There’s nothing really new in this paper, which is a review partly written in response to the controversial Wag TV documentary ‘The Great Global Warming Swindle.’ Not good news from the point of view of being objective, and I doubt that it’s a coincidence that the paper has found it’s way into the same journal that published Svensmark’s cosmic ray-cloud experiment. The Royal Society are very excited too: ‘Global warming: A Proceedings A paper shows that the Sun is not a factor in recent climate change!’
The Abstract states:
“There is considerable evidence for solar influence on the Earth’s pre-industrial climate and the Sun may well have been a factor in post-industrial climate change in the first half of the last century. Here we show that over the past 20 years, all the trends in the Sun that could have had an influence on the Earth’s climate have been in the opposite direction to that required to explain the observed rise in global mean temperatures.”
An extract from the paper says:
“…it is possible that the decline seen since 1985 marks the beginning of the end of the recent grand maximum in solar activity and the cosmogenic isotope record suggests that even if the present decline is interrupted in the near future, mean values will decline over the next century. This would reduce the solar forcing of climate, but to what extent this might counteract the effect of anthropogenic warming, if at all, is certainly not yet known.”
The paper concludes:
“There are many interesting palaeoclimate studies that suggest that solar variability had an influence on pre-industrial climate. There are also some detection–attribution studies using global climate models that suggest there was a detectable influence of solar variability in the first half of the twentieth century and that the solar radiative forcing variations were amplified by some mechanism that is, as yet, unknown. However, these findings are not relevant to any debates about modern climate change. Our results show that the observed rapid rise in global mean temperatures seen after 1985 cannot be ascribed to solar variability, whichever of the mechanisms is invoked and no matter how much the solar variation is amplified.”
L&F are therefore supportive of a past and relatively recent solar influence on climate, with an ‘unknown’ amplification mechanism. Furthermore, they acknowledge that the ‘grand maximum’ of solar activity seems to be coming to an end, which raises the possibility of global cooling, long predicted by the likes of Fairbridge and Shirley (1987).
Let’s take a look at some of the contentious points relating to L&F and TGGWS :
1. Solar cycle length v temperature
The use of the 1991 Friis-Christensen and Lassen graph of solar cycle length plotted against mean surface temperature attracted much criticism because the correlation diverged after the paper was published. The graph was lifted directly from F-C & L in order to demonstrate a solar link to climate.
The sunspot cycle length data finishes after 1980 – at least 1985 – the graph just looks like it finished in 1980 because the dots are plotted in the centre of the cycle.
Additionally, cosmic ray data goes back to the 1950’s, so Lockwood is the one ignoring data that doesn’t suit him by starting the graphs at 1975 which we know was a turning point in temperature.
2. Smoothing and sunspot cycle length
When Lockwood smoothes his graph to expose the long-term trends, he basically averages the readings over the length of one sunspot cycle. Like F-C & L, he plots the result in the MIDDLE of the data range. So each point on his graph is a combination of the previous 5 years’ data with the 5 years in the FUTURE. This is the same as the FC& L graph, but Lockwood uses it to make it look like the solar activity started to fall away long before it actually did.
3. The data itself
There are several different sets of data used:
a. Total solar irradiance TSI – amount of energy arriving from sun – correlated with sunspot cycle.
(There has been some debate about the preference for Frohlich’s own PMOD data set over the ACRIM data, and the adjustment to the Lean TSI reconstruction data 2 months before the publication of the L & F paper, but I don’t intend to dwell on that here!)
b. Number of sunspots observed – averaged over a month
c Length of sunspot cycle (varies 9-11.5 years)
d Direct measurements of cosmic rays – cosmic rays are lower when sunspots higher because the solar magnetic field blocks them.
(N.B. The Berrylium10 proxy for cosmic ray flux is formed by 1 GeV cosmic rays, whereas it is 10 GeV cosmic rays that are of interest and responsible for atmospheric ionisation. Ion chambers are sensitive to very high cosmic ray energies of 10’s of GeV.)
Comparing Lockwood’s paper with Lassen’s, the main difference is that Lassen’s stops in the late 1980s whereas Lockwood’s includes one more sunspot cycle peaking in 2001.
The sunspot cycle peaks grow higher through the 1970, 1980 and 1990 peaks, which are all very large in the context of the last 150 years, and 2001 is considerably lower.
Equally, the minima in cosmic ray flux (measured at the edge of space by Lockwood) get deeper up to 1990, but the 2001 one is shallower again – about the same as 1980.
So any divergence between the solar record and the temperature record only begins in the last ten years or so, even failing to allow for the “middle of cycle plot” – not in the last 20 like Lockwood says.
L & F says that “Earth’s surface air temperature does not respond to the (11 year) solar cycle…..(due to)…long thermal time constants associated with……the oceans”
In other words, 10 years is far too short a time to show any effect from long-term solar changes. Interestingly, the temperature graph seems to level off around 2003 – as you would expect if there were a lag.
However, a new GRL paper by Camp and Tung, published 18th July 2007, claims that: “By projecting surface temperature data (1959–2004) onto the spatial structure obtained objectively from the composite mean difference between solar max and solar min years, we obtain a global warming signal of almost 0.2°K attributable to the 11-year solar cycle. The statistical significance of such a globally coherent solar response at the surface is established for the first time.”
Summary:
The ‘science’ is far from ‘settled.’
Solar activity is higher than it has been for at least 1000 years.
IPCC AR4 rates the ‘level of scientific understanding’ of ‘solar irradiance’ as ‘low,’ other solar factors have a LOSU of ‘very low.’ The emphasis is always on irradiance rather than eruptivity, which I believe is much more important.
Small solar changes seem to have a much larger influence on climate than expected, suggesting an unknown amplification mechanism.
Global mean surface temperatures have levelled off since the 1998 El Nino, and there has been little or no ocean warming for the past 5 years according to the ARGO network.
Solar cycle length, sunspots, irradiance, are general indicators of solar activity. Nir Shaviv sees no reason why the length of the solar cycle should be related to solar activity – it could be a coincidence, and it is largely a phenomenon of the Northern Hemisphere. That said, the correlation between solar cycle length and a long mean surface temperature series has also been observed at Armagh Observatory in Northern Ireland.
There is also an interesting paper from 2005, by Hengyi Weng entitled ‘The influence of the 11 yr solar cycle on the interannual-centennial climate variability.’ There is also a summary here entitled ‘Influence of the 11-year solar cycle more significant than previously thought.’
The full paper is here:
http://tinyurl.com/94dtf
Any hypothesis involving correlations between 2 variables out of many is likely to diverge at some point. The attempted 20th century correlation of CO2 and temperature diverged from the 1940’s to 1970’s, yet the hypothesis wasn’t abandoned. Instead cooling due to sulphate aerosols was touted as an explanation. A cue for another blog post perhaps!
Paul Biggs
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
“Any hypothesis involving correlations between 2 variables out of many is likely to diverge at some point.”
This is such a specious statement. Correlations between two variables can diverge for serveal reasons, depending on what type of divergence is occurring. If the relationship is non-linear, then the divergence is maybe just a result of that relationship and entirely explainable. If the divergence is from a linear relationship then it may be due to noise, or more broadly, some other independent or partially dependent variable. Or maybe it infers, actually, that the variables have little association.
This does not infer that ‘all relationships should diverge’- it infers that if they do diverge, you should have an explanation if you would like to reject the null hypothesis that they are unrelated.
“The attempted 20th century correlation of CO2 and temperature diverged from the 1940’s to 1970’s, yet the hypothesis wasn’t abandoned. Instead cooling due to sulphate aerosols was touted as an explanation.”
This result wasn’t ‘touted’ by anyone, it was shown in repeated modelling experiments that sought to attribute global climate change to multiple forcing factors- and attempted to partition the forcing accordingly. These simulations showed that if you forced the climate with all the significant forcing factors of the 20th century, you quite accurately reproduced the spatio-temporal characteristics of the observed record.
Note the use of the term spatio-temporal climate indicator. Paul’s post infers that the attribution of 20th century climate change is done using global mean temperature alone. It is not, this is deliberately misleading. The attribution is done using optimal fingerprints of climate change- key spatial patterns that capture the telltale space and time characteristics of the forcing response. This is many, many more degrees of freedom than a paired correlation. Several spacial indices are also used- all additional lines of evidence.
These studies- there have been numerous for both global and regional climate- consistently show that greenhouse gases are the main driver of twentieth century climate change- with contributions from an absence of volcanic forcing and from solar forcing. No study, using fingerprints or otherwise, has shown that solar changes can explain late 20th century climate change. Several signatures that are explainable are- more rapidly warming night-time temperatures, more rapidly warming winters, greater warming at the poles, and cooling in the stratosphere. None of these changes correlate with solar either- but they do with CO2.
Not only does Paul fail to provide good evidence that the Sun is correlated with global temperature- he has no other theory on what is causing other significant changes in climate which must be occurring- since two pairs are in his words ‘likely to diverge’. And on the basis of this flimsy half-baked analysis, he is willing to dismiss GHGs. Astounding.
Space – the aerosol explanation for 1940’s to 1970’s cooling doesn’t stand up to scritiny. Live in a computer modelled world if you want to.
IPCC Fourth Assessment Report Second Draft chapter 2, page 30, says:
However, over the same period SO2 emissions have been increasing significantly from Asia which is estimated to currently emit 17TgSyr-1 (Streets et al., 2003) and from developing countries (e.g., Boucher and Pham, 2002). The net result of these combined regional reductions and increases leads to uncertainty in whether the global SO2 has increased or decreased since the 1980s (Lefohn et al., 1999; Van Aardenne et al., 2001; Boucher and Pham, 2002),
The above was changed for the final report, but on 18th July 2007 we have a new paper:
Manktelow, P. T.; Mann, G. W.; Carslaw, K. S.; Spracklen, D. V.; Chipperfield, M. P.
Regional and global trends in sulfate aerosol since the 1980s
Geophys. Res. Lett., Vol. 34, No. 14, L14803
10.1029/2006GL028668
In the last two decades anthropogenic SO2 emissions have decreased across Europe and North America but have increased across Asia. Long-term surface observations suggest that atmospheric sulfate concentrations have followed trends in sulfur emissions more closely across Asia, than across the USA and Europe. We use a global model of chemistry and aerosol to understand changes in the regional sulfur budget between 1985 and 2000. For every 1% decrease in SO2 emissions over Europe and the USA the modelled sulfate column burden decreased by 0.65%, while over Asia a 1% increase in SO2 resulted in a 0.88% increase in sulfate. The different responses can be explained by the availability of oxidant in cloud. We find that because emissions have moved southward to latitudes where in-cloud oxidation is less oxidant limited, the 12% reduction in global SO2 emissions between 1985 and 2000 caused only a 3% decrease in global sulfate.
I suggest you also read my subsequent post about aerosols:
http://www.jennifermarohasy.com/blog/archives/002199.html
I haven’t discussed GHG’s here – the post is about a paper that claims to provide evidence for solar influence on climate up to about 20 years ago, and wonders what will happen to climate as a result of a near future fall in solar activity.
Space.
As matter of interest, can you point me to the particular evidence that you are using to support.
1.More rapidly warming night time temperatures.
2.More rapidly warming winters.
3.Greater warming at the poles
4.Cooling in the stratosphere.
In the case of 1 & 2, is the evidence in both hemispheres and across multiple continents.
Perhaps I am less well informed than some other people on this thread, but it seems that sulphate aerosols are advanced to explain the negative correlation between temperature and CO2 between 1940s and 1970s?? (ie increasing aerosols outweighting increasing CO2 over this period).
But aerosols can hardly have decreased since the 1970s given the rise in GDP, industrial production and fossil fuel consumption (which has accelerated over the recent PRC boom). Aerosols may well have significantly decreased in Europe & North America but have dramatically risen in Asia.
Also can anyone point me to some credible account of why aerosols lower temperatures? Since smog is basically a brown haze, I am intuitively surprised that it reflects sunlight back into space
Paul does not have to “provide good evidence that the Sun is correlated with global temperature”, Lockwood and Frohlich do.
From their abstract; “there is considerable evidence for solar influence on the Earth’s pre-industrial climate and the Sun may well have been a factor in post-industrial climate change in the first half of the last century”
Bill, you gotta lot of reading to do, suggest you start with the 3rd assessment report- if this thread is still going on Monday- I’ll post you some references.
Malcolm- I’m not at work, so a screen dump from google scholar will have to do
There are many papers I have missed, can always look through the references of the review papers.
Hegerl, G.C., T.R. Karl, M. Allen, N.L. Bindoff, N. Gillett, D. Karoly, X. Zhang, F.W. Zwiers, 2006: Climate change detection and attribution: beyond mean temperature signals. Journal of Climate, 19, 5058-5077.
Estimation of natural and anthropogenic contributions to 20th century temperature change –
SFB Tett, GS Jones, PA Stott, DC Hill, JFB … – J. Geophys. Res, 2002 – metoffice.com
… to 20 th Century Temperature Change S IMON FB T ETT , G ARETH S. J ONES , P ETER
A. S TOTT , D AVID C. H ILL † , J OHN FB M ITCHELL , M YLES R. A LLEN †‡ , W ILLIAM
J. I NGRAM , … [1999]; Hegerl et al. [2000b]; Stott et al. …
Probable causes of late twentieth century tropospheric temperature trends – all 3 versions »
… Tett, MR Allen, DE Parker, PA Stott, GS Jones, TJ … – Climate Dynamics, 2003 – Springer
Abstract We assess the most probable causes of late twentieth century
(1960–1994) tropospheric temperature changes. Optimal detection techniques are
used to compare observed spatio-temporal patterns of near- surface and …
Detection of human influence on sea-level pressure. – all 6 versions »
NP Gillett, FW Zwiers, AJ Weaver, PA Stott – Nature, 2003 – ncbi.nlm.nih.gov
Greenhouse gases and tropospheric sulphate aerosols–the main human influences
on climate–have been shown to have had a detectable effect on surface air
temperature, the temperature of the free troposphere and stratosphere and …
Cited by 50 – Related Articles – Web Search – BL Direct
Attribution of regional-scale temperature changes to anthropogenic and natural causes -\
PA Stott – Geophys. Res. Lett, 2003 – geog.ox.ac.uk
Peter A. Stott Met Office, Hadley Centre for Climate Prediction and Research,
Bracknell, Berkshire, UK Received 13 March 2003; revised 2 June 2003; accepted 5
June 2003; published 16 July 2003. [ 1 ] The causes of twentieth century …
Cited by 47 – Related Articles – View as HTML – Web Search – BL Direct
Detecting and attributing external influences on the climate system: A review of recent advances – all 4 versions »
… P Jones, B Santer, R Schnur, P Stott, K Taylor, S … – Journal of Climate, 2005 – llnl.gov
Simple indices of global climate variability and change Part II: attribution of climate change … – all 6 versions »
K Braganza, DJ Karoly, AC Hirst, P Stott, RJ … – Climate Dynamics, 2004 – Springer
Abstract Five simple indices of surface temperature are used to investigate the
influence of anthropogenic and natural (solar irradiance and volcanic aerosol)
forcing on observed climate change during the twentieth cen- tury. These …
Cited by 8 – Related Articles – Web Search – BL Direct
Detection of a Human Influence on North American Climate – all 7 versions »
DJ Karoly, K Braganza, PA Stott, JM Arblaster, GA … – 2003 – sciencemag.org
Several indices of large-scale patterns of surface temperature variation were
used to investigate climate change in North America over the 20th century. The
observed variability of these indices was simulated well by a number of …
Cited by 28 – Related Articles – Web Search
Simple indices of global climate variability and change: Part I-variability and correlation … – all 10 versions »
K Braganza, D Karoly, A Hirst, M Mann, P Stott, R … – Climate Dynamics, 2003 – Springer
Abstract Some simple indices are used to describe global climate variability in
observational data and climate model simulations. The indices are surface
temperature based and include the global-mean, the land–ocean contrast, …
Cited by 17 – Related Articles – Web Search – BL Direct
Diurnal temperature range as an index of global climate change during the twentieth century – all 8 versions »
K Braganza, DJ Karoly, JM Arblaster – Geophysical Research Letters, 2004 – nersc.no
JM Arblaster National Center for Atmospheric Research (NCAR), Boulder, Colorado,
USA Received 15 March 2004; revised 12 May 2004; accepted 7 June 2004; published
13 July 2004. [ 1 ] The usefulness of global-average diurnal temperature …
Cited by 9 – Related Articles – View as HTML – Web Search – BL Direct
Zhang, X., F.W. Zwiers and P.A. Stott, 2006: Multi-model multi-signal climate change detection at regional scale. Journal of Climate, 19, 4294-4307.
Paul Biggs, what sort of scrutiny are you talking about? Your mental arithmetic that partitions the relative forcing? don’t see any quantification in your analysis. None. You haven’t estimated the relative size of the radiative forcing mechanisms or their contribution to a quantity like global mean temperature. Speaking of which, why don’t you also use the spatial fingerprints to assess the relative contributions like real studies do?
You can’t discount paired correlation for global mean temperature and then use flimsy paired correlation as proof of something else. How about follow up the different lines of evidence presented in the short reading list I have provided?
Rather than speak of ‘ups and downs’ do some math.
And I’m sorry you choose to dis the models so flippantly as a last resort. I am happy to use numerical models- just as you are happy to conduct an uncontrolled experiment on the actual climate system. What do you suggest, build another Earth replica to test atmospheric chemistry? You need a model dude. Against the models you have what? Nothing. Zip. Just spurious hand waving arguments that are basically unfit for publishing anywhere but a blog. Do some reading. Science is about being a sceptic- Be a real one.
“Paul does not have to “provide good evidence that the Sun is correlated with global temperature”, Lockwood and Frohlich do.
From their abstract; “there is considerable evidence for solar influence on the Earth’s pre-industrial climate and the Sun may well have been a factor in post-industrial climate change in the first half of the last century”
Again, no one is disputing the Sun is a radiative forcing mechanism- but how strong is it? What is the strength relative to CO2 forcing? We need some numbers like in the literature not hand waving. The sun might explain some aspects of late 20th C climate, but why does it diverge from global mean temperature so much. Because divergences are ‘likely’ is no where near a sufficient argument by Paul. If you think you can attribute the warming to the Sun when it doesn’t match temperature, or spatial fingerprints- then there is no use being reasonable with you- bizarre.
Oh- I should add, the partitioning of forcing and contribution to climate change can be found in the literature I’ve posted. Quantified, with uncertainties- didn’t here any of YOU guys talking about your uncertainty….
If I get a stupid question that indicates you haven’t even bothered to read the literature- I’ll just leave it.
Space – you don’t seem to have read all of my blog post or my subsequent comment.
A paper here from Lockwood et al:
http://adsabs.harvard.edu/abs/2003EAEJA….14600C
Are models underestimating the effect of solar forcing on climate?
There are a range of ways forcing mechanisms can be under or over estimated. These are the very things you have to factor in when quantifying. Some of the uncertainty lies in the linear decomposition, Some in other estimates. These things are considered if you read the papers. You are still hand waving. You are also selectively isolating the solar signal uncertainty.
Read the papers- they do not hide the sources of forcing uncertainty. It doesn’t affect the very strong attribution to CO2. And the paper you have posted is written by optimal fingerprinters themselves.
Based on the magnitude of solar forcing, you would need to magnify it by a few orders of magnitude to capture observed warming. Possible, but much less likely compared to the very close match to CO2 in magnitude and time evolution.
And none of the magnitude uncertainties have anything to do with the pattern of the response, which is very unsolar and very CO2. You have NEVER addressed this.
The balance of the evidence shows CO2 to be the most likely cause- and shows very strongly that it is radiatively powerful. The authors of the paper you have posted all have studies, some in the previous post- that conclude the balance of evidence shows CO2 to be the most likely cause.
If you had evidence this strong against a drug, it wouldn’t be on the market. Period. You can tell the scientists that they don’t know what they are talking about, but you are no different from someone that concludes vaccinations are unsafe for their children.
What you are trying to do is disprove that CO2 is important to warming, since a whole bunch of evidence shows it is- and you haven’t done that at all.
And you know you need a model.
This argument is now becoming circular, because you are unfamiliar with the literature and haven’t understood what it concludes.
PS- what IS your theory for the pattern responses- DTR, vertical temp etc. NOT being consistent with solar forcing? Seems a serious oversite for someone concerned with uncertainties.
Space – we are looking at L&F’s methodology for reducing the solar influence to zero for the past 20 years.
Why do the IPCC have a ‘low’ and ‘very low’ LOSU for solar factors in IPCC AR4 SPM – is it a misprint?
This new paper is interesting:
http://www.sciencedaily.com/releases/2007/08/070801175711.htm
‘The authors show that this mechanism explains all global temperature tendency changes and El Nino variability in the 20th century.’
Shouldn’t ask questions like that Paul:
Solar irradiance B 3 Low
CERTAINTIES: Measurements over last 25 years; proxy indicators of solar activity
UNCERTAINTIES Relationship between proxy data and total solar irradiance; indirect ozone effects
BASIS OF RF RANGE Range from available reconstructions of solar irradiance and their qualitative assessment.
On that paper – now you’re getting a bit more interesting. I said 12 months ago here why wouldn’t a serious contrarian run an oceanic angle?
But it’s a bit all over the shop isn’t it. Seems like – “it could be this” – “or this” – “or what about this?” “OK OK – how about this?”
We wouldn’t want to present scientific uncertainty as certainty, would we? IPCC solar LOSU, Lockwood’s smoothing, the Lockwood ‘lag?’
The climate system could be poised for a period of cooling – the Sun’s polar fields are the most stunted they have been since records began in the 1950’s, solar activity heading for a crash, warming stalled. Even Lockwood ponders an impending fall in solar activity without knowing what effect that will have.
Hansen bangs on about heat stored in the oceans from 0.2 wm-2 – there’s easily the equivalent 0.8 wm-2 from solar which is enough to have driven 20th century warmth.
The flaw in the sulfate aerosols theory is that the temperatures made a series of abrupt changes inthe 1940s while the supply of sulfates did no such thing. It has rightly been pointed out that while US/euro sulfate emissions dropped, the rest of the worlds emissions increased. But it is also a fact of history that these emissions did not suddenly appear in volumes sufficient to alter temperatures. There was a gradual increase, and this gradual increase is not matched by a more gradual change in atmospheric temperatures.
Well the IPCC they haven’t have they. You asked the question which they had already answered. So why pose it.
If the solar output reduces you will get the relevant amount of cooling. CO2 is only a radiation recycler not a primary driver.
However none of this does anything about loyalty to the CO2 physics. Paul if we assume you are correct on a receding solar output then when solar warming returns then the CO2 amplification will be back with a vengeance.
On aerosols – well no – not really – the combination of modelling all forcings based on the data sets we have (as we have discussed before) – seems to track the 20th century’s temperature pattern quite well.
Luke
IF there is a cooling attributable to the sun – well wouldn’t that show that CO2 is a non event?
As I understand, a doubling of CO2 causes only about 1 degree of warming, so “CO2 amplification coming back with a vengeance” is scaremongering given that we will be starting from a higher base.
cheers
Arnost
Nope – as you should know by now my response will be – total forcing = solar + greenhouse – aerosols – volcanism +/- various albedo changes
Total forcing depends what the sum total is.
If the planet was dark CO2 wouldn’t warm anything up by itself – it simply recycles some of the surface emitted radiation.
You need to start thinking about systems and combined factors. No need to be an exclusivist.
And assuming the Medieval Optimum was solar in origin then with the current amount of CO2 it would be that much warmer again if it was the current day.
I would have thought that many AGWers would give you 3C for climate sensitivity (2x CO2. There’s obviously a range. Dana Royer’s paleo work gives at least 1.5 and a best fit at 2.9C. http://droyer.web.wesleyan.edu/climate_sensitivity.pdf
“Dark” meaning nowhere near a star/sun.
Luke gives us, “total forcing = solar + greenhouse – aerosols – volcanism +/- various albedo changes”.
But he conveniently fails to mention that most of the climate spivs are fixated on “major” albedo changes in the Arctic winter, that may amount to 0.2W/m2, while “minor” albedo changes in the tropical summer, that can amount to 7+W/m2, are dismissed as externalities. In fact, the mere mention of such inconsistencies on the part of his boorish broederbond is usually enough to trigger a barf of sneer and insult.
“on “major” albedo changes in the Arctic winter” – we are – reference pls !
Mean Grott likes to fantasise heavily. Normally we’re just sitting still while a torrent of expletives and abuse predictably flows forth again from every press report on every paper he hasn’t read. zzzzzzzzzzzzzzzzz Really it is getting very tedious.
In all the ruckus Moot Point must find it difficult to realise any point we’re actually making. One tries to be patient with him.
When it comes to “a torrent of expletives and abuse” you have excelled Luke.
when it comes to role models, you are wanting.
Time and time again this is where you lose the argument , you prove yourself to be emotive, fragile, abusive and generally unpleasant.
You know the old saying about vinegar and flies?
Yes indeed – wanting to give you some more. Just apply the standards consistently Dear sweet Rog.
Lost an argument – huh ? Rog do you think I really get revved up by you. And remember you’re here with the rest of us misfits -you could be debating Space but I’m more interesting. How flattering to be public enemy #1. Now be good or Enforcer Jen will in here slashing and deleting.
Rog
are you serious?? Luke provides numerous scientific references, then is expected to put up with the likes of Mott and Schiller ignoring all that work, when they just resort to gutter level abuse in response.
Have a look at MBH’98 figure 7:
http://stephenschneider.stanford.edu/Publications/PDF_Papers/MannBradleyHughes1998.pdf
Observe Luke’s sidestep with a request for references on the Arctic albedo issue. My what a short memory for a guy who actually emailed me the papers by Flanner et al on Arctic Black Carbon only last week. And discussed at length on this blog.
So lets try this once more. Many of the climate cadres like to focus on major percentage changes to low energy albedo in the Arctic winter while ignoring minor percentage changes to very high energy albedo in the tropical and sub-tropical summers.
http://en.wikipedia.org/wiki/Image:Insolation.png shows annual mean insolation with arctic insolation in the order of 60-80W/m2 while tropical and sub-tropical insolation is in the range from 200-260W/m2. The contrast between an Arctic winter and a subtropical summer is even more extreme.
A change in albedo from forest to pasture in the subtropics can register a 5 percentage point change, from say, 15% to 20% of insolation so at 240W/m2 the change would be from 36W/m2 to 48W/m2 and bring on a significant cooling effect.
Broadscale vegetation thickenning from pastured woodland to dense regrowth would involve a commensurate reduction in albedo in the order of 12W/m2 and produce a significant warming effect.
In contrast, Luke’s mates, like Flanner et al, have been busy modelling the impact of Black Carbon on winter and spring snowpack. And by their own admission, the impact on insolation is in the order of 0.2W/m2.
So one hectare of vegetation thickenning would achieve the same albedo change as 60 hectares of black carbon in snow. So Australia’s 90 million hectares of woodland thickenning will have produced the same albedo change as 5400 million hectares (54 million Km2) of black carbon snow pack.
That is the equivalent of the entire area north of Lat. 52N, including areas of ice free ocean.
And when the contrast between thickenned vegetation and grazed out pasture is considered, the variance can be double this figure, with a ten percentage change in albedo and a 24w/m2 energy shift which dwarfs the small change involved with black carbon on winter ice.
[note, no insults and no excuse for Luke to avoid a response]
Mottsa – you’re like a boxer that’s had too many fights. Dazed, angry and always on for it.
You’re asserting I’m suggesting big albedo changes in the Artic ? I am? You’re suggesting we’re saying all sorts of things.
If you read these blog archives I think you’ll find I have posted long ago on forest/grass albedo issues.
As for Luke’s mates? err who’s that?? Hansen I assume.
So did you actually read the Flanners paper I supplied instead of opining on it a prioi without reading. Did you notice the area under consideration was larger than the Arctic. Did you notice “The greatest instantaneous forcing is over the Tibetan Plateau, exceeding 20 W m2 in some places
during spring. These results indicate that snow darkening is an important component of
carbon aerosol climate forcing.”
Did you notice the detail on scavenging, hydrophilic and hydrophobic aspects of the melt and carbon soot response.
Now go back and read the satirical torrents you’ve subjected us to on the issue.
You may have noticed the paper was more than you thought – so maybe we now might get your more considered opinion.
Nice try, 20W/m2 for a few weeks in spring. The numbers for the tropics are annual means, not isolated instances. And the area north of Lat.52N, that I mentioned above, is a lot more than the Arctic.
It should also be noted that most of the Tibetan Plateau is at an altitude from 4000m to 6000m. At about 5,500m the mass of the total column of air above the ground is only half of what it would be at sea level. And this means that the long wave radiation has only half the mass of atmosphere to absorb the reflected solar energy.
And this means that more than half of the 20W/m2 of radiative forcing will not be absorbed by the atmosphere at all. It will simply bounce off into space as part of the planetary albedo.
Put simply, at high altitude, if the atmospheric mass is not there to absorb the radiation then the actual amount of radiative forcing becomes less and less relevant. It is one thing to measure the reflectance of various surfaces but the portion of that reflectance that is actually absorbed is another thing altogether.
And it also follows, from my above post, that when discussing radiative forcing at altitudes as high as the Tibetan Plateau, if the total atmospheric mass is only half of what it would be at any point at sea level then the total volume of CO2 is also only half of what it would be above any point at sea level.
And it is for this reason that albedo scare stories for Greenland (altitude 2000m) and Antarctica (3000m) must be taken with an additional grain of salt.
Totally naive in your response. The increase in forcing is 20W. That’s 20 W. That’s 20W !! That’s it. “Increase in forcing”. You have to factor that into the spring snow melt calculations. And in a region, Tibet, where we seem to have rapid increases in snow melt.
(1) you’re making the running and raving on albedo on this paper
(2) you’ve missed it as you haven’t considered the area insisting on the Arctic yet having been given 3 hints you’re wrong – seeing how long the bull will keep charging !!
(3) you’ve jumped your conclusions on what the paper was saying before reading
(4) you’ve been putting words into our mouths as to what the paper is saying – did you read the conclusions? and as we protest – you insert more.
(5) you silly stupid sneering comment on doggy doo in the snow shown up for the detailed consideration of scavenging, hydrophobic and hydrophilic properties of soot presented – all when you had not read it.
(6) much of Hansen’s comments are on the relatively unknown aspects of ice sheet disintegration aided by small amounts of ice melt. Not ice melt of the whole thing. Why because he cites that has happened in the past from the paleo evidence – we are not at that point yet. Hansen and others make the point that the mechanics of ice sheet movements are not understood by the 4AR. However given any formal calculation we are at the moment left with the 4AR’s 38cm or so by 2100. And as for the Greenland paleo paper only goobers would not have read down to the end on the commentaries where it says that if the sea level rise didn’t come from Greenland then look more closely at Antarctica.
(7) Much of the ice sheet disintegration work from 2006 publishing had caveats on decadal variability. See “work in progress”.
(8) So we may be only around some previous 20th century period of Arctic melt at this stage but we’re going way beyond that temperature wise with business as usual scenarios. Which given the blogs arguments here tend towards – essentially what business as usual with CO2 growth is what you’ve all mostly recommended – or even more – Paul Biggs would go for broke – suggesting we recklessly build coal fired plants at will. “Do ya good – put hair on your chest”.
(9) You’d be pretty naive to think God would give you all the cryosphere climate change evidence on a platter. Of course it’s spotty. But the consequences are significant. Expected value = probability of event “times” economic impact of it happening = amount of risk analysis that’s reasonable.
(10)Flanner’s paper isn’t definitive – it’s another brick in the wall of the story. Just as the Asian brown haze story is as well. Last time I brought up Rotstayn’s work here nobody cared.
(11) So you’ve put total abuse on me over this paper when you hadn’t read it or contemplated it with a calm fair mind. A boorish loud opinionated pissing contest at the front bar style discussion. Including all your predictable abuse of “dumb turds” etc.
So you might contemplate why you don’t get blog respect from the AGW camp. But you might also contemplate why we still continue to address your points.
Lacking any provocation from recent posts, Luke vents his late night spleen with responses to past exchanges, to avoid the issues.
It is clearly stated to be 20W/m2 at a given point in time, April-June. My references to thickening in Australia were annual means so multiply the Aust numbers by at least a factor of 4 to get like with like.
Still bunging on about it not being all Arctic when Flanner states,
“The 1998 and 2001 land snowmelt rates north of 50N are 28% and 19% greater in the month
preceding maximum melt of control simulations without BC in snow. With climate feedbacks, global annual mean 2-meter air temperature warms 0.15 and 0.10C, when BC is included in snow, whereas annual arctic warming is 1.61 and 0.50C. Stronger high latitude climate response in 1998 than 2001 is at least partially caused by boreal fires, which account for nearly all of the 35% biomass burning contribution to 1998 arctic
forcing”.
So while he has obviously made reference to the tibetan plateau, it is equally clear that if one is discussing climate forcing by BC in snow then one is primarily discussing the area north of Lat.50N, as I have consistently mentioned.
Note the reference to 4ARs upper estimate of SL rise, not the full range from 7cm to 38cm. Just a we slip there, amongst many.
It is also worth noting that no attempt appears to have been made to determine what the pre-industrial black carbon levels in snowpack have been. The experimental approach has been to determine the outcomes with and without BC and we are given a forcing estimate of 0.1C. But are we to seriously believe that forest fires did not occur in pre-industrial times?
Luke argues as if I were disputing the science when all along it has been clear that it was the interpretations and significance that has been projected onto the science that is at issue.
And even in the extreme case of the Tibetan Plateau, exactly how much ‘warming’ will ensue by adding 20W/m2 to a location that is, because of it’s altitude, 40C colder than the sea level equivalent? See http://www.accesstibettour.com/altitude-temperature.html and note the “maximum and miximum(sic) for Lhasa in May with warm daytime temps and night time minimums that are still capable of refreezing any daytime meltwater on the plateau.
Ian Mott – “And it also follows, from my above post, that when discussing radiative forcing at altitudes as high as the Tibetan Plateau, if the total atmospheric mass is only half of what it would be at any point at sea level then the total volume of CO2 is also only half of what it would be above any point at sea level.”
However if you understand how CO2 works in the different layers of the atmosphere this would not be a problem:
“Measurements done for the US Air Force drew scientists’ attention to the details of the absorption, and especially at high altitudes. At low pressure the spikes become much more sharply defined, like a picket fence. There are gaps between the H2O lines where radiation can get through unless blocked by CO2 lines. Moreover, researchers had become acutely aware of how very dry the air gets at upper altitudes — indeed the stratosphere has scarcely any water vapor at all. By contrast, CO2 is well mixed all through the atmosphere, so as you look higher it becomes relatively more significant. The main points could have been understood already in the 1930s if scientists had looked at the greenhouse effect closely (in fact one physicist, E.O. Hulbert, did make a pretty good calculation, but the matter was of so little interest that nobody noticed.)”
http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/
As always if you want the correct answer go to the site that has the real science.
Ian, regardless of what your envelope says about Tibet reports are most concerning: http://www.unep.org/Documents.Multilingual/Default.asp?DocumentID=512&ArticleID=5600&l=en
Therefore a contemplation of the research results are worthwhile. Not definitive perhaps – worthwhile and deserving of some respect by firstly reading the paper.
On sea level – nope you’ve goofed again – 38cm is a mid-level range. 38 is the upper range for one scenario. I could have quoted much higher.
The authors have data with and without large forest fires. They even comment themselves that this requires further work.
And since when has a single number, in this case, 38, been regarded as a range. The facts are that you could have quoted the range of numbers but did not. The authors, Flanner et al, may well have data with and without large forest fires but it must be said again that they appear to have assumed that forest fires and other (non-volcanic)black carbon emissions are all of recent, post industrial origin.
Ender. Your quote is off-topic. Do you agree or not that when comparing two sites, one at sea level and one at 5,400m, that the atmosphere above the site at 5,400m will be very similar to the top half of the one at sea level?
You can try all the spin you want, and all the plugs you want for other blogs, but the fact remains that the capacity of atmosphere above a site at 5,400m to absorb heat is only half of the capacity of the atmosphere above a site at sea level. And this means that a simple measurement of reduced albedo cannot be assumed to be fully transferred to the atmosphere. This is because the mass of the atmosphere above any point, and therefore the mass of CO2 above any point, is highly variable.
On land at 500m above sea level the mass of the atmosphere is approximately 95.5% of the mass above land at sea level.
At 1000m above SL the mass of the atmosphere is approximately 90% of the sea level equivalent.
At 2000m above SL the mass of the atmosphere is approximately 79.5% of the sea level equivalent.
At 3000m above SL the mass of the atmosphere is approximately 70% of the sea level equivalent.
At 4000m above SL the mass of the atmosphere is approximately 61.5% of the sea level equivalent.
Big deal, you say?
Most of Mexico is between 2000m and 3000m, as is the western third of the USA and a third each of Peru, Chile and Bolivia. Ditto for half of Iran, Turkey and two thirds of Afganistan with 70-79% of heat retention capacity. More than half of Siberia, all of Mongolia and half of China (ex Tibet) is also between 1000m and 2000m altitude with between 80 and 90% of standard heat retention capacity.
And, of course, Greenland and Antarctica, both in the 2000m to 3000m range.
Ooooo picky now are we. Since when do you quote ranges – OK we’ll be insisting on error bounds now on every number you quote. Jeezzz. The point of the 38cm is that it is the upper “limit” of a low range scenario and a middling number in other ranges. The point is that it’s a low way off metres which I think was the aspect of discussion. OK then 0.18cm to 0.59cm from all scenarios. Oh look the mid-point is 0.38cm. Happy now.
As for all the fiddly diddly about height of Tibet I think you will find a thing called a climate model which simulates such things – perhaps you might read up and tell us if they do ! Instead of creating unnecessary points of proof. Jeeez. You see someone with less ego would actually check out what they’re dealing with instead of concluding that the modellers haven’t thought about such things.
One can reasonably assume that the modellers haven’t thought about things like impact of altitude on heat balance if none of the researchers or bloggistas have bothered to mention it before. I don’t recall any mention of it in the Swiss albedo research. All that talk about snow pack albedo and no-one bothered to mention a major source of variation that you claim has been considered all along?
It is just the kind of ‘inconvenient’ factor that does tend to be left out. But this is your standard side-step, isn’t it? It is OK if the researcher left out a consideration because someone else included it in one of the numerous versions of their GCM.
And the fact that you haven’t dumped a stack of references on the issue is a pretty good indicator that they may not have considered it at all. Goaaarn Luke, get the departmental librarian on the job for us and show me up. Here’s your chance, I can’t wait.
Gee I think you’ve probably got us with that one. You win. I think you should write a major piece exposing these flaws. I reckon you’ve got the modellers done like dinners. They’ll be saying “golly if only had an accountant on the team”. We’re sure sorry”. You’ll be so famous with your insight on how the modellers have left out the orography.
And also BTW you’ve reopened the batting here quite nicely now – I’m sure your upcoming paper will also be dealing with the importance of the upper atmosphere energy budget – a mere trifle but I’m sure your local librarian can easily dig out the references for you – they’re so knowledgeable as you already know – you can just toddle in with any old question and they seem to know the answer. Amazing really. So over to you – Ender we’ll just wait here till Ian reports back.
You miss my point, Luke, I wouldn’t mind at all if you were to prove me wrong. A bit of ribbing on a blog is a small price to pay for a deeper understanding of the issue. Especially when it is you that seems to be publicly funded for the work you do. At least have a go.
Nope I’m not publicly funded to argue with you on climate change. Private interest only.
Anyway if you insist:
Journal Theoretical and Applied Climatology
ISSN 0177-798X (Print) 1434-4483 (Online)
Issue Volume 77, Numbers 1-2 / March, 2004
DOI 10.1007/s00704-004-0038-7
Greenhouse effect and altitude gradients over the Alps – by surface longwave radiation measurements and model calculated LOR
R. Philipona1, B. Dürr1 and C. Marty1
(1) Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center, Davos Dorf, Switzerland
The greenhouse effect has been investigated predominantly with satellite measurements, but more than 90% of the greenhouse radiative flux affecting Earths surface temperature and humidity originates from a 1000 meter layer above the surface. Here we show that substantial improvements on surface longwave radiation measurements and very good agreement with radiative transfer model calculations allow the clear-sky greenhouse effect be determined with measured surface longwave radiation and calculated longwave outgoing radiation at the top of the atmosphere. The cloud radiative forcing is determined by measured net longwave fluxes and added to the clear-sky greenhouse effect to determine the all-sky greenhouse effect. Longwave radiation measurements at different altitudes were used to determine the clear-sky and all-sky annual and seasonal greenhouse effect and altitude gradients over the Alps. Linear altitude gradients are measured for clear-sky situations, whereas the all-sky greenhouse effect is strongly influenced by varying, cloud amounts at different altitudes. Large diurnal and seasonal variations show the importance of surface heating and cooling effects and demonstrate the strong coupling of the greenhouse effect to surface temperature and humidity.
I’m sure your helpful librarian can get you the full paper. Ender gave you the hint before and you ignored him.
Ian Mott – “Ender. Your quote is off-topic. Do you agree or not that when comparing two sites, one at sea level and one at 5,400m, that the atmosphere above the site at 5,400m will be very similar to the top half of the one at sea level?
You can try all the spin you want, and all the plugs you want for other blogs, but the fact remains that the capacity of atmosphere above a site at 5,400m to absorb heat is only half of the capacity of the atmosphere above a site at sea level.”
Right so first you say that the atmosphere at seal level is very similar to 5400m and then you say that they are completely different?????.
However at 5400m the water vapour componet is lower so the CO2 has a greater window to absorb longwave radiation. I guess you have a reference to research to back up you claim that “but the fact remains that the capacity of atmosphere above a site at 5,400m to absorb heat is only half of the capacity of the atmosphere above a site at sea level.”
I have not seen this fact anywhere – perhaps you can supply the reference.
Interestingly Realclimate have just come out with “The CO2 problem in 6 easy steps”
http://www.realclimate.org/index.php/archives/2007/08/the-co2-problem-in-6-easy-steps/#more-462
Just the sort of things inquiring minds need.
It just dumped my response and am out of time. will get back later.
Ender, Google “atmospheric pressure” and check out any number of sites that explain the change in pressure, and therefore the mass of atmosphere above any altitude. Or is that the old comprehension problem again?
Once more, the total mass of air above some land that is 5400m above sea level is the same as the mass of air that is ABOVE a point that is 5400m higher than some land or ocean at sea level. And at the sea level site, the mass below 5400m is equal to the mass above.
Ergo, as the capacity of the atmosphere above any location to absorb heat is directly related to the mass of that atmosphere, then the atmosphere above the Tibetan Plateau has only half the capacity to absorb heat that a sea level site will have.
Not so fast Luke. It may well be the case that 90% of SURFACE TEMP comes from the lowest 1000m but that does not alter the fact that the lowest 1000m on the Tibetan Plateau is only half the density of a sea level site and therefore is only capable of half the comparable radiative forcing.
Philipona seems to indicate that this might have been taken into account IN HIS PAPER but Flanner appears to have simply rattled off the raw radiative forcing numbers at ground level without consideration of altitude. Ditto for all the works on Greenland and Antarctic albedo.
Yep and so there’s still plenty of atmosphere to go.
The forcings were done in concert with a GCM – so you need to know what’s in CAM 3 before you can progress your attack.
Ian Mott – “Ergo, as the capacity of the atmosphere above any location to absorb heat is directly related to the mass of that atmosphere, then the atmosphere above the Tibetan Plateau has only half the capacity to absorb heat that a sea level site will have.”
So you have taken in nothing about the subtleties of radiation and atmospheric absorption and are going with the linear ‘less atmosphere less absorption despite two referenced articles from atmospheric physicists that lay out in clear terms that the atmosphere does not behave in this simple linear manner.
This is why I asked you for the studies or references that confirm what you are trying to pass off as fact. So far you have failed to post such a reference so what you are saying can be completely discounted as you, as far as I know, are not an authority on atmospheric physics.
It appears that GISS has re-ranked the US temperature anomalies for the last 120 years. Luke, is this what you were hinting at the other day?
The new data can be found here: http://data.giss.nasa.gov/gistemp/graphs/Fig.D.txt
The old data (from the Wayback Machine to end 2005 can be found here:
http://web.archive.org/web/20060110100426/http://data.giss.nasa.gov/gistemp/graphs/Fig.D.txt
There is a 0.2-0.3C decrease post 2000 in the US temperature anomaly. See more at CA.
There appears to be no adjustment to the GISS global temps. It will be interesting to see if these are also adjusted. If they are, I guess these will be mpre in line with the HadCRU temps and the satellite LT temp records.
cheers
Arnost
No just a cold bias in the recent CRU ocean data. Early days still but maybe 2005 was the warmest. Wouldn’t that create a stink.
No, Ender, the “subtleties of radiation and atmospheric absorption”, are just that, SUBTLETIES. They can alter the variances due to altitude in either direction but in all bar the most minor altitude differences, they do not change the dominant impact of atmospheric mass on radiative forcing.
And it must be said that this is a rather interesting, if not hypocritical, tack for you to take, given the frequency and stridency of claims that atmospheric CO2 is uniformly spread and delivering a linearly proportionate forcing.
A new critique of L&F here:
http://scienceandpublicpolicy.org/images/stories/papers/originals/UnrulySunne/SPPI07_aug8_finalLockwoodpaper.pdf