New solar paper

A new paper by Gareth Jones, Mike Lockwood and Peter Stott says that future reductions in solar output will have a limited impact on global warming projections, based on the output from their climate model.

During the 20th century, solar activity increased in magnitude to a so-called grand maximum. It is probable that this high level of solar activity is at or near its end. It is of great interest whether any future reduction in solar activity could have a significant impact on climate that could partially offset the projected anthropogenic warming. Observations and reconstructions of solar activity over the last 9000 years are used as a constraint on possible future variations to produce probability distributions of total solar irradiance over the next 100 years. Using this information, with a simple climate model, we present results of the potential implications for future projections of climate on decadal to multidecadal timescales. Using one of the most recent reconstructions of historic total solar irradiance, the likely reduction in the warming by 2100 is found to be between 0.06 and 0.1 K, a very small fraction of the projected anthropogenic warming. However, if past total solar irradiance variations are larger and climate models substantially underestimate the response to solar variations, then there is a potential for a reduction in solar activity to mitigate a small proportion of the future warming, a scenario we cannot totally rule out. While the Sun is not expected to provide substantial delays in the time to reach critical temperature thresholds, any small delays it might provide are likely to be greater for lower anthropogenic emissions scenarios than for higher-emissions scenarios.

I hope they have made suitable caveats about the validation (or lack of it) of their computer model's ability to project future global warming.

Comments

[Martin A]

Mar 5, 2012 at 5:37 PM HaroldW

Martin A --
I believe the discrepancy is between the lifetime of an individual molecule of CO2, and the persistence of atmospheric CO2 levels. The oceanic and biological fluxes of CO2 are quite large -- I seem to recall a small kerfuffle here some months back related to the topic. Hence, an individual CO2 molecule is liable to be cycled over a relatively short period, 5 to 10 years off the top of my head. However, the net imbalance in CO2 is a small fraction of the annual fluxes, and it is contended that CO2 levels will remain elevated for centuries even if all anthropogenic emissions ceased. Again going by memory -- always dangerous -- the evidence in favor of this is down to fitting the observed CO2 history to a model of carbon sinks. Perhaps Dr Betts will provide a more authoritative explanation.

Richard Betts has posted a follow-up comment - thank you, Richard.

He mentions processes operating on various timescales.

My recollection is that the reduction of atmospheric C14, following the cessation of atmospheric nuke testing, followed extremely closely a simple exponential decay. (If you plot the log of the remaining C14 as a function of time, you get an almost perfect straight line.) This means that there is just one dominating dynamic process for the removal of radioactive CO2 from the atmosphere.

I remember what you said about an equilibrium process going on being explained to me, and how this changes everything, but I simply did not get it. It seemed to me that the (statistical) half life of a CO2 molecule in the atmosphere has to be the same as the half life of an injected pulse of CO2. (When I explained that I did not get it and why I did not get it, I was treated as a malevolent imbecile.)

So far as I can see, the dynamics of the disappearance of CO2 from the atmosphere have simply got to be extremely linear* - because of the tiny concentrations we are talking about. If you put a pulse into a linear system, you can work out the response to that pulse, independently of what any other signals present in the system are doing.

So, so far as I could see, the decline in the level of radioactive CO2 after about 1962 simply has to have the same dynamics as the decline of any pulse of non-radioactive CO2 injected into the atmosphere. (Apart, of course, from differences due to the slight difference in molecular weight.)

I must take another look at the data - in particular, to remind myself what was the time constant.

Here is a graph on a linear scale . Even looking at it on a linear scale, you can see that the time constant is a few decades, rather than hundreds or thousands of years.

* "linear" means the differential equations are linear, so the superposition principle can be used - signals may be present simultaneously but they do not interact, so they can be analysed independently.

[Gixxerboy]

Richard Betts

Thanks for commenting here and taking the time to answer so many questions.

It is interesting that the Ineson at al paper you linked to says:

If the updated measurements of solar ultraviolet irradiance are correct, low solar activity, as observed during recent years, drives cold winters in northern Europe and the United States, and mild winters over southern Europe and Canada, with little direct change in globally averaged temperature.

When in fact the cold has been widespread across all those areas. And further afield - in 2009/10 it was snowing in Seoul as well as being bitterly cold across Europe and North America. Am I missing something?

[michael hart]

Martin A,
I think you are probably correct. I certainly agree with your reasoning. This is something I have been meaning to look into for a while. One of the last interesting posts I read on the matter asserted that the IPCC model [I think it was described as the "Berne model"] fell short for the same reasons. I shall try and describe it.

The conundrum faced by the IPCC was described as this:
Either
a) The measured/modelled amount of annual depletion of anthropogenic carbon dioxide from the atmosphere is only about 50% of that released, or,
b) The time constant for the C02 removal is much shorter than than the value they have accepted. Despite many pre-existing contradictory studies, including the one you mention, they opted to accept arguments for C02 being a 'long lived' atmospheric gas. Why?

The consequences of not accepting b) means accepting a shorter C02 "residence time" in the atmosphere. Essentially, this would mean that human effects are likely small and, if they really did turn out bad, they could be QUICKLY REVERSED. Clearly not an acceptable paradigm.

So they have opted to accept explanation a). Scientifically, this appears equally unacceptable. This is the reason why they cannot account for what happens to ~50% of the C02 we emit every year. As we emit more, and ever rising, amounts of C02 this amount rises. But it always remains ~50%. If it appears to remain constant then nobody gets alarmed about how this enormous error is getting bigger and bigger as we emit more C02.

I don't even think the EU loses 50% of it's budget every year! But this remains the least worst option when modelling the carbon cycle! Please carry on your researches and let us know if you find otherwise. I'll do my best to do the same.

[geronimo]

"That petition (which I signed) wasn't in support of CRU, it was in support of the main 2 conclusions that (a) the world is warming and (b) it's probably due to human influence. Yes it was motivated by Climategate, but not in a "we love CRU" way but in a "we stand by our science" way."

Thanks fornyour response Richard, if I may I'll take exception to your explanation of Dr. Slingo's decision to spend taxpayer's money on a round Robin. First off it was about an "attack on climate scientists" at least accruing to Dr. Sling and her then boss. What came from the emails wasn't an attack on climate science, it was confirmation that some people, at the heart of the IPCC, were up to no good. I have no ethical problems with people exposing malfeasance, whether it's Gleick, or whoever exposed the shenanigans at the heart of the IPCC. I'm also sure that the people in the Met Office are as fine a bunch of scientists you'd expect to meet on a long day's march, but they are activists. If they weren't they'd have held their counsel until the full import of the stolen emails was revealed and had replied to that. They didn't and now they are conspiring to keep the malfeasance secret, by staying silent.

If your world view is important enough for you to to ignore crimes by those who o you see as being on your "side" you are on a slippery slope. Those emails.weren't taken out of context they were in context and Slingo and others who aspire to be senior in their career have to understand that they have a duty to challenge wrongdoing from everybody, even if those involved in it are "allies" in the "cause".

[HaroldW]

Pharos -
Thanks for the link to the paper.

[James Evans]

I've got to remember to stop wearing my invisibility cloak when I join these discussions.

[Martin A]

Mar 6, 2012 at 4:29 AM geronimo

...I have no ethical problems with people exposing malfeasance, whether it's Gleick, or whoever exposed the shenanigans at the heart of the IPCC...

Huh? Gleick exposed no malfeasance whatsoever, so far as I can see. But identity theft and forgery definitely qualify as 'malfeasance' in my book.

[Lord Beaverbrook]

I've got to remember to stop wearing my invisibility cloak when I join these discussions.
Mar 6, 2012 at 6:49 AM | James Evan

James if necessary see here, there are a lot of questions and some may unfortunately be overlooked.

[Richard Betts]

Mar 6, 2012 at 4:29 AM | geronimo

Hi geronimo

This is getting significantly off-topic, but I'll make one last response to this point because it's important.

In order to put one's name to the statement from the UK science community, it wasn't necessary to have read all (or indeed any) of the Climategate emails. The statement says:

We, members of the UK science community, have the utmost confidence in the observational evidence for global warming and the scientific basis for concluding that it is due primarily to human activities. The evidence and the science are deep and extensive. They come from decades of painstaking and meticulous research, by many thousands of scientists across the world who adhere to the highest levels of professional integrity. That research has been subject to peer review and publication, providing traceability of the evidence and support for the scientific method.

The science of climate change draws on fundamental research from an increasing number of disciplines, many of which are represented here. As professional scientists, from students to senior professors, we uphold the findings of the IPCC Fourth Assessment Report, which concludes that 'Warming of the climate system is unequivocal' and that 'Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations'.

The statement did not mention CRU or any other specific institution.

Whatever behaviour or attitudes are revealed / perceived in the emails, this makes no difference to the scientific evidence, which comes from much wider and longer-standing sources.

Even Steve McIntyre said:

just because they were acting like jerks, didn’t mean that the indices themselves were in major error.

The emails were being used to undermine the science in general, and that was the reason for the petition. One could even speculate that some people signed it not in support of the emailers, but in spite of them.

Cheers,

Richard

[Richard Betts]

Mar 6, 2012 at 6:49 AM | James Evans

I've got to remember to stop wearing my invisibility cloak when I join these discussions.

Hi James,

I'm really sorry, your question was a good one but required me to go and look up a paper, hence the delay.

We did a simulated of the last 500 years with HadCM3, which is written up in this paper by Tett et al (2007)

The shape of the simulated temperature graph depends on natural internal variability and external forcings. The Tett et al paper concludes:

The natural forcing used in our experiment increases decadal–centennial time-scale and large spatial scale climate variability, relative to internal variability, as diagnosed from a control simulation.

However, if by "hockey stick shape" you mean a 20th century uptick then yes, the model gives that (mainly in response to anthropogenic forcings). However this simulation didn't go back as far as the MWP, if that's what you're interested in.

I can email you a copy of the paper if you like.

Incidentally, there is discussion of this paper in the Climategate II emails, in fact this is one of the reasons I turn up there!

Cheers

Richard

[Lord Beaverbrook]

Richard.

From the new Solar paper:

Using this information, with a simple climate model, we present results of the potential implications for future projections of climate on decadal to multidecadal timescales.

Would it be possible to clarify what a simple climate model would be in relation to say what is used for the UKMO decadal forecasts?

[Richard Betts]

Mar 6, 2012 at 9:59 AM | Lord Beaverbrook

Would it be possible to clarify what a simple climate model would be in relation to say what is used for the UKMO decadal forecasts?

Sure.

The decadal forecasts (and main IPCC projections) are done with General Circulation Models (GCMs) which not only simulate the Earth's energy balance but also the water cycle and the fluid dynamics of atmospheric and oceanic circulation. In the case of the Met Office model, it's the same model as that used for weather forecasts. They take ages to run even on supercomputers (eg: it takes several months to do a single IPCC simulation from 1850 to 2100).

Simple climate models focus just on global-scale processes, particularly the energy balance, and are much quicker to run than GCMs, and also easier to understand because they are not so complex. The trade-off is that you can't explicitly represent the transport of energy within the atmosphere and oceans (eg: from equator to pole) so that aspect has to be approximated.

So both types of model have their uses. One is more comprehensive but slow and hard to understand, the other is less comprehensive but faster and easier to understand.

Cheers

Richard

[Hilary Ostrov]

@Richard Betts Mar 6, 2012 at 9:28 AM

The emails were being used to undermine the science in general, and that was the reason for the petition.

By whom? If anything was being "undermined" surely it was the (obviously misplaced) confidence in the integrity of "the emailers" - and they succeeded in doing that all by themselves, did they not?

One could even speculate that some people signed it not in support of the emailers, but in spite of them.

Considering that the petition contained absolutely no mention of "the emailers" and/or their "transgressions", I'm not sure how one might arrive at such a speculation!

Particularly in light of the comments made by Slingo during the course of the press coverage that followed - in which, to the best of my recollection, she was exceedingly careful to make no reference to any transgressions on the part of "the emailers".

In light of the above, IMHO, geronimo's point still stands - and bears repeating:

Those emails.weren't taken out of context they were in context and Slingo and others who aspire to be senior in their career have to understand that they have a duty to challenge wrongdoing from everybody, even if those involved in it are "allies" in the "cause".

[TerryS]

I've skimmed through Joos Et al 2001 and in order for them to arrive at CO2 having a long lifetime (half-life) in the atmosphere they needed to assume a climate sensitivity of 4.5C and a massive loss of carbon from soil and litter (instead of soil and litter being a carbon sink) due to a high warming rate.
Another assumption is that CO2 does not have a single "lifetime" in the atmosphere, but instead the lifetime changes as the temperature changes.

One thing I never saw in there was an estimate for the lifetime of CO2 when the atmospheric concentration was 278ppm (the year 1765 according to the paper). At that point in time approximately 800Gt of CO2 was being cycled annually. In order for this amount of CO2 recycling to occur and to result in an atmospheric concentration of 278ppm the half life would have to be less than 5 years.

Paper is available here

[lapogus]

Richard - once again thanks for coming here and answering questions. I think I must also have an invisibility cloak as I have now asked you at least two times for a comment on a what Pharos described as a landmark post by Dr Norman Page back on February 5th. It was the last comment on page 1 - http://www.bishop-hill.net/blog/2012/2/5/leake-on-the-temperature-plateau.html#comments - the text is text below and as we are discussing models I think it is appropriate to re-post it here:

There is currently a difference in approach to climate science between the sceptical Baconian - empirical approach solidly based on data and the Platonic IPCC - Met Office approach - based on theoretical assumptions built into climate models.The question arises from the recent Muller - BEST furore -What is the best metric for a global measure of and for discussion of global warming or cooling. For some years I have suggested in various web comments and on my blog that the Hadley Sea Surface Temperature data is the best metric for the following reasons . (Anyone can check this data for themselves - Google Hadley Cru -- scroll down to SST GL and check the annual numbers.)
1. Oceans cover about 70% of the surface.
2. Because of the thermal inertia of water – short term noise is smoothed out.
3. All the questions re UHI, changes in land use local topographic effects etc are simply sidestepped.
4. Perhaps most importantly – what we really need to measure is the enthalpy of the system – the land measurements do not capture this aspect because the relative humidity at the time of temperature measurement is ignored. In water the temperature changes are a good measure of relative enthalpy changes.
5. It is very clear that the most direct means to short term and decadal length predictions is through the study of the interactions of the atmospheric sytems ,ocean currents and temperature regimes – PDO ,ENSO. SOI AMO AO etc etc. and the SST is a major measure of these systems.Certainly the SST data has its own problems but these are much less than those of the land data.

What does the SST data show? The 5 year moving SST temperature average shows that the warming trend peaked in 2003 and a simple regression analysis shows a nine year global SST cooling trend since then .The data shows warming from 1900 - 1940 ,cooling from 1940 to about 1975 and warming from 1975 – 2003. CO2 levels rose monotonically during this entire period.There has been no net warming since 1997 - 15 years with CO2 up 7.9 % and no net warming. Anthropogenic CO2 has some effect but our knowledge of the natural drivers is still so poor that we cannot accurately estimate what the anthropogenic CO2 contribution is. Since 2003 CO2 has risen further and yet the global temperature trend since then is negative. This is obviously a short term on which to base predictions but all statistical analyses of particular time series must be interpreted in conjunction with other ongoing events and in the context of declining solar magnetic field strength and activity – to the extent of a possible Dalton or Maunder minimum and the negative phase of the Pacific Decadal a global 20 – 30 year cooling spell is more likely than a warming trend.

It is clear that the IPCC models , on which AL Gore based his entire anti CO2 scare campaign ,have been wrongly framed. and their predictions have failed completely.This paradigm was never well founded ,but ,in recent years, the entire basis for the Climate and Temperature trends and predictions of dangerous warming in the 2007 IPCC Ar4 Summary for Policy Makers has been destroyed. First - this Summary is inconsistent with the AR4 WG1 Science section. It should be noted that the Summary was published before the WG1 report and the editors of the Summary , incredibly ,asked the authors of the Science report to make their reports conform to the Summary rather than the other way around. When this was not done the Science section was simply ignored..
I give one egregious example - there are many others.Most of the predicted disasters are based on climate models.Even the Modelers themselves say that they do not make predictions . The models produce projections or scenarios which are no more accurate than the assumptions,algorithms and data , often of poor quality,which were put into them. In reality they are no more than expensive drafting tools to produce power point slides to illustrate the ideas and prejudices of their creators. The IPCC science section AR4 WG1 section 8.6.4 deals with the reliability of the climate models .This IPCC science section on models itself concludes:

"Moreover it is not yet clear which tests are critical for constraining the future projections,consequently a set of model metrics that might be used to narrow the range of plausible climate change feedbacks and climate sensitivity has yet to be developed"

What could be clearer. The IPCC itself says that we don't even know what metrics to put into the models to test their reliability.- i.e. we don't know what future temperatures will be and we can't yet calculate the climate sensitivity to anthropogenic CO2.This also begs a further question of what mere assumptions went into the "plausible" models to be tested anyway. Nevertheless this statement was ignored by the editors who produced the Summary. Here predictions of disaster were illegitimately given "with high confidence." in complete contradiction to several sections of the WG1 science section where uncertainties and error bars were discussed.
The recent Lockwood et al paper now accepts the likelihood of 2-3 decades of solar relative inactivity but again trots out a fatuous Met Office climate model to "prove" that the politically correct warming trend will continue. It's about time they recognised that these models are structured incorrectly and are useless for predicting future temperatures because their built in assumptions on forcings and feedbacks are simply wrong.
Feb 5, 2012 at 8:01 PM | Unregistered Commenter Dr Norman Page

As I said in a subsequent comment, (and again in another thread a few days later), I would really appreciate your response to Dr Page's analysis, thanks.

[Richard Betts]

Hi Hilary

You're right that some of the authors of the emails didn't do themselves any favours. Phil Jones himself admitted that.

But my recollection was that the discussion went far beyond the actual content of the emails and the authors of those emails. In fact, there is a lot of talk here on BH about the integrity of climate science in general, which (it seems to me, anyway) arises from those emails and the coverage of them. However, if people here want to say I'm wrong and their impression of climate science (and climate scientists) in general was not tainted by Climategate, then please do so!

Hence one of my motivations for engaging here is to try to show that we are more open to discussion of the science than people think.

My speculation, which I admit is only speculation, arises from the fact that level-headed people like Mosher and Fuller wrote books about the emails which condemned the content but still concluded that the basis science (humans are probably exerting a warming influence on climate) is sound.

Cheers

Richard

[Richard Betts]

Hi lapogus

Sorry, I simply can't keep up - and I did respond to your comment on Unthreaded!

:-)

I'll respond later.

Cheers

Rcihard

[Breath of Fresh Air]

I am findiing it hard to reconcile the following part of the

http://www.metoffice.gov.uk/news/releases/archive/2009/science-community-statement

We, members of the UK science community, have the utmost confidence in the observational evidence for global warming and the scientific basis for concluding that it is due primarily to human activities. The evidence and the science are deep and extensive.

with RB's comment

Of course the models remain highly uncertain for this, so it ends up as an excercise in scenario planning as opposed to prediction, but we are making progress..... :-)

[lapogus]

Richard - if you have already answered this on one of the previous threads, and I missed it, sincere apologies.

[John Shade]

It is an idle thought I know, but I occasionally wonder how it would be now if the GCMs had never been invented. I think we'd perhaps need a few more surface weather stations to supplement the satellites and keep weather forecasting at its best (a best which is inevitably constrained by the turbulent behaviour the atmosphere on a wide, and very relevant, range of space and timescales).

We might suffer a possibly detectable drop in weather forecasting skill if we travelled back in time to erase the models, but we'd have removed a weapon from the armoury of those who are irresponsible enough to seek to scare us with their tales of imminent doom based on zero observational evidence of anything odd going on in the vehicles of that doom: winds, rains, sea levels etc.

We'd also have had perchance a more extensive examination of the physics and other aspects of the science, free from the wet-blanket effect that computer modellers can bring with their dark arts and all but impenetrable claims and obsessions - for some, the virtual world of their software can become more vivid, more 'real', and more congenial than the even messier real one. There is something about computers that can get in the way of thinking and of conversation - something to do with a sense of a black-box that we scarce know how to argue with and which we know is capable of computational chores that we cannot begin to match with pencil and paper and spreadsheats.

Would the IPCC have fizzled out without its very own version of 'the computer says' that so helped the Club of Rome in their previous foray into mass scaremongering called 'Limits of Growth'? I am inclined to think so, and I think some considerable opprobrium belongs upon computer models and their keepers during the Foot and Mouth fiasco in the UK. Our peculiar, almost superstitious, fear of computers and our readily exercised panic around them was also illustrated by the Year 2000 shenanigans over what could and should have been a matter of routine review and testing.

But the genie is out, we have them and they seem get more funding year after year. What can be done to protect us from further harm from them? This is tricky. Their keepers are scarce likely to go big on any notion that they are so feeble in the face of the immense complexity of the system that they should have no more impact on public policy than a Mystic Meg, or a Whittaker's Almanack. They needs must urge us to believe that if not yet, then at least just around the corner, great benefits will follow from climate modelling. And of course, they may be right, and we may even get technical breakthoughs that no one has even imagined yet. I think it a good thing that some people should pursue them for research just in case. But we need more public recognition of the dangers of them.

[Martin A]

Mar 6, 2012 at 4:28 AM michael hart

But this remains the least worst option when modelling the carbon cycle! Please carry on your researches and let us know if you find otherwise. I'll do my best to do the same.

Michael, thanks for the encouragement. I'll look into it a bit more.

There are differing accounts...

Richard Betts kindly gave a reference to the IPCC Fourth Assessment Report

"...the decay of a pulse of CO2 with time t is given by

0.22 + 0.26 exp(-t/173) + 0.34 exp(-t/18.5) + 0.19 exp (-t/1.19)"

(I have cut down the number of decimal places which implied 4-figure accuracy of the parameters.)

From simple arguments about the kind of physical systems that can and cannot have such an impulse response, I find this model implausible - quite apart from the notion that 22% of a pulse of CO2 remains in the atmosphere indefinitely. ( I can see how that might be argued but I think that such an argument would only apply with truly collossal quantities of CO2 resulting in the sea fizzing like Coca Cola.)

It is also hard to square with a Nature report Carbon is forever saying

'the 2007 report describes its gradual dissipation over time, saying, "About 50% of a CO2 increase will be removed from the atmosphere within 30 years, and a further 30% will be removed within a few centuries. The remaining 20% may stay in the atmosphere for many thousands of years.'

To me, the evidence of the nuclear tests says clearly and unequivocally that pulse of CO2 disappears exponentially, with a time constant of around 2 - 3 decades.

I'll look into it a bit more and maybe post something on "Discussion" if our host permits.

[Mike Jackson]

if people here want to say ...their impression of climate science ...was not tainted by Climategate, then please do so!

Richard, for heaven's sake! Of course our impression of climate science was tainted. Why ever would it not be?
We have arguably the most influential, certainly the most voluble and the best-known climate scientists admitting in emails
- that they are prepared to consider destroying data in order to avoid FoIA enquiries,
- that they are prepared to obfuscate and delay in order to frustrate those enquiries,
- that they are prepared to use bullying tactics to prevent the publication of papers which do not conform to their view of climate science,
- that they are prepared to 'adjust' data in order to gloss over inconvenient results which cast doubt on previous claims (Briffa's tree rings post-1960),
- that they are prepared to use statistical methods which will (conveniently) produce the graph that they need to "prove" their case for modern warming ...,
- ... and then defend that graph to the death when it's proved to be simply an artefact of their method.
In addition
- they have sold their collective souls to an organisation that is happy to break its own rules in order to furnish the "right" political message on climate,
- they have willingly (at least in public) gone along with the errors that their collegaues have been making and which the know to be errors.

I coiuld go on for another page. Why on earth would our views not be tainted by this sort of behaviour? As a dozen or more scientific (in which I include technology and engineering) professionals have stated repeatedly on this site, any one aspect of this behaviour would have been sufficient in their professions to earn at the very least a reprimand and in several cases dismissal for misconduct.
So what makes these guys so special?

[Lord Beaverbrook]

Richard,

Would you expect then that the extremely complex GCM which not only simulates the Earth's energy balance but also the water cycle and the fluid dynamics of atmospheric and oceanic circulation used by the UKMO to predict weather and climate to be more accurate than a simple climate model?

The former giving an increasingly positive divergence from observational temperatures since the reduced activity of the Sun in the decadal forecasts and the later being used to predict that the reduced activity will not affect Global temperatures to any extent on 100 year timescale against forecasts.

However, if past total solar irradiance variations are larger and climate models substantially underestimate the response to solar variations, then there is a potential for a reduction in solar activity to mitigate a small proportion of the future warming, a scenario we cannot totally rule out.

Might this area be worthy of more attention than something just not to be ruled out?

[Don Keiller]

Richard, the "Climategate" emails showed that the authors of many of the key papers underpining Climate Science had serious doubts about them in private.

Remember that when Climategate I was released it was said that this was a samml subset of emails "taken out of context".
Climategate II placed alot of these emails in context and there is still the vast majority waiting unreleased.

If CRU wished to place these emails "in context" and demonstrate that they are a small subset of "cherry picked" quotes they have an easy option.
Release then (excluding personal details) to the general public.

That they have chosen not to do so speaks volumes.
Instead they have deliberately and systematically used spurious legal arguments, some of which were rejected by the Infornation Commissioner. Others I have shown to be false in a court of law.

They have deliberately frustrated legitimate FOIA requests by means of illegal deletions and transfers of emails and they have discussed ways to discredit those, including me, who have made such legitimate requests.

So excuse me if I do not trust these lying, conspiring cheats any further than I can throw them.

[Pharos]

Just by way of recollection on the impact of the Climategate emails concerning the veracity of climate science itself, a number of significant concerns were summarised into a submission by the Institute of Physics in Feb 2010 to the HoC Select Committee Review, below

http://www.publications.parliament.uk/pa/cm200910/cmselect/cmsctech/memo/climatedata/uc3902.htm

The subsequent inquiries mainly skidded around these issues with the gymnastic skill of Olympic slalom champions.

[James Evans]

Richard,

Thanks for the reply.

"However, if by 'hockey stick shape' you mean a 20th century uptick then yes, the model gives that (mainly in response to anthropogenic forcings). However this simulation didn't go back as far as the MWP, if that's what you're interested in."

Surely you'll get a hockey stick however far back you go. If you assume that volcanic forcing is randomly spaced along the time axis, and short-lived, and all the other forcings are miniscule compared with anthropogenic forcing, then you'll get a wobbly flat line followed by an uptick. Won't that always be the result, given the assumptions? I could dust off my old ZX Spectrum and get it to draw a few of those graphs if you like. :)

"Incidentally, there is discussion of this paper in the Climategate II emails, in fact this is one of the reasons I turn up there!"

Yes, there are some familiar names in the vast list of scientists who worked on that paper.

[geronimo]

Hi Richard, maybe it's off topic, or maybe I haven't explained myself well enough. The Slingo "oath of allegiance" is the reason why I'm suspect of papers coming from model runs by Met Offic scientists. To a man and woman they've signed on to the meme that humans have caused most of the recent warming, supposedley to protect climate science from attack, but widely seen as a letter of support for the CRU given it's timing, so the only surprise Woukd be if they did say the sun was a driver of climate (I can't believe we're having a conversation in which scientist are playing down the role of the sun in driving climate). Incidentally, the only attacks I saw on climate science was in the Climategate emails.

As for the observable evidence that CO2 has given rise to most of the warming in the 20th century, is there a citation for that?

Thanks for engaging.

[James Evans]

Richard,

BTW, you wrote:

"The shape of the simulated temperature graph depends on natural internal variability and external forcings. The Tett et al paper concludes:"

The natural forcing used in our experiment increases decadal–centennial time-scale and large spatial scale climate variability, relative to internal variability, as diagnosed from a control simulation.

Questions:

1) Why on earth did you quote this tiny statement as being the conclusion of the paper?

2) Does the phrase "natural internal variability" equate to "we'll stick in a bit of random noise because we don't really understand the physical processes"?

3) How is this an "experiment"?

4) How much value should be put on a "diagnosis" from a "control simulation" when we're just running in circles feeding the same old assumptions into computer programs?

[sHx]

Don Keiller:
"Richard, the "Climategate" emails showed that the authors of many of the key papers underpining Climate Science had serious doubts about them in private."

Indeed, who could forget Keith Briffa's private confession (pleading?) to his colleagues that the recent warming was probably matched during the medieval period?

He wouldn't say anything like that publicly because of the need for a 'nice, tidy story'. You don't want to confuse the hoi polloi by making things look more complicated. Never mind that Briffa, had he spoken in public, would be speaking to his fellow scientists in peer-reviewed journals, not necessarily to the ignorant public at large through a radio chat show.

Climategate emails showed not only how climate scientists scratched each other's back, but also how they refrained from throwing stones at each other's glasshouse. The 'vast body of literature', as global warming activists often say of climate science, seems to have come about by scientists complimenting each other's papers rather than being critical.

I do appreciate Richard Betts' efforts to regain public respect and trust for his institution and scientific discipline, but it is all too little too late.

In my personal opinion, at this stage, the reputation and credibility of climate science is marginally better than that of horoscope science. Each time I hear of climate scientists and their super-duper computer models I think of Thrasyllus (Roman emperor Tiberius' astrologer) and his astrological charts: "Come on! My calculations prove it. The chart never lies."

[Richard Betts]

Mar 6, 2012 at 7:26 PM | James Evans

Hi James

1) Why on earth did you quote this tiny statement as being the conclusion of the paper?

OK, sorry, it was just a particularly relevant bit of the abstract, that's all.

2) Does the phrase "natural internal variability" equate to "we'll stick in a bit of random noise because we don't really understand the physical processes"?

No. We don't prescribe the internal variability in GCMs, it emerges as a natural consequence of the simulated fluid dynamics and thermodynamics in a coupled atmosphere-ocean system on a rotating sphere heated by an external source (the sun). Phenomena like ENSO and monsoons just emerge, fairly(!) realistically, which is one of the things I find remarkable about GCMs.

3) How is this an "experiment"?

Hmmm, that's traditional modeller-speak for a set of simulations with systematic differences in input variables - probably ill-advised (there are two schools of thought about whether that term should be used or not, Simon Tett clearly thought it was OK to use). If you see me using that term, remind me not to!! :-)

4) How much value should be put on a "diagnosis" from a "control simulation" when we're just running in circles feeding the same old assumptions into computer programs?

Unforced simulations (control) are useful for showing what natural internal variability emerges from the model. This can be compared with observed variability to see if the model is doing the right thing, but of course establishing which aspects of variability in the observations are internal variability as opposed to forced variability is of course very difficult. Life would be so much easier if we had a second real Earth we could compare with this one..... :-)

Cheers

Richard

[James Evans]

Richard,

Thanks for taking the time to answer those questions.

On the other point, do you agree that the assumptions being made by the models will tend to give hockey stick shaped graphs? (If you assume that volcanic forcing is randomly spaced along the time axis, and short-lived, and all the other forcings are miniscule compared with anthropogenic forcing, then you'll get a wobbly flat line followed by an uptick.)

[TerryS]

Re: Martin A

0.22 + 0.26 exp(-t/173) + 0.34 exp(-t/18.5) + 0.19 exp (-t/1.19)

An interesting equation.

Lets say that you release R1 amount of CO2 today and R2 amount in 5 years time.
If R1 = 1Gt and R2 = 0.735Gt then the following happens:

In 5 years time R1 will have 0.735Gt remaining and R2 will be released. R1 and R2 are both exactly the same quantities.

In 10 years time R1 will have 0.663Gt remaining and R2 will have 0.540Gt remaining. In the 5 year period R1 will have reduced by 0.072Gt and R2 will have reduced by 0.190Gt or over 2.5 times the amount of R1.

That equation effectively means that you can never know how long before 1Gt of CO2 will reduce by half unless you know when it entered the atmosphere.

[Jane Coles]

I urge anyone who has followed this thread thus far to pursue the link that lapogus provided a couple of days ago. Turn to page 6 of that 2009 document and compare the Hadley Centre's "scenario independent .. climate model prediction" hockey stick graph with Richard Betts's comments here. Browse the rest of the document and you will see that his employer is not a scientific institution (except in a very specialist sense).

[michael hart]

Terry S,
You can extract time constants (rate constants, half-lives, call them what you will) from such equations without knowing the start point or the starting amounts. I have done so for 1st and 2nd order exponential decays. Under certain conditions and making certain assumptions (which must be stated and justified) fitting a triple exponential decay such as the one above is mathematically trivial. Of course the curve-fit must be better [in the above] case than would a second- or first-order exponential decay. And the rate constants must vary significantly, otherwise you have Occam's Razor hanging over your head. I used to study and work alongside people doing this who reminded us that if you want to, you can fit most natural data in the universe to a 3rd order exponentials.

In my case the system was, like radioactive decays, much simplified by being irreversible so I was able to ignore the rate constant for the reverse reactions. Probably not a safe assumption when dealing with CO2 equilibration in the atmosphere and oceans!! So this experiment is already not a simple one. The atomic bomb pulses of 14C in the system may turn out to be some of the most valuable and unrepeatable experiments ever done on this subject. [Just like the tracer experiments used to investigate the biochemistry of the Krebs-TCA cycle after WW II]

[Richard Betts]

Hi lapogus & Dr Norman Page

Sorry for taking so long to respond here. (Incidentally, when I said above that I'd responded to you on unthreaded, I meant that I'd responded to a different comment you had made there, not this one here. I just meant that I'm not ignoring you personally!) :-)

Thank you Dr Page for your comments on the Hadley Centre SST dataset. I guess you are referring to the lower figure on this page? Yes, the smoothed curve (blue) does indeed show a downtick since 2003. However, it should be noted that short-lived downticks also appear earlier in the record - variability around the long-term mean. What has happened in the last few years may very well still just be internal variability in the system - or alternatively there may have been some change in the balance of the various forcings (GHGs, aerosols, solar etc). It's not clear yet. I see you do acknowledge that this 8-9 year period is still a somewhat short one to be the basis for predictions. I'm not convinced that the downtick is long enough to indicate a permanent shift in the long-term trend.

Does this invalidate the models? No. If we look at the decadal forecast of global mean temperatures made in 2005 (the right-hand of the three portions of the red plume on the graph) and compare it with the observations (black curve) we see that the observations still fell within the uncertainty range for the forecast - just about, anyway!

You say:

to the extent of a possible Dalton or Maunder minimum and the negative phase of the Pacific Decadal a global 20 – 30 year cooling spell is more likely than a warming trend.

Thank you for making such an explicit and testable statement. For the Met Office forecast, let's look again at the decadal forecast page and this time look at the blue plume. This is our forecast for the next 10 years - a general resumption of warming, although again with variability on interannual timescales about the long-term warming trend. A key point is that even the lower end of the uncertainty plume is indicating some level of warming relative to recent years. (NB The uncertainty range indicates the region within which the observations are expected to be for 90% of the time.)

So, we both have put our cards on the table and made our statements about what we expect to happen over the next decade. Let's come back in 10 years and see who's right!

Thanks again lapogus for drawing my attention to Dr Page's post, and sorry again for repeatedly missing it and taking a few days to answer this time.

Cheers

Richard

[michael hart]

Thank you, Richard Betts. I've bookmarked the page.
All the best!

[HaroldW]

Dr Betts -
Just above Jane Coles links to a MO graph on temperature history. (Her comment Mar 7, 2012 at 12:14 PM.) This graph was mentioned in a prior BH post. I believe the graph is misleading, and I wonder if you might bring this criticism to the attention of the MO.

The graph misrepresents the uncertainty in the past record. The label on the shaded region in the past is described as the "range of temperatures from natural records (e.g. ice cores)". The region seems to have been derived from IPCC AR4 Figure 6.10(b), by considering, for each year, the lowest and highest points of various Northern Hemisphere reconstructions. However, the individual curves of the IPCC figure represent reconstruction means, and each curve has an uncertainty associated with the reconstruction which is not conveyed in the MO depiction. For example, looking at the MO graph, one would infer that we knew the average temperature of the year 1000 fairly exactly, because the reconstruction means all happen to intersect (nearly) there. The picture which should have been provided is Figure 6.10(c), which indicates not only the uncertainty associated with the differences between the various reconstruction means, but also the inherent uncertainties in each reconstruction.

[Richard Betts]

Jane Coles, HaroldW,

Thanks very much for that, well spotted. I'll pass that on.

Cheers

Richard

[lapogus]

Richard - thanks for finding the time to respond to Dr Page's comment. I am glad you are accepting that you/the MO has put your cards on the table, as you say time will tell. I don't think we will have to wait 10 years though, I think only a couple of more years of flat lining or cooling will be enough to expose the models as too simplistic and erroneous in their assumptions. As Dr Page summarises:

"It's about time they recognised that these models are structured incorrectly and are useless for predicting future temperatures because their built in assumptions on forcings and feedbacks are simply wrong."

So I suppose we will just have to agree on having to wait and see what happens to global temps (though I think Dr Page makes good another good point that the Hadley SST is a better metric than the land surface records). Thanks for your input again. And also for beginning to ask questions about the misleading graph in the appalling piece of propoganda produced by the Met Office in 2009. Note that it was me who initially linked to this as evidenece that the Met Office has been at the forefront of alarmism and green activism, despite your contention. I hope you now agree that it was alarmist and did try to suggest that we should all change the way we live our lives etc.

Cheers all the same and have a good weekend.

[Tim Curtin]

This Thread may well be dormant, but I only just got linked to it, so here goes.

I am referring to Richard Betts' comment "The bottom line is that even if global CO2 emissions peaked and then began to decline very soon, atmospheric CO2 concentrations would not fall anywhere near so rapidly - CO2 would remain near current levels for many decades" (5 March 2012 5.27 pm).

However it is a fact that on average since 1958 no less than 56% of annual total emissions of CO2 from burning of hydrocarbons and alleged land use change have been absorbed by the biota of the oceans and the land and by the oceans themselves.
In 2009-2010, total emissions amounted to 34 GtCO2, of which only 12.6 GtCO2 (2.6 ppm) remained airborne in the atmosphere, and 21.4 GtCO2 p.a. were absorbed by the oceanic and terrestrial sinks. So “even if global CO2 emissions peaked” the atmospheric concentration would fall by 21.4 GtCO2 p.a. (cet.par.), or 4.4 ppm p.a., and by 2037 the atmospheric concentration would be back at the glorious pre-industrial level of 280 ppm that sustained a global population of less than 1 billion.
So one would like to see Betts’ explanation of why “CO2 would remain near current levels for many decades”.

Back in 2007 The Royal Economic Society's Newsletter published a short piece of mine that showed how quickly atmospheric CO2 declines to the pre-industrial level if global absorption of atmospheric CO2 continues at the present rate after emissions cease, it's at my website www.timcurtin.com
- see "An overdue letter from Albert Einstein to President Bush".