2010 Likely to be the Warmest Year on Record

[Samm]

No problems. You are debating well and reading the references. You're also polite which I think is a plus in any debate. (And it's something sadly lacking in the climate debate. Name calling and point scoring seems to be the usual order of the day. As the comments sections of Realclimate or Whats Up With That demonstrate.)

 

Thank you. I find it rather funny that the people in the comments sections often devolve into flaming on those climate blogs.

 

Quite possible. I came across the YD event while looking for examples of catastrophic change around the 9,000 BC mark. Meltwater intrusions into the North Atlantic fit the bill and might have been devastating when you work out how much water it takes and how fast it has to be added. Some of the papers on this are very scary. But intensely interesting as it deals with how an ice shield melts. We know the ice "receeded", but did it melt from the front, the top or the bottom? Or a combination? Differing theories lead to very different scenarios concerning the end of the Ice Age and what happened to the areas in front of the ice.

 

Hmm. I probably should do a little more reading into that.

 

Agreed. But if you've been shot enough by enough people you would start to wonder yourself. A good example of what happens to those who don't toe the "consensus" line are some questions asked of Judith Curry recently by the person who edits her "Sourcewatch" page, I'll quote the email in full from here. http://judithcurry.c...t/#comment-6964

 

So by starting a blog and engaging with sceptics some think it reasonable to assume that she is either mentally impaired or being threatened and/or blackmailed?

 

Yeah. That's pretty deplorable. I don't think anyone really deserves that sort of treatment for, almost anything. I mean, what's the writer of the email trying to do? Curry's not even a skeptic herself..

 

However, Spencer does seem a little weird. I can understand getting aggravated by his current predicament, but he seems a lot more accusational than that.

 

WRT clouds and the forcing/feedback question. Climatology views clouds only as a temperature feedback, working much the way you describe. In the short term clouds can drive temps, for example a cloudy night is warmer than a cloudless night. The nub of the disagreement in this area concerns whether clouds respond to other forcings as well. GCRs come to mind, also changes in ocean currents. Should clouds respond to these on a long term basis then they are still a feedback to those forcings but they become a forcing in terms of temperature.

 

The question here is this "Do clouds only respond to temperature changes?" If the answer is yes, then they are a temperature feedback, but if the answer is no then they become a feedback for something else, but a temperature forcing. Messy as hell, but that is why Dr. Curry descibed climate as a "wicked problem" in her testimony to Congress.

 

GCRs? I'm not exactly sure what that stands for, sorry.

 

However, changes in ocean currents are they influenced by anything external greatly? I mean, it seems to me as if they're just a feedback of temperature, salinity and the Coriolis force. All of which are either internal, salinity and temperature or relatively stable, the Coriolis force.

 

I'll do some digging, it's been a while since I've looked at the paleo papers closely. I'll have to get back to you on this.

 

Okay, that'd be great.

 

Look at the graph of Holocene temps you posted. while the resolution isn't great the period around 1500 AD is easily the lowest temps for more than 10,000 years. A point that you might want to consider too. If the resolution of the graph is too low to show the modern "extreme" warming, then it is too low to show any other examples of "extreme" warming as well.

 

That is true. the resolution would prohibit us from seeing the more extreme and short term changes in temperature. I don't dispute that Little Ice Age shows up on that graph, although, it doesn't really appear on the peer-reviewed global reconstructions. So, I'm saying that I'm unsure of it's magnitude.

 

Remember that the "Global" reconstructions are based on interpolating specific sites or small regions, if there was a way to quantify the advance and retreat on the basis of temperature, the Alps could be used as a proxy for paleo reconstructions.

 

Sure, that would be a good thing. Especially if it could be calibrated against the instrumental temperature record.

 

Anyway you might be interested in the results of Ljungqvist, F.C. 2010. The data is available on the NOAA siteand the graph looks like this; (Although this is extra tropical NH, not global.)

 

Again much closer to Moberg 2005 than any others.

 

Although this graph is probably fairly accurate, it is only a proxy reconstruction and lacks the instrumental temperatures in the last 150 years. The actual paper says the following:

 

The temperature of the last two decades, however, is possibly higher than during any previous time in the past two millennia, although this is only seen in the instrumental temperature data and not in the multi-proxy reconstruction itself.

 

Basically, they haven't provided the instrumental record for comparison and to construe this as a complete temperature reconstruction would be a little dishonest. It should be considered a proxy-reconstruction only.

 

As much as I admire and respect swansont, a couple of blog articles do not refute a peer reviewed paper. McShane and Wyner has been published in the Annals of Applied Statistics as a discussion paper with invited discussion from both the climate and statistical communities, as well as a reply from McShane and Wyner. http://www.imstat.or...next_issue.html The papers are at the bottom of the page. I'm still working my way through them and freely admit that the technical bits are way above my pay grade, but it would appear that the statistical community is not as sure of the statistical methodologies used by climatologists as the climatologists are.

 

I believe that Swansont addressed this.

 

That the data diverges from the temperature record is called the Divergence Problem. Dropping the data because it might weaken your case is called being dishonest, alternatively only showing data that strengthens your case is called "Cherry Picking". The data is not "wrong", the data simply is. Truncating the data rather than explaining the divergence can only be called "very poor science".

 

Well... I can't see the issue with truncating data that disagrees with more accurate data. The proxies are probably less accurate than the instrumental record, and in order to make it a valid reconstruction you've actually got to reconstruct the temperatures to the best of your ability. Including data that is known to be wrong after a certain point on the graph can be misleading especially if the graph is meant to be a complete(ish) record of temperatures. I wouldn't consider it Cherry Picking.

 

I sincerely doubt that any practicing researcher on this forum would dump part of his/her data from an experiment. they would dump the lot and start again or find a good and sensible reason. Saying it's the "Divergence Problem" is as factually meaningless as saying "Pink fairies did it".

 

Although the Divergence Problem is unexplained, it is known to exist among scientists. I'm pretty sure that they understand that tree-ring data starts to diverge from the instrumental record from around the 1950s onwards. It would be dishonest to include data that is known to be inaccurate from that point onwards. It would be akin to attempting to carbon date dinosaur fossils and then talk about their age based on the carbon dating. Carbon dating works, only within a certain range of circumstances, and dinosaur fossils aren't included in that set of circumstances. I imagine it would be a similar case here.

[JohnB]

First off. Swansont, if I've offended you, I apologise. I didn't notice the "submitted" (it might be an old link). The paper has been "accepted" for some time. Publication was held off until the Journal could get the replies, critiques and response from the authors. From my POV Deepclimate etc were blogs responding to an accepted paper and therefore don't carry the same weight as the responses provided to the Journal.

 

McShane and Wyner do conclude that;

Using our model, we calculate that there is a 36% posterior probability that 1998 was the warmest year over the past thousand. If we consider rolling decades, 1997-2006 is the warmest on record; our model gives an 80% chance that it was the warmest in the past thousand years.

 

They also conclude (and I think this is quite important);

It is widely hoped that multi-proxy models have the power to detect (i) how warm the Medieval Warm Period was, (ii) how sharply temperatures increased during it, and (iii) to compare these two features to the past decade’s high temperatures and sharp run-up. Since our model cannot detect the recent temperature change, detection of dramatic changes hundreds of years ago seems out of the question.

 

Which speaks towards the rate of change.

 

And from their Conclusions section;

Consequently, the long flat handle of the hockey stick is best understood to be a feature of regression and less a reflection of our knowledge of the truth.

 

Samm, I think that many of the blogs are a waste of time, and the tone of many put me off. I like the articles at WUWT but generally skim the comments to see if anybody has posted a useful link rather than wasting my time reading the comments. WUWT would be much better if Willis Eschenbach or Bob Tisdale would actually submit for publication. They appear to know their stuff but I'd rather see the fight in the literature than in a blog. For example Bob Tisdale has shown rather convincingly that a very good fit to the instrumental temp curve is given by a constant .5 degree/century increase with a superimposed 60 year harmonic cycle (PDO and ENSO). The correlation is something like .87 IIRC, but I'd like to see it published rather than blogged. Lucias Blackboard is one that looks at things in detail. I tend to spend my time at Keith Kloors or lurking at Judith Currys.

 

I don't look much at the "Warmista" blogs, either because of their tone or moderation policy. (Some of them come across as borderline "tin hat" brigade. ) The important thing is to not judge the person by the blog. I've found all Climatologists respond to specific questions if asked politely. (In fact only one ever didn't respond to an email and I found out later that he was off sick for about 4 months with a severe illness so I'm not about to complain.)

 

Hmm. I probably should do a little more reading into that.

 

It doesn't make much difference in the current climate debate but it is interesting. If you read non modern climate change paleo you'll see that there were two sides. The Gradualists who have held sway pretty much since the beginning and the Catastrophists. Gradualists believe that the climate is huge and has great inertia, it can only change naturally at very slow speeds. Temperature rose, the ice gradually receeded, the sea levels gradually rose. (That's how it was phrased when I was in school.) They have the mental picture of the ice shield melting and feeding creeks and rivers with maybe the occasional flood event.

 

Catastrophists have a different view. For them things can change very rapidly indeed. If the ice shield melts from the top then you would finish up with lakes of water on top of the ice held back by ice "dams". Think of light rain on a car bonnet. You get all those little pools of water and then one finally moves, it flows into another, and another and another picking up volume and speed as it goes. Now imagine the same thing happening on the top of 2 million square miles of ice shield with not only the area involved but also the drop of two miles of altitude to feed the speed. I remember reading one paper from the 80s (?) where the maths was done. Imagine a wall of ice cold water 500 feet high and nearly 100 miles wide and travelling at nearly 300 miles per hour with the force of over 1,000 cubic miles of water behind it smashing into the Atlantic. More than enough to disrupt the AMOC I would think. From start to finish less than 12 hours and within 4 days the NH goes from deglaciation to full blown ice age conditions.

 

Like I said earlier, scary as hell.

 

As you might realise, I tend to side with the catastrophists. I believe that the climate can change rapidly and globally from purely natural causes. The changes we have seen in the last 140 odd years is orders of magnitude less than has occurred in the past from purely natural forcings. Given this I'm naturally sceptical of people who claim that the current rate of change is "unprecedented".

 

GCRs? I'm not exactly sure what that stands for, sorry.

 

However, changes in ocean currents are they influenced by anything external greatly? I mean, it seems to me as if they're just a feedback of temperature, salinity and the Coriolis force. All of which are either internal, salinity and temperature or relatively stable, the Coriolis force.

 

"Galactic Cosmic Rays", the things CERN are looking into in the CLOUD experiments.

 

Currents are constantly changing on a global scale. A major event took place 55 million years ago when North and South America joined to block the Equatorial current into the Pacific. A mere 12,000 years ago Britain was part of Europe and most of the North Sea was grassland. Indonesia was one large land mass and America and Russia were joined by the Bering Strait land bridge so there was no water movement between the Pacific and Arctic oceans. These events changed the ocean currents and added millions of square miles of water from which evaporation could occur. Major events like these do indeed change the currents and effect cloud cover.

 

On a smaller scale it's still going on. Due to the weight of the extra water since the last ice age the sea bottom is slowly sinking and since it lost the weight the land is still rising. Parts of Canada are rising at a rate of 2 cm per year. It's called "Post Glacial Isostatic Rebound". Scotland is rising and England is sinking. Silt from rivers is being deposited on Continental shelves making them slightly shallower and forcing the deeper currents upwards. In August 2006 the crew of the yacht Maiken witnessed the birth of an island in the Pacific.(The pics were floating around the net via email.) Another in the Pacific in 2000. The island Surtsey came from 130 metres down to be born between 1963 and 1967. The mid Atlantic Ridge runs from north to south with resulting islands from 71⁰ north to 54⁰ south and is in constant motion.

 

Individually the movements are small, but a new island must divert the currents around it and the effect is probably cumulative. Many people start from the basis that the planet is stable and pretty much unchanging. I start from the basis that the planet is dynamic and in constant motion and change. Temperatures wax and wane, storm intensities grow and diminish. The only constant in the climate system is that it will change, with or without the actions of man and we had better get used to the idea. Where this leads to a practical difference is that if you believe that climate to be relatively constant and slow changing, then you will believe it easy to find an anthropogenic signal in the data. However if you consider the climate to be relatively volatile then you will believe it far more difficult to find a signal in the data.

 

Basically, they haven't provided the instrumental record for comparison and to construe this as a complete temperature reconstruction would be a little dishonest. It should be considered a proxy-reconstruction only.

 

They don't have to do your work for you, you know. The reconstruction is calibrated to the same baseline average as the GISS and HADCRUT. In general proxy reconstructions are considered complete reconstructions even without the instrumental periods being used. Because the instrumental period is derived directly from the data it isn't deemed part of a "reconstruction". The term reconstruction is reserved for work where the temperature has to be inferred from proxies. It's a terminology thing, nothing more.

 

Well... I can't see the issue with truncating data that disagrees with more accurate data. The proxies are probably less accurate than the instrumental record, and in order to make it a valid reconstruction you've actually got to reconstruct the temperatures to the best of your ability. Including data that is known to be wrong after a certain point on the graph can be misleading especially if the graph is meant to be a complete(ish) record of temperatures. I wouldn't consider it Cherry Picking.

 

Not quite. Remember that the theoretical basis of the reconstruction is that since the tree rings (or whatever) change in a regular fashion during the current period dependant upon temperature they will therefore respond the same way to previous temperatures. The proof of the methodology lies in the correlation between tree ring width and temperature over the instrumental period. Hence a lack of correlation reduces confidence in the methodology. Showing the divergence and offering an explanation as to why it is occurring and why your methodology is therefore still sound is good science. Truncating the data because it casts doubt on your methodology is nothing more than very bad science.

 

The value of a proxy in a paleo reconstruction is a direct function of how well it correlates to the temperature record, that is how and why you choose proxies. You can't cut out the bit you don't like and tell people that the correlation is great, you have to show the full data and if there is a divergence, explain it. The explanation so far, which boils down to "There is an unknown factor, probably of anthropogenic origin" is bloody weak from my POV.

 

As an aside there was a link to a paper some time ago at ClimateAudit concerning this. Apparently many tree proxies are chosen because they are at the tree line, or vegetation border. The paper showed that some trees grow along the ground until the temps reached a certain point and then they started growing straight up. This led to a great change in tree ring width and density which might go a long way to explaining the divergence problem.

 

You should also be aware that the truncating is not being done to a proxy, it is being done to complete and published reconstructions. Specifically Briffa 2001 is truncated at 1960, with a couple of others in 1980. By truncating them you can say "See, the reconstructions roughly agree" without someone looking at the last 50 years and asking "Hang on, what's going on here?" I call that marketing, not science. This was "Mikes Nature trick" to "hide the decline".

[Samm]

Samm, I think that many of the blogs are a waste of time, and the tone of many put me off. I like the articles at WUWT but generally skim the comments to see if anybody has posted a useful link rather than wasting my time reading the comments. WUWT would be much better if Willis Eschenbach or Bob Tisdale would actually submit for publication. They appear to know their stuff but I'd rather see the fight in the literature than in a blog. For example Bob Tisdale has shown rather convincingly that a very good fit to the instrumental temp curve is given by a constant .5 degree/century increase with a superimposed 60 year harmonic cycle (PDO and ENSO). The correlation is something like .87 IIRC, but I'd like to see it published rather than blogged. Lucias Blackboard is one that looks at things in detail. I tend to spend my time at Keith Kloors or lurking at Judith Currys.

Yeah, I'd like to see it in literature as well. It's more permanent, and adds a sense of reliability to the source. Speaking of which, that the constant 0.5 degree/100 years with a superimposed 60 year harmonic cycle, what does it show?

 

I don't look much at the "Warmista" blogs, either because of their tone or moderation policy. (Some of them come across as borderline "tin hat" brigade. ) The important thing is to not judge the person by the blog. I've found all Climatologists respond to specific questions if asked politely. (In fact only one ever didn't respond to an email and I found out later that he was off sick for about 4 months with a severe illness so I'm not about to complain.)

Right. I suppose that speaks about the general niceness of climate scientists then.

 

It doesn't make much difference in the current climate debate but it is interesting. If you read non modern climate change paleo you'll see that there were two sides. The Gradualists who have held sway pretty much since the beginning and the Catastrophists. Gradualists believe that the climate is huge and has great inertia, it can only change naturally at very slow speeds. Temperature rose, the ice gradually receeded, the sea levels gradually rose. (That's how it was phrased when I was in school.) They have the mental picture of the ice shield melting and feeding creeks and rivers with maybe the occasional flood event.

 

Catastrophists have a different view. For them things can change very rapidly indeed. If the ice shield melts from the top then you would finish up with lakes of water on top of the ice held back by ice "dams". Think of light rain on a car bonnet. You get all those little pools of water and then one finally moves, it flows into another, and another and another picking up volume and speed as it goes. Now imagine the same thing happening on the top of 2 million square miles of ice shield with not only the area involved but also the drop of two miles of altitude to feed the speed. I remember reading one paper from the 80s (?) where the maths was done. Imagine a wall of ice cold water 500 feet high and nearly 100 miles wide and travelling at nearly 300 miles per hour with the force of over 1,000 cubic miles of water behind it smashing into the Atlantic. More than enough to disrupt the AMOC I would think. From start to finish less than 12 hours and within 4 days the NH goes from deglaciation to full blown ice age conditions.

 

Like I said earlier, scary as hell.

 

As you might realise, I tend to side with the catastrophists. I believe that the climate can change rapidly and globally from purely natural causes. The changes we have seen in the last 140 odd years is orders of magnitude less than has occurred in the past from purely natural forcings. Given this I'm naturally sceptical of people who claim that the current rate of change is "unprecedented".

Yeah, that sounds quite severe. I agree what you're saying in that abrupt climate change can occur, but that is usually caused by very extreme circumstances. Such circumstances don't seem to be occurring at the moment, the only thing extreme appears is the level of greenhouse gas increase. This probably lends some justification to the belief that we may undergo serious climate change in the future. Far more serious than we are experiencing at the moment. Given that greenhouse gases affect temperature, would you agree with the notion that steps should be taken to minimise greenhouse gas emissions?

 

"Galactic Cosmic Rays", the things CERN are looking into in the CLOUD experiments.

Right. I thought so, but you never really know for sure until somebody explains them to you.

 

Currents are constantly changing on a global scale. A major event took place 55 million years ago when North and South America joined to block the Equatorial current into the Pacific. A mere 12,000 years ago Britain was part of Europe and most of the North Sea was grassland. Indonesia was one large land mass and America and Russia were joined by the Bering Strait land bridge so there was no water movement between the Pacific and Arctic oceans. These events changed the ocean currents and added millions of square miles of water from which evaporation could occur. Major events like these do indeed change the currents and effect cloud cover.

 

On a smaller scale it's still going on. Due to the weight of the extra water since the last ice age the sea bottom is slowly sinking and since it lost the weight the land is still rising. Parts of Canada are rising at a rate of 2 cm per year. It's called "Post Glacial Isostatic Rebound". Scotland is rising and England is sinking. Silt from rivers is being deposited on Continental shelves making them slightly shallower and forcing the deeper currents upwards. In August 2006 the crew of the yacht Maiken witnessed the birth of an island in the Pacific.(The pics were floating around the net via email.) Another in the Pacific in 2000. The island Surtsey came from 130 metres down to be born between 1963 and 1967. The mid Atlantic Ridge runs from north to south with resulting islands from 71⁰ north to 54⁰ south and is in constant motion.

 

Individually the movements are small, but a new island must divert the currents around it and the effect is probably cumulative. Many people start from the basis that the planet is stable and pretty much unchanging. I start from the basis that the planet is dynamic and in constant motion and change. Temperatures wax and wane, storm intensities grow and diminish. The only constant in the climate system is that it will change, with or without the actions of man and we had better get used to the idea. Where this leads to a practical difference is that if you believe that climate to be relatively constant and slow changing, then you will believe it easy to find an anthropogenic signal in the data. However if you consider the climate to be relatively volatile then you will believe it far more difficult to find a signal in the data.

Yeah, I suppose I was probably wrong about currents only having a few inputs, I neglected to include the input of plate tectonics and sea levels. However, I don't believe that plate tectonics, being awfully slow moving would be able to affect the ocean currents enough to produce the significant warming we are experiencing at the moment. As for sea levels, I believe that they are a feedback of climate. I don't think there's very much that affects cloud cover that isn't a feedback of climate.

 

They don't have to do your work for you, you know. The reconstruction is calibrated to the same baseline average as the GISS and HADCRUT. In general proxy reconstructions are considered complete reconstructions even without the instrumental periods being used. Because the instrumental period is derived directly from the data it isn't deemed part of a "reconstruction". The term reconstruction is reserved for work where the temperature has to be inferred from proxies. It's a terminology thing, nothing more.

Okay, I suppose I was wrong there.

 

Not quite. Remember that the theoretical basis of the reconstruction is that since the tree rings (or whatever) change in a regular fashion during the current period dependant upon temperature they will therefore respond the same way to previous temperatures. The proof of the methodology lies in the correlation between tree ring width and temperature over the instrumental period. Hence a lack of correlation reduces confidence in the methodology. Showing the divergence and offering an explanation as to why it is occurring and why your methodology is therefore still sound is good science. Truncating the data because it casts doubt on your methodology is nothing more than very bad science.

 

The value of a proxy in a paleo reconstruction is a direct function of how well it correlates to the temperature record, that is how and why you choose proxies. You can't cut out the bit you don't like and tell people that the correlation is great, you have to show the full data and if there is a divergence, explain it. The explanation so far, which boils down to "There is an unknown factor, probably of anthropogenic origin" is bloody weak from my POV.

 

As an aside there was a link to a paper some time ago at ClimateAudit concerning this. Apparently many tree proxies are chosen because they are at the tree line, or vegetation border. The paper showed that some trees grow along the ground until the temps reached a certain point and then they started growing straight up. This led to a great change in tree ring width and density which might go a long way to explaining the divergence problem.

 

You should also be aware that the truncating is not being done to a proxy, it is being done to complete and published reconstructions. Specifically Briffa 2001 is truncated at 1960, with a couple of others in 1980. By truncating them you can say "See, the reconstructions roughly agree" without someone looking at the last 50 years and asking "Hang on, what's going on here?" I call that marketing, not science. This was "Mikes Nature trick" to "hide the decline".

Well, I doubt that the data was truncated solely because it casted doubt on their methodology. It is cut out, because the data is wrong from there on. If you are trying to do a reconstruction, that displays the temperatures as accurately as possible, truncating the data that is wrong, from when it starts to be wrong is understandable. I agree, it would be better to show the divergence and explain it, but there is no current explanation for it. In fact, it would probably better to just be honest about it and show the proxies to the present and mention that from 1980 onwards they disagree with the instrumental record for reasons unknown. However, it didn't but that doesn't entirely invalidate the data we are seeing.

Edited December 23, 2010 by Samm

[swansont]

First off. Swansont, if I've offended you, I apologise. I didn't notice the "submitted" (it might be an old link). The paper has been "accepted" for some time. Publication was held off until the Journal could get the replies, critiques and response from the authors. From my POV Deepclimate etc were blogs responding to an accepted paper and therefore don't carry the same weight as the responses provided to the Journal.

 

Not a problem. It wasn't your link, so it wasn't your obligation to provide a citation. The blogs were responding to a preprint, and those concerns look to have been submitted to the journal.

[cypress]

 

McShane and Wyner do conclude that;

Using our model, we calculate that there is a 36% posterior probability that 1998 was the warmest year over the past thousand. If we consider rolling decades, 1997-2006 is the warmest on record; our model gives an 80% chance that it was the warmest in the past thousand years.

 

 

They also conclude (and I think this is quite important);

It is widely hoped that multi-proxy models have the power to detect (i) how warm the Medieval Warm Period was, (ii) how sharply temperatures increased during it, and (iii) to compare these two features to the past decade’s high temperatures and sharp run-up. Since our model cannot detect the recent temperature change, detection of dramatic changes hundreds of years ago seems out of the question.

 

Which speaks towards the rate of change.

 

And from their Conclusions section;

Consequently, the long flat handle of the hockey stick is best understood to be a feature of regression and less a reflection of our knowledge of the truth.

 

Right, and these of course being the primary conclusions of the study and resulting paper, that the reconstruction is primarily a feature of mathematical manipulation than a representative model of truth. reconstructions using other data sources including for example ice cores provide a very different picture as other graphs linked on this site demonstrate. Is there a good reason to conclude that the Mann reconstruction reflects reality? I don't see it.

[JohnB]

Yeah, I'd like to see it in literature as well. It's more permanent, and adds a sense of reliability to the source. Speaking of which, that the constant 0.5 degree/100 years with a superimposed 60 year harmonic cycle, what does it show?

 

I'll have to search deeper, but here is one post covering the period 1880 up to today WRT the ENSO and PDO.

 

While the period since 1860 has seen a general warming trend it is important to realise that there are in fact three warming periods within. 1860 - 1880 warmed, 1880 - 1910 cooled, 1910 - 1940 warmed again, 1940 - 1970 cooled slightly, 1970 - 2000 warmed again and 2000- 2010 has done bugger all.

 

Sorry about the size, but it was the only version of the graph I could find.

 

There has never been any suggestion that the first two warming periods had anything to do with human emissions of CO2, they are accepted as being totally natural in causation. This may or may not be true BTW, however if we assumed a CO2 component in them we would have to show vastly increased warming in the third period and this is not apparent. (Because CO2 forcing would have to be much larger than we think.)

 

The rates of warming are as follows;

Period Length Trend (Degrees C per decade) Significance

1860-1880 21 0.163 Yes

1910-1940 31 0.15 Yes

1975-1998 24 0.166 Yes

1975-2009 35 0.161 Yes

 

As is readily seen there is no statistical difference between the two "natural" warming periods and the supposedly "unnatural" most recent one. In a BBC inteviewPhil Jones had this to say;

So, in answer to the question, the warming rates for all 4 periods are similar and not statistically significantly different from each other.

 

I give you two hypotheses;

 

1. That the first two warmings were natural and the third was caused by CO2. This happened in such a way as to amazingly fit the observed warming/cooling cycle (for period) and also in a freak of improbability produced a trend not in any way different from the previous two "natural" warmings. That the natural forcings stopped in the period 1940 - 1970 and CO2 took over producing exactly the same forcing over the same period as the natural forcings. OR

2. That a natural warming/cooling cycle is occurring and the CO2 signature (forcing) is so small that it makes no statistical difference to the trends. IOW, there is no sign of CO2 forcing.

 

However. Neither hypothesis explain the cause of the natural warming. Number 2 also leaves us with a problem. We know from radiative physics that an increase in CO2 must cause warming. (About 1.1 degrees for a doubling) This is why climate is a "wicked" problem.

 

I must admit that one thing the graph does suggest to me is that while CO2 may not contribute much to the warming part of the cycle, it does have an effect on the cooling part. The cooling from 1880 -1910 was much greater than the cooling from 1940 - 1970 and since 2000 it's been about level. This is sort of consistent with the idea that while CO2 doesn't lead to warmer days, it does lead to warmer nights.

 

Yeah, that sounds quite severe. I agree what you're saying in that abrupt climate change can occur, but that is usually caused by very extreme circumstances. Such circumstances don't seem to be occurring at the moment, the only thing extreme appears is the level of greenhouse gas increase. This probably lends some justification to the belief that we may undergo serious climate change in the future. Far more serious than we are experiencing at the moment. Given that greenhouse gases affect temperature, would you agree with the notion that steps should be taken to minimise greenhouse gas emissions?

 

They were extreme circumstances and the climate response was equally extreme. But the current temperature cycle isn't extreme in any way so it doesn't require extreme natural forcings. Right from the beginning we have assumed (Note that in the Gradualist/Catastrophists debate the grads believe that natural climate forcings are small and that temp changes of more than about .2⁰/century are caused by freak events whilke the catasts think that natural forcings are large and that temp changes of 1.0⁰/century are not unusual.) that the climate response to natural forcings is small and that CO2 is a primary driver. One of the arguments against larger variations in history is that if they exist then sensitivity to CO2 is larger than assumed and the CO2 problem is therefore much worse. An alternate view is that while climate variability in the past was larger than the hockey stick shows, it was driven by natural forcings and not CO2, meaning that CO2 sensitivity may be lower than we think.

 

10 years ago, climate models centred around a 4⁰ warming for a doubling of CO2 (counting feedbacks etc) they are now converging on about 2.4⁰. A very recent paper from a NASA team (described here) puts the warming from a doubling from todays 390 ppm to 780 ppm at 1.65⁰. Treating the climate as a purely physical object responding only to the laws of physics seems to be a bad approach. The climate is a biosphere which while it follows physical laws (in detail) is much harder to quantify in a model.

 

Note that if this new figure is correct, it allows for much greater variation in paleo climate without an increase in CO2 sensitivity, meaning that natural effects must be greater than previously assumed.

 

Yeah, I suppose I was probably wrong about currents only having a few inputs, I neglected to include the input of plate tectonics and sea levels. However, I don't believe that plate tectonics, being awfully slow moving would be able to affect the ocean currents enough to produce the significant warming we are experiencing at the moment. As for sea levels, I believe that they are a feedback of climate. I don't think there's very much that affects cloud cover that isn't a feedback of climate.

 

The thing that must be realised is that in reality there is no such thing as "Climate" as a distinct entity. There are only forcings and feedbacks. In the natural world I've yet to see anything that isn't a feedback of (or is uneffected by) something else. Clouds might be a temperature forcing, but they are also a feedback to temperature, GCRs and changing currents. GCRs are effected by the Suns magnetic field (and Thor only knows what all the things are that effect currents). Even natural increases/decreases in CO2 are feedbacks for temperatures and other factors. Climate could be described as an equation where every variable is a function of two or more other variables. Everything is a "forcing" of climate and everything is a "feedback" of climate.

 

Well, I doubt that the data was truncated solely because it casted doubt on their methodology. It is cut out, because the data is wrong from there on. If you are trying to do a reconstruction, that displays the temperatures as accurately as possible, truncating the data that is wrong, from when it starts to be wrong is understandable. I agree, it would be better to show the divergence and explain it, but there is no current explanation for it. In fact, it would probably better to just be honest about it and show the proxies to the present and mention that from 1980 onwards they disagree with the instrumental record for reasons unknown. However, it didn't but that doesn't entirely invalidate the data we are seeing.

 

I doubt that it was truncated because it cast doubt on the methodology too. This is an area where background becomes important, and the word "fraud" gets used. Some scientists get all huffy and defensive, but the word is used in one language (business) and is heard in the other language (science). In business we have a thing called "Full Disclosure". If I were preparing a spaghetti graph for the CEO and I left out data because I "knew" it was wrong and he/she found out, I would probably get fired. If that graph was to be used in a Propectus for investors and the deletion was discovered, I would be charged with and jailed for, fraud. In the business world any deletion or modification of data in a public report is considered fraud. That is my world and the rules I have to live and work by. Full Disclosure, always, no excuses allowed. It doesn't matter why it was done, the fact is that it was done and in the business world would be automatically considered fraud.

 

Do I think that fraud was committed? No, not at all. But keep in mind that if I had done a graph for a Prospectus using the same methods, I would be in jail. There are two very distinct sets of rules here and I have to ask why climate scientists (or anybody else) should get a free pass in areas where I would be charged with a crime.

 

Climate is a big issue and we are talking about trillions of dollars. I simply think that science should be held to the same standard as business is. (And we've seen that even with the checks and balances, business can still go very wrong) It comes down to trust. You don't trust a businessman that hides or deletes data, why should you trust a scientist that does the same thing?

[swansont]

I think the graph is in error to the point of being a straw man. The green line is one effect, with the black line being the result of a number of causes. The temperature dip near 1910, for example, was due in large part to a number of very large volcanoes. The resulting upslope is then due, in part, from the removal of the cooling effects of those volcanoes. The graph also shows emissions rather than concentration of CO2, and the two are not the same thing. e.g. emissions could be flat, but a reduction in removal capability (from, say, land use effects, or ocean saturation or solubility changes) would result in an increase in CO2 concentration.

 

Your two hypotheses represent a false dilemma. There are a number of contributions to consider, and boiling it down to something that is almost an all-or-nothing choice is too simplistic.

 

 

I doubt that it was truncated because it cast doubt on the methodology too. This is an area where background becomes important, and the word "fraud" gets used. Some scientists get all huffy and defensive, but the word is used in one language (business) and is heard in the other language (science). In business we have a thing called "Full Disclosure". If I were preparing a spaghetti graph for the CEO and I left out data because I "knew" it was wrong and he/she found out, I would probably get fired. If that graph was to be used in a Propectus for investors and the deletion was discovered, I would be charged with and jailed for, fraud. In the business world any deletion or modification of data in a public report is considered fraud. That is my world and the rules I have to live and work by. Full Disclosure, always, no excuses allowed. It doesn't matter why it was done, the fact is that it was done and in the business world would be automatically considered fraud.

 

Do I think that fraud was committed? No, not at all. But keep in mind that if I had done a graph for a Prospectus using the same methods, I would be in jail. There are two very distinct sets of rules here and I have to ask why climate scientists (or anybody else) should get a free pass in areas where I would be charged with a crime.

 

Climate is a big issue and we are talking about trillions of dollars. I simply think that science should be held to the same standard as business is. (And we've seen that even with the checks and balances, business can still go very wrong) It comes down to trust. You don't trust a businessman that hides or deletes data, why should you trust a scientist that does the same thing?

 

Seriously? Let's turn this around. If you had data you knew to be wrong (you sell shoes, and the new guy starts counting shoes rather than pairs in his report. So his "1000" actually means 500 pairs), wouldn't that be fraud? Wouldn't you get fired or go to jail for reporting that you sold 1000 pairs of shoes, when in reality you sold 500? I would have thought you would go back and fix the problem — do it the right way, and then toss out the wrong numbers.

 

The calibration problem has been disclosed. It's not been kept secret. It doesn't work at some point, and so those data aren't used where they are known to be wrong.

 

I toss out data all the time. You find out a component in your experiment was turned off or broken, and the answer you get is meaningless. There is absolutely no reason to report results you know were not arrived at properly.

[Samm]

I'll have to search deeper, but here is one post covering the period 1880 up to today WRT the ENSO and PDO.

 

While the period since 1860 has seen a general warming trend it is important to realise that there are in fact three warming periods within. 1860 - 1880 warmed, 1880 - 1910 cooled, 1910 - 1940 warmed again, 1940 - 1970 cooled slightly, 1970 - 2000 warmed again and 2000- 2010 has done bugger all.

 

There has never been any suggestion that the first two warming periods had anything to do with human emissions of CO2, they are accepted as being totally natural in causation. This may or may not be true BTW, however if we assumed a CO2 component in them we would have to show vastly increased warming in the third period and this is not apparent. (Because CO2 forcing would have to be much larger than we think.)

 

The rates of warming are as follows;

Period Length Trend (Degrees C per decade) Significance

1860-1880 21 0.163 Yes

1910-1940 31 0.15 Yes

1975-1998 24 0.166 Yes

1975-2009 35 0.161 Yes

 

As is readily seen there is no statistical difference between the two "natural" warming periods and the supposedly "unnatural" most recent one. In a BBC inteviewPhil Jones had this to say;

 

I give you two hypotheses;

 

1. That the first two warmings were natural and the third was caused by CO2. This happened in such a way as to amazingly fit the observed warming/cooling cycle (for period) and also in a freak of improbability produced a trend not in any way different from the previous two "natural" warmings. That the natural forcings stopped in the period 1940 - 1970 and CO2 took over producing exactly the same forcing over the same period as the natural forcings. OR

2. That a natural warming/cooling cycle is occurring and the CO2 signature (forcing) is so small that it makes no statistical difference to the trends. IOW, there is no sign of CO2 forcing.

 

However. Neither hypothesis explain the cause of the natural warming. Number 2 also leaves us with a problem. We know from radiative physics that an increase in CO2 must cause warming. (About 1.1 degrees for a doubling) This is why climate is a "wicked" problem.

 

I must admit that one thing the graph does suggest to me is that while CO2 may not contribute much to the warming part of the cycle, it does have an effect on the cooling part. The cooling from 1880 -1910 was much greater than the cooling from 1940 - 1970 and since 2000 it's been about level. This is sort of consistent with the idea that while CO2 doesn't lead to warmer days, it does lead to warmer nights.

The graph, it's a strawman. That doesn't show the actual level of CO2 in the atmosphere, it shows the level of CO2 Emissions. Additionally, there is actually a delay between the time the CO2 is emitted and the entirety of its effects are felt.

 

There appears to be nothing wrong with hypothesis 1. The fact is that although the warming periods are similar, the causes of them can differ. ENSO oscillations and other climatic variations still influence the current warming we are seeing. The fact is that the warming period in the past was probably caused by such effects, while today's warming is probably anthropogenic and influenced by such effects. That could in part explain why the the current warming is very similar to the warming in the recent past.

 

The reason latest period of warming is considered anthropogenic is because we know that we emit greenhouse gases, and there appears to be little else that can account for the recent warming. Solar Irradience has remained much the same, ENSO forcing isn't high enough and fluctuates far too rapidly and volcanic eruptions should be cooling the climate. Despite all this, we are seeing significant levels of warming. The similarity between the warming we are experiencing at the moment and the warming in the past doesn't invalidate this reasoning.

 

They were extreme circumstances and the climate response was equally extreme. But the current temperature cycle isn't extreme in any way so it doesn't require extreme natural forcings. Right from the beginning we have assumed (Note that in the Gradualist/Catastrophists debate the grads believe that natural climate forcings are small and that temp changes of more than about .2⁰/century are caused by freak events whilke the catasts think that natural forcings are large and that temp changes of 1.0⁰/century are not unusual.) that the climate response to natural forcings is small and that CO2 is a primary driver. One of the arguments against larger variations in history is that if they exist then sensitivity to CO2 is larger than assumed and the CO2 problem is therefore much worse. An alternate view is that while climate variability in the past was larger than the hockey stick shows, it was driven by natural forcings and not CO2, meaning that CO2 sensitivity may be lower than we think.

Temperature changes of 1 degree/century do seem out of the ordinary. In fact coming out of the ice-age had a slower rate of warming than 1 degree/century. Then again, I don't suppose that actually accounts for decadal or centennial fluctuations. Additionally, nothing of that magnitude or rate appears in the temperature reconstructions over the past 2000 years. This in effect means that either temperature reconstructions are completely and utterly fail, or that 1 degree/century warming doesn't happen all that often, without anthropogenic interference. I believe that latter is more likely.

 

10 years ago, climate models centred around a 4⁰ warming for a doubling of CO2 (counting feedbacks etc) they are now converging on about 2.4⁰. A very recent paper from a NASA team (described here) puts the warming from a doubling from todays 390 ppm to 780 ppm at 1.65⁰. Treating the climate as a purely physical object responding only to the laws of physics seems to be a bad approach. The climate is a biosphere which while it follows physical laws (in detail) is much harder to quantify in a model.

 

Note that if this new figure is correct, it allows for much greater variation in paleo climate without an increase in CO2 sensitivity, meaning that natural effects must be greater than previously assumed.

Sure, if that new figure is correct, that means that increases in CO2 have less of an effect on the climate than originally expected. However, it should be noted that figure is in the minority and disagrees with many other papers. That figure although reassuring should probably be taken with a pinch of salt.

 

The thing that must be realised is that in reality there is no such thing as "Climate" as a distinct entity. There are only forcings and feedbacks. In the natural world I've yet to see anything that isn't a feedback of (or is uneffected by) something else. Clouds might be a temperature forcing, but they are also a feedback to temperature, GCRs and changing currents. GCRs are effected by the Suns magnetic field (and Thor only knows what all the things are that effect currents). Even natural increases/decreases in CO2 are feedbacks for temperatures and other factors. Climate could be described as an equation where every variable is a function of two or more other variables. Everything is a "forcing" of climate and everything is a "feedback" of climate.

 

Though it is true that everything is fundamentally influenced by other things, it would probably be more correct to consider everything to be a feedback, instead of a forcing. However, the distinction should be made between feedbacks of the internal and feedbacks of the man-made and external. The fact is that all significant variations in feedbacks are internal or man-made. The fact is that the internal feedbacks are driven by for want of a better word, climate, while man-made feedbacks are not, and influence climate.

Edited December 29, 2010 by Samm

[JohnB]

On the graph and strawmen. Frankly I didn't even look at the green line as it wasn't germane to the point. The point was that there have been three warming periods, which the graph showed, that was why I used it. Nowhere in my post did I mention the CO2 part of the graph. Since I only used it to demonstrate the existence of the three periods, I think that you both demolished strawmen.

 

Swansont, I'm thinking of it this way. Suppose those lines were the profitability of various depts in a company. Generally the trend is up but some depts are down. Can I cut them because it "doesn't matter" for the general picture of company profitability? Can I cut them because I know the data is "wrong" and given time I can come up with a really good reason why they are diverging? The answer to both is "No". I have to show the lot, warts and all. These rules are put in place because it is simple human nature to rationalise and "Gild the Lilly" in reports. I simply assume that those involved in science are humans and have the same frailties as the rest of the population and that therefore the same rules should apply. I'm most interested to hear a reason why science is in some way special and should be exempt.

 

The other problem with this truncating is that it is circular reasoning. The hypothesis behind the reconstructions is that ring width, density, varves, etc respond in a linear fashion to changes in temperature. What you are essentially defending is the idea that all data that contradicts the hypothesis is "wrong" and can be thrown out. Therefore all data remaining confirms the hypothesis and the hypothesis is therefore right. You've explained before that you throw out data and I have no doubt you do. But, you throw it because you know it is wrong or defective, not because it contradicts your initial hypothesis.

 

Hypothesis: All swans are white. Any data concerning black swans is therfore wrong and can be discarded. Therefore all data confirms that all swans are white. Hypothesis proven?

 

There appears to be nothing wrong with hypothesis 1. The fact is that although the warming periods are similar, the causes of them can differ. ENSO oscillations and other climatic variations still influence the current warming we are seeing. The fact is that the warming period in the past was probably caused by such effects, while today's warming is probably anthropogenic and influenced by such effects. That could in part explain why the the current warming is very similar to the warming in the recent past.

 

The reason latest period of warming is considered anthropogenic is because we know that we emit greenhouse gases, and there appears to be little else that can account for the recent warming. Solar Irradience has remained much the same, ENSO forcing isn't high enough and fluctuates far too rapidly and volcanic eruptions should be cooling the climate. Despite all this, we are seeing significant levels of warming. The similarity between the warming we are experiencing at the moment and the warming in the past doesn't invalidate this reasoning.

Sorry to use an "Argument from Incredulity", but really what would be the odds that the third period of warming in a non-linear chaotic system would be exactly the same as the previous ones from natural causes? Note that the "We can't think of anything else to account for the warming" is an "argument from ignorance".

 

Can you prove the ENSO forcing isn't high enough? Nobody else has. TSI is the same, but has its content changed? What would be the effect on the climate of an increase in incoming short wave radiation? How does you theory account for the current lack of warming? Natural variations cancelling out the CO2 forcing? And these natural variations are amazingly growing in strength at exactly the right rate to counteract the influence of the CO2?

 

The difference here is in approach. If we assume that internal forcings and variabliity are large then CO2 becomes a minor player and the temp changes seen fit rather easily. The sun was at its most energetic for quite some time during most of the 20th C. Allow for a bit of lag. Apply a 60 year oscillation for the PDO etc. Simple answer. But if you want CO2 to be a major player you need a large number of highly unlikely events to transpire to fit the record.

 

You need the natural forcings for the first two warmings to phase out at such a time and at such a rate as to allow CO2 to "take over". You need aerosols to increase and at such a time and at such a rate as to emulate the (possibly) volcanic cooling of 1880-1910. You then need those aerosols to decrease at such a time and at such a rate as to allow the warming from CO2 to equal the forcings from the earlier periods. And from 2000 to present you now need to find this magical place that the missing heat has gone to and is apparently "hiding". Either that or you need to find the negative forcing that is growing at such a rate as to almost exactly cancel the CO2 forcing. All these things are required if CO2 is a major player.

 

All this makes my position very difficult. Reason tells me that CO2 should be a minor player in the climate system, but I trust the physicists who say that we should have had some .6 degrees warming from CO2 increase. Which is why I sometimes seem to bat for both sides. I'm sceptical of the idea that CO2 is a major player but I'm also sceptical of any explanation that accounts for the warming without CO2. There is way too much either/or, it must be this or that, no middle road. For example it seems reasonable to me that for the period 1970-2000 with the PDO etc in positive mode they account for half the warming with CO2 the other half. Now they have essentially switched to negative mode, their negative forcing counteracts the CO2s positive forcing. I know it's not strictly accurate, but I hope you see my point. Both sides are simply too certain of their correctness.

 

I don't know if it's true, but I've read on the net that the Scottish legal system has a third category besides "Guilty" and "Innocent", that category is "Not Proven". That best sums up my position. I don't find CO2 guilty or innocent, I find the case "Not Proven".

 

Temperature changes of 1 degree/century do seem out of the ordinary. In fact coming out of the ice-age had a slower rate of warming than 1 degree/century. Then again, I don't suppose that actually accounts for decadal or centennial fluctuations. Additionally, nothing of that magnitude or rate appears in the temperature reconstructions over the past 2000 years. This in effect means that either temperature reconstructions are completely and utterly fail, or that 1 degree/century warming doesn't happen all that often, without anthropogenic interference. I believe that latter is more likely.

But it hasn't 1 degree in a century, has it? It's been about .7 degrees in a century and a half. One of the things that bugs the daylights out of me is that every time you see one of the ice core records, the last 10,000 years is a great big splodge on the end. We know the temps go up and down, because it's a tall splodge, but a detailed look would be nice. Is the current rate unusual? If we plot the Greenland data from Alley R.B. 2004 from the NCDC, we get this for the last 10,000 years.

 

Do you see anything particularly unusual about the current period? I don't. So let's look a bit further back, 50,000 years.

 

Yes, sharp rises in temperature sure seem unusual, don't they? Granted, there will be high latitude amplification, but the temps sure changed a lot. I'd say that a degree per century isn't that unusual at all.

 

Sure, if that new figure is correct, that means that increases in CO2 have less of an effect on the climate than originally expected. However, it should be noted that figure is in the minority and disagrees with many other papers. That figure although reassuring should probably be taken with a pinch of salt.

It wasn't that long ago that 2.4 was the minority and 4 degrees was the majority. It's about science, not a popularity contest. I'm much happier letting the science develop without suggesting what they should find.

 

Though it is true that everything is fundamentally influenced by other things, it would probably be more correct to consider everything to be a feedback, instead of a forcing. However, the distinction should be made between feedbacks of the internal and feedbacks of the man-made and external. The fact is that all significant variations in feedbacks are internal or man-made. The fact is that the internal feedbacks are driven by for want of a better word, climate, while man-made feedbacks are not, and influence climate.

Definitely. I was referring to the natural forcings and feedbacks in the climate system. Sorry for not being clear on that. I would think that human influence and the Sun would be the only external forcings that aren't effected by something else.

[swansont]

Swansont, I'm thinking of it this way. Suppose those lines were the profitability of various depts in a company. Generally the trend is up but some depts are down. Can I cut them because it "doesn't matter" for the general picture of company profitability? Can I cut them because I know the data is "wrong" and given time I can come up with a really good reason why they are diverging? The answer to both is "No". I have to show the lot, warts and all. These rules are put in place because it is simple human nature to rationalise and "Gild the Lilly" in reports. I simply assume that those involved in science are humans and have the same frailties as the rest of the population and that therefore the same rules should apply. I'm most interested to hear a reason why science is in some way special and should be exempt.

 

The problem with your analogy is that the data in it are correct, and you are ignoring them. In the divergence problem, the calibrations are actually wrong. For whatever reason (and there are a few likely candidates) the algorithm give the wrong answer. It is as you dropped a calculator and afterwards it had a glitch, and you got the wrong numbers for the profits. And you knew this. You wouldn't use any numbers from that calculator from the time after you dropped it. You have no confidence they are correct.

 

The other problem with this truncating is that it is circular reasoning. The hypothesis behind the reconstructions is that ring width, density, varves, etc respond in a linear fashion to changes in temperature. What you are essentially defending is the idea that all data that contradicts the hypothesis is "wrong" and can be thrown out. Therefore all data remaining confirms the hypothesis and the hypothesis is therefore right. You've explained before that you throw out data and I have no doubt you do. But, you throw it because you know it is wrong or defective, not because it contradicts your initial hypothesis.

 

It's not circular. The different systems all agree over a long span. It's exceedingly unlikely that it would occur without the relationships being causal. And that's science. Dropped items might fall at 9.8 m/s^2 by chance, but that's a hard sell.

 

Hypothesis: All swans are white. Any data concerning black swans is therfore wrong and can be discarded. Therefore all data confirms that all swans are white. Hypothesis proven?

 

No; that's a straw man.

[CaptainPanic]

It's funny that in the Netherlands, as well as in the UK, this was the coldest year in 16 years, and significantly below the long term average.

 

Over here, the skeptics are screaming 'victory', lol.

 

At this current point in time, it looks as if it's becoming increasingly obvious that anthropogenic climate change is occurring.

 

If by that you mean that this single new data point (or the data points gathered in the last 12 months) moves the correlation coefficient a little bit closer to 1, slightly strengthening the correlation between the manmade CO2 emissions and temperature increase, and slightly reducing uncertainty... then you might have a point.

 

If, however, you mean that the fact that this was the warmest year on record means that this single data point proves the global warming all by itself, then you're completely wrong.

[swansont]

It's funny that in the Netherlands, as well as in the UK, this was the coldest year in 16 years, and significantly below the long term average.

 

Over here, the skeptics are screaming 'victory', lol.

 

 

 

If by that you mean that this single new data point (or the data points gathered in the last 12 months) moves the correlation coefficient a little bit closer to 1, slightly strengthening the correlation between the manmade CO2 emissions and temperature increase, and slightly reducing uncertainty... then you might have a point.

 

If, however, you mean that the fact that this was the warmest year on record means that this single data point proves the global warming all by itself, then you're completely wrong.

 

 

Noi single data point proves anything right just as no single data point proves anything wrong. (Just as weather is not climate) Which is why linking to a single paper and declaring that it refutes the theory, or a specific region being cold refutes AGW, is preposterous.

 

What one has to do is look at the entire volume of evidence.

[Samm]

Sorry to use an "Argument from Incredulity", but really what would be the odds that the third period of warming in a non-linear chaotic system would be exactly the same as the previous ones from natural causes? Note that the "We can't think of anything else to account for the warming" is an "argument from ignorance".

First of all, it is not exactly the same. The most recent one lasted longer and warmed more than the previous periods of warming. And what are the odds of a non-linear chaotic system producing similar outputs if the most of the inputs remain much the same. I don't see it is as too improbable.

 

Can you prove the ENSO forcing isn't high enough? Nobody else has. TSI is the same, but has its content changed? What would be the effect on the climate of an increase in incoming short wave radiation? How does you theory account for the current lack of warming? Natural variations cancelling out the CO2 forcing? And these natural variations are amazingly growing in strength at exactly the right rate to counteract the influence of the CO2?

Well, I can cite a paper that supports these statements. I can't prove it, I can provide evidence in it's favour. Here is a graph depicting the temperature rise due to the various different influences on climate. From Lean, J. L., and D. H. Rind (2008).

 

 

Additionally, the "current lack of warming" isn't really doing the data justice. It's a currently lack of statistically significant warming, at the 95% significance level. Here's what Phil Jones would like to say:

 

I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level. The positive trend is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods.

The difference here is in approach. If we assume that internal forcings and variabliity are large then CO2 becomes a minor player and the temp changes seen fit rather easily. The sun was at its most energetic for quite some time during most of the 20th C. Allow for a bit of lag. Apply a 60 year oscillation for the PDO etc. Simple answer. But if you want CO2 to be a major player you need a large number of highly unlikely events to transpire to fit the record.

 

You need the natural forcings for the first two warmings to phase out at such a time and at such a rate as to allow CO2 to "take over". You need aerosols to increase and at such a time and at such a rate as to emulate the (possibly) volcanic cooling of 1880-1910. You then need those aerosols to decrease at such a time and at such a rate as to allow the warming from CO2 to equal the forcings from the earlier periods. And from 2000 to present you now need to find this magical place that the missing heat has gone to and is apparently "hiding". Either that or you need to find the negative forcing that is growing at such a rate as to almost exactly cancel the CO2 forcing. All these things are required if CO2 is a major player..

First of all, according to the graph above, the "current lack of warming", which isn't really a current lack of warming, can be explained by a decrease in the solar irradiance, and a decrease in ENSO forcing. The period of cooling seem between 1880-1910 according to the graph, appear to be due to volcanic aerosols and low levels of solar irradiance, coupled with a low level of anthropogenic forcing.

 

All this makes my position very difficult. Reason tells me that CO2 should be a minor player in the climate system, but I trust the physicists who say that we should have had some .6 degrees warming from CO2 increase. Which is why I sometimes seem to bat for both sides. I'm sceptical of the idea that CO2 is a major player but I'm also sceptical of any explanation that accounts for the warming without CO2. There is way too much either/or, it must be this or that, no middle road. For example it seems reasonable to me that for the period 1970-2000 with the PDO etc in positive mode they account for half the warming with CO2 the other half. Now they have essentially switched to negative mode, their negative forcing counteracts the CO2s positive forcing. I know it's not strictly accurate, but I hope you see my point. Both sides are simply too certain of their correctness.

Okay, I understand what you're saying. Natural influences appear to influence the short-term greatly, but over the long-term CO2 seems to win out. Any explanation that says it's only CO2, or only natural causes, behind any climate phenomenon, is likely to be wrong. I concede that solar irradiance, appears to have helped along the greenhouse effect (see graph), and feedbacks play a significant role.

 

I don't know if it's true, but I've read on the net that the Scottish legal system has a third category besides "Guilty" and "Innocent", that category is "Not Proven". That best sums up my position. I don't find CO2 guilty or innocent, I find the case "Not Proven".

I'd consider it to be probably guilty. Not 100% sure, but it's definitely better safe than sorry.

 

But it hasn't 1 degree in a century, has it? It's been about .7 degrees in a century and a half. One of the things that bugs the daylights out of me is that every time you see one of the ice core records, the last 10,000 years is a great big splodge on the end. We know the temps go up and down, because it's a tall splodge, but a detailed look would be nice. Is the current rate unusual? If we plot the Greenland data from Alley R.B. 2004 from the NCDC, we get this for the last 10,000 years.

 

Do you see anything particularly unusual about the current period? I don't. So let's look a bit further back, 50,000 years.

 

Yes, sharp rises in temperature sure seem unusual, don't they? Granted, there will be high latitude amplification, but the temps sure changed a lot. I'd say that a degree per century isn't that unusual at all.

We'd have to figure out the actual rates of temperature rise for those spikes. Additionally, that is only one proxy, it doesn't invalidate reconstructions that either take it's data into account, or use a number of other proxies.

 

It wasn't that long ago that 2.4 was the minority and 4 degrees was the majority. It's about science, not a popularity contest. I'm much happier letting the science develop without suggesting what they should find.

 

Yes, true, however, my point is that you shouldn't base your conclusions on just one new paper, especially when it contradicts a whole number of others.

 

Definitely. I was referring to the natural forcings and feedbacks in the climate system. Sorry for not being clear on that. I would think that human influence and the Sun would be the only external forcings that aren't effected by something else.

Indeed.

If by that you mean that this single new data point (or the data points gathered in the last 12 months) moves the correlation coefficient a little bit closer to 1, slightly strengthening the correlation between the manmade CO2 emissions and temperature increase, and slightly reducing uncertainty... then you might have a point.

 

If, however, you mean that the fact that this was the warmest year on record means that this single data point proves the global warming all by itself, then you're completely wrong.

The former rather than the latter.

Edited December 30, 2010 by Samm

[JohnB]

Sorry for the delay, but I was enjoying Christmas.

 

Swansont, I fear that you are missing my point. The graph we are talking about is not data, but published papers. Hence it is akin to preparing a spaghetti graph of the final financial reports for several departments. From this POV it doesn't matter if they dropped their calculator or not, the line was their final report and to truncate is illegal. The reasoning is irrelevent, it is the act that is wrong. I can see that from your POV it isn't a big thing, but can you see that in my world the act itself is a crime? To present or imply the spaghetti graph is a complete and accurate record of the performance of the depts is a lie because some of them have been truncated. This is a crime in the business world. The reasoning is simple, most people just look at the pictures to get an idea of the general situation and only read the full reports for certain details. Therefore the pictures must be full and complete. Anything else is illegal.

 

Those are the rules I live and work by. The act of truncating is illegal. Any reasoning as to why it is justified can be saved for when I brief my Defense Counsel. I can no more question the illegality of the act than I could question the Law of Gravity. In my world, it just is.

 

I put it to you that since these reports are being used to advise and justify policies and investments of billions of dollars, then they must surely be made to meet the same requirements and standards as a business report.

 

Samm.

First of all, it is not exactly the same. The most recent one lasted longer and warmed more than the previous periods of warming. And what are the odds of a non-linear chaotic system producing similar outputs if the most of the inputs remain much the same. I don't see it is as too improbable.

But that isn't the argument, is it? The argument is that the third warming is the result of a totally different set of forcings from the other two yet achieved an almost identical result.

 

The Lean and Rind paper was one I hadn't seen. The links to the full have stopped working for some reason, but I'm glad i read it before they dropped out. Have you seen L&R 2009? I'm most pleased to see their short term checkable predictions from their developed model. I do have concerns in that as they note in their Summary section, L&R 2008 only accounted for 76% of the varience between 1889 and the present. A 24% wild card adds a big "If" to the equation. However we will be able to see the robustness of the model within a few years, something that has been sadly lacking previously.

 

First of all, according to the graph above, the "current lack of warming", which isn't really a current lack of warming, can be explained by a decrease in the solar irradiance, and a decrease in ENSO forcing.

I don't like to parse paragraphs but I thought this sentence should be addressed separately. Firstly, on a purely logical basis, if there is a "lack of warming" with a decreased ENSO and SI, then where is your CO2 forcing? If there is warming with high SI and positive ENSO and a "lack of warming" without them, then by what logical process can CO2 be claimed to be a major climate driver?

 

Is there a lack of warming in the first place? I would say so. When we look at UAH temp series;

 

After the recovery from the post 1998 El Nino event, most of this decade has been remarkably stable. 2008 - 2010 could be described as a dip and a rise. Note however that the temps are dropping again rapidly and we are now back to .18 degrees which is about where it's been for most of the decade. so fankly I'm not seeing much in the way of underlying CO2 forcings, the temps are back to where they were 9 odd years ago despite the increase in CO2.

 

On volcanics. One of the major papers in this area was Glecker et al 2006 which showed that volcanics were a long term forcing using 12 models. One of the authors has recently published (it's "in print" in GRL) pointing out the rather obvious flaw in the original paper. A dsicussion of the Gregory paper and it's implications for volcanic forcings in climate models can be found here. Put simply, the models showed that from a zero volcanic forcing start, they could accurately mimic the 20th C temps and that volcanic forcings from events like Krakatoa lasted well into the 20th C. Gregory points out that if the conclusions are true, then the models should not be run with a zero volcanic forcings start as the real situation is that the 1880 start will have forcings from volcanoes in the previous 80-100 years.

 

In essence the difference is this;

 

Volcanoes don't have a long term effect on the climate, only short term ones after their eruptions, or perhaps more exactly, the long term forcing is a constant or nearly so. This leads to some problems with IPCC AR4 8.7.2.3 and the long term forcings assumed in models. As an aside I found it most interesting reading an exchange between Gavin Schmidt and Judith Curry where Gavin commented that the forcings used in models for the IPCC are supplied by the IPCC which implied that they might not be the same as the modellers themselves would choose. Rather more interesting is that a number of the inputs for IPCC climate models are the outputs of population and economic models. I can only conclude that the IPCC economic models are somehow far more accurate than anybody elses.

 

Okay, I understand what you're saying. Natural influences appear to influence the short-term greatly, but over the long-term CO2 seems to win out. Any explanation that says it's only CO2, or only natural causes, behind any climate phenomenon, is likely to be wrong. I concede that solar irradiance, appears to have helped along the greenhouse effect (see graph), and feedbacks play a significant role.

 

Not quite. CO2 may win out over the long term or it may not. Although I am saying that any explanation that only includes natural or anthopogenic causes must be wrong. I must add that I think that we are underestimating the natural forcings in the long term view. Going back to the UAH graph we can see a drop of .5 degrees just after the 1998 El Nino event. Given that natural forcings can change global temps by .5 degrees in 18 months it strikes me as a bit far fetched to think that they cannot do the same on centennial scales.

 

As the paper quoted above showed we may have made some severe mistakes in the values attributed to natural forcings. The Glecker paper implies that the effect of volcanic aerosols are compounding, producing an increasing negative forcing that counteracts the increasing positive forcing for CO2. If this is not correct and volcanics do not compound, then the models are vastly over estimating the positive forcing of CO2. I must add though that L&R do not reference Glecker in their 2009 paper, I don't know if they did in the 2008 one.

 

We'd have to figure out the actual rates of temperature rise for those spikes. Additionally, that is only one proxy, it doesn't invalidate reconstructions that either take it's data into account, or use a number of other proxies.

The first isn't too hard. Using the data we find the temps went from -49.6025 at 27,346 BP to -38.7156 at 27,774 BP, a change of 11 degrees in 400 years. If we assume that latitudinal amplification trebles the global reaction, we could imply a global change of 2.75 degrees or .685 degrees per century. As a back of the envelope, I don't see this as really different from the .7 degrees over the last hundred years or so. Again it would appear that the warming of the 20th C is not exceptional in any way.

 

Yes, it is only one proxy, but we have to work with what we have. The number of long term proxies is increasing but there are calibration problems. For example this paperdiscusses the problems with South America. Basically we have the cores etc, but good instrumental series to calibrate against are lacking. While some are long, most are only 30-50 years which isn't really enough to provide both a calibration and verification period. Similarly this White Paper from NOAA discusses some of the problems with speliotherms etc. I can't prove it, but it strikes me that my own nation Australia is also falling very short on financing the research that needs to be done WRT long term proxies for our continent.

 

As (I think) Kevin Trenberth said; "It's hard to find data when there is none".

 

The difficulty is that we have short term high resolution proxies and long term low resolution proxies, what we need are long term high resolution ones and ice cores seem to be about the best bet. Speliotherms and varves can give good high resolution however the dating is sometimes a problem. I reccommend this sitefor a good overview on proxies. Following the links makes for very interesting reading on the subject.

 

As to whether it invalidates other studies, that depends on the proxies chosen both in the original studies and those that followed. For example, the iconic MBH paper shows the 20th C to be quite unusual, yes? However to quote from Eiríksson et all 2006;

While a number of records indicate a warming of coastal and shelf waters during the last 200 years, the twentieth century does not appear to be unusual when the proxy records spanning the last two millennia are examined.

 

If you look at this pageyou will see individual proxy temperature reconstructions tha tcover the globe, all showing a MWP and LIA. One has to wonder exactly how, given that so many proxies abound showing both these features existed on a planetary scale, MBH and subsequent papers fail to show it. Maybe it depends on the proxies you choose and the weighting that you give them?

 

Yes, true, however, my point is that you shouldn't base your conclusions on just one new paper, especially when it contradicts a whole number of others.

I'm not, one data point proves nothing. However may I point out (with tongue very firmly in cheek) that the general trend for climate sensitivity is very much a downward trend?

 

Cheers.

[swansont]

Sorry for the delay, but I was enjoying Christmas.

 

Swansont, I fear that you are missing my point. The graph we are talking about is not data, but published papers. Hence it is akin to preparing a spaghetti graph of the final financial reports for several departments. From this POV it doesn't matter if they dropped their calculator or not, the line was their final report and to truncate is illegal. The reasoning is irrelevent, it is the act that is wrong. I can see that from your POV it isn't a big thing, but can you see that in my world the act itself is a crime? To present or imply the spaghetti graph is a complete and accurate record of the performance of the depts is a lie because some of them have been truncated. This is a crime in the business world. The reasoning is simple, most people just look at the pictures to get an idea of the general situation and only read the full reports for certain details. Therefore the pictures must be full and complete. Anything else is illegal.

 

Those are the rules I live and work by. The act of truncating is illegal. Any reasoning as to why it is justified can be saved for when I brief my Defense Counsel. I can no more question the illegality of the act than I could question the Law of Gravity. In my world, it just is.

 

 

I must be.

 

It sounds like you're telling me that fixing a known error is illegal. You just have to live with it, as if the act of putting it on paper makes it correct, and you must proceed from that point as if it were the truth. That's hard to believe. It's also hard to reconcile with reports of "restated earnings" I hear from time to time after a company has found an error in an audit.

[cypress]

I must be.

 

It sounds like you're telling me that fixing a known error is illegal. You just have to live with it, as if the act of putting it on paper makes it correct, and you must proceed from that point as if it were the truth. That's hard to believe. It's also hard to reconcile with reports of "restated earnings" I hear from time to time after a company has found an error in an audit.

 

The act of making errors in deliverables involving contracts surrounding matters of substance is often illegal, and discovering and reporting the error often results in legal fines. Correcting the error is not illegal but it is a requirement. Restated business performance reports in my business often involves a fine for the error.

 

John seems to be making a fair point that because the interpretation of this information has significant implications, it is critical that the report be correct and that those who provide it exercise due diligence in the process of reporting and describing the implications.

[JohnB]

Thanks Cypress. I was trying to get the concept across because with the differences between national laws, I couldn't use specifics.

 

I think there are quite a few areas where the worldviews diverge and the divergence is greatly under rated. I notice much the same thing but in the other direction in the accusations against Dr. Wegman. From the business POV he did some summaries and paraphrasing, and used some boilerplate as background info, big deal. However using words without giving direct credit is the high crime of plagiarism in Academia.

 

Swansont I suppose the easiest way to put it is this. If it was about finances, could your reasons convince the taxman?

[swansont]

Swansont I suppose the easiest way to put it is this. If it was about finances, could your reasons convince the taxman?

 

I have no doubt. The wrong numbers are tossed out and the right numbers are being used, and that's what the taxman (and the scientists) are interested in.

[JohnB]

Except that the "right" numbers aren't being used, are they? There is just a deletion.

[IronParrot]

I think 2010 is the warmest for now , because this year is "I don't know".

[JohnB]

A new reconstruction is out that people might find interesting. The abstract is here. Note that it is a Central Europe and not a N Hemisphere or Global reconstruction.

 

Probably to the consternation of both sides of the climate debate;

Recent warming is unprecedented, but modern hydroclimatic variations may have at times been exceeded in magnitude and duration.

 

So while it appears to warmer than any time in the last 2,500 years the actual warming rate and duration is less than seen previously. There is a reasonably comprehensive write up in Der Spiegel covering the main points of the paper. Put bluntly warm = good and cold = bad.

 

Some in the blogosphere are noting the extreme lengths that the MSM are going to in avoiding using the word "cold" in connection with previous periods of disaster and death.

 

On a similar line I notice that weather is now climate for the CC crowd. Kevin Trenberth has no reluctance in placing at least some of the blame for the recent Queensland floods on Global Warming. The inference is, as always, that warmer means more extreme events. Well, if you want to use a Qld event as "proof" then you should really check the actual facts before opening your mouth and inserting your foot.

 

 

As can be readily seen, flood events became less common as temperature rose during the last 150 years. There were 5 events around or larger than the 1974 peak in the 60 year period from 1840 - 1900 and 2 since 1900. (1974 and 2010) What do you call your theory when it doesn't match the observed facts?

 

For a bit of colour I quote from the diary of the explorer John Oxley who investigated the Brisbane River in 1824. On the 19th September he wrote;

"the starboard bank an elevated flat of rich land, declining to a point where had evidently by its sandy shore and pebbly surface, been at some time washed by an inundation; a flood would be too weak an expression to use for a collection of water rising to the full height (full fifty feet) which the appearance of the shore here renders possible."

 

The above info and quote are from the Australian Bureau of Meteorology.

[SMF]

JohnB. You are, admittedly, using local weather to make arguments about global climate. This doesn’t seem to be appropriate. Finding specific local regions that differ from the global mean, or predictions resulting from warming, is a non-issue.

 

Also, all of the big factors that affect climate are pretty much known and this is why the current warming is well researched. What specific combination of these known factors that caused local or global changes in the past, prior to the instrumental record, are less sure, although there are some pretty good hypotheses that have support. It doesn’t seem that knowing exactly how warm or cold Europe was from the paleoclimate data, for example, is very relevant to the current situation. SM

 

 

[JohnB]

Actually SMF, I'm not, Trenberth is. If someone who should know better wants to use short term local weather events to push his case can you tell me why it is incorrect to use long term weather records to show him wrong? Pointing to some weather events as proof of his hypothesis is just as silly as pointing to other events as disproof. The simple fact is that we will get heavy rains and flooding when a strong La Nina follows a strong El Nino. Always have and always will, there is zip correllation between flood events and CO2 increase in Australias weather history.

 

If you don't want to use floods, how about Cyclones? Cyclones hit the Australian East Coast on;

24th March 1890

1st February 1893

12-14 February 1898

21st January 1918

10th March 1918

9th February 1927

12th March 1934

2-3 rd March 1949

20th February 1954

28-30th January 1967

17th January 1970

24th December 1971

24th January 1974

17-21st March 2006

 

The historical data shows that rather than an increase in such events as the warming continued, there has in fact been a decrease in this region.

 

If we widen the net to include all Cyclones since 1970 in the entire Australian region which will take in from the Eastern Indian Ocean to the Western Pacific and include all non landfalling Cyclones the number per year is;

 

1970:1

1971:4

1972:4

1973:15

1974:13

1975:10

1976:16

1977:13

1978:8

1979:13

1980:19

1981:12

1982:12

1983:14

1984:17

1985:14

1986:14

1987:7

1988:6

1989:13

1990:13

1991:9

1992:10

1993:8

1994:11

1995:9

1996:16

1997:10

1998:11

1999:11

2000:11

2001:9

2002:8

2003:9

2004:10

2005:10

2006:11

2007:9

2008:8

2009:9

2010:9

 

Once again zero correllation over the entire bloody region. If anything it can be very well argued that Cyclones were more common when the temps were cooler in late 70s to mid 80s. The period 1976 -1986 which was before the warming really began (or was just starting) had only one year with less than 12 Cyclones whereas since 1991 there has only been one year with more than 12.

 

My point is that Trenberth must be really short of actual evidence for his theory if he needs to go to cherry picking weather events to back up his arguments.

 

But this is still regional. Let's look at the World Acumulated Cyclone Index and see how much more common big storms a Cyclones, Typhoons, Hurricanes, etc are;

 

 

As can be readily seen, the increase in CO2 and rise in temperature has led to a great increase in the severity of Cyclones...........

 

Oh wait, sorry, we appear to be at a 30 year low in the index, both for the Northern Hemisphere and the World.

 

To cite Maue (2009) or Maue and Hart (2011).

 

Overall, since 1979:

**Global Tropical Cyclone ACE shows no upward trend.

**Northern Hemisphere TC ACE shows no upward trend.

**Southern Hemisphere TC ACE shows no upward trend.

**North Atlantic TC ACE has doubled since 1995, exactly compensated by a halving of Eastern Pacific ACE. It appears that in the context of global and NH ACE, the NATL increases are at the expense of the other basins, or simply within the common climate framework.

**Global TCs of Tropical Storm force show no upward trend in frequency.

**Global TCs of Hurricane Force + show no upward trend in frequency.

 

 

For the calendar-year 2010:

**66-tropical cyclones globally, the fewest in the reliable record (since at least 1970)

**46-tropical cyclones in the Northern Hemisphere, fewest since 1977

**Global calendar year ACE total of 529 was the lowest since 1977.

**The Northern Hemisphere ACE total of 373 was the lowest since 1977.

**Combined North Eastern and Western Pacific ACE total of 171 lowest since at least 1970.

**Western North Pacific had 8 Typhoons fewest in at least 65-years of records.

**Eastern North Pacific had 8 TCs: 3 were hurricanes, the fewest since at least 1970.

**North Atlantic ACE for 2010 was 170, the 11th most since 1950, and most since 2005.

 

Again, if you have to cherry pick freak (and not so freak) weather events to bolster your theory, you must be very, very short on actual evidence. Climate pseudo science at its best.

 

*The "you" used in the above is a general "you" referring to AGW supporters and is not meant to imply you, SMF, personally.*

 

SMF, from your second paragraph it appears that you have not looked at the subject much in depth. I suggest you do so. A number of the major forcings we have yet to quantify, for example we aren't sure of the sign of clouds, let alone the magnitude of the forcing.

 

Paleoclimate data is important because we use it to derive the climate sensitivity which we then feed into the models to arrive at projections for future change. A good Central Europe reconstruction is invaluable for checking the ability to hindcast a climate change on a regional level. Indeed, one of the reasons that the original MBH reconstruction recieved such a hot reception was that it went against hundreds of years of historical records that showed the MWP and LIA.

 

Cheers.

Edited January 17, 2011 by JohnB

[SMF]

JohnB:

 

Your assessment of my knowledge regarding climate issues on the basis of two short paragraphs is demeaning.

 

Your multiple negative references to what Kevin Trenberth, a highly respected climate scientist, has said have been asserted without any reference to what he actually said, where he said it, and the full context within which he said it. This is highly inappropriate in a science forum, don’t you think?

 

Finally, I will reassert that you are putting too much emphasis on the shape of the shaft of the hockey stick. There is quite a bit of information about it that can be jiggled up and down a little as research continues, but it is the blade that should be the center of attention.

 

SM

 

 

[swansont]

Except that the "right" numbers aren't being used, are they? There is just a deletion.

 

Yes, they are. Unless you are talking about some situation I'm not aware of; I though we were talking about the proxy calibration divergence problem.