Our favourite TV meteorologist Paul Hudson wrote this three years ago. It still seems pertinent and fresh.
What happened to global warming?
9 Oct 2009
By Paul Hudson
This headline may come as a bit of a surprise, so too might that fact that the warmest year recorded globally was not in 2008 or 2007, but in 1998.
But it is true. For the last 11 years we have not observed any increase in global temperatures.
And our climate models did not forecast it, even though man-made carbon dioxide, the gas thought to be responsible for warming our planet, has continued to rise.
So what on Earth is going on?
Climate change sceptics, who passionately and consistently argue that man’s influence on our climate is overstated, say they saw it coming.
They argue that there are natural cycles, over which we have no control, that dictate how warm the planet is. But what is the evidence for this?
During the last few decades of the 20th Century, our planet did warm quickly.
Sceptics argue that the warming we observed was down to the energy from the Sun increasing. After all 98% of the Earth’s warmth comes from the Sun.
But research conducted two years ago, and published by the Royal Society, seemed to rule out solar influences.
The scientists’ main approach was simple: to look at solar output and cosmic ray intensity over the last 30-40 years, and compare those trends with the graph for global average surface temperature.
And the results were clear. “Warming in the last 20 to 40 years can’t have been caused by solar activity,” said Dr Piers Forster from Leeds University, a leading contributor to this year’s Intergovernmental Panel on Climate Change (IPCC).
But one solar scientist Piers Corbyn from Weatheraction, a company specialising in long range weather forecasting, disagrees.
He claims that solar charged particles impact us far more than is currently accepted, so much so he says that they are almost entirely responsible for what happens to global temperatures.
He is so excited by what he has discovered that he plans to tell the international scientific community at a conference in London at the end of the month.
If proved correct, this could revolutionise the whole subject.
OCEAN CYCLES
What is really interesting at the moment is what is happening to our oceans. They are the Earth’s great heat stores.
According to research conducted by Professor Don Easterbrook from Western Washington University last November, the oceans and global temperatures are correlated.
The oceans, he says, have a cycle in which they warm and cool cyclically. The most important one is the Pacific decadal oscillation (PDO).
For much of the 1980s and 1990s, it was in a positive cycle, that means warmer than average. And observations have revealed that global temperatures were warm too.
But in the last few years it has been losing its warmth and has recently started to cool down.
These cycles in the past have lasted for nearly 30 years.
So could global temperatures follow? The global cooling from 1945 to 1977 coincided with one of these cold Pacific cycles.
Professor Easterbrook says: “The PDO cool mode has replaced the warm mode in the Pacific Ocean, virtually assuring us of about 30 years of global cooling.”
So what does it all mean? Climate change sceptics argue that this is evidence that they have been right all along.
They say there are so many other natural causes for warming and cooling, that even if man is warming the planet, it is a small part compared with nature.
But those scientists who are equally passionate about man’s influence on global warming argue that their science is solid.
The UK Met Office’s Hadley Centre, responsible for future climate predictions, says it incorporates solar variation and ocean cycles into its climate models, and that they are nothing new.
In fact, the centre says they are just two of the whole host of known factors that influence global temperatures – all of which are accounted for by its models.
Read the rest here:
Tallbloke's Talkshop 
Yes, I would go along with Dr. Corbyn’s claim, except I don’t think it is actual particles themselves, but the electric currents induction caused by the geomagnetic storms ( proton rain) in the Earth’s polar areas.
Yes, again I agree with Dr. Easterbrook too.
Some time ago I put both together and what do we get is the decadal and multi-decadal North Hemisphere’s natural temperature oscillations.
http://www.vukcevic.talktalk.net/GSC1.htm
We are on a top temperature plateau of the 21 Cty. Reaching the end of this plateau,
global temps can only go downwards after 2046. A paper on this is to follow in the next
few weeks…..JS
“This headline may come as a bit of a surprise, so too might that fact that the warmest year recorded globally was not in 2008 or 2007, but in 1998.”
hadcrut3 global warmest year 1998 at +0.55
http://www.cru.uea.ac.uk/cru/info/warming/
GIss global warmest year tie, 2005 and 2010 at +0.61
http://www.giss.nasa.gov/research/news/20110112/
NOAA global warmest year tie, 2005 and 2010 at +0.63
BEST land surface warmest year 2005 at +1.05
Click to access annual-comparison.pdf
This was written in 2009, before the 2010 figures were in, but can that first sentence still be justified?
J. S.
Looks like we might agree
http://www.vukcevic.talktalk.net/CET-NV.htm
Entropic man says:
September 24, 2012 at 5:17 pm
Entropic man, I agree that any comment regarding ‘which was the warmest year’ should be qualified with the dataset being used.
However, I also think that saying 1998 was the warmest is a fair call (no more than that), given that both satellite datasets (UAH and RSS) also have 1998 as the warmest. Fair because the shape (not necessarily the anomaly figures) of the HadCRUt3 is matched very closely by the satellite sets. Due to the constant manipulation and massaging performed by pretty much all the datasets, it is a bit of a minefield!
That’s how I would justify it… if I had to.:)
UAH: http://1.2.3.4/bmi/www.climate4you.com/images/MSU%20UAH%20GlobalMonthlyTempSince1979%20With37monthRunningAverage.gif
RSS:
HadCRUt3:
NCDC:
GISS:
Yes, I think all evidence is confirming a shift in weather/climate into cooling mode. Both the sun and Earth (and I suspect all other bodies in out solar system) are back in a position where they are receiving less charge from the galactic core for the next 100y of so (cool half of de Vries cycle).
Just returned from a holiday to Alaska. The natives were all saying that Autumn is 3 weeks early this year, and I saw lots of fresh snow on the mountains, some of the white stuff on;y 300ft or so above sea level. I also visited the Grand Pacific Glacier which is 35 miles long, 2 miles wide and 180ft high. On average it grows at a rate of 4 ft per day, however it is currently growing at 12ft per day, and the Tarr inlet of glacier bay is covered in a thick, slushy layer of ice.
Mr, Bryant, I’m afraid my computer won’t connect to your links, so we’ll have to agree to differ on that one for now.
I do wonder how it can be simultaneously asserted that all the datasets are massaged, manipulated and unreliable, while using them to confidently predict that warming has stopped.
Tenuc, Alaska has had one of its coldest Winters and a poor Summer in 2012, with less thawing than usual. The same jetstream behaviour that warmed the Eastern US and cooled Western Europe this year, has channelled colder winds across Alaska. La Nina did’nt help.
Entropic man,
Sorry you couldn’t open the links.
I suggest you try going to the excellent website: climate4you.com
Down the left hand bar go to ‘Global Temperatures’
Then, again on the left hand bar, go to ‘Recent Land Surface Temperatures’. Don’t worry, it’s not all land only.
Then scroll down to see clear graphs of the 5 main datasets: UAH/RSS/HadCRUt/NCDC and GISS
That should help you see what my links showed.
You missed my main point that the two satellite datasets also show 1998 to be the warmest. I’m not really interested in playing ‘dataset tennis’ but you cannot ignore the satellite data. Not one of the datasets is raw, hence my comment about manipulation/massage. I was making no critical point about that manipulation other than that to acknowledge it happens. The reason I wanted you to look at the ‘shape’ of the graphs is that they tend to use different base lines, so the actual anomaly figures such as those you quoted are misleading. As for BEST, if you can come up with any data BEST uses which is relevant but not obtained and then adjusted from previous datasets, please let me know.
As for your comment:
“I do wonder how it can be simultaneously asserted that all the datasets are massaged, manipulated and unreliable, while using them to confidently predict that warming has stopped.”
Please do not put words in my mouth. I never ‘confidently predict’ anything. It’s a mugs game, as most pro-cAGW commenters have found out to their chagrin. However, in terms of whether or not ‘warming has stopped’ it is just a matter of degree and interpretation of the datasets. The only comment I will make on that particular subject is to state that the overall (linear) trend since 1850 (using the HadCRUt3 dataset – because that is the oldest and the one used by the IPCC initially) has not changed that much (it’s about 0.05C per decade). The steepest trend was actually in 1878! Therefore the warming cannot be increasing at an accelerative rate, which is what is ‘predicted’ by the CO2=cAGW ‘theory’. The fact remains that ALL the datasets show that the current ‘global temperature’ is significantly LESS than it was in 1998.
I hope that makes my position clear to you. I was, after all, merely trying to answer your question.
Regards,
vukcevic says, September 24, 2012 at 1:12 pm
I concur. Corbyn and Easterbrook make more sense than the IPCC, UEA, NOAA, GISS, GHCHN, the BBC, PBS, Nature, Michael Mann, Kevin Trenberth, James Hansen, Gavin Schmidt, Tamino and a busload of demented statisticians.
Fortunately people are realizing that a warmer climate is preferable to another “Little Ice Age”.
The only thing I would like to know from Paul Hudson is whether he got forwarded on Mon 12 Oct 2009 a chain of emails from Stephen Schneider.
[Reply] That misunderstanding was laid to rest long ago.
Mr. Bryant, careful with that word “significantly”. It was only last year that the hadcrut3 data had a long enough baseline for them to say that the temperature changes observed since 1995 were 95% significant in the full statistical sense.
http://www.redorbit.com/news/science/2062709/scientist_says_global_warming_is_now_significant/
As for the BEST data, I’ll let them speak for themselves.You can also access the papers they’ve submitted for peer review from the same page.
http://berkeleyearth.org/results-summary/
Note particularly this paragraph in the summary.
“Berkeley Earth also has carefully studied issues raised by skeptics, such as possible biases from urban heating, data selection, poor station quality, and data adjustment. We have demonstrated that these do not unduly bias the results.”
The urban heating paper discussing how they addressed the bias problem is at-
Click to access uhi-revised-june-26.pdf
[Reply] They didn’t address the problems with the underlying GHCN data they used, which are serious. See Watts 2012 draft
I checked the UAH graph at Roy Spencer’s website.
http://www.drroyspencer.com/latest-global-temperatures/
The 1998 peak is way outside the normal range for the data and stands out in isolation from the years around it. I would regard it as meeting the definition of a statistical outlier.
http://mathworld.wolfram.com/Outlier.html
Note particularly the advice at the end.
“When performing least squares fitting to data, it is often best to discard outliers before computing the line of best fit.”
To get a proper picture of the underlying pattern in the UAH data I would suggest that the 1998 peak would be better ignored, rather than being used as used as the starting point for a best fit line.
[Reply] If the ’98 El Nino consisted of a single data point, you might be right. But it doesn’t, and you’re not.
The 1998 peak was not a single datum point, but it was a single event. I am unhappy using an exceptional El Nino year as the starting point for a best fit line, as I would be unhappy using 1991, the year of the Mount Pinatubo eruption.1998 was unusually warm; 1991 was unusually cool. Neither is representative of the long term trend.
Regarding the Watts 2012 paper, I’ve read it and took part in the crowd peer review of its first draft on WUWT. It also has problems with its data.
[Reply] Who is using 1998 as “the start of a best fit line”? Not Paul Hudson.
Entropic man,
Further to Tallbloke’s reply, it would be interesting to contemplate if the same ‘ignoring’ had been applied when 1998 was being heralded as ‘proof’ that CO2 emissions could cause significant (nb) global warming.
cAGW proponents want to use 1998 when it suits them, then ignore it when it doesn’t. Lately they’ve been saying, “…well, 1998 was an extreme El Nino…”. Now you’re calling it an outlier. Where, in 1998, were the statistical experts stating that it was just an outlier and that the warming would not continue to increase?
You originally asked if the statement “The warmest year globally was 1998.” could be justified. I have given you four datasets: UAH/RSS/HadCRUt3 and NCDC (that’s two satellite and two terrestrial) which support the statement. Now you’re trying to denounce the satellite data and use GISS. If you don’t like the datasets, that is your prerogative. It’s obvious you don’t think the statement is justified, so good luck to you; you have provided the answer yourself.
I think the first to use the “no warming since 1998” line was Robert Carter. I’ve been hit over the head with it many times on sceptic websites and I still regard it as a naiveiy oversimplified interpretation of the data.
I am not complaining about it as a measurement. Four datasets out of six do show the peak of the 1998 El Nino peak as the highest recorded global average temperature, the other two show 2005 or 2010. As for the statisticians, in 1998 nobody knew whether it was an acceleration of the trend, or an outlier. That came with a further 15 years data, just as we will need to wait a decade or two to see if this year’s Arctic and Antarctic ice extent records were outliers or trend indicators.
I’m more interested in what the long term temperature trend is going to do.It has been flattening in recent years, which may be due to decreased warming or due to changes in the way the heat is distributed. That’s a more interesting question, and not one to be answered by quibbling over details.
Until we get a 20+ year baseline allowing confirmation of the null hypothesis or the alternate hypothesis to 95% confidence levels, accepters and sceptics are both speculating on inadequate data. Meanwhile alarmists and deniers try to make political hay.
I agree with Paul Hudson that “For the last 11 years we have not observed any increase in global temperatures.” What leaves me unhappy is the unjustified way in which some people make the leap to “Climate change has stopped, we can relax.”
The record looks symmetrical about 2005. Ocean heat content fell from 2004. It fits with my own solar theory. We now await developments.
Entropic man,
I agree with much of what you say in your last post. It has a balanced ring about it. I also agree that the long term trend is much more interesting and informative.
Using the HadCRUt3 set (which is the oldest), the overall trend is appx 0.05C per decade. With regards to “what the long term trend will do”, I can only guess. However, what I can say is that there is currently no acceleration in that overall trend. As you say, the trend has flattened over the past 15 years or so. The steepest point was about 1878 with a trend of 0.9Cpd or so. It was about 0.06Cpd around the turn of the century (the second steepest trend). Either way, there doesn’t seem to be much in the way of either acceleration or deceleration. In my opinion, it is the predicted acceleration that is the problem. There is no real, empirical evidence to support such a prediction. The prediction is based on models. Some people use short-term trends using a different starting point to make their point. This achieves nothing other than proving that short term trends vary more than long term trends – which is obvious. The only real way to identify an acceleration is to see if the overall trend (linear from the origin) becomes steeper. If it does, then it can safely be said that acceleration has taken place. This has not happened with HadCRUt3, although it may have happened with GISS. Either way (again), the difference is very small.
I appreciate the statisticians could not predict the future in 1998 regarding 1998 being an outlier but, unfortunately, that is exactly what some ‘scientists’ did. They made a prediction based on a short term sub-trend in a longer term trend, which itself was spliced onto a totally different dataset. The really sad thing is now they may just be realising that it wasn’t the start of the ‘catastrophic acceleration’ but they haven’t got the courage to say it. So they just perpetuate the predictions based on a postulation based on an assumption, and then blame the datasets for not agreeing with their original hypothesis.
I’m not sure who is saying ‘climate change has stopped’. As far as I am concerned, climate change has never stopped. Climate has always changed over differing periods. the term ‘climate change’ has effectively been hijacked to replace ‘global warming’ because it covers more eventualities, and is therefore less likely to be refuted.
Regards,
ps, What is your interpretation of ‘the null hypothesis’?
Entropic man
I argue that the 1997/8 El Nino is a valid start point although the sort of criticisms you make may be why some sceptics concede and go to 2001. However, it is hardly a naĂŻve determination as you assert when you consider:
a) That particular El Nino is not exceptional as claimed (sometimes called a “super El Nino”) when compared on the following NOAA graph, and is part of the temperature record: http://www.esrl.noaa.gov/psd/enso/mei/ts.gif
b) The IPCC and Manna man were delighted to use the 1998 temperature, rather than the considerably lower figures in 1999/2000, when it suited their purpose in the 3AR 2001 report.
c) 1998 was followed by a sharp drop in temperatures from the 1999/2000 La Nina which can be regarded as a “correction” or smoothing of natural variations in the net consequences. See Hadcrut data as was preferred by the IPCC: http://www.cru.uea.ac.uk/cru/data/temperature/nhshgl.gif
I don’t know why you dismiss Bob Carter!
Re ‘global’ warming, Antarctic sea ice extent continues its long-term (seasonal) upward trend.
http://stevengoddard.wordpress.com/2012/09/26/antarctica-gains-2400-manhattans-of-ice-overnight/
Today could be a ‘record’ i.e. since satellite measuring began in 1979.
[Reply] Rescued from spam bin – sorry about that
Arfur Bryant says:
September 27, 2012 at 12:21 am
Erratum:
Line 7 of the above post. The 1878 trend should read 0.09Cpd!
I have been looking at CET montly max and min temperatures. I have tried to find two years, one from the past and one recent, where the same month had the same temperature.
Here are a few I have found.
October 1878 max 13.5°C min 6.9°C. October 2010 max 13.6 min 6.9°C.
November 1881 max 11.6 min 6.1 November 2006 max 11.5 min 4.7°C
July 1889 max 19.6 min 11.0 July 2012 max 19.6 min 11.5.
I can’t see a pattern of minimums getting warmer due to increased CO2.
Bob Fernley-Jones
You should try WUWT, the discussion there can get very dogmatic and downright hostile. Several commenters there showed me Woodforthetrees graphs showing temperatures starting at 1998 and a flat best fit line, convinced that it was a killer argument. It seems to be a common sceptic meme. I spent a couple of months debating there, which may have overexposed me to some of the more excessive attitudes expressed in the debate. If I start showing similar habits a gentle “relax” would be appreciated. A statement by Robert Carter similar to Paul Hudson’s may have been overinflated by the enthusiasts.
Its much more civilized here.
.
“it suited their purpose” seems to be a common claim. I’ve seen it used as a debating tactic by advocates on both sides trying to discredit evidence from their opponents.You should resist that temptation, It turns a scientific disussion into a debate, a much lower form of interaction.
Regarding the temperature and ENSO graphs, The 1998 El Nino was no larger, but rather more prolonged than its nearest modern equivalent in 1983. It also had a much greater impact on the Hadcrut temperature record. It would be interesting to know why.
Looking at Hadcrut , it is tempting to date the flattening from 2002. That date crops up regularly. The various Arctic graphs show changes in slope around then, and Tallbloke has a thread running here regarding a 2002 step change in Arctic OLR. My old unscientific gut feeling is that in retrospect 2002 may be identified as one of those fashionable tipping points, though its anyone’s guess so far in which direction its tipping.
Arfur Bryant
I think you mean maximum slope in 1978 🙂
I’m not a great fan of the acceleration argument. With a relatively constant rise in atmospheric CO2 and a logarithmic effect of CO2 on warming, the only acceleration could come from an increased % of secondary forcing. This and other uncertainties are presumably why IPCC is giving probabilities, rather than definitive predictions.
The “climate change has stopped (or is about to destroy us)” brigades tend to be those with a political or economic interest, rather than the scientists. Every short term trend gets jumped on. I remember a GWPF report last Winter saying that Winter ice extent figures near the long term average showed that “global warming has stopped”. That disappeared from their site quite quickly.
“Unusual” dry, wet and cold weather has battered the UK from all directions this year . Eastern Europe has heat and drought. Record Antarctic high and Arctic low ice extents occur in the same month. The US Midwest experiences record high temperatures, record low temperatures and a drought, all in the same Summer. Alaska has its coldest year for decades.
With oddities popping up all over, stability seems to be in short supply at present. It is why I prefer to use “climate change”, rather than “global warming”. It better reflects that the reality is a lot more complicated than anyone expected.
Regarding the null hypothesis. In the context of climate change the discussion has tended to polarise into three camps:- cAGW, temperature increase due to other causes and those who say no increase is taking place.
Thinking specifically about temperature change, the null hypothesis would be that, over whatever time period you discuss, temperature shows no long term trend. The alternative hypothesis would be that there is a long term trend. To confidently accept the null hypothesis would require a statistically calculated probability of a trend below 5%. To confidently accept a trend the probability would need to exceed 95%.
For 1995-2009 CRU calculate a probability of a rising temperature trend just above the 95% significance level.
Very few of the trends shown in climate data reach that level of confidence. Two that do are the recent ice extents. The Antarctic maximum extent was 2.5 sigmas above the long term average, probability of chance occurance about 1%. The Arctic minimum was almost 6 sigmas below the average, probability of chance occurance 0.001%(?).
Political advocates of climate change would be tempted to point at the Arctic, sceptics would point at the Antarctic. I’m developing a tendency to mutter into my cocoa.
Kelvin Vaughan
Did you encounter Hansen’s recent discussion paper? It suggested that one effect of climate change would be to cause frequency distributions in temperature records to widen and drift to the right, with the minima remaining stable and maxima tending to increase with time.
http://www.giss.nasa.gov/research/briefs/hansen_17/
Entropic man says:
September 27, 2012 at 6:56 pm
Kelvin Vaughan
Did you encounter Hansen’s recent discussion paper? It suggested that one effect of climate change would be to cause frequency distributions in temperature records to widen and drift to the right, with the minima remaining stable and maxima tending to increase with time.
http://www.giss.nasa.gov/research/briefs/hansen_17/
I dont see any increase in CET maxima during June July and August
1881 June 21.0 July 22.8 August 21.2.
The closest I can find is 2003 June 21.1 July 22.2 August 23.5
and 2010 June 20.4 July 21.3 August 19.3.
There are less colder summers since 1990.
I think he’s talking about long term statistical changes, on the scale of decades, in the likelihood of extreme temperatures, particularly an increase in the frequency of heat waves and record high temperatures. This probably wont show in monthly sequences taken from individual years
Entropic man,
I suggest that you take a closer look at the NOAA graph:
I think you are being a bit picky to suggest that the 1997/8 El Nino is significantly greater than that of 1982/3 according to the data shown.
Notice too that there is a lot more blue below the line than red above between 1950 and 1977, and it was in the 70’s that some alarmists were warning of a coming ice-age because of the long period of cooling after 1940.
Between 1977 and 1998, there is a reverse of this situation when there was a warming phase.
Since 1998 the blue area below the line roughly matches the red above, and the trend has been flat.
On the basis of the NOAA graph, there is a much better correlation between global temperature and ENSO than there is with CO2, but of course correlation does not prove cause, remarkable though it may be.
Here is the HADCRUT graph again showing the three periods of: Cooling – Warming – Flat:
BTW, strangely, Hadcrut use a 21-year CPA simplified Gaussian smoothing method which cannot be applied for the last ten years because data would be required out to 2022 around the centre point average. (They fiddle it)
Entropic man,
Aaaah, cocoa! I hope you enjoyed it!:)
No, I really did mean maximum slope 1878! Check the data. Actually, here is one for you (but i know you don’t always like woodfortrees…):
http://www.woodfortrees.org/plot/hadcrut3gl/from:1850/to:2012/mean:60/plot/hadcrut3gl/from:1850/to:1879/trend/plot/hadcrut3gl/from:1850/to:1943/trend/plot/hadcrut3gl/from:1850/to:1998/trend
It just shows that the overall trend is not necessarily highest around 1998 or later (but it is close).
I’m glad you find this website more civilised. So do I.
Anyway, back to the discussion…
The IPCC, in the case of acceleration of global warming, didn’t make predictions or talk in probabilities; they made a direct statement:
“Note that for shorter recent periods, the slope is greater, indicating accelÂerated warming.” This was from FAQ 3.1, Fig 1, narrative.
It proves the point about short term trends, which is why I prefer the long term trends (but still within a single dataset). But the point is that they (IPCC) talk in terms of accelerated warming when the long term trend does not necessarily support their statement.
You state:
[“With oddities popping up all over, stability seems to be in short supply at present. It is why I prefer to use “climate change”, rather than “global warming”. It better reflects that the reality is a lot more complicated than anyone expected.”]
But the problem is that the ‘climate change’ meme is predicated on the idea that CO2 is capable of having a significant (!) – or even catastrophic – effect on global climate. So, when you use the phrase ‘climate change’, I suspect you are taking the same specious route. I agree, and have already said, that the climate changes, but I do not use it in the same context. You will find that some modern dictionaries actually define climate change as anthropogenic. Older dictionaries did not.
Re [“Regarding the null hypothesis. In the context of climate change the discussion has tended to polarise into three camps:- cAGW, temperature increase due to other causes and those who say no increase is taking place.”]
I don’t entirely agree with those three divisions, although I’m probably picking hairs. Yes, cAGW is camp 1. I am not aware of anyone falling into camp 3 but I accept it is a possible camp. I tend to fall into camp 2 but you have left out one important aspect, and that is the degree of warming caused by CO2 (and other non-condensing greenhouse gasses). I would never say that ALL warming is due to other causes but I would certainly say that MOST of the observed warming cannot be attributed to CO2 (et al). This opinion is based on evidence, not theory or models. I will happily elucidate but I fear everyone else would be bored. Either way, if camp 2 exists, I am in camp 4!
Thanks for explaining your interpretation of the null hypothesis. In which case, I totally accept that there is a long term warming trend. As I have said before, it is roughly 0.05 C per decade. This means I do not ‘deny’ warming has taken place. I can’t see how anyone could justify such a statement. The difference between ‘warmism’ and scepticism is, to me, the difference in the degree of effectiveness of the nGHGs.
I’m enjoying the chat, by the way!
Regards,
Er… I meant splitting hairs, not picking hairs!
Yuk.
Arfur Bryant
Just for fun I added a 1950 to 2011 slope to your graph, avoiding the 1040s El Nino peak discussed elsewhere on TT.
http://www.woodfortrees.org/plot/hadcrut3gl/from:1850/to:2012/mean:60/plot/hadcrut3gl/from:1850/to:1879/trend/plot/hadcrut3gl/from:1850/to:1943/trend/plot/hadcrut3gl/from:1850/to:1998/trend/plot/hadcrut3gl/from:1950/to:2011/trend
My camps were probably splitting a continuum from the environmentalist hysteria to head-in the-sand denial. I’ve encountered the full range among amateur pundits online at one time or another, though the professionals cluster much closer to the centre.
I sit at the lower end of IPCC’s midrange position, mildly cAGW, though recent events are making me nervous.
I’m quite happy with the temperature records, though they should be showing +/- 0.1C 95% confidence limits on the averages.This is why I am reluctant to read too much into small or short term variations. For example, the last few years of Hadcrut look very like the latter half of the 1960s. Regarding acceleration, my graph shows the ends of the data above the 1950-2011 best fit line, with the middle sagging below it. That’s the shape of an accelerating trend.However, the variation is all within that +/- 0.1C margin from the best fit line, so it has no statistical significance. Whether acceleration exists or not then becomes a matter of belief, rather than science.
Regarding CO2, I’ve had the opportunity to measure the infrared spectrum of CO2 in King’s College , London as a student. I’ve also observed the 15micrometre back radiation one frosty night outside Cambridge with a mate who borrowed a spectrometer from his work.
I dont have enough maths to do a full analysis, but what I could check matched what the scientists tell us. This was something I always told my pupils. Where possible, check what people tell you for yourself; if it matches then you can have more confidence in the rest of what they say. If it does not match, distrust the rest.
I’ve also watched bird and fish species appear in my locality in recent years which would normally be outside their Northern limit.
Bob Fernley-Jones
The two El Ninos reached the same departure. The 1997/8 event shows much more area under the curve and a double peak, almost like two overlapping events. It also had a much greater impact on global temperature. Of the two, I would still regard the second as the more energetic.
ENSO is a change in water distribution. El Nino brings warmer water to the surface and heats the air above it as the water cools. La Nina brings up cold water and cools the atmosphere as the water warms. Over the longer term they are energy neutral, as the El Nino releases heat trapped during La Nina. I am happy with the short term effect on temperatures on a scale of a few years. You will see a correalation between ENSO and temperature, but on an approximately cyclic basis.On a scale of a century I see no way of powering a long term warming trend using ENSO because it lacks an energy source of its own.
My own interpretation of the temperature data is a long term underlying warming trend over the last 130 years due to the effect of increasing CO2 overpowering Milankovich cooling, with periods of flatter and steeper slope as ENSO, NAO, solar cycles etc affect heat flow within the system.
Hadcruts 21 year smoothing system does make it difficult to judge the effect of changes within the last ten years. I’m happy to wait, trading longer term reliability of the data for short term uncertainty.
“They fiddle it” is political lobbyist talk, not science.
Entropic man,
By starting at an intermediate point, what you have done is to insert a short-term trend line into the long-term graph. Of course you can get short term accelerations, decelerations, coolings and no change lines but they won’t indicate an overall acceleration until the overall trend line from the origin becomes steeper than the 1878 point. That was my point. If the overall trend line exceeds that slope in the future, then you will have an overall acceleration. The ‘flattening’ since 1998/2002 (take your pick) has effectively stopped such an acceleration, if only temporarily. That is what we will have to wait and see!
Now to CO2:
[“Regarding CO2, I’ve had the opportunity to measure the infrared spectrum of CO2 in King’s College , London as a student. I’ve also observed the 15micrometre back radiation one frosty night outside Cambridge with a mate who borrowed a spectrometer from his work.”]
I ave absolutely no doubt that you have measured such radiation. But measuring that radiation in no way validates the CO2=cAGW theory! Radiation is not heat, but I’m sure you know that. What you (and your mate) have to ask yourself is ‘How much heat is being produced by this radiation?’
So, you have to try to identify how much of the Greenhouse Effect is contributed by CO2 (and other nGHGs). Once you can answer that question, you can make an acceptable stab at figuring out how much a doubling of CO2 will contribute. The trouble is…
There is absolutely NO empirical evidence to support the theory. I’ll try to explain:
Most of the pro-cAGW commenters (eg Schmidt, Trenberth, Lacis, scienceofdoom) will say that the answer to the question (without a question mark) in bold above is between 20 and 26%. I can provide references if you wish. So here’s the rub:
The current GE is 33 deg C (and CO2 = appx 400ppm).
25% of 33 is 8.25C (I used 25% as a rough mean of their opinions).
The total warming since 1850 (IPCC start of accurate data) is appx 0.9C.
Therefore the GE in 1850 was 32.1C (and CO2 = 280ppm).
25% of 32.1C is appx 8C
The obvious question (which these guys HATE to be asked) is “Why does 280ppm contribute 8 degrees C to the GE in 1850, and yet a 40% increase in CO2 possibly contribute an unknown portion of 0.9 degrees C since then?”
The problem is they don’t know. They try to argue that CO2 radiation didn’t start having an effect until after 1950, and that was the cause of the 1970-1998 warming, but then they can’t explain the very similar warming between 1910 and 1945. Apparently, THAT one was due to natural variation. But if natural variation can cause a 0.7C rise in thirty years, why does the later 0.7C rise in 28 years have to be caused by CO2? Unfortunately, their radiative physics does not explain this anomaly. That is because they base their argument on an assumption – that Arrhenius was correct. Unfortunately, scientific method dictates that if the data does not support the theory, then the theory should be reconsidered, as opposed to adjusting the data.
Now its my turn to mutter into my cocoa… 🙂
ps, As for your final sentence:
[‘I’ve also watched bird and fish species appear in my locality in recent years which would normally be outside their Northern limit.”]
When you say normally, do you mean ‘in your lifetime’? Can I assume you live in England?
Here is the world’s longest running temperature dataset:
Note that the total rise of temperature in England is about 1.5 deg C in 353 years. Also please note that 2012 (if you go to the data link) is running cooler than 2011 by about 0.3 deg C.
This doesn’t seem to indicate a climatic criterion for the establishment of new species. Could it be there is another reason?
Arfur Bryant.
Tired and busy. I’ll get back to you after the weekend.
Never retire! You get less stamia and more busy!
http://www.woodfortrees.org/plot/hadcrut3gl/from:1850/to:2012/mean:60/plot/hadcrut3gl/from:1850/to:1879/trend/plot/hadcrut3gl/from:1850/to:1943/trend/plot/hadcrut3gl/from:1850/to:1998/trend/plot/hadcrut3gl/from:1950/to:2011/trend/plot/hadcrut3gl/from:1850/to:2011/mean:60/offset:0.1/plot/hadcrut3gl/from:1850/to:2011/mean:60/offset:-0.1
I’ve added approximate 95% confidence limits for the Hadcrut3 data. The actual uncertainty figure of +/- 0.1C came from BEST, but since the raw data is the same for all, Hadcrut3 should be similar.
One formulation of the 95% confidence limits idea is this. If 1000 different organisations had set up independant station networks and satellites and each measured temperatures for a year, 19 out of every 20 of them would record a global average for that year within the 95% confidence limits shown.
You can see why I am reluctant to claim significant acceleration after 1950. My best fit line touches the lower boundaries in 1950 and 2011,and the upper boundary around 1980, but does not go outside the boundaries. I chose 1950 because it gives the longest possible baseline uninterupted by the large variabilities of the first half of the 20th century. Your 1878 line is also contained within the 95% confidence limits, and is not statistically significant.
Incidentally, if you want to know if averages from different years differ significantly, check the boundaries. If the upper boundary for lower average, and the lower boundary for the higher average do not overlap there is a 95% probability that they are part of different samples, ie something has changed in the environment from which the measurements are being taken.
The best fit for the 60 year period from 1950 slopes at 0.012C/year or 0.12C/decade. Take two alternatives, continued temperaturee stability and continued warming at 0.12C/decade. Starting from 2002 their 95% confidence limits should no longer overlap after 0.2/0.012=17 years, in 2019 if warming continues at its previous rate, If warming continues more slowly or stops, significant divergence will take place later or not at all. If warming accelerates divergence will occur earlier.
Shall we check in 2019?
Regarding CO2, I did not take intensity readings at that time, but they have been measured. An alternative is to measure the intensities in the OLR spectrum and then use the area missing between the observed OLR intensity and the calculated black body intensity around 15 micrometres to calculate the amount of heat retained by CO2. Combining ground and satellite data gives the worldwide average of 33W/M^2. you quoted.
“Why does 280ppm contribute 8 degrees C to the GE in 1850, and yet a 40% increase in CO2 possibly contribute an unknown portion of 0.9 degrees C since then?”
Stripping out a lot of complexity each 1C warming at the surface requires an extra 3.7W/M^2.
Assuming 33W/^M2 at 400ppm(probably a bit low) that gives 33/3.7=8.9C of warming.
CO2 level was 280ppm in the 1880s, Thal gives (280/400)*8,9=7C.
The prediction from this admittedly crude calculation is that the observed change in CO2 should be producing a change of 1.9C, We observe around 0.9C so far.
There are two main reasons for this.
Firstly, the relationship between CO2 concentration and its warming effect is logarithmic, not linear. Each extra ppm added has less heating effect than the one before. This means that my simple calculation assuming a linear relationship overestimated the warming effect of extra CO2.
The second reason is lag. The atmosphere has a low heat capacity, so a small change in energy content can produce a large temperature change. The atmospheric reacts very qouckly to energy changes. Think of the large air temperature differences between day and night.
The land reacts more slowly, with a lag between air temperature and surface temperature.
The oceans react most slowly. Water has a very high heat capacity, so even a small temperature change needs a lot of energy ( think how much electricity you use boiling a kettle!). To produce that 1.9C warming you have to warm the air, the ground and 280 million cubic miles of water.
We’ve observed 0.9C since 1880 suggesting that we would reach equilibrium in (1.9/0.9)*130=274 years. That would be 2154.
That is probably a time overestimate for several reasons.
The rate of heat transfer would increase as the temperature gradient between water and air increased.
It assumes that the CO2 concentration has been 400ppm since 1880. In fact the concentration, and the warming effect have increased gradually. The future warming will be faster.
It assumes that CO2 stays at 400ppm, which looks unlikely.
Finally we have completely ignored secondary forcing, grist for another day.
Regarding animal distributions. In my youth around 1960 I used to visit my aunt in Margate and heard collared doves for the first time, then found only in Kent and along the South coast. I remember asking what they were, having never heard them or seen them before. When I left home in 1971 they were colonising Cambridgeshire. They reached my home in Northern Ireland in the latter 1990s and have been regular attenders at my bird table ever since. Through my lifetime they’ve spread North at an average rate of 10 miles a year.
My sea fishing friends in Donegal have observed the same. The submerged wrecks they fish around are changing. Old familiar species are declining and colonisers normally associated with SW England or France are establishing themselves.
Retirement? Tell me about it! I retired from the military last year and I’m still doing the same job without the uniform and just as busy and, currently, spending just as much time away!
“plus ça change, plus c’est la mĂŞme chose”!
Re 95%, what you say makes a lot of sense, and I would love to check again in 2019! 🙂
By the way, does applying a 60 month smoothing change much?
Away for a bit. Back soon.
OK, CO2…
First of all, I didn’t quote 33W/m2. I quoted 33 deg C, which is accepted by the IPCC as being the numerical value of the Greenhouse Effect. Whether it IS or not is a different argument, but lets assume they are right (not many people argue this ‘fact’). Therefore, the rest of your calculations are misplaced. I am arguing from the point of view of evidence. We ‘know’ the GE is 33C. We ‘know the CO2 is 400ppm. We ‘know’ the warming has been 0.9C since 1850 and we ‘know the Co2 level was 280ppm in 1850. Those are as close to ‘facts’ as it is possible to get in the climate debate.
Therefore, we can legitimately question the theory, as a whopping 40% increase in CO2 has, apparently, been responsible for ‘a portion’ of the 0.9C rise.
Your argument assumes that all of that 0.9C is caused by CO2:
“The prediction from this admittedly crude calculation is that the observed change in CO2 should be producing a change of 1.9C, We observe around 0.9C so far.
The big problem here is that it is inconceivable (unless you are a diehard warmist) that CO2 can be responsible for ALL of the 0.9C warming. Even the IPCC do not say that! In addition, the fact that there has been a rise of 0.7-ishC before 1950 must give the objective observer the possibility that factors other than CO2 can produce such warming. Otherwise, one is left with the logical fallacy that CO2 is responsible for warming, and ‘something else’ is responsible for cooling. This is just daft. The only logical answer is that (assuming there is anything valid about the CO2=cAGW theory) CO2 is responsible for a portion of the 0.9C. The portion could be anywhere from 0.1 to 0.8C, but it can’t be 0.9 and it is unlikely to be zero because there is no doubt that CO2 has radiative properties. My problem with CO2 is that it does not exist in sufficient quantities to make a significant difference in global temperature. This argument is supported by my question about how 280ppm can be responsible for a large portion, and 400ppm not make much difference.
Now to your two reasons…
Log effect. I suspect you are a mathematician, yes? Ok, you are correct that the effect of CO2 is logarithmic. If the end result of various doublings to get 280ppm in 1850 is 8C out of 32.1C, what is the calculation for the next doubling? Or what is it for an additional 40%? 1.4logn? I don’t know, but whatever it is, it virtually ends the case for cAGW being the end result of CO2 increase, because the observed rise will not be able to get much larger because of the log effect. In addition, we may be close to saturation level in which case any additional CO2 will have no significant effect. Remember that CO2 is only responsible for part of the observed rise. Even if you take 0.5C as the part played by a 40% increase in CO2, then, due to the log effect, the rise for a doubling (100%) of CO2 is going to be around 1C (because, as you say, it is not a linear relationship). Hence the projected (by models) climate sensitivity of appx 3C is greatly overestimated.
Lag. There is absolutely NO evidence to support the idea of lag. None at all. If there was, the temperature would be increasing at a greater than expected rate. Yes, the heat capacity of the oceans is vastly greater than the atmosphere, and yet we are expected to believe that the atmospheric warming is somehow transmitted into the deep ocean without any correlated rise in ocean surface temperature. This defies logic, reason and science. Plenty of pro-caGW commenters want to use lag as the ‘get out of jail free’ card but, again, the facts do not support that assertion. There has been, according to the IPCC, an anthropogenic effect since 1750 (but lets ignore the amount pre 1850, as any temperature rise is un-observed). So, since 1850 the lag has had a chance to be slowly effective. Up until 1998 one could argue that the late twentieth century warming was partially caused by lag. SInce 1998, that lag has been either non-existent or, and this is most telling, overwhelmed by the other (natural?) factors. This is a crucial point; the ‘significant’ radiative effect of CO2, reinforced by the ‘lag’ effect, has been overwhelmed by other, cooling, factors. All this at a time when the world is expected to believe that the warming (and secondary) impacts are meant to be increasing, not decreasing. I refer to one of my earlier posts: If the data does not support the theory, then re-visit the theory, not the data! Your 1.9C figure is based on assumptions and models, which produce the quoted 3C rise for equilibrium climate sensitivity.
Much as I’ve grown to like and respect you (and I very much appreciate the tone of the discussion), your comment “The future warming will be faster.” is a triumph of spin over substance. There is no way that conclusion can be drawn from an objective analysis of observed data.
Yes please, can we leave secondary forcing out of it for the time being?LOL
Wildlife…
I appreciate that your own experience lends you to believe a migration of 10 miles a year but, according to the RSPB, Collared Doves can be found throughout the UK, and have colonised rapidly since their introduction in the 1950s…
http://www.rspb.org.uk/wildlife/birdguide/name/c/collareddove/index.aspx
They were actually north of Cambridgeshire before you left:
http://www.dalswildlifesite.com/thecollareddove.htm
Donegal is indeed beautiful. I do not know how much the waters there have warmed but the global rise in Sea Surface Temprerature is just under 0.4C is 33 years:
HadSST2 GlobalMonthlyTempSince1979 With37monthRunningAverage.gif
That’s about 0.12Cpd. Maybe that is enough for new species to migrate, but…
How much of that is due to CO2? 🙂
Kind regards,
60 month smoothing takes off that jagged appearance you get from the stochastic nature of the data, with weather changes from year to year superimposed on any long term trend.
The birds, as you say first crossed the Channel and the North Sea into the mildest parts of the UK in the 1950s and spread out West and North from there. I was interested to see one source describe a drop in Collared Dove garden visits in recent years, They speculated on Wood Pigeon competition; I though of recent colder Winters.
Retired science teacher. I like back-of -the-envelope calculations. They leave out a lot of detail, but give a quick feel for the situation.
The accepted total backradiation is about 180W/M^2, of which the main contributor is is water as clouds or vapour. CO2 produces around 33W directly, about enough for a 10C effect. The rest comes from secondary forcing due to extra water vapour and increases in other gases. My simplified calculation assumed that all the change was due to increased CO2, directly from its back radiation and indirectly from its secondary forcing. Your point was about timescales rather than detailed mechanisms.
IPCC discusses this in more detail in AR4, and its range of predictions and probabilities are based on uncertainties in the degree of forcing with increased CO2.
Heat enters the oceans by direct absorbtion of direct radiation and back radiation, and by exchange of heat with the atmosphere. The timescale to reach equilibrium depends on the rate of mixing. The first few metres are mixed by wave action and can change in days or weeks. Mixing extra heat into the top 200 metres(continental margin depths) takes a year and to heat the full depth of 2 miles or more takes from decades to centuries. For some of the deep currents of the thermohaline circulation a millenium would be necessary. If there is no lag the whole ocean would need instant heat transfer.In practice, to bring the whole ocean into equilibrium with a warmer atmosphere would take a considerable time.
“Future warming {of the oceans}will be faster” came from physics. Heat flow rate across a boundary is proportional to the temperature gradient in degrees Kelvin. Because of the lag in transferring heat to the oceans, the gradient between air and sea surface temperatures is likely to get larger rather than smaller in the near future.
Incidentally, if you think in K rather than C, as the modellers do, things sound less extreme. I’ve seen people argue that a change in temperature from 10C to 11C is an increase of 10%, when the correct calcuation is an increase from 283K to 284K, an increase of 0.35%. If I said that an increase of 0.005% in CO2 might produce produce a temperature increase of 1C, a layman might say “That’s a unreasonably big effect”
If I said that a 40% increase in CO2 increased temperatures by 0.35%, many laymen would say “That’s not much!”
Of course, both statements say exactly the same, but this is how the propoganda game is played.
Thinking about the effect of temperature on species, they can be surprisingly sensitive to small temperature differences. Go to a mountainous area and look at the natural treeline. It cuts off over a very short vertical distance. With the lapse rate cooling at 2C per 1000 feet that’s 0.1C for a vertical rise of 50feet, and most treelines go from full growth to nothing in less than that.
Entropic Man: “I like back-of -the-envelope calculations. They leave out a lot of detail, but give a quick feel for the situation.”
“Heat enters the oceans by direct absorbtion of direct radiation and back radiation”
Solar radiation penetrates the surface and is absorbed from a couple of centimetres to over 100m down. The vortices that form between waves below the surface mix down warmed water.
Back radiation can’t penetrate beyond its own wavelength and consequently causes a rapid rise in the temperature of the top layer of molecules in the ocean surface. This causes prompt evaporation of water molecules which due to the enthalpy involved cools the surface rather than warms it.
The two processes are different and have different effect. The back of your envelope is sufficiently large to write misleading precis upon, but science doesn’t proceed on precis.
” an increase from 283K to 284K, an increase of 0.35%”
Yes, and considering solar variation over the C20th may be around 0.1%, and Nir Shaviv found a terrestrial amplification of solar variation over the 11 year cycle of x5 in his study of using the ocean as a calorimeter, it may well be that solar variation can account for all of global warming.
Treelines were at considerably higher altitudes in the Medieval warm period, and the bronze age. Their northerly limits in Scandinavia were at higher latitudes too.
“The two processes are different and have different effect. The back of your envelope is sufficiently large to write misleading precis upon, but science doesn’t proceed on precis.”
My calculation responded to a specific question. It addressed the time lag between an increase in energy input to Earth’s energy budget, and the system reaching equilibrium. I think the warming comes from more CO2, but the same applies wherever the extra heat comes from.
I’ve used the back-of -the envelope technique before in scientific, engineering and domestic situations. It grossly simplifies a complex situation, giving a quick appoximate answer which tells you whether a more detailed calculation would be worthwhile.
” an increase from 283K to 284K, an increase of 0.35%”
Again you miss the point. My comment referred to the tendency for numbers and statistics to be presented in whatever way suits the propoganda argument, and gave different examples. I was discussing debating technique, not the data itself. We’ll discuss that elsewhere.
“Treelines were at considerably higher altitudes in the Medieval warm period, and the bronze age. Their northerly limits in Scandinavia were at higher latitudes too.”
That’s three times I’ve been misunderstood.
Mr. Bryant expressed surprise that small changes in temperature could affect species distributions, Treelines are a graphic example of how sensitive organisms can be to small temperature changes.
Treelines are a useful temperature proxy, as you describe. I’m quite happy with the Medieval warm period and higher past temperatures. I regard the the higher temperatures shown in past millenia as evidence that we should be in the slow temperature decline phase of an interglacial, around 0.1C per milennium.
This raises the question, why are treelines now rising?
http://www.springerlink.com/content/k50650p20lju224l/
“60 month smoothing takes off that jagged appearance you get from the stochastic nature of the data, with weather changes from year to year superimposed on any long term trend.”
What it also does is effectively reduce the period of no (or very little or negative) warming since 1998. Smoothing is a neat statistical trick. I can’t help wondering whether the MBH98 graph would have had the same political impact if it had been drawn with 60 month smoothing…
By the way, your best fit line does go outside the 95% upper limit around 1972. But the main point about your graph versus mine is that my trends are overall trends, from the start of the dataset. I have said before that there can be many short term trends which are either accelerative, decelerative or flat. If the 1878 trend line is surpassed by another trend line drawn from the start of the dataset, then one can say the overall trend is accelerating.
CO2: Are you seriously saying that you believe CO2 contributes 10C to the Greenhouse Effect? Please refer to my earlier argument regarding the lack of evidence to support this. If CO2 contributes 10C now, then it must have contributed slightly more than 7C in 1850, before a 40% rise. If it contributed 7C in 1850, then other GHGs must have contributed 25.1C (7+25.1=32.1, which was the GE in 1850). If CO2 contributes 10C today, then other GHGs only contribute 23C. So you are saying that water vapour and the other non-condensing GHGs have actually reduced their contribution? In spite of other nGHGS increasing at rates equal to or greater than 40%?
This is what becomes of arguing from a theory – which is based on an assumption. I am arguing from evidence and reason. One of us will be vindicated in time – say another 10 years or so? I seriously hope we’re around to discuss it again! 🙂
However, when considering the efficacy of CO2 as a GHG, you should realise that every CO2 molecule in the (well mixed) atmosphere is surrounded by about 2500 molecules that are INCAPABLE of being warmed by radiation. In fact, only 99.6% of the dry atmosphere is capable of being warmed by radiation. Add water vapour (about 2.5% ish) and you still have 99.6 out of a possible 102.5% which is incapable of being warmed radiatively. How are these molecules warmed? By conduction (low energy collisions). This is why water vapour contributes much more to the GE, because it exists in far greater quantities and can impact more radiatively inert molecules, in addition to its ability to absorb radiation.
“If there is no lag the whole ocean would need instant heat transfer.” Now you know perfectly well that we were discussing the lag of CO2 effect on the atmosphere. Of course there would be a lag in ocean heating but, again, you then have to explain how a small amount of atmospheric heating can be transferred to the ocean depths without any correspondingly large rise in surface temperature, which has been warming at a relatively gentle rate of about 0.1C per decade since the start of the HadSST2 dataset.
What has happened to the heat as it has descended through the surface?
““Future warming {of the oceans}will be faster” came from physics. Heat flow rate across a boundary is proportional to the temperature gradient in degrees Kelvin. Because of the lag in transferring heat to the oceans, the gradient between air and sea surface temperatures is likely to get larger rather than smaller in the near future.”
Ok, maybe I misinterpreted the ‘faster warming’ thing, especially as the {of the oceans} bit was omitted. However, that last sentence doesn’t appear to be reflected in observed data, especially as the SST graph looks an awful lot like the HadCRUt3 graph!
“…but this is how the propoganda game is played.” Yes, I’m sure the claim that a doubling of CO2 will lead to a warming of 1% wouldn’t be quite so well received by the politicians or the MSM! LOL
As for treelines, I’ve seen lots thanks. Are they the ‘tipping point’ equivalent of arboreal manifestations? Obviously, temperature is one factor in their formation, as is water, soil depth, nutrient availability, snow amount… Interestingly though, for your contemplation, but it is probably worthwhile to note that the treeline in Scotland (Lat 57 deg N) is appx 1600ft, whereas the Norway (Lat 61deg N) treeline is appx 3600 ft, and the Canadian Rockies (Lat 51 deg N) treeline is at 7900 ft. Curious, eh?
I think the argument of global warming by species abundance probably needs some more data…
Fond regards,
Very quickly, for I’ve to get up early tomorrow.
Damn the political impact. I want to know what the planet’s doing. Averages should be chosen for maximum information, not to support one point of view.
Distinguish between primary forcing around 10C from the direct effect of CO2 and the 23C odd from secondary forcing as humidity and cloud cover increase as a result of the CO2’s warming.
Do not think of CO2 warming the atmosphere directly in low humidities. Think of it as warming the ground by back radiation, which then warms the atmosphere by convection. At high humidities you do get some direct heating of the atmosphere as radiation from CO2 and water vapour interact.
I do not think of atmospheric temperatures in isolation. They are what we can measure best, but are part of an interacting system of air, land, water and ice, which all exchange energy and all influence changes and new equilibria.
Treelines vary according to complex variables, of which January temperature is probably the most important. There is a useful Wikpedia entry on this. A lot of the variability you describe across the world is probably due to different tree species with different temperature tolerances. I doubt that the same species define the treeline in Britain, Norway, the Canadian Rockies and Kilimanjaro.
Using the variation with time of the treeline in a single location would probably give the most useful climate information, because all other factors remain relatively constant.
Entropic man,
“Damn the political impact…”.
I’d love to but the Climate debate is predicated on the political impact. Any scientific impact from the MBH98 graph has been adverse from the point of view of the authors. If the pro-cAGW commenters were to stick just to science, there would never have been a ‘catastrophic’ aspect. There simply IS NO EVIDENCE to support any indication of catastrophe from increasing CO2. All the pro-cAGW commenters have is a theory. Actually its not even a theory, maybe not even a hypothesis, its a postulate (or postulation, if you prefer) without any evidence. Any projection based on models (the algorithmic input of which is decided by assumption) is not evidence Evidence is what the planet says, so see below…
“I want to know what the planet’s doing.”
Well, it is revolving in space around the Sun, the same as it has for billions of years. The climate has rarely been constant during that time. Certainly not to within the sort of temperature change we have seen since ‘accurate’ measurements were possible. Don’t get bogged down into the ‘right now’ and listen to doomsayers who have no scientific integrity and relatively little objective thought. Here are some more details (call them facts if you like):
1. The measured global temperature has risen by less than 1 degree Celsius in over 160 years.
2. The measured temperature of England has risen but about 1 deg Celsius in over 350 years. (Longest running dataset on the planet.)
3. No-one (but no-one) can say exactly why the warming has happened but it has to be a combination of factors in order to explain the several warming and cooling periods. Pro-cAGW commenters can’t have their cake and eat it, especially if they want to call it science.
4. The sea surface temperature has risen by 0.3 C in the last 30 years.
5. The Arctic sea ice has decreased, its true, but the Antarctic sea ice has grown. Globally, not much change (but what’s it got to do with CO2?)
6. Scientific method commands that a ‘theory’ must be validated by supporting data. If the data does not support, then re-visit the theory.
7. The total concentration of all nGHGs in the atmosphere amounts to less than 400ppm, or 0.04%.
8. There is no evidential proof of ‘thermal lag’ as far as the atmosphere is concerned.
9. There is no evidential proof that CO2 can significantly affect the global temperature. If you have any (not from a model) then please present it.
“Averages should be chosen for maximum information, not to support one point of view.” Change the first word to ‘Observed data’ and I wholeheartedly agree.
All convection does is transport warm air from one altitude to another (horizontally by advection). The warm air it contains is warm due to conduction. Any heat transfer at higher altitudes is also by conduction. Only 0.04% of the dry atmosphere is radiative.
My argument against your ’10 deg C’ assertion still stands. If you can explain why such a ‘powerful’ GHG can be increased by 40% (and greater increases in Methane and other GHGs) has only resulted in an unknown portion of such a small temperature increase, without invoking ‘lag’ or other such unproven factors, please do so.
Additionally, water vapour does not need CO2 to warm it. It can absorb LW IR directly from the planet. The secondary warming you speak of has – again – no evidential support and has to be negligible or else the temperature rise would be much greater.
If you can provide some data on treeline variation in a single location which supports your assertion, I’d love to see it.
Finally, you say:
“I do not think of atmospheric temperatures in isolation. They are what we can measure best, but are part of an interacting system of air, land, water and ice, which all exchange energy and all influence changes and new equilibria.”
I agree 100%. So where do you see the evidence of catastrophe in all this? Facts, not hype.
Regards,
Entropic,
Apologies, I have just re-read your link to treeline in a single location. Please ignore my request for the data. Must have just missed it in your post.
Arfur
Can we concentrate on the science, not the politics.
You quote a 0.3C increase in sea temperature over the last 30 years, while the records show a 0.5C-0.6C air temperature increase. Is this not a lag? This is why air temperatures are increasing slower than you expect; part of the extra energy you expect to appear as higher air temperatures is being diverted to warming millions of cubic miles of seawater. (and a bit of ice 🙂 )
Regarding the ice.
http://nsidc.org/arcticseaicenews/
Look particularly at the graphs of Arctic and Antarctic ice extent, both showing records. Look at the records in the context of the +/-2SD bands. The Antarctic maximum is 2.5 SD, 0.9%, above the long term mean. The Arctic minimum is 6SD, 49%, below the mean. I would not describe one as balancing the other.
For a description of the effect of increased CO2 I refer you to Hansen’s original 1981 paper.
Click to access Hansen81_CO2_Impact.pdf
There’s also a detailed discussion of the evidence in AR4. For a summary look in the FAQ section.
Click to access ar4-wg1-chapter2.pdf
Catastrophe?
We’ve been running this experiment to increase the CO2 content of the atmosphere way beyond its normal upper boundary for 130 years. The climate normally reacts to change over centuries or milennia.The results wont be in for some time yet, though some parts of the experiment are starting to show interesting behaviour. I expect to convincingly answer that part of your question in about another hundred years.
Can we concentrate on the science, not the politics.
You say that and give me a Hansen paper? LOL In which he talks about a 70M rise in sea level, the flooding of Louisiana (5M rise) and the rapid disintegration of the West Antarctic ice sheet. All based on models! That is supposed to be science? Hansen (and the the IPCC) predicts a 0.2C per decade rise in global temperature which has demonstrably NOT happened, even using GISS:
http://rankexploits.com/musings/2012/arima11-mc-corrected-gistemp-trends-inconsistent-with-0-2cdecade/
I keep saying that using an argument based on models is not providing evidence. The evidence does not support the models. Therefore, logically and scientifically the models are wrong. Therefore the theory is either wrong or at least needs re-thinking. Constantly throwing models at me as evidence is not going to change that simple scientific fact.
Sea Ice. A picture paints a thousand words:
NSIDC GlobalArcticAntarctic SeaIceArea.gif
Yes, I accept that the total global sea ice has dropped. The question is: what has it got to do with CO2? From the graph, the global drop is visible but not in any way cause for concern. Hansen’s paper (again) talks about the opening of the North West passage as if that was a bad thing (it’s not) and actually discusses the complete melting of the polar ice cap. Only another 3.4 million Km2 to go. Further, I suggest to you that air temperature is not the reason for sea ice melting (apart from a small amount of sublimation) – local sea temperature is much more likely but that is probably a different debate.
The description of the effects of CO2 (again from the Hansen paper) is ALL based on models and theory (and on assumption). A 5 to 10C rise expected in Northern Latitudes? Facts, not hype, please!
Again, your link to AR4 does not provide evidence. Model output does not provide evidence. Observed data provides evidence.
The ‘experiment’ (it’s not, really). CO2 “…way beyond its normal upper boundary”. There is a normal boundary? A 130 year time frame? What caused the MWP? Constant CO2 level?
You say we could get an answer in 100 years. How many more years of no significant warming will it take for you to reduce that assessment? I would say 10 years – at most. But then I would be guilty of making predictions – which I try to avoid!
Regards,
Just realised I didn’t respond to your question: “Is this not a lag?”
No, it’s not. It’s evidence that the atmosphere has a greater temperature variation than the ocean. On any given day around your neck of the woods, the diurnal temperature can change by 8 deg C whereas the sea temperature will change by only a couple of degrees.
To show you it’s not lag, look at these two graphs:
HadSST2
HadSST2 GlobalMonthlyTempSince1979 With37monthRunningAverage.gif
HadCRUT3
HadCRUT3 GlobalMonthlyTempSince1979 With37monthRunningAverage.gif
Look at them both on the same screen. Note that:
They both peak between 1998 and 1999. Therefore no lag.
They both trough between 2000 and 2001. Therefore no lag.
They both show a sharp dip in 2008. Therefore no lag.
They both show a double peak either side of 2010. No lag.
If there was the type of lag you surmise, the ocean peaks and troughs would be later than the near-surface data, and the sea temperature graph would show an increase greater than the near surface temp. From observation, this does not happen. The two graphs are virtually identical in shape.
Your diatribe about Hansen and IPCC deserves no reply.
Regarding air and sea temperature changes, consider specific heat.
Air has a density of 1.293kg/m^3 at STP and a specific heat capacity of 1.006 kJ/kg/K.
To warm 1m^3 of air by 1K would require 1.293*1.006=1.3kJ.
Water has a density of 1000kg/m^3 and a specific heat capacity of 4186kJ/kg/K.
To warm 1m^3 of water by 1K would require 1000*4.186=4186kJ.
By mass water requires 4.16 times as much energy as air for each 1K rise.
By volume water requires 3220 times as much energy as air for each 1K rise.
This means that water has much greater thermal inertia and responds very much more slowly to changes in energy input than air. Oceans and atmosphere eventually reach equilibrium.Because of the enormously greater energy needed to change the temperature of the oceans, the time taken to reach equilibrium depends mostly on the rate at which the oceans absorb heat, rather than the rate of warming of the atmosphere.
“Your diatribe about Hansen and IPCC deserves no reply.”
Then don’t use his deeply political paper as evidence. You introduced it, not me.
At the risk of our civilised debate degenerating, you appear to be getting selective as to which of my points you want to address.
Additionally, you are completely missing the point about oceans and ‘lag’. According to your comments about heat capacity:
“By mass water requires 4.16 times as much energy as air for each 1K rise.
By volume water requires 3220 times as much energy as air for each 1K rise.”
I don’t have a problem with that; how does it help your case? Look at the graphs I linked to again (which, by the way, are observed data) again and explain why there is no lag in the water temperature being warmed versus the air temperature being warmed? And then explain why the OHC increase has happened without a corresponding surface warming. And then explain what it has to do with CO2 at a concentration of less than 400ppm in the atmosphere with a vastly lower specific heat capacity than the oceans. And then go back to your original question about whether the comment at the initial post could be justified.
And, if you’re gong to be selective, we may as well stop. Some sort of comment on the graphs I linked to would seem to be in order. I would hate to ruin what has been a most stimulating debate.
Regards,
I dont have time at the moment to properly research more than one thread, so I concentrated
on lag.
Check your last post but one. The links you gave to hadcrut have not come up as links, so I have been unable to access them in the few late night minutes I’ve had available these last few days.
We do seem to be arguing at cross purposes, so it is probably time to stop. We’ll resume later on another thread, possibly when Mr. Seifert’s paper comes out.
I have noticed lately that as the sun is setting it is a lot brighter than normal. Usually it is a deep red and you can stare at it comfortably. Recently it has been bright and lacking it’s red colour, enough that you can’t stare at it. Is this because all the recent rain has cleared dust out of the atmosphere?
The September minimum temperatures for Central England have also been a lot lower than for a quite a while, suggesting the sky has less dust in it.
Entropic man,
OK, we’ll call it a day until we get another chance. Thanks very much for the stimulating and intelligent discussion.
As to the links, I am surprised they don’t open. They are links to http://www.climate4you.com which is a very useful site and portrays the data in graph form. All the linked data is available from the menu bar on the left.
All the very best to you.
Regards,
Arfur
Kelvin Vaughan
Sorry I can’t help there Kelvin. I’m in the Middle East at the moment and there is plenty of dust in the atmosphere here! 🙂
The gods gave me an unexpected free evening, so one last encore. Look at page 959 of Hansen’s 1981 paper.
Click to access Hansen81_CO2_Impact.pdf
It spends most of a page discussing the same oceanic warming mechanisms I’ve been trying to get over to you.
Look at Fig.1 on page 960. In 1981 he expected 373ppm CO2 for 2000, twenty years ahead. The actual mean figure for 2000 was 368ppm.
Using the 373ppm estimate Fig 1 predicts possible temperature rises based on his model, with different rates of oceanic warming.The actual rise since 1880 to 2000 based on Hadcrut3 is from an anomaly of -0.25C to 0.45C, an increase of 0.7C. This is well within the bounds of Fig 1’s range of predicted possible temperature increases for 2000.
Look at Figure 5 on page 963. The graph most relevant is the comparison between model and observation for CO2+volcanos+sun in part b. Note the close match.
A model designed forty years ago made good aftercast predictions for previous decades and a forecast of temperature 20 years ahead, which is a good match for 2000 observations.
The reason why the sceptics throw so much ridicule, so many ad hominen attacks and so much venom at Hansen and his 1981 paper is not because it was wrong, but because it was,in retrospect, correct.
[Reply] This is argument by assertion, which is discouraged here. Different people find Hansen’s arguments ridiculous for different reasons. Not least because he keeps adjusting the temperature record to match his theory. Also, just because his spread of estimates covers HADcrut3 doesn’t mean his hypothesis is correct. Correlation does not necessarily imply causation. I can provide an equally if not more plausible scenario to match the observed change in temperature based on natural variations of Sun, ENSO and Atlantic Multidecadal Oscillation. https://tallbloke.files.wordpress.com/2012/10/ssn-soi-amo2.png Pre 1917 all the HADsst2gl temps seem to have been dropped by 0.25C. This is backed up by a comparison with NMAT, night-time marine air temperature.
Just found out that the monthly max and mins for CET since April have been near enough the same as 1878. If it carries on the same we are in for another cold December like 2010.
Entropic man,
For the umpteenth time you need to look at data, not models.
Now, before I go further, I can’t remember making an ad hominem comment since I’ve been commenting on climate blogs, so rest assured on that score.
Hansen’s paper uses ‘aftercast’ data to come up with a close match on observations that have already happened! Well, boogaloo. Forgive me if I’m seriously unimpressed. I can come up with a close match by drawing a smooth line along the observed data and, hey presto!
So lets look at what really happened after 1980…
The DATA from HadCRUt3 is here:
http://www.metoffice.gov.uk/hadobs/hadcrut3/diagnostics/comparison.html
Just follow the ‘annual data’ link after the first graph
Or try:
http://www.metoffice.gov.uk/hadobs/hadcrut3/diagnostics/global/nh+sh/annual
It will download automatically (it does on my mac, anyway) and you will have the actual data of annual temperatures.
Please note the annual figure for these years:
1880 = -0.209
1980 = 0.101
2000 = 0.239
You will note that is a difference of 0.45C (not 0.7C as you stated). This puts it below the band of ‘probably warming’ in Fig 1.
Now look at Fig 1 again. It shows a (what looks like) exponential curve which implies continuation after 2000. Do you have the model output for the years after 2000? Can you imagine that the curve would have showed zero warming after 2000? Just because a model ‘fits’ for a very short time period doesn’t mean that the model is correct, especially when the model uses figures that have already been observed. The true test of a model is is forecasting ability. And limiting the forecasting to twenty years (1980 to 2000) is pretty poor confidence.
And, in any case, as Tallbloke says, correlation (especially over 20 years) does not necessarily imply causation. Hansen has effectively reduced the period of forecast to twenty years and people have fallen for it. There is no justification for lauding this paper when the last 14 years or so has seen no warming. All of a sudden, Fig 1 doesn’t look quite so relevant, does it? It is also quite telling that Hansen chose 1880 as a start point, just after a drop of over 0.2C in temperature. Why not use the entire dataset? I also note you have completely ignored the fact that Hansen littered the paper with alarmist conjecture. There is no room for that in a truly scientific paper. Maybe that’s why sceptics don’t like him.
And if the e-folding time to equilibrium is appx 6 years, what’s happened to the thermal lag over the past 14 years? What we should do is ask Hansen to run the same models with the same algorithms further past 2000 and see what comes up.
Anyway, I thought we’d stopped the discussion? 🙂
” ad hominem”
Sorry, I spent too much time on WUWT, where ad hominems are part of their stock-in-trade. Also, beware of words like “ridiculous”. I’ve come to regard such emotional language as indicating that the user has crossed from scientific debate into rhetoric.
Mathematical models are widely used, to simulate systems in which algorithms can stand in for physical processes. These include structural analysis, aerodynamics and climate.
A useful model must pass three tests.
1) Design. It must provide a valid mathematical analog for the physical processes and causal relationships in the system to be modelled.
2) Test. Given basic physical parameters from a known starting point the model it should be able to derive the later development of that system, which can then be compared with observations.
3) Prediction. Given the physical parameters for an unknown situation, the model should be able to derive the future state of the system. This can then be compared with observations made after the event.
How does Hansen’s model meet these tests?
Design? I am not competent to judge. The model passed peer review and developed versions are still in use for weather forecasting and climate research.
Test? Figure 5 in the paper compared the derived states from the model with actual observations, with a good fit between them. This confirms that the algorithms successfully simulate the physics and the causal relationships involved.Do not sneer at such testing. Would you drive a car with electronic handling aids if it had not undergone such testing?
Prediction? The temperature figures I gave were 5 year averages taken from the hadcrut 3 graph for 1880 and 2000. They fit Figure 1 in the paper, the prediction for 1880 to 2000. The other datasets vary in their exact figures, and also fit within the probable range in Fig 1. Figure 6 gave a range of predictions to 2100, depending on different economic and CO2 growth scenarios; which we are not yet in a position to test.
From a 2011 perspective I regard the model as validated.
I have to go. My wife is unwell.
Entropic man,
Firstly, please don’t apologise for caring for your wife! That is far more important than having an online discussion. I sincerely hope she recovers soon.
I realise that we have moved pretty far from the original thread. I don’t have a huge problem with that, but the discussion has certainly lost its way. We a re now engaged in an esoteric debate about models, which neither of us are probably expert in. But I’ll engage…
Let us not be under a misapprehension about the efficacy and veracity of models in different disciplines. An engineering model uses far more exact and known parameters than a climate model. The algorithms used to test components are far more accurately established than, say feedback forcing in a GCM. There really is no comparison. Additionally, engineering models tend to be proved correct. Again, this does not compare with climate models.
I doubt that you could provide evidence of one original IPCC model that has proved accurate today (accurate to any reasonable amount).
The IPCC AR4, Summary for PolicyMakers states:
“For the next two decades, a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios.”
This has been shown to be not observed:
http://rankexploits.com/musings/2012/arima11-mc-corrected-gistemp-trends-inconsistent-with-0-2cdecade/
Your Hansen Fig 1 graph uses aftercast figures until 1980, then a projection to 2000. Aftercast models are ALWAYS a better fit than forecast models! I ask you again to look at the graph and say whether you think the curve as shown would imply a continually accelerating warming. The figure bears no relation to what has been observed between 1980 and 2012. I have given you actual data to prove to you that your estimated 0.7C rise was wrong. You prefer to use a 5-year average from a graph. If your Hansen model-graph was true, the extrapolation of the curve beyond 2000 would lead to a much higher figure for global temperature than we see today. You say the Hansen model is validated. I say it is not. I suspect we will simply have to disagree on that.
As for ad hominems, I wouldn’t single out WUWT as the main culprit. There are many others. I can’t stand ad hominems anywhere, and have suffered some of the worst on Judith Curry’s site. I much prefer rational debate. (which is what I think we have had here.)
Regards and all the best to your wife.
Thanks. Kathleen is worried about our daughter, holidaying in Israel and Jordan.
I had time to chase some data tables, rather than reading small graphs.
Hadcrut3, 1881 to 2000, -0.263 to 0.271=0.534C( you are right, my estimate from the graph was too large)
GISS , 1880 to 2000, -0.3 to +0.47=0.77C
NOAA, 1880 to 2000 -0.49 to 0.62=1.11C
UAH, 2000, 0.56 (nothing for 1880, of course). To approximate, if you take an average 1880 value from the other three datasets UAH gives an increase from -0.35 to 0.56 and a change of 0.91C
Reading directly off the Figure 1 graph, Hansen’s probable warming range to 2000 was from about 0.48C to 0.76C. Hadcrut3 is near the bottom of the range, GISS is on his upper boundary. NOAA and UAH are both above his upper boundary. Possible interpretations? Some of the datasets are overeeading; Hansen’s predictions were conservative; we know damn all about whats happening and this discussion is all hot air.
Regarding current temperatures, lets wait for the 21st century baseline to extend a bit, until we can see whatever pattern becomes significant.
Remember, developing a model is an iterative process I think you miss the point of aftercasts. They are used to tune the model, adjusting parameters with large 95% confidence limits such as secondary forcing until the output, in this case temperature variation, agrees with observation. In the process you gain insight into likely actual values for the parameters concerned.
This is not determinist, which is why Hansen, IPCC and others using models give a range of predicted outcomes with probabilities, rather than exact values. I sometimes think sceptics are like politicians, expecting impractical levels of precision in the predictions they ask of climate scientists.
One side issue arising from this discussion is the problem of correalation and causation. Do you know of any generally accepted procedure for deciding whether causation is involved? For example people wearing shorts are more likely to buy ice cream. This is correalation without causation. Ice cream sales do correalate with increased daytime temperatures, which is genuine causation.
Perhaps to demonstrate causation you need to demonstrate a mechanism linking the variables. I see a causal link between increased CO2 and increased temperature, because I accept the mechanism. You do not accept the mechanism, and therefore do not accept the causation.
Your link attempts to falsify the AR4 prediction by using the post 2000 data to show rates of warming decreasing. Since the temperature data does show a flattening in the last decade, a rate decrease would be expected. Once again, the implication that long term warming has stopped is a step too far.Remember,we’ve already discussed the uncertainties involved and people’s tendency to read too much into short term variations.
We have drifted a long way, and I’m off for a couple of weeks holiday. We’ll fence again.
Entropic:
if you take an average 1880 value from the other three datasets UAH gives an increase from -0.35 to 0.56 and a change of 0.91C
You can’t do this estimate, because UAH uses a different baseline climatology range of years.
we know damn all about whats happening and this discussion is all hot air.
Regarding current temperatures, lets wait for the 21st century baseline to extend a bit, until we can see whatever pattern becomes significant.
Agreed.
In the process you gain insight into likely actual values for the parameters concerned.
Not if you can produce an equally plausible model with different parameters which are within their uncertainty range. e.g. https://tallbloke.files.wordpress.com/2012/10/ssn-soi-amo2.png
I sometimes think sceptics are like politicians, expecting impractical levels of precision in the predictions they ask of climate scientists
Decade long downturns in temperature unforced by volcanoes were not expected or predicted. But Hansen et al will not discuss the cause of the hiatus in warming because the implication is that the negative phase of natural variation is more powerful than co2. The obvious logical deduction is that natural variation contributed at least half the late C20th warming in a previous positive phase.
I see a causal link between increased CO2 and increased temperature, because I accept the mechanism. You do not accept the mechanism, and therefore do not accept the causation.
Temperature changes precede co2 changes at all timescales. Cause precedes effect. Co2 levels are strongly temperature dependent. If they also caused temperature change, there would be a strong positive feedback. This is not observed.
the implication that long term warming has stopped is a step too far,we’ve already discussed the uncertainties involved and people’s tendency to read too much into short term variations
Sceptics say 30 years of warming is short term variation, because it’s only around half the length of the big oceanic cycles. In the case of the late C20th warming from 1975-2005, it’s the positive, warming side of the AMO cycle. Therefore claiming that there is a long term warming not due to natural variation is a step too far anyway.
I hope you and the missus have a relaxing holiday.
Entropic man,
Basically, what Tallbloke said!
It wouldn’t be fair to argue your points again as you are about to leave on holiday, so I will leave it here. However, I would like the opportunity to argue those specific points at a later date, as i believe you are missing out some fairly large logical fallacies in your thinking. I’m itching to comment but I’ll defer!
Enjoy your holiday.
Regards,
Arfur