warmer. Why?
Perhaps the scientific questions will be answered due to new information related to the cycle 24 changes.
At first I thought perhaps this would simply mean some form of delay in the application of the 11 year cycle and so the “wrong sign” could be made to make sense in terms of the correlation between solar and temperature that is generally observed… but I see that “maunder minimum” bit and all bets are off. I am very glad that that satellite is up there and that the questions are getting asked. Now all I need is the patience to wait for actual answers.
…and a way to explain to the ignoranti that this doesn’t throw all the rest of what we know into the scrap heap… as they are already claiming.
This is slightly off topic but I don’t understand how anyone can doubt climate change due to greenhouse gases after having read Plass’s article from 1956. You referenced it some time ago and it can be found here:
Variation in carbon levels is the only explanation for ice ages that has anything like the proper time frame. Solar variation is far too short a cycle.
Comment by Michael Doliner — 12 Oct 2010 @ 9:14 AM
Deranged Melanie Philips is at it again – see spectator extract further below – but could anyone share some insight into the physicist Harold Lewis. It won’t surprise you that he is not a climate scientist? For such a ‘distinguished’ scientist there appears to be very little about him at the University of California, Santa Barbara website; he hasn’t even got a wiki entry. He appears to be a nuclear engineer with a handful of publications in less than outstanding journals.
‘Decency fights back’
Straws in the wind, maybe, but in the last few days there have been heartening signs of people making a stand for truth, decency and integrity. The first was the resignation from the American Physical Society of Hal Lewis, Emeritus Professor of Physics at the University of California and a scientist of distinction, in protest at the attempt by the APS to shut down debate about its endorsement of anthropogenic global warming. It is a magisterial rebuke which stands witness to the devastating corruption of science represented by the AGW scam. Here’s a sample of Prof Lewis’s resignation letter:
It is of course, the global warming scam, with the (literally) trillions of dollars driving it, that has corrupted so many scientists, and has carried APS before it like a rogue wave. It is the greatest and most successful pseudoscientific fraud I have seen in my long life as a physicist. Anyone who has the faintest doubt that this is so should force himself to read the ClimateGate documents, which lay it bare. (Montford’s book organizes the facts very well.) I don’t believe that any real physicist, nay scientist, can read that stuff without revulsion. I would almost make that revulsion a definition of the word scientist.
So what has the APS, as an organization, done in the face of this challenge? It has accepted the corruption as the norm, and gone along with it….
Please note I didn’t say “read it all”. Melanie Phillips said it! You might find it useful not to shoot the messenger. Raising awareness of the contrarian mindset is not the most redundant exercise; at the very least it allows us to appreciate their appalling scientific ignorance.
That said, chewing broken glass is probably the better option compared to anything Mel P writes.
My fire was not directed at you, and sorry if some of the vitriol splashed your way.
However, I think we spend way too much time paying attention to what are in effect, morons and loons. If they rejected the heliocentric solar system, they would be called such. If they rejected evolution, they would be called such. Likewise, smoking related illness, HIV-AIDS causation, etc. The fact that some of these loons and morons hold power and influence should not increase the attention we pay them.
71 John P. Reisman (OSS Foundation):
\Triple redundancy = MilSpec\
NO. For integrated circuits [ICs] and electronics parts in general: A machine sorts them into categories after they are made. The classes start with Class S then Class M [Mil spec] then……memory fails. Consumer spec is just above broken.
Comment by Edward Greisch — 13 Oct 2010 @ 12:16 PM
#102–good edit. (Including correct agreement as to number!)
By the way, I’d like to offer belated thanks to readers here–and of course, the moderators, who’ve allowed various shameless plugs like this one at (hopefully) discreet intervals–who’ve taken time to read and sometimes comment on my backgrounders on global warming science.
The milestone that prompts this commentt is the recent achievement of over 1,000 page views for the most-viewed article–fittingly, that on the life, work and times of John Tyndall:
Coming up behind are the articles on Arrhenius and Fourier–the former will probably hit 1,000 about five months out, the latter about 10. It’s education on the retail scale, I suppose, but satisfying none the less.
“I think we spend way too much time paying attention to what are in effect, morons and loons.”
Well, you can’t whack every mole, and they just pop back up anyway. OTOH, I’d submit that the problem is no longer one of a few marginal or isolated noise makers, that it’s getting worse, and that there doesn’t seem to be an effective way to leverage the situation. Maybe I’m overly pessimistic.
Without examining Haig’s calculation, unless the total albedo integrated over the spectrum is lower, I can’t fathom why the surface temperature would increase with decrease in TSI. The stratosphere temperature is not nearly high enough to make a marginal boost compensate (through radiation, since ~ T^4) for the increase in total energy supplied to the atmosphere. Right? Therefore, I would still expect surface temperatures to decrease with decreasing TSI, albeit with possibly longer delay…
The impending TeaPublican victories in America tell us that we can expect no rational behaviour from the American people until the current generation has expired.
Isolate, Encapsulate, Constrain.
We don’t expect to see much climate science coming from America once the teapublican budget cuts kick in.
Comment by Shandahr Sheppe — 13 Oct 2010 @ 11:00 PM
“OTOH, I’d submit that the problem is no longer one of a few marginal or isolated noise makers, that it’s getting worse, and that there doesn’t seem to be an effective way to leverage the situation.” – 109
Your observations are correct of course, and the reason is obvious, but still unfathomable to most scientists who spend their days surrounded by reasonably rational people.
The denialist insanity is almost exclusively concentrated in the Conservative American population who have decided to reject reality and place their faith in Conservative Political Dogma.
This isn’t rational of course, but mass self delusion is common in history.
As I have said many times, there is only cure for this Conservative disease and it is death.
Now given that the current “educate the willfully ignorant” strategy has clearly failed, (no surprise there) what strategy is best to adopt now?
Some here seem to believe that it should be more of the same.
Of course that is a presc.x.ription for continued failure, and given the stakes evidence of insanity IMO.
Just curious: I expect that the solar spectrum is unchanged as far as photosynthesis is concerned. To get maximum plant growth we need maximum photons of the right wavelengths + keeping the temperature where it was before GW. Geoengineering would give us fewer photons in hot climate = less food.
Don’t some plants get sunburned in excess UV? There are more constraints than we realized.
#118–I suppose it depends upon what you call “geo-engineering.” For schemes that affect global albedo, yes. For schemes that affect local or regional albedos, or that affect carbon fixation/sequestration, no.
Margo Meade, I know of no remedy for ignorance other than education. The problem in this case is that the public are too distracted by the circuses to realize the bread is being stolen from their plates, let alone realize that they face a less immediate threat.
I would submit, however, that any strategy for renewing democracy must be at its root democratic. If the species turns out to be too dumb to survive, as I have said, at least those of us intelligent enough to perceive it will have an answer to the Fermi Paradox.
@114 Margo: The deniers smell a conspiracy, and no amount of scientific evidence is going to convince them otherwise. Climate science is heading for a rough couple of years, until sometime in the future the effects of climate change become so glaringly obvious in their daily lives that only the most foolhardy will persist in their denialism. We can only hope they don’t do too much damage in the mean time.
Comment by Paul van Egmond — 14 Oct 2010 @ 10:22 AM
While we are on the subject of educating morons and loons, can we do something about those who exaggerate the effects of global warming in an attempt to create a impending catastrophy. It is no wonder that belief in global warming has waned recently. If one person claims that no warming will occur, and another claims that it will twice as much as actual, they are both off by 100%.
As far as geoengineering is concerned, that is tops on the list of bad ideas. Part of the increase in plant growth and food production was due to the increased atmospheric CO2 levels and warmer temperatures. Decreasing sunlight and temperatures will decrease plant growth.
#126–I should probably be the one to apologize, for riding a hobby horse (AKA pet peeve.) A particularly bone-headed denialist I frequently encounter is addicted to that particular spelling, and it probably helped induce the knee-jerk editorial response.
…can we do something about those who exaggerate the effects of global warming in an attempt to create a impending catastrophe…
I’d agree with this, except I don’t ever actually hear this except on denier blogs claiming it’s been done by “alarmists.”
Or, to put it a little more clearly, those “impending catastrophes” you are referencing are in fact very real… 30 to 100 years down the line. No one is saying it’s going to happen tomorrow. What they are saying is that if we wait 30 or 100 years to take action, then it will be way, way too late, and by that point they will be very serious, world changing catastrophes.
It all depends on how close to the edge we want to ride, and how much we want to stick it to our children/grandchildren for our own creature comforts and presumed entitlement lifestyle in the present.
So the people that say “that’s silly, look, nothing’s happened yet, there are no catastrophes” either aren’t listening or aren’t thinking it through.
Dan H. asks, “While we are on the subject of educating morons and loons, can we do something about those who exaggerate the effects of global warming in an attempt to create a impending catastrophy. It is no wonder that belief in global warming has waned recently. If one person claims that no warming will occur, and another claims that it will twice as much as actual, they are both off by 100%.”
Well, except zero warming would imply CO2 sensitivity of 0, and there is zero probabiliy of that. Double current warming estimates requires a CO2 sensitivity of 5.5-6, and that cannot be ruled out at better than the 98% confidence level. Not equivalent. The problem, Dan, is that we cannot bound the effects of the warming. We don’t know how bad they will be just yet, but we know they will be worse than anything we’ve faced in the history of civilization.
We do not know what the overall effects will be. But does that mean making claims of 3C warming in the next 90 years is better than making claims of no warming. Those that assume a positive cloud feedback arrive at your implied climate sensitivity in the 2.75-3.0 range, which with the expected 40% increase in atmospheric CO2, would result in less than 1.5C of warming by 2100.
How do we know that it will be worse than anything we’ve faced in the history of civilization? The last ice age was quite rough on many species.
The “impending catastrophes” are only real if they actually happen. I am not saying that they cannot happen, but that we do not know if or when they could happen. We are speculating using several assumptions, which in turn have a high degree of uncertainty.
Yes, Bob, it is usually denier sites than claim exaggeration by alarmists, and conversely, alarmist sites that claim deniers are spreading misinformation. I have yet to find a site that is truly neutral on this topic. Those that believe in warming continuing on its current pace are branded by both sides as climate morons and loons as Ray so eloquently referred to them.
[Response: Please provide just one example from one of our RealClimate posts of what you consider exaggeration, because we all think we're pretty conservative here.--eric]
Well, this gets us back to the territory of the “Warmer and warmer” post. Due to the challenges of scientific attribution, it’s hard to know whether or not some catastrophes that have occurred are, or are not, due to climate change.
Russian heatwave? Maybe.
Pakistani floods? Maybe.
Pine bark beetle pandemic? Probably, but can’t be completely sure.
Katrina? Could have contributed. . .
2003 European heatwave. 30% increased probability (IIRC.)
Hmm. That’s many, many billions of dollars and many thousands of premature deaths that we’re talking about here. What about some non-human impacts?
From today’s in-box: Long term 80% decline in krill population? Could be, but. . .
Possible increased mortality in whale populations feeding on krill? Well, is mortality up in fact?
But, as Ray points out, it seems that some people persistently suffer the illusion that uncertainty is their friend. That is, they persistently say that because we aren’t completely sure, action is inappropriate. But the flip side is that it is entirely possible that we have suffered catastrophes already due to climate change, and that clear signs of severe biological consequences are currently unfolding in front of us.
So, what is a “catastrophe?” How do we recognize it? And how do we relate it to climate change, and our own actions? Clearly there is a concerted campaign to minimize or deny any danger, and clearly it plays into “common sense” and emotional comfort. Clearly there have been some who sensationalize, perhaps in partial compensation for the fact that scientific objectivity and caution have the unavoidable side effect of minimizing possible consequences. (Or at least making them sound kinda boring.)
At the end of the day, it’s a matter of attitude and judgment. Some people, confronted with a minor skin lesion, will decide it’s nothing. Others will immediately make an appointment with their GP or dermatologist. More often than not, it probably IS nothing–but which group has the higher survival rate, I wonder?
Dan H (14 October 2010 at 10:44 AM) asks “can we do something about those who exaggerate the effects of global warming in an attempt to create a impending catastrophy.”
I have heard claims about people exaggerating the effects of global warming but have rarely seen it done. Dan, could you give us links to one or two people who you think are exaggerating the situation?
Dan H.: I agree with your basic premise that “the warmists” do more harm than good. I personally find it very frustrating when people use lies, distortions and misinformation in support of a conclusion that I agree with, or in the name of a cause that I believe in.
We are better than that. And if we’re not, then we should be. We certainly have no need to stoop to denier tricks to make a point.
Just to reassure the moderators: this sort of hysteria is frequently to be found in the comments, but I have never observed it in articles or comments from the RC authors.
Dan H. – your numeric assertions seem a little off to me. Climate sensitivity is “likely to be in the range 2 to 4.5°C” and may be higher. However, climate sensitivity is not the same as the projected temperature rise over a given period. The UK Met Office predicts a rise of 2.1 – 7.1 degrees (from pre-industrial levels) by 2100. But the low end of this estimate stipulates immediate emissions reductions. If we follow “business as usual”, the projection is 5.5 – 7.1 degrees. If we subtract the rise we have already seen, that’s still likely to be a further increase of 5 degrees by the end of the century.
This seems like a sober analysis to me. How did you arrive at your numbers? What emissions model are you assuming?
Those that assume a positive cloud feedback arrive at your implied climate sensitivity in the 2.75-3.0 range…
It’s not “assumed,” it’s inferred from our understanding of the physics and the systems involved. That understanding isn’t perfect, but it’s not the sort of casual assumption that you are implying.
My understanding is also that the increase in sensitivity arises not from a “positive cloud feedback” but rather a positive water vapor feedback (which is different, and much easier to predict). The important distinction in climate sensitivity is the lack of a significant negative feedback from clouds as expected by some scientists (Spencer, Lindzen) or the possibility of some degree of positive feedback from clouds (in addition to water vapor) depending on the nature/location of the formation of those anomalous clouds.
The estimates of climate sensitivity are also supported by a completely separate line of inquiry, the study of paleoclimate, which also points rather consistently to the same range of climate sensitivity. At the same time, the history of the earth’s climate seems to very distinctly preclude the idea of low climate sensitivity.
The “impending catastrophes” are only real if they actually happen.
Statements like this always make me think of the joke about the guy who jumped off of the skyscraper, and was heard to say as he passed an open window “so far, so good.”
We are speculating using several assumptions, which in turn have a high degree of uncertainty.
This is patently false, and if you believe it, you have not sufficiently studied or do not sufficiently understand the science. Very, very few assumptions are involved, and so far those assumptions that have been made are proving to be too conservative, i.e. things are looking to be worse than originally expected.
…and conversely, alarmist sites that claim deniers are spreading misinformation.
Because they are, and the misinformation is rampant. I could list about a zillion examples, with links, but it would be pointless because you already know it to be true. In fact, I challenge you to provide links to three denier sites that do not spread misinformation.
I have yet to find a site that is truly neutral on this topic.
That’s because you are not neutral yourself. You steadfastly desire that it be a non-problem, so your condition for “neutral” is a site that says “well, both sides have good points, so let’s just wait and see.” “Neutral” does not mean give equal weight to every crazy proposition and predilection to the point of insanity.
Which is the really big problem… “wait and see” and “let’s be careful about this, we don’t have enough information to take action” is equivalent to “hope for the best, and if not, oh well, so what if millions or hundreds of millions die fifty years from now?”
The main problem here seems to be that you honestly believe that there is not much in the way of evidence, that the jury is very out, and no one really knows what is happening. This is not at all the case.
Those that believe in warming continuing on its current pace are branded by both sides as climate morons and loons as Ray so eloquently referred to them.
This is unclear. What do you mean by this? Please clarify.
Dan H. wrote: “How do we know that it will be worse than anything we’ve faced in the history of civilization? The last ice age was quite rough on many species.”
The last ice age predates the history of civilization.
If you are comfortable with the idea that the future of “civilization” will be a very small number of people struggling to survive as gatherer-hunters in a dying biosphere, then there is really nothing to worry about.
After all, worse things than that have happened to the Earth in the past, and even though 90 percent of species went extinct, life went on, and it only took millions of years for a robust, diverse, thriving biosphere to regenerate.
Comment by SecularAnimist — 15 Oct 2010 @ 11:12 AM
First off, clouds are still a large uncertainty, whether you personally believe this or not. This ranges from positive to negative feedback due to increased cloudiness and also a positive feedback due to decreased cloudiness, all associated with increases in atmospheric CO2 concentrations. I am not questioning the water vapor feedback, only clouds.
There is plenty of evidence; people are just using it improperly. How many people have extrapolated the temperature increase from 1979-1998 or the flat line since?
As far as a clarification in your last post, just read some of the recent posts.
You can Didactylos above to the list of exaggerators.
Dan H. says, “But does that mean making claims of 3C warming in the next 90 years is better than making claims of no warming.”
Simply, flat-assed wrong. Did you even bother to read my post? Dude, what is the probability that CO2 sensitivity is zero based on the evidence we have. I will tell you: it is zero. What is the probability that it is above 3 degrees per doubling? Better than 50%
Here’s the deal, Dan. In risk assessment, the first step is to ascertain whether the threat is credible. Since a CO2 sensitivity of more than 2 degrees per doubling will result in significant stress on the planet’s carrying capacity, I claim that we have 95% confidence that the threat is credible. That is more than sufficient to establish the credibility of the threat.
Now step 2. Bound the risk (=probability of threat x cost if realized). Oops! Big problem. Cost of a rise in temperature diverges as we get near 6 -8 degrees. Even at 3 degrees it is quite significant and has a significant high-side tail. When you cannot bound risk, Dan, the only responsible risk reduction strategy is to avoid risk.
So, Dan, on the one hand, we have nearly everybody who has actually studied the issue voicing serious concerns, and then we have people like you who can’t be bothered saying “Oh, it’ll be all right,” and complaining the the informed are alarmed and therefore alarmist.
I am not questioning the water vapor feedback, only clouds.
You missed the point. What you previously had said (which is completely incorrect):
Those that assume a positive cloud feedback arrive at your implied climate sensitivity in the 2.75-3.0 range…
This implies, to me, that you believe that a positive cloud feedback is required for the sensitivity in the range 2.75-3.0C.
But this is not the case. That range arises primarily (but not only) from water vapor feedback, not from a positive cloud feedback. There is a difference, and it’s important.
…clouds are still a large uncertainty, whether you personally believe this or not…
I don’t dispute this. What I dispute is (a) that this is necessarily tied to current projections of climate sensitivity (it’s not), and (b) that there is any solid scientific evidence in favor of the case for a strong negative feedback from clouds.
There is small handful of scientists making a case for it, and in two decades they’ve been unable to advance that case through scientific means (only through propaganda and rousing, sarcastic speeches at Heartland “climate” conferences). I’m not a big fan of believing people just because they say something and it sounds like what I’d like to hear.
…a positive feedback due to decreased cloudiness…
A minor correction, although this in a nutshell demonstrates how very weak your own understanding of the science is, and should be a signal to you that you should study more before settling on your own opinions.
Positive feedback from clouds would be due to an increased greenhouse effect from the cloud themselves, not a decrease in clouds. This is in contrast to a negative effect which would primarily come from an increased albedo. The main distinction here is in what sort and how many additional clouds might form in a warmer world; high clouds made of relatively transparent ice crystals, or lower level clouds consisting of water droplets… as well as whether or not those clouds tend to form earlier in the day (so their impact on albedo is relevant) or later in the day and persist through the night (when change in albedo is irrelevant).
Clouds made of ice crystals will have a minimal effect on albedo, and so let in the same amount of sunlight, while still having a greenhouse effect. Clouds made of water droplets, and present in daytime, could increase the earth’s albedo, reflecting back more incoming radiation than it is trapping through a greenhouse effect.
But as I said… right now there are multiple lines of evidence that show a sensitivity in the range of 2C-6C (but scientists go with the 2C-3C range), and no reliable evidence that I am aware of that puts climate sensitivity any lower.
There is plenty of evidence; people are just using it improperly.
Yes, you make that very clear.
…or the flat line since?
Flat line? Have you looked at temperatures for the past 14 months (with every single month in the top 4, if not 1 or 2, for the past 100 years)? Please visit Dr. Roy Spencer’s site for AMSU temps. Check the boxes for every year, hit the “Redraw” button, and tell me what you see.
I’m sorry, Dan H. I completely misunderstood you. People don’t come with handy “denier” labels around their neck, it is something that we have to work out based on what people say, and whether they are susceptible to reason.
It transpires that your idea of “exaggeration” is simply any number that you find inconvenient, and has nothing to do with whether the number can be supported by solid evidence, or whether it is a reasonable estimate given the stated assumptions.
“How many people have extrapolated the temperature increase from 1979-1998 or the flat line since?”
See, statements like this are what get you in trouble – and reveal that you actually are so far out of your depth that we should call the Coastguard.
Please don’t let this put you off. There is a simple solution to not knowing things. Learn. Ask. Understand.
Comment by David B. Benson — 15 Oct 2010 @ 4:19 PM
I was confused, thinking that the quotes from Drs. Le Quere and Richardson rather undercut Dan’s point of an expected 3C (or less) temperature increase. Instead, they are being cited to show “exaggeration.”
But don’t BAU projections run as high as 7C? And is there any indication at this point of significant deviation from BAU?
Don’t mean to sound pessimistic here, but if LeQuere and Richardson are in the high end of the expected range, they aren’t at the extreme high end. And they definitely aren’t beyond it, which is what I’d have thought a claim of “exaggeration” would imply.
Would it be fair to say that if the UV reduction was greater than expected and consequently stratospheric cooling was more to do with UV reduction and less to do with any arguments of increased atmospheric temperature gradient then the argument that stratospheric cooling justifies AGW equally diminishes?
[Response: No, you are confusing timescales. This analysis was based on a 3 year time period - stratospheric cooling related to GHGs has been seen over decades - and the solar UV contribution (even if this new data is right) would still have lead to a warmer stratosphere. Still contradictory. - gavin]
Is it not true that the SIM data has only been collected since 2003? It seems to me that unless we have the equivalent of that SIM data then we cant confidently claim anything about the previous decades in the light of this result.
We do occasionally see exaggerated claims, by amateurs. Usually it is because they are using rhetorical, rather than mathematical reasoning, such as mistaking any positive feedback as implying instability. Also a lot of amateurs think warming will cause methane hydrates to destabilize yielding the end of the world as far as life is concerned, whereas professionals look at the scales of things, and the timescales for change and don’t make such statements.
The below statement was part of a commentary in The Detroit News, a paper that consistently runs commentaries and editorials lambasting the science of global warming. Would anyone like to comment on it? I’ve not heard of any decline in the number of temperature reporting stations in Canada.
NASA’s chief global warming exaggerator, James Hansen, was caught doctoring temperature data in several clever maneuvers. He oversaw the elimination of a dramatic reduction of world temperature recording stations.
San Jose computer programmer E.M. Smith uncovered the data and found NASA “systematically eliminated 75 percent of the world’s stations with a clear bias towards removing higher latitude, high altitude and rural locations.”
The number of reporting stations in Canada was reduced from 600 to 35, with the traditionally colder areas no longer part of the equation, therefore leaving the overall world temperatures to skew toward an artificially higher figure.
In 2008, Hansen entered September temperature data for the month of October in compiling numbers to support another scare about warming, once again trying to falsely distort a climate record. He claimed it was a simple error, which would be an acceptable explanation from a layman but not from the person in charge of NASA’s climate projects.
Sault Ste. Marie, MI
Comment by Roger Blanchard — 16 Oct 2010 @ 7:35 AM
Clearly whoever’s writing this stuff doesn’t understand anomalies. Reducing information from higher latitudes, if it were done at all, would lead to showing *less* warming rather than more. Because temperatures have increased much, much more in these areas than in the tropics.
Do they seriously expect us to believe that climate science is done by fifth graders adding up raw numbers from around the world and producing a simple average?
Good question, Roger. (Though I’m biassed in your favor, as a Soo boy myself–albeit on the Canadian side.)
Easy answer, though–this allegation is not based in reality to any great degree. The 2008 error did happen, but it clearly was an error, for reasons which have been very thoroughly discussed on this site. (And there is no reason to attribute it to Dr. Hansen personally; he’s not the guy doing the “donkey work.”) See:
The other matter is more puzzling, to me at least. I can’t find any indication as to why Mr. Smith–a serial denialist crank blogger under the name “chiefio”–thinks that this is the case. The Canadian stations still exist, and still report. It’s conceivable that there was a period while Canadian reports were still incomplete, and that for a time there was missing data. But you can–and I have–go to the data online and see reports from a great many Canadian stations. It had been alleged on a news site–consequent to “chiefio’s” allegations–that there was just one temperature station left in the Canadian Arctic. But I counted something like 20 north of the Arctic circle.
If you’d like to have a look for yourself, you can access the data here:
BTW, the removal of colder stations would not introduce a warmer bias even if it had actually occurred, since the data deals with anomalies not absolute temperatures. (And yes, folks have taken the trouble to work the math on that analysis; it’s not just an expectation.) But chiefio didn’t get that, and neither did Joe D’Aleo and Anthony Watts, who promulgated similar baseless allegations.
Personally, I’d love to see them sued for defamation, but I know civil actions can be a huge, huge pain and the smart move is usually to refrain. The only such action I know of is in Canada, where Dr. Andrew Weaver sued for, well, blatant lies printed about him. (Oh, and of course in the UK Dr. Pachaury did get a settlement out of–the “Telly,” wasn’t it?–for defaming him with baseless allegations of profiteering. Rumored to have run to six figures, and at that supposedly just covered legal costs.)
Shandahr Sheppe (151), I don’t know if this applies to the study itself or not, but your description puts a decidedly prejudicial bent on it. “Refuse to understand/learn is a pejorative twist on “don’t understand/believe.” And, “[doesn't] accept that the greenhouse effect refers to gases in the atmosphere that trap heat.” — they refuse to accept/understand that heat trapping gases is what is even being referred to?? Or is it that they don’t believe the ‘it’ is correct? The last point (75%….) is the only one devoid of prejudicial pejorative twists.
You should give a link or pointer when you copypaste stuff; quotation marks would help distinguish (if that’s the right word) what you made up from what you’re copypasting. Picking a likely string from what you posted, Google finds “about 1,690,000 results” — you’ve got an ancient tarball there.
Roger Blanchard, Tamino drove a stake through the heart of this zombie argument. Not only did the eliminaton of the statons not introduce a warming bias, if anything it resulted in a slight cooling. This is not just a lie, it is a discredited lie, unworthy of a news orgaization…which I suppose makes it just fine for the Detroit News–yet another publcation that ought to be published on 4 inch paper squares rolled around a cardboard tube.
Roger, Gavin already responded to this story before. It is a libelous claim by Watts & D’Aleo, published by SPPI (the document was recently modified, after too many people showed it contained many falsehoods, but has not become much better).
Short story: the inability of certain people, in particular Smith, Watts and D’Aleo to understand the concept of temperature anomaly, combined with their unwillingness to do actual data analysis, resulted in their claim that disappearance (not removal) of measuring stations at high latitude and high altitude would result in a warming bias. People who know a bit more and DO the data analysis, found that, if anything, the absence of those stations introduces a slight COOLING trend. Quite the opposite of the claim, but no surprise there…
Regarding NASA removing data stations: GISTEMP uses the NCDC data set, over which it has no control. In addition, there was a big concerted effort in the mid 1990s to obtain a lot of unreported historical data from many data stations.
The “rural stations” removal claim is again due to the inability to understand absolute numbers and, in this case, ratio. The ratio between rural and urban stations remained approximately the same, but since there were many more rural stations, “more” were “removed”.
And does anyone even need to respond to the ridiculous claim that Hansen deliberately changed data to “support another scare” ?
The below statement was part of a commentary in The Detroit News,
San Jose computer programmer E.M. Smith uncovered the data and found NASA “systematically eliminated 75 percent of the world’s stations with a clear bias towards removing higher latitude, high altitude and rural locations.”
Update: Some comments on the John Coleman/KUSI/Joe D’Aleo/E. M. Smith accusations about the temperature records. Their claim is apparently that coastal station absolute temperatures are being used to estimate the current absolute temperatures in mountain regions and that the anomalies there are warm because the coast is warmer than the mountain. This is simply wrong. What is actually done is that temperature anomalies are calculated locally from local baselines, and these anomalies can be interpolated over quite large distances. This is perfectly fine and checkable by looking at the pairwise correlations at the monthly stations between different stations (London-Paris or New York-Cleveland or LA-San Francisco). The second thread in their ‘accusation’ is that the agencies are deleting records, but this just underscores their lack of understanding of where the GHCN data set actually comes from. This is thoroughly discussed in Peterson and Vose (1997) which indicates where the data came from and which data streams give real time updates. The principle one is the CLIMAT updates of monthly mean temperature via the WMO network of reports. These are distributed by the Nat. Met. Services who have decided which stations they choose to produce monthly mean data for (and how it is calculated) and is absolutely nothing to do with NCDC or NASA.
Further Update: NCDC has a good description of their procedures now available, and Zeke Hausfather has a very good explanation of the real issues on the Yale Forum.
Yes, Rod B: the term “refusing to understand” should only be applied to those who have been closely engaged in the climate conversation, and have had the same basic facts repeated to them time and time again, over a period of years, and who still pretend not to understand. Those people refuse to learn or understand. They even refuse to think for themselves.
It isn’t fair to apply the term to people who simply don’t care.
“Do they seriously expect us to believe that climate science is done by fifth graders adding up raw numbers from around the world and producing a simple average?” – 155
They don’t expect (YOU) to believe that. They expect their conservative target audience to believe that.
And they do.
They live in a world where the ability to multiply and divide is considered high edgeamakaschuns.
If that is all you know, what else could there possibly be? Statistics? Well that’s all lies, isn’t it?
And since there is nothing else, then either the grade school math is wrong or it’s all a conspiracy.
What else could it possibly be?
The fact is, the adult American population is in general functioning at such a low intellectual level that they aren’t capable of comprehending even simple scientific concepts, and certainly no math with a complexity beyond division.
Need you look any further than the election of George Bush Jr. – Twice. The verdect in the OJ Simpson Trial, and the impending election of the – I am not a witch – TeaPublicans, the abandonment of Evolution as a theory etc. etc. etc.
These are not anomolies, there are far too many examples of this behaviour amongst the American Population.
They can not be educated. There is insufficient time. Science offers can provide no rapid solution to the education of the willfully ignorant.
Another path must be taken. And that path is political.
Just so there’s no confusion, there is a sharp drop in the number of Canadian stations reported in the GHCN v.2 from 623 in 1989, to a low of 36 in 2003-4, up to 49 presently, if I’ve counted correctly.
I hasten to add that the Detroit News commentary is blatantly false and defamatory in all other respects. Neither NASA nor Dr Hansen are responsible for what is included in the GHCN, and the drop in station numbers matters not a whit to the global temperature record, for the reasons already cited in the comments above.
“but your description puts a decidedly prejudicial bent on it.” – 157
For the last 20 years the scientific community has attempted to educate these people on the issue, and they remain ignorant of the basic facts of the matter – like the fact that the existance of CO2 in the atmosphere reduces the rate of heat flow out of the atmosphere.
With such a track record the phrase “refuses to understand” is a more accurate discription than “does not understand”.
The refusal results from a political ideology that rejects all evidence and logic that runs counter to the ideology’s core thesis. In this case the core thesis is that government is pure evil and that exponential growth can continue indefinately.
I suggest you do some reading about the opinions of the late Cornucopian Economest Julian Simon.
Comment by Shandahr Sheppe — 16 Oct 2010 @ 2:59 PM
>>Short story: the inability of certain people, in particular Smith, Watts and D’Aleo to understand the concept of temperature anomaly
Actually, I don’t really fully understand it! Could someone explain it to me? You get a set temperatures for February 2009, in Boston, MA. You have a set for Fitchburg, MA, and San Fransisco, all the for the same month. A year later you have data for the same cities. What is anomalous? What do you do with the data to determine if February was colder or warmer in 2010 for Massachusetts, and then for California?
“but your description puts a decidedly prejudicial bent on it.” – 157
I should add that your objection is in effect a claim that the American People are not intelligent enough to be engaged in willful self deceit.
Comment by Shandahr Sheppe — 16 Oct 2010 @ 3:02 PM
The commenter doesn’t understand the difference between warm temperatures and a warming temperature trend. Most of the stations eliminated (for reasons other than sinister conspiracy, by the way) were in colder climates. That does NOT mean eliminating them would cool the TREND. In fact, since global warming increases nearer the poles, any bias it introduced would be toward cooling, not warming.
169 Barton said: “The commenter doesn’t understand the difference between warm temperatures and a warming temperature trend.”
Maybe he did understand or maybe he didn’t. The author of the piece was mendacious enough to give Pinocchio nightmares.
Comment by John E. Pearson — 16 Oct 2010 @ 7:20 PM
When you are concerned with anomalies, you are looking at how the temperature differs from a mean for some reference period. Thus, you are not concerned with the absolute temperature at a location, but how much warmer or cooler it was than “normal”. Thus, all you can say is that, for example, San Francisco had a cooler than normal winter while Connecticut had a warmer than normal winter.
“We don’t know how bad they will be just yet, but we know they will be worse than anything we’ve faced in the history of civilization”
“Please provide just one example from one of our RealClimate posts of what you consider exaggeration, because we all think we’re pretty conservative here.–eric]”
There you go Eric. Ray was happy to help the poster out and provide you with an example. We don’t even know the results of global warming will be catastrophic at all much less worse than such events as WW1 and WW2.
Now since so many of the posts seem to mention deniers I was wondering if anyone could provide me with the definition of a denier. Is it someone that denies the evidence? Or is it just someone that denies your point of view? Or is a denier something else entirely? It really isn’t all that clear to me. Part of the reason it isn’t all that clear is because the word is tossed around so often and yet the comments proceed on as if everything was happening as modeled and there was no countering evidence at all.
“Reconstruction of regional mean sea level anomalies from tide gauges using neural networks” this study questions the accuracy of sea level rise acceleration
“Global depletion of groundwater resources” this study questions the accuracy of sea level rise attribution
“What Do Observational Datasets Say about Modeled Tropospheric Temperature Trends since 1979″ this study questions the accuracy of the models in regards to the troposphere
“Ozone and temperature trends in the upper stratosphere at five stations of the Network for the Detection of Atmospheric Composition Change” this study questions the accuracy of the models with regards to the stratosphere
“Uncertainty in ocean mass trends from GRACE” this study questions the accuracy of sea level rise as measured by GRACE
“Recent energy balance of Eartht” this study questions the existance of a large radiative imbalance
“WHY HASN’T EARTH WARMED AS MUCH AS EXPECTED?” this paper questions the accuracy of climate sensitivity as modeled
So there is evidence that runs counter to the prevailing point of view here. If one comments as if there isn’t are they a denier?
[Response: These roads have deep ruts, but I'll assume the route is new to you. A denier is one who refuses to believe something when experts in the area in question have demonstrated that the preponderance of evidence supports it. In relation to climate science, it refers by far the most often, to those who deny the likely range of radiative forcing and/or consequent surface T changes to be caused by greenhouse gas inreases. Your selection of studies carries little meaning when viewed from this perspective, because (aside from the lack of specific citations), they tell nothing whatsoever about their validity, nor the many studies that might well contradict them, and hence the overall balance of evidence.--Jim]
I wouldn’t say the road is new to me as regards reading the word. I’ve been reading it for about 3 years now. I just have never seen anyone give the word a definition. Is it based on the climate sensitivity then? Does one become a denier below 1.5C as in AR3 or must they have advanced to 2.0C as in AR4? I assume there is no upper limit given the long tail on the skewed bell curve of possible sensitivities. Is there a political component to being a denier? For instance if a person were to say the evidence led them to conclude the sensitivity is closer to 1C then it is to 2C but they supported co2 mitigation would they still be a denier? I understand this may be a touchy subject but I find it rather interesting.
To stop all this dreary debate about data manipulation and elimination which eventually gets into every thread on here, we need a global dataset with appropriate change-control process and quality control. The numbers would be transparent for all then. Simple really…
stevenc #173, and for the benefit of casual readers coming by here,
Eric was obviously asking for examples of exaggeration from the RealClimate team, the ones who write the original posts and moderators’ responses in green. The rest of us, who just comment here, are a mixed bag including fruits and nuts. And contrary to popular belief in some quarters, the moderators have a very light touch. Pouncing on some comment as proof of exaggeration by RealClimate is therefore beside the point. (For the record, I certainly don’t include Ray among the fruits and nuts, and I think the points he makes about assessing the risks of global warming are generally among the most valuable contributions in the comments section.)
Spot on: Speaking as the kind of amateur you mention, if it hadn’t been for this site I’d have worried a lot about all the methane hydrates going ‘poof’ and causing a Venus-style runaway greenhouse. Alexander Pope was spot on, too: “…But drinking largely sobers us again.”
BPL: What part of “drought is going to increase until harvests fail all over the globe” did you not understand?
“Reanalysis of Historical Climate Data for Key Atmospheric Features: Implications for Attribution of Causes of Observed Change
Final Report, Synthesis and Assessment Product 1.3 CCSP, 2008:It is unlikely that a systematic change
has occurred in either the frequency or
area coverage of severe drought over the
contiguous United States from the midtwentieth
century to the present.sh, *”
This study indicates that there is no trend towards that prediction in the United States. Thus all over the world may have to be refined somewhat.
Stevenc @173blockquote>We don’t even know the results of global warming will be catastrophic at all much less worse than such events as WW1 and WW2.
The pine bark beetle is spreading through British Columbia and into Alberta because for several years there has not been a winter cold enough to kill them off. It’s been estimated that this will cost BC alone more than 11,000 jobs. This is one of the more minor consequences but already global warming is having serious effects.
I have been attacked brutally on this site for that exact stance. I made the statement that 6C of warming was an exaggeration, and was lambasted for it. I believe that the expected warming will be closer to 1C than 3C, and have been called all sorts of names, and been accused of being ignorant in the climate sciences. Apparently, one higher prediction one makes for future temperature rises, the higher esteem in which they are held by the people here. But make a lower prediction, and you are branded a heretic.
[Response: Don't be ridiculous. Your confusion between a projection for 2100, and climate sensitivity is what attracted criticism. Along with the lack of any actual evidence for your supposed preference. If you are more careful in what you claim, and if you actually back up your claims with some actual evidence, you'll find people more willing to engage. - gavin]
Gavin, I know this is off topic but in our community we’ve been debating AGW in our local paper. I’m trying to find out exactly how governments and their scientists and how the research is finally settled.
The latest exchange that I’m to respond to: “For a good lesson on prejudice and unfounded reason look to the UN IPCC where science reports are approved line by line by hundreds of scientist and governments and in many cases, government scientist who found good reasons to include prejudice.
Like Murari Lal, the scientist in charge of the IPCC’s chapter on Asia, who knew that chapter contained unfounded scientific facts that were later traced to a scientist giving unfounded off the cuff estimates over the phone to an over-zealous reporter selling eco news some 10 years earlier.
Her explanation_ \We thought that if we can highlight it, it will impact policy makers and politicians and encourage them to take some concrete action.\
Well, give her a Noble prize or is it Oscar, devil knows if there’s a difference.
The IPCC comprises both scientists and more than 130 governments who approve IPCC reports line by line. That’s right, governments approve the science published. “
I’ve tried to find an article here that would give me the skinny on how the researcher, government and the IPPC get it all together with your search engine. If you or some poster could link me to the information and can make my reply. The only instance I know of governments approving the science was when the Bush administration had a undergrad journalism major editing the work of NASA phd’s on AGW.
Thank you for the responses concerning my question. Although it won’t change the editorial perspective of The Detroit News, I think it’s important to provide an intelligent response.
Sault Ste. Marie, MI
Comment by Roger Blanchard — 17 Oct 2010 @ 8:45 AM
Amazing! I was actually one of the few who backed up my claims with links. Very few people here post evidence for their statements. Here is a link entailing some of the uncertainties with climate sensitivity, and partially why some posted sensitivies do not match the observed data. http://www.princeton.edu/~lam/documents/RoyceLam.pdf
I apologize if people here have been confused by my posts, but to claim that I am confused is unfounded. If by being careful you imply that I should agree with others, that will not happen. If I disagree , I will say so, but I will do it in a cordial manner. Scientists often disagree, and can discuss their disagreements without rudeness.
[Response: The paper you link is not very coherent I'm afraid. They have not understood what the IPCC sensitivity range is actually based on (try reading Annan and Hargreaves (2006) for instance), they do not take into account that the 20th Century has multiple forcings - including aerosols - and they spend way too much time thinking that Douglass has anything valid to say about climate. Yet you think that an unpublished note is more convincing than all the work that really has been done on sensitivity. Curious. - gavin]
Stevenc, you’ve confused “posts” (the first thing in a thread, signed by one of the RC Contributors) with “comments” that follow the posts, that can be written by anyone.
Click the “About” tab at the top of the page, then click the list of Working Climate Scientists in the first line of text. See also the sidebar for science sources; sometimes guest scientists also author main posts.
“Denialism is the employment of rhetorical tactics to give the appearance of argument or legitimate debate, when in actuality there is none. These false arguments are used when one has few or no facts to support one’s viewpoint against a scientific consensus or against overwhelming evidence to the contrary. They are effective in distracting from actual useful debate using emotionally appealing, but ultimately empty and illogical assertions.
“Examples of common topics in which denialists employ their tactics include: Creationism/Intelligent Design, Global Warming denialism, Holocaust denial, HIV/AIDS denialism, 9/11 conspiracies, Tobacco Carcinogenecity denialism (the first organized corporate campaign), anti-vaccination/mercury autism denialism and anti-animal testing/animal rights extremist denialism. Denialism spans the ideological spectrum, and is about tactics rather than politics or partisanship…
“5 general tactics are used by denialists to sow confusion. They are conspiracy, selectivity (cherry-picking), fake experts, impossible expectations (also known as moving goalposts), and general fallacies of logic.”
– fake experts
– impossible expectations
– general fallacies of logic
I suspect that while some denialists do this consciously, others are just completely clueless and couldn’t reason their way out of a paper bag, which is why they get tangled up in this nonsense like flies in a spider’s web.
…and that’s fine. Nobody is going to mock you because of a belief. People believe all sorts of silly things. But the basis for your belief – now that is open to robust questioning. And in your case, your belief is based on nothing but hope.
Clinging to your belief despite the problems does not entitle you to criticise actual quantitative estimates based on the best available science because and only because they disagree with your belief.
That’s what makes you look silly. And if you think this is a “brutal attack”, then evidently you are completely unfamiliar with having to defend your ideas.
You need to stop mixing your own predictions in the same sentence with actual scientific estimates. They just don’t compare. I did give you the benefit of the doubt and I search back through your comments looking for any reliable source that you might have based your predictions on. I came up with nothing.
The sad thing is that you started off making such a reasonable point, that exaggerations are bad. It turns out that the only exaggeration is your gross underestimation of the projected warming under BAU scenarios.
First, allow me to clarify. The problem is not merely climate change. It is climate change, with its adverse affect on drought, extreme weather, crop yield, coastlines and infrastructure, occurring as global populaion peaks around 10 billion aroun 2050. There are many studies attesting to the reality and severity of all these threats.
I leave it as an exercise to you to add up the cost of all the real estate and infrastructure that will be lost to a sea level rise of 7 meters. Hint: Don’t forget Manhattan. Now compare that to the losses of the two world wars. Hell, compare it to the losses just on 9/11, which triggered an expediture of over a trillion dollars. And realize, Steve, that sea level rise is probably among the least of our worries.
Now from the way in which you throw out a single study with an incomplete reference to challenge certain aspects of these threats, I’m going to guess you ae not a scientist. I’m even going to guess lawyer, since your goal appears to be passing the straight-face test and duping the gullible.
As to the definition of a denialist, I think a good definition is one who refuses to acknowledge the current state of the evidence and its implications. Thus, suggesting that CO2 sensitivity is less than 2.1 degrees per doubling of CO2 would qualify one for that epithet at the 90% confidence level.
Dan H. said: “I was actually one of the few who backed up my claims with links. Is that a joke? The only links that I see in your previous posts are to perfectly reasonable assessments of temperature rise, which you then label as “exaggeration” based on nothing but your own opinion.
And when you do eventually provide a source for your projection, it comes from an unpublished paper by two retired mechanics professors. Yes, that’s credible. Well, more credible than your word alone, but if you can’t see that it doesn’t stack up well against the huge body of evidence from the IPCC, then I can understand that, too. I don’t believe you understood a single word of the link you provided. And, as such, how can you possibly judge it?
How can one make sensible interpretations of topics that one can’t understand? This is a serious question, and one that faces all of us very frequently. May I suggest that searching for the few outliers and claiming they are right in the face of the evidence is not a good strategy?
There is a serious lack of knowledge of intermediate processes linking solar activity and climate change. I think it may be the existence of physical process I named ‘North Atlantic precursor’ as plotted in: http://www.vukcevic.talktalk.net/CET-SSN-NAP.htm
All three sets of data are well known and widely available but is there a connection?
Accepted, correlation is no causation; to have correlation for two sets of unrelated data is not unusual, but to have correlation for three sets of unrelated data it just may be more than just coincidence.
Hank Roberts, thanks for the minutia but helpful info in #184. I never knew how to distinguish threads, posts, and comments. Is “sub thread” an accepted term for a lengthy OT discussion within a thread?
Dan H, you’re on a fool’s mission. For evidence you have to refer to a paper or text. When you do that you have to provide a paper published in a recognized scientific journal. If you do that you then need it published in a related subset of scientific journals. Then the paper would have to be written by a pedigreed author. Then the pedigreed author can’t be a loner but needs a few other supporting pedigreed scientists. Then, of course, not just any PhDs, but those who studied climatology. Don’t know what the next hurdle would be — I don’t recall seeing anything this far along. But rest assured you will never ever be able to provide acceptable supporting evidence for any questioning assertions, no matter how small!
[Response: You are trying to be funny, but actually you are making a good point. There is a tremendous amount of knowledge and expertise on all of these issues in the literature, and for every valid point, there is plenty of supporting evidence from multiple groups all around the world. And you are correct in stating that unpublished and factually dubiously 'papers' that someone finds on the internet are not going to match up to that or get much respect from scientists. But it does not follow that you someone won't be able to find supporting evidence for some assertion, it's just that you need to restrict yourself to assertions that have some basis in reality. It's not too much of burden really. - gavin]
“A denier is one who refuses to believe something when experts in the area in question have demonstrated that the preponderance of evidence supports it.”
So it all comes down to the evidence. But this is not very straight forward is it. How do you distill all the information, or cut away all the unnecessary assumptions?
[Response: What, you expect an answer to that in a sentence or two I suppose? Well here it is then: you study the subject intensely for years on end, making a career out if it, until you acquire the necessary analytical skills to do so, that's how.--Jim]
How about Occam’s razor? It is not necessary for trace greenhouse gases to sustain the water vapor. The heat content of the ocean (quite large) is more than adequate to sustain the water vapor.
[Response: Prove it.--Jim]
Thus, while the non-condensing greenhouse gases are important, these gases are unlikely to moderate our watery planet (the preponderance of evidence is sounding more like “I work at NASA so I’m right”).
PS for Dan H.– this is a good place to check assertions before copypasting: http://www.skepticalscience.com/contradictions.php
Good points have support from multiple sources; flaky ideas often contradict one another and yet you find sites promoting many of them simultaneously.
Rod @ 196: So-called “skeptics” of AGW theory demand nothing less from climate scientists (and most often that’s not even good enough for them), yet you complain and cry “foul” when it’s required of someone making an argument against AGW theory. What’s up with . . . sigh . . .
It is not necessary for trace greenhouse gases to sustain the water vapor. The heat content of the ocean (quite large) is more than adequate to sustain the water vapor.
The wind is the force that transports most all water vapor from surface water into air. Declining air pressure also speeds up the transport of water vapor into air.
Evaporation of water in still air is slow process. Set out pan of water in the kitchen and measure how long it takes to evaporate. Then refill the pan and the use a small fan to blow air across the surface of the water.
The time for evaporation will be greatly reduced.
Comment by Harol-radd Pierce Jr — 17 Oct 2010 @ 6:27 PM
Average Person @197 — Without CO2, temperature would plumet well below the freezing point of water. There goes the water vapor.
Comment by David B. Benson — 17 Oct 2010 @ 7:00 PM
Average Person, we have something in common. Neither of us has any idea what you are talking about!
You say, “the preponderance of evidence is sounding more like ‘I work at NASA so I’m right.’”
I’m sorry, too many big words? How about “the vast majority of the evidence”. Or how about just “the evidence”. The greenhouse effect raises Earth’s temperature by about 33 Kelvins. CO2 is responsible for about 7 of those degrees. We know this. We’ve known it for about a century. Yes water vapor is important. However, without CO2, we’d be living (or rather not living) on a ball of ice.
Average person @197. The quantity of heat in the ocean (except as far as it affects sea surface temperatures is not the issue). The issue with regards to the atmospheric concentration of water vapour is that it is a balance between two processes, the avaporation of water, and condensation -either as dew/frost or as precipitation. So while the non-condesable GHGes may only directly raise the average temperature by a litte bit, that small temperature rise alters the rates of both these processes in favor of more atmospheric water vapor. That is why we consider it to be a feedback, because it amplifies the effect of the noncondesable gases. Trying to argue in the rhetorical sense, that since water vapor does most of the heavy lifting warming wise, the others don’t matter is wrong scientifically. Unfortuantely there is no escape from having to make mathematical models, and then use mathematics to tell us the effects of various things. trying to avoid math, and modeling in favour of rhetorical argumentation is a horribly error prone process. Thats why math is pretty much the language of science.
“I was wondering if anyone could provide me with the definition of a denier.”
Someone who is in denial. Wikipedia has it spot on:
“Denial is a defense mechanism postulated by Sigmund Freud, in which a person is faced with a fact that is too uncomfortable to accept and rejects it instead, insisting that it is not true despite what may be overwhelming evidence.”
Describes the reaction to climate change perfectly.
David B. Benson says on 17 October 2010 at 7:00 PM:
“Average Person @197 — Without CO2, temperature would plumet well below the freezing point of water. There goes the water vapor”
That is absolute nonsense and just flat out wrong. In the tropics there is about 12 of light and 12 hours of darkness and at the equinoxes the sun is directly overhead. There is no way the tropics are going to freeze up.
[Response: The Lacis et al experiments (like similar results in Voigt and Marotzke (2009)), show that without CO2, water vapour decreases precipitously, and the global mean temperature goes well below freezing. Unfortunately, your determination that this is nonsense is not much of a rebuttal. How about some actual evidence? - gavin]
As the earth orbits the sun, one hemisphere heats ups for about six months while the other hemisphere cools down. At about the 50 deg latitude there are about 16 hrs of daylight in summer.
At 0 deg C there is 4.85 g or 269 millimoles of water vapor for 100% humidity but only 0.76 g or 17.4 millimoles of CO2 per cu meter. The OH2 to CO2 ratio is 15 to 1. To first approximation and all other things being equal, OH2 molecules absorb 94% of the IR light (i.e., the out-going long wavelenght IR).
At 30 deg C there is 30.4 g or 1,690 millimoles of water vapor for 100% humidity but only 0.61 g or 13.8 millimoles of CO2 per cu meter. There is less CO2 because air is about 20% less than dry air at STP. In this case, OH2 molecules would absorb about 99.2% of the IR light.
At -10 deg C there is 2.4 g or 133 millimoles of water vapor per cu meter for 100% humidity.
In a desert at 20 deg C and about 4% rel humidity there are equal amounts of OH2 and CO2 molecules.
Although humidity is quite variable through out atmosphere, water vapor will absorb most of the IR light most of the time.
Comment by Harol-radd Pierce Jr — 18 Oct 2010 @ 4:51 AM
CM, #164–Thanks for clarifying. I knew there was a drop–albeit one considerably exaggerrated in some respects–but find it hard to tell (looking at GHCN tables) what “counts” at which point. Is it really just as simple as who issued a report in which year, or is there a requirement for number of years reporting at a given point? Or is that in Vose & Peterson somewhere?
Also, presumably some of this data could be “brought in” still, as many of the stations are reporting to Environment Canada, but for some reason are not having the data forwarded to GHCN–yes? (You can view reports for them on Environment Canada’s website–mostly hourly temps are available.)
Are there any satellites (with sufficient resolution in light intensity) which have been trained consistently on astronomical objects with a reasonably high albedo (Jupiter or other planets, or asteroids) which could be used as a proxy for the intensity of solar light in the visible spectrum? That is, could the SORCE result (increase in visible light during a TSI low) be confirmed by comparing minor changes in intensity in images gathered for astronomical/planetary study purposes? If so, might it be possible to confirm or refute the SORCE results by using planetary images, and then to study those images for periods prior to SORCE becoming operational?
Or is there too much variability in planetary/asteroid albedo for that level of granularity? Or is there no such satellite to begin with (either appropriately sensitive to intensity, or with consistently measurable images in the desired time frames)?
What “experiments”? The results from climate model runs are just computational speculation and conjecture and do not count as valid experimental results.
What metric do you use for CO2 in climate model calculations? If it is ppmv, then your models and results are absolutely worthless. The metric that should be used is either mass per unit volume or millimoles per unit volume.
After analysis, the concentration for CO2 in a sample of local air is reported for purified dry air (PDA) which does not occur in the earth’s atmosphere and is comprised of nitrogen, oxygen, the inert gases, which are the fixed gases, and CO2, The composition of PDA (i.e., the relative amounts of the fixed gases) is fairly uniform through out the atmosphere and is idependent of location, elevation, pressure, temperature, and humidity except for minor local variations in particular with respect to CO2. This is the origin of the term “well-mixed atmospheric gases.”
For PDA at STP (i.e., 273.15 K and 1 atm. pressure), there are presently about 390 ml, 17.4 millimoles, 766 mg, or 0.000766 kg of CO2 in 1 cubic meter. The density of PDA at STP is 1.29 kg per cubic meter.
In real air there is no unifrom distributon of the masses of the consituents including water vapor and clouds in the atmosphere in space and time as is shown by daily weather maps of the various regions of the earth. High pressure cells have more mass of the gases than do low pressure cells, and thus there is no uniform distribution of CO2 in the atmosphere. Air containing water vapor is less dense than dry air and has less mass of fixed gases and CO2
Clouds are liquid water in the air, and the tiny droplets of water will contain the atmospheric gases, the amount of which will depend on local temperature and pressure. Since clouds move about they can transport CO2 in the liquid phase from location to location. Depending on local conditions, they can release into local air some on the gases or evaporate and release all the gases and water vapor. The clouds can also release rain drops which will carry the atmospheric gases to the earth’s surface.
The positive water feed back hypothesis is wishful thinking, i.e., speculation. The wind is the most important mechanism that transports water from the oceans,lakes, ponds, etc onto and into the land. Air pressure also influnces humidity. High pressure cell have dry hot or cold air whereas low pressure cells usually bring rain, snow, or ice pellets.
BTW, what is the geomerty of the atmosphere and the earth used in climate models calculations?
[Response: So let me get this straight, you think that your back of the envelope hand waving trumps a calculation made using a climate model? On the basis of what? If you can find a similar calculation (that takes account of the atmopsheric and ocean heat transports, the change in latent and sensible heat, the shifts in the radiative effect as the concentrations of various components decrease etc. and that gives a dramatically different answer, then we can compare. But simply to assert that the answer is unpalatable to you is no argument at all. And for your information, positive water vapour feedback is not 'wishful thinking' (I would much prefer that it was smaller than it is), but rather an experimentally and observationally determined fact. Read Dessler, Sherwood, Del Genio or Soden etc. etc.
You ask a couple of questions that make it clear that you are not very familiar with climate models (which is no problem), but perhaps you should investigate the answers before so forthrightly and unequivocally condemning them. FYI, climate models use spherical geometry and calculate radiative transfer using the appropriate concentration units. - gavin]
Comment by Harol-radd Pierce Jr — 18 Oct 2010 @ 9:29 AM
Harol-Radd Pierce Jr.
Read this article on the relative roles of the various greenhouse gases in the atmosphere. Also this PhysOrg article has a good writeup on the Schmidt et al 2010 JGR paper.
The clear take-home point is that while water vapor is the “most important” greenhouse gas in terms of amount of infrared absorption (which is closer to half of the absorbed IR than the 94% number you quoted), it is ultimately the trace molecules (CO2 primarily, which do not condense from an Earthlike atmosphere) that controls the supporting framework for the terrestrial greenhouse, and what governs its ability to change in time.
Finally, other feedbacks mean that the Earth’s climate would change enormously if you removed all of the CO2 from the atmosphere. First the water vapor feedback becomes relatively unimportant in the limit of the cold temperatures being considered, but what’s more, the albedo of the planet heightens considerably. In this GISS model, the global mean temperature drops on the order of 35 K by removing just CO2 from the atmosphere (much more than the no-feedback 7 K number quoted by Ray Ladbury). This means the greenhouse effect can account indirectly for even more than 33 K of warming and without it the planet is undoubtedly in a deep snowball. And CO2 provides the skeletal structure for this effect.
Harol-radd Pierce Jr (208), relative and absolute humidity charts assume a ubiquitous source of water to provide the vapor. I’m not sure what the source would be at -10C (let alone -34C). I think sublimation produces magnitudes less vapor than evaporation, though I don’t have the numbers and might be a bit off in scope. Where would your 2.4 g/cu.m. at -10C come from?
This guy copypastes under multiple names, if anyone’s trying to keep track of his seltzer-cloud theory, e.g.
Aug 27, 2010 … Since clouds move about they can transport CO2 in the liquid phase from location to location. Depending on local conditions, they can … http://www.drroyspencer.com/…/our-jgr-paper-on-feedbacks-is-published/
Sep 24, 2010 … Since clouds move about, they can transport CO2 in the liquid phase from location to location. Depending on local conditions, they can …
To Gavin and others – a question regarding CO2-mediated forcing in the absence of feedbacks. Specifically, how do models estimate the effect of a CO2 doubling to yield an estimated 1.2 C change, such as the one cited in the recent paper by Lacis et al?
In the 1981 Hansen et al Science paper (with Andy Lacis as a coauthor), the Earth’s effective emission temperature (255 K) is related to the surface temperature via a flux-weighted mean radiating altitude and a constant lapse rate. The constancy of the lapse rate requires that any calculated change at a specified altitude will be matched by the same change at the surface. Using the Stefan-Boltzmann equation, the calculated change for the generally accepted forcing of 3.7 W/m^2 (it was 3.8 in the Hansen paper) yields a temperature change of 1 C rather than the 1.2 C of the models.
In the Hansen et al paper, the above relationship was described as an approximation rather than an identity, and it seems clear that the models have used a different approach to the calculation of the no-feedback temperature change – one that may not rely on a single averaged “emission altitude” together with a fixed lapse rate applied to that altitude. My question is “in what way do the models depart from that simplified formulation?” Lapse rates are not identical in all parts of the globe, and I suppose an averaging in the 2x CO2 scenario could change the weighting so that the average lapse rate changes, but from my reading of how the results are calculated, that does not seem to be the explanation.
Are forcings for different spectral bands computed differently and then combined into a weighted average, each representing a different radiating altitude? What other variables contribute to the difference between the 1 deg C and the 1.2 deg C estimates for the 2x CO2 scenario? If lapse rate constancy is assumed, a 1.2 C difference at the surface implies a 1.2 C difference at every given altitude above that still follows the same lapse rate.
[Response: The no-feedback temperature change in a global model will of course be weighted by area and time and is not as simple as assuming S-B at the emission level. It will be different in the tropics and the poles and the weighting will vary as well. - gavin]
212 Chris remarked to the Radd dude that: “it is ultimately the trace molecules (CO2 primarily, which do not condense from an Earthlike atmosphere) ”
The Radd dude lives in an alternate reality in which CO2 is transported in the liquid phase at atmospheric pressure.
“Since clouds move about they can transport CO2 in the liquid phase from location to location. “
Comment by John E. Pearson — 18 Oct 2010 @ 12:20 PM
Re 211 Harol-radd Pierce Jr -
1. a molecule of one substance and a molecule of another substance cannot be expected to be equal
2. in sufficiently warm humid conditions, water vapor would absorb nearly 100 % of LW radiation from the surface, but still leave plenty of room for other greenhouse gases (and/or higher level clouds) to contribute to the greenhouse effect. How? Because the optical thickness of the water vapor is concentrated near the surface (more so than well-mixed gases), where it is at a similar temperature to the surface. The near-surface water vapor and low-level clouds can only reduce the OLR to a flux corresponding to such temperatures (in some conditions they can actually increase the OLR – nocturnal or other inversions). A significant amount of the opacity of well-mixed gases, and higher-level water vapor and clouds, sits ‘on top’ of the lower atmosphere, is found where temperatures are generally much colder, and thus can reduce the OLR more.
3. Yes, gases dissolve in water. The actual mass of water in clouds is quite small, and the amount of gas that can be carried in such form is very small (though I don’t know the exact numbers offhand- perhaps you could provide them? Note that the volume of condensede water is a very small fraction of the volume of air in a cloud.). There is a cummulative effect over many thousands of years whereby CO2 is removed from the atmosphere (tending to respond to climate so as to balance slow geologic emission – organic sequestration), though this isn’t simply because CO2 dissolves in rain – it is because that rain, with the slight acidity from that CO2 and sometimes some other things, can chemically weather exposed rock surfaces, washing ions such as Ca++ into the ocean, … (bunch of other stuff) … etc. (I don’t know the ratio of CO2 dissolved in rain to the CO2 actually sequestered from the atmosphere by the chemical weathering by that rain – suspect it’s quite a bit larger than 1 – but anyway, the point is that the processes that add and remove CO2 from the air (particularly photosynthesis and respiration/decomposition/combustion) can’t, except in some environments particularly near the surface (under a forest canopy, for example) generally keep up with the mixing of the air by atmospheric circulation to make much difference to the bulk of the atmosphere, so much as to be important to radiation (some variation is detectable and interesting but that doesn’t make it all-important).
4. Aside from water vapor and clouds, and temperature variations, the greenhouse effect would be reduced in low-pressure systems and increased in high pressure systems; however, lapse rates and cloud and water vapor also vary. The variability of surface pressure on a horizontal surface is generally quite small relative to the total; of course the variability due to topography is important, hence higher elevations would (for the same albedo) tend to be cooler even without mixing, and can, like places with dry air and clear skies, have larger diurnal temperature ranges. Radiation can significantly alter temperature near the surface over land over short time periods, but otherwise the effects of radiation on global climate are more important via cummulative effects over longer time periods.
5. Water vapor is transported by atmospheric flow. It is removed by condensation and added by evaporation. Temperature affects those last two in a direct way.
The idea that clouds can transport CO2 in the liquid phase appears to be believed by one person. Sorry Mr. Pierce, but even Roy Spencer rejected that idea. The idea that gases such as CO2 are not evenly distributed in the atmosphere, similar to water vapor, is also not readily accepted (apart from source releases, the gases mix in relatively short time frames, otherwise we would be blanket on the surface with the heavier gases and suffocate).
Removing all the CO2 from the atmosphere, besides being impossible, would yield calculated results which have no meaning (similar to dividing by zero). The interactions cannot simply be removed for calculation purposes. Hence, certain assumptions are made regarding temperatures, OLR, lapse rates, etc. These values are not perfect, and uncertainties in these calculations become multiplied when feedbacks are included.
That editorial – “With one exception, none of the Republicans running for the Senate… accept the scientific consensus that humans are largely responsible for global warming.”
Back on topic, what I don’t understand is why this paper is seen as so significant vs global warming. If anything, it seems to me as a total amateur that even if confirmed, if anything it further reduces the already relatively small effect of the solar cycle and makes it even less likely to be the sun wot did it. Have I misunderstood something ?
Harol-radd Pierce Jr initiated quite an interesting exchange, with Gavin and Chris Colose providing useful links.
In this series of comments, I first want to mention that CUP will soon publish Ray Pierrehumbert’s \Principles of Plantetary CLimates\. For this small matter and for many others, perhaps larger issues, I encourage you to pre-order (or request a nearby lending library to pre-order [I have]) a copy or several to lend out yourselves.
The second thing is that at least once in the remore past, Terra did freeze over, or nearly completely so (the geologists argue this small point): http://en.wikipedia.org/wiki/Snowball_Earth
and then this leads make to Professor Pierrehumbert’s book, but I won’t give away the answer.
Comment by David B. Benson — 18 Oct 2010 @ 4:34 PM
The only surprise for me was the narrow band of above freezing temperatures directly along the equator. Standard pen&paper approximations don’t find that effect. Perhaps it goes away after a millenium or two?
Comment by David B. Benson — 18 Oct 2010 @ 5:18 PM
203, Ray Ladbury: The greenhouse effect raises Earth’s temperature by about 33 Kelvins. CO2 is responsible for about 7 of those degrees. We know this. We’ve known it for about a century. Yes water vapor is important. However, without CO2, we’d be living (or rather not living) on a ball of ice.
What would be the distribution of temperature without CO2? Would there be no seasons (temporal distribution generally)? Would the equatorial regions be as frozen as the Andes (geographic distribution generally)?
Nice, you don’t allow me to respond to comments directed at me but you allow comments that are directed at me. That is low and doing so shows your level of integrity. I disagreed with you before but respected you. Feel free to scratch the last part of that now.
Horold and others:
You can actually measure return IR radiation pretty easily. I have one of those infrared thermoters, mine cost $100, but you can find some models at half to a quarter of that cost. They have a cone of sensitivity of a few degrees (narrow field of view costs more). So you can point them up at the sky and measure the effective temperature of the sky. If you do it you will discover some things, dry clear skies are cooler than dry (humid skies). Clouds warm things significantly. You can use Stephan-Boltzman to estimate downgoing (and upgoing) IR fluxes, etc.
Figure 2: … Quicktime movie (10.3 MB) of a Varanger simulation which combines reduced solar luminosity, 40 ppm CO2, and reduced ocean heat transport. The simulation runs 60 model years from initial, non-snowball conditions until an equilibrium result is obtained.
HP, that less water evaporates in colder air is an observed fact, AND one theoretically explained by statistical mechanics and physical chemistry, AND one mathematically described by the Clausius-Clapeyron relation. If the Earth gets cold enough, water vapor drops precipitously and the tropics freeze along with everything else. There is good geological evidence that it has already happened at least three times (the Huronian, Vendian, and Sturtian glaciations). Google “Snowball Earth.”
[off-topic] Re: GHCN station numbers / Canada / Detroit News story,
correction to my #164: With duplicate time series removed, I get 496 Canadian stations in 1989, rather than 623, and a somewhat less sharp drop, since the other numbers I gave are not affected.
Kevin McKinney #209,
- Uh, for each year, I’m just counting the number of lines in the v2.mean dataset with Canadian station data for that year, and (after slapping forehead) eliminating duplicates (where there’s more than one line with the same station and same year). Was that clear? For the whole v2.mean dataset, I find I can very closely replicate the Peterson & Vose 1997 [PV97] graph, so I just may have chanced on the same method. (Don’t speak Fortran, so haven’t used the tools provided with GHCN.)
- The GHCN v2 dataset already includes stations with at least 10 years of data, PV97 say.
- It is my understanding that only a limited subset of stations are being updated automatically in real time (see PV97, “Updates”), and the retro-active filling-in of more station records takes place irregularly, as and if someone takes the trouble. But a GHCN v3 is now in beta, and it looks like that’s where the action is these days (see Zeke Hausfather’s sneak peak, including yet another look at how little the global mean temp record is affected by these ups and downs).
Kevin, I do count you among the interesting! And thanks a lot, but I’m an amateur, learning as I go, so take my stuff with a pinch of salt. When something looks like it can be done in 20 lines of Perl, I just get this urge to try. Oh, and I meant “peek”, not “peak”.
You are so right! Just using common sense (and, of course, fizzix), I’d computorionally guesstimate that the maximum, worst case swing for the earth’s surface temperature is at most 3%, maybe 4%! That’s a small number, right?
Let’s see, earth’s surface, 281K, times 4% divided by 100 = 11.24˚C maximum warming, which is hair more than 20˚ F.
Apologies to all. In my haste, I apparently mis-spelled “computortionally”.
[These are just the sort of errors that come back to haunt the well-meaning researcher, scientist or just plain smarter-than-everyone-else-because-I-said-so-and-anyway-who-the-heck-are-you-to-question-me sort of person.]
Jacon Mack said: “there are great limits to how mcuh the globe can warm”
What, then, is the upper limit?
We can’t use temperatures from millions of years ago, because the sun is hotter now. How can we place an upper limit?
If we suppose that we release all the stored carbon (from fossil fuels, ice, tundra, clathrates, etc) so that the atmosphere returns to a state not seen for many millions of years – and add in the effects of a hotter sun – I can’t see any hypothetical “upper limit” being particularly beneficial for humanity.
240: Jacob Mack said: “there are great limits to how mcuh the globe can warm based again on simple physics.”
Nonsense. Let’s hear your simple physics that limits warming to less than, say, 20C.
Comment by John E. Pearson — 21 Oct 2010 @ 8:13 AM
“there are great limits to how mcuh the globe can warm based again on simple physics.”
Well, there is always thermodynamics. That says we can’t get the planet any hotterthan the surface of the sun. Although that’s hardly a useful constraint on our models.
Also, the fact that no fossil remains of humans were discovered from the eocene period. Clearly that is proof that humans couldn’t live in such a warm climate ;-)
Comment by Paul van Egmond — 21 Oct 2010 @ 4:23 PM
250 (Paul van Egmond),
If I may, I don’t believe that any human fossils have ever been found that are younger than 30,000 years old. This suggests to me that humans are in fact already extinct, quite probably because they were unable to adapt to the current climate.
Thanks for your response.
I’m sorry for my mistake.
I think this article (Atmospheric CO2: Principal Control Knob Governing Earth’s Temperature
Andrew A. Lacis,* Gavin A. Schmidt, David Rind, Reto A. Ruedy)
is fascinating and deserves perhaps a RealClimate article (it is only a suggestion).
I’m still amazed by this sudden expansion of coverage of low clouds when the temperature has only fallen slightly.
This would show a nonlinearity of cloud feedback.
Do you think that there is symmetry of this phenomenon if we increase sharply the amount of CO2?
[Response: The change from 1xCO2 to 0 is a much bigger deal than 1xCO2 to 2xCO2, and so linear assumptions about the response are not really valid - for instance, the climate sensitivity for removing all GHGs is at least 1 C/(W/m2) (and may be higher) which is significantly larger than the sensitivity for 2xCO2 in the same model 0.68 C/(W/m2). - gavin]
I think that if you measure IR radiation as described, you will trick yourself into believing that the atmosphere is already saturated with CO2.
The key fact is that there is secondary radiation due to warmed air that gets warmed by absorbing IR radiation. That is a cooling mechanism that continues to get made less effective, long after the direct path is fully saturated.