Bishop Hill Conveying truth 4
Apr 3, 2012 Climate: Models As my thoughts have turned increasingly to climate models in recent months, I thought I might take a look to see how Julia Slingo described these mathematical behemoths in the briefing she sent up to central government in the wake of Climategate - I have criticised this document on a number of occasions in the past (1, 2, 3).
Considering just how central climate models are to the case for DAGW* I was taken aback by how little Slingo had to say on the subject. And what she said was, to say the least, surprising. Here it is:
Models have been used that take into account all the factors that influence climate. These models have been able to simulate the historic changes in global and regional temperatures and have shown that most the warming over the past half century has been caused by the rise in greenhouse gas concentrations.
There are a couple of passim mentions elsewhere in the document, but in essence that is what the Met Office feels that people in government need to know about climate models.
It's hard to know where to begin. I wonder whether anyone will seek to defend Slingo's paper as a fair representation of the reliability and importance of climate models.
Readers should feel free to critique Slingo's words, but please avoid venting. I'm more interested in what policymakers should be told about climate models. I think we should allow ourselves slightly more space than Slingo - shall we say eight sentences?
*Dangerous anthropogenic global warming - "dangerous" being perhaps a less emotive term than "catastrophic".
Reader Comments (111)
How about:
"Climate models, like any attempt at looking 100 years into the future, are of inherently problematic reliability. Currently we rely on models that are continuously fine-tuned after the fact to reproduce actual climate observations. To date none has proved able to do so predictively any better than conventional weather forecasting techniques, and neither for obvious reasons has any been checked for accuracy on a multi-decadal time period. Nonetheless, and subject to the assumptions used, they broadly bear out the hypothesis that human emissions of greenhouses gases have contributed to a raising of the temperature, and predict that they will continue to do so."
"Bear in mind that you policymakers don't do uncertainty, you just want to know if the models are RIGHT or WRONG. If we, the model-makers, believe they are 'mostly' or 'likely' more right than wrong, we will tell you that, but you ask us to approximate to one of the two required answers. So we will round the answer to RIGHT. So you policymakers can tell the public that the models are RIGHT, even when they patently aren't to any engineering degree of tolerance."
And as a result of her apparent certainty, we have HMG offering £1bn to anyone who can capture CO2, whose role in this remains unproven and inconclusive. It might also be worth pointing out to them (and to the Beeb, who seem utterly unable to question the assumption) that even if we captured every last molecule of CO2 here, that gain would have been cancelled out by India and China in a matter of months.
I give up.
Since of course these models do not take into account all the factors that influence climate (if they did, they would not be models - they'd be miracles), and they have not been able to simulate (in any predictive as opposed to tuning sense) many noteworthy 'changes in global and regional temperatures', and have failed to convince me (and many more others!) 'that most [of] the warming over the past half century has been caused by the rise in greenhouse gas concentrations.', I do have to wonder.
In particular, I wonder that if she really believes that quoted paragraph, is she a suitable person for the position she occupies?
I also wonder that if she does not really believe that quoted paragraph, is she a suitable person for the position she occupies?
Dire consequences were predicted 10 years ago about the euro. Without a lender of last resort, it was calculated that it must fail.
Did anyone in the system take any notice.
I don't think so.
Complicated as the common currency is; we know far more about how monetery systems work than we do about how the climate works.
Richard Betts (and others) have made a point of talking about projections and not predictions (apologies in advance if I misrepresent)
When you look at how the mainstream media and various interested parties bring in talk of model output, it seems that models are accorded the rhetorical weight of a prediction, but without the same accountability that a hard prediction would attract.
I'd expect that this would happen when a story is simplified for mass consumption on occasion, but I'd also expect that a briefing of this type should make these implicit limitations explicit.
I'd go for:
"Models have been developed that take into account many of the known factors that influence climate. These models have been able to approximate historic changes in global and regional temperatures. Their output for the past 50 years is consistent with the instrumental record, and with a climate that is sensitive to CO2. Comparatively little effort has been expended on developing models that are not sensitive to CO2 in this way."
Woe, Woe and Thrice, Woe
senna the soothsayer
One would imagine that a scientist offering a balanced overview of climate models to the government would need to show how the models performed in absolute terms before talking about how well they matched the "changes".
A plot similar to the one plotted by Lucia in her post (below) would help
http://rankexploits.com/musings/2009/fact-6a-model-simulations-dont-match-average-surface-temperature-of-the-earth/
-click on the graph to enlarge it.
She is claming regional? wow just wow!
Thus all the parameters in the IPCC reports that say low confidence or little us known
Overall cloud feedback, and sign + or negative, when did we discover that (sarcasm off)
Oceanic oscillations, even BEST suggested that agw may be overestimated.
Did she really say that?
Should we get a fee voolbrars dye to natural variability, ie cooling oceans or somesuch.What will they say, beyond tetrospectively predicting it, and using this uncertainty to ask for more money for a bigger computer
Fee foolbrars dye.....
I hate Android, do you think Exxon will give me an iphone
...what policymakers should be told about climate models:
1) ... most [climate model] scientists don’t even really understand the nature of politics and policy-making processes.
2) ... they are doing a lousy job in terms of lobbying and influencing the public and policy debate...
3) ..[climate model] scientists who seek such authority are perfect allies to campaigners who seek to exploit the authority of science for their own political gain.
4) The best and most effective ways of communicating [climate model] science therefore seem to be those that separate knowledge from decision, that provide policy-makers with options instead of imperatives, and with ‘what if’ instead of ‘will happen inevitably’
5) Those seeking greater political authority for [climate model] science may actually be contributing to a loss of trust in institutions of science among parts of society.
6) If [climate model] science is to well serve democratic governance, then the [climate model] scientific community needs to move beyond exhortation.
7) .....???
8) :-)
http://rogerpielkejr.blogspot.se/2012/04/who-has-authority-in-political-debates.html
"a fee voolbrars dye"
Put that in a government report and no-one would query it.
I think fee voolbrars dye may have been featured in the Sur/acestatiQns.org project.
"The very best climate models that we have, which we believe contain every possible variable that can apply, were unable to predict what has happened to global temperatures over the last 15 years. In fact, and much to our embarrassment, they've been unable to predict what temperatures will be in a small corner of Northern Europe, just 2 or 3 months into the future.
However, we are confident that the same models, with a little tweaking (which will only cost you X million quid, here are my bank account details) can accurately predict what will happen to global temperatures over the next 85 years, and you should formulate a policy response accordingly."
I wonder whether anyone will seek to defend Slingo's paper as a fair representation of the reliability and importance of climate models.
Richard Betts does
It is probably impossible now to convince the policy makers that the models are anything other than experimentally verified codes. Proponents of these computer games will never have admitted the factors that might have falsified their claims. Such as the lack of the tropical atmospheric hot spot. And, of course the failure to forecast zero warming over the past ten or more years. They will convince the policy makers that all the 'lost' energy has gone to the deep oceans. Where, of course, we are unable to carry out any measurements.
They will only have stressed that the "models have been able to simulate the historic changes in global and regional temperatures.." This will be accepted, by politicians as empirical verification. They will not have admitted that the need to assume a positive feedback mechanism is dubious in the extreme. And the will never admit the degree of tuning necessary to get the 'right answers.'
I am afraid that changing the minds of the likes of Huhne, Cameron, Hague and Yeo is nigh impossible. Too much is at stake. Only a complete change in the views of the Royal Society and the Met Office will cause the politicians to think again. A sceptical President of the RS would do wonders. Added of course, to a sceptical Chief Scientific Advisor.
Sorry to be so pessimistic, but I have had years of fruitless correspondence with my MP and with various Energy and Climate Change and Environmental Secretarys to have any hopes of a change in direction. All we can hope for now is a complete about face by the president of the USA.
jamesp: "... even if we captured every last molecule of CO2 here, that gain would have been cancelled out by India and China in a matter of months."
Way off James, if we stopped producing CO2 in it's entirety it would take China alone 3.5 weeks to produce our total annual CO2 output.
Mrsean2k -
Have a look at page 6 of the following Met Office publication:
Alarmist Bollocks 2009 where the very scary hockeystick curve is clearly labelled "Climate model prediction".
The graph also suggests that ice core records show that current temperatures are between 0.5C and 1C warmer than they were during the MWP, which is at best very questionable and more likely complete bollocks. http://mclean.ch/climate/Ice_cores.htm
Any comment or clarification Richard?
@Peter Stroud 11:09
...the models are anything other than experimentally
verifiedunverified codes...Peter Stroud. Spot on, but the probability of even a Republican president facing down the hysteria is low. We will have to wait many decades for this to wash through our politics, all we can do is hope that we don't lose our democratic processes and that politicians, who are constantly lobbied by the likes of Dr. Slingo, remain afraid to put the more draconian and crazy policies pushed by the greenies in place lest they, like the Labor Party in Queensland are consigned to the dustbin of history by an angry electorate.
Geronimo
"Way off James"
Well, I didn't want to overstate it! What I meant, though, was the time for them to increase their output by the amount we had (hypothetically) reduced it by. Still not very long, I grant you...
Wow. As Barry (but hopefully with fewer typos... ;-) ) I'm amazed that she claims success for regional predictions.
Here's my slightly lengthy attempt (I didn't have time to make it short) at a summary as I view it (I'm not an expert...).
(1) The basic properties of CO2 are such that one can fairly simply predict that increased concentrations will lead to a slight increase in global temperature, of the order of 1 degree.
(2) To make a more confident prediction, one must understand how other features in the climate system react to increased CO2, i.e. one must understand all the feedback mechanisms. The physics of the atmosphere, and the coupling of the latter to oceans, the biosphere, and land, are extremely complex, so modelling of all these feedbacks based on first principles (the known properties of UV, visible and IR radiation, of heat, and of gases and liquids, as determined in the laboratory) is very difficult. Any success in the area is a reflection of extremely hard work by a very dedicated body of scientists.
(3) Weather prediction models of this type are quite successful in predicting short term (< 1 week) behaviour in a regional way, but due to the chaotic nature of the atmosphere, have almost no predictive power beyond that. Many known (and perhaps unknown) processes lead to significant natural variability in temperatures over months, years and perhaps decades.
(4) Models of the evolution of climate on the timescale of years to centuries therefore cannot possibly aim to predict detailed individual outcomes (how warm it will be in Scotland in March 2019), but instead set out to predict mean climate outcomes (e.g. mean temperature in Northern Europe in 2020-30, or mean global temperature). This makes it hard to compare predictions to outcomes.
(5) Models are fairly successful in retrodicting mean global temperatures for the 20th century. Success in reproducing other features of the climate system (e.g. rainfall, regional temperature changes) is much more limited. Attempts to model past climate while not including the rise in CO2 concentrations are less successful; this is one of the major arguments supporting the AGW hypothesis.
(6) Although models are developed from first principles, and attempt to use only well-known historical properties of the atmosphere (e.g. past CO2 or aerosol) concentrations, the accuracy with which these parameters are known is sometimes low. Also, the physical properties of aerosol and clouds are still not fully understood.
(7) Although models are not explicitly 'tuned' to reproduce known historical outcomes, a much better test of predictive skill of models is their ability to make genuine predictions of future climate outcomes. So far, the track record of forward prediction from models is far from excellent, typically not outperforming predictions based e.g. on linear extrapolation of past trends.
Apr 3, 2012 at 11:06 AM stephen richards
Give the guy a break. He's got a mortgage to pay. It can't be 100% fun being beaten up several times a week. How many of us would have gone public to say that the Chief Scientist of the lab we worked for was talking utter crap?
After Climategate, even the scientific establishment reluctantly accepted that climate science's line "skeptic = lunatic" did not compute.
At that point, the management of the Met Office quite obviously decided "OK, we have to engage with skeptics". Betts was approved for the role (notice how - with the possible exception of "Frank" - you never get other Met Office staff posting here?). It must be difficult dancing on eggs.
Models have been used that take into account all the factors that influence climate. These models have been able to simulate the historic changes in global and regional temperatures
It would be a suprise if they did anything other as they were tuned to the historic changes in the first place. As new factors that inluence climate are being discovered on a regular basis, the models ability to predict future climate is of course as near to zero as makes no difference.
Slingo had better realise soon [before being cited for incompetence] that these climate models were broken from the very start. It's because they are based on the mistakes in Manabe and Wetherald 1967 who assumed no heat capacity for the Earth's surface and that the IR emitted from the surface is the black body S-B level for its average temperature in a vacuum.
The net effect of the second claim is to increase heat energy in the Earth's system by a factor of 2.7 [Trenbert et. al. 2009 energy budget], 4.3 for absorbed IR energy. They justification for this entirely fallacious state of affairs [really you have coupled convection and radiation with equilibrium set by the 160 W/m^2 SW energy, not the 396 W/m^2 IR for 16 °C plus the thermals and evapo-transpiration] is the claim of 'back radiation' of 333 W/m^2.
This is based on the assumption that the signal measured by pygeometers is real. It isn't because the device simply shields half the Prevost exchange energy interchange in the atmosphere and measures temperature convolved with effective emissivity.
Every process engineer shown the IPCC claims laughs out loud and blurts out 'No-one can be that stupid!'. So, Slingo, show you are not stupid by admitting the Met Office and the rest of the IPCC modellers have got it very wrong. As for Betts, you lot are on a hiding to nothing now real scientists and engineers have seen these and the other three BAD mistakes.
The statement, "Models have been used that take into account all the factors that influence climate." is factually incorrect.
It is both philosophically untrue (i.e. it is scientifically illiterate in that there must be factors that we are simply not yet aware of), and historically untrue, in that we now know there are effects; feedbacks, cosmic rays etc, for which the variables are simply unknown at this point. The models do not take all these factors into account.
How can this level of ignorance be ignored, let alone rewarded and celebrated?
Apr 3, 2012 at 11:49 AM | Unregistered CommenterStuck-record
Don't you get it? It's a SCAM. The Met Office - as confirmed by the appointment of Napier as its chair - was given the task of coming up with the 'evidence' for CAGW. It saw it as its job. That's why it was given its £400M (or whatever) budget.
Now that its task has been accomplished (and the climate has failed to oblige), its top management are no doubt asking themselves "what do we do now?".
They can't predict
They can't project
They can't forecast
They can't hindcast
They are complex
And they are crude
They may be certain of some things
But they are uncertain of others
To put it bluntly, at this stage of their development climate models are as reliable as the astrological charts of Thrasyllus.
Other than that, climate models are useful tools for shaping policy.
Stuck-record: 'How can this level of ignorance be ignored, let alone rewarded and celebrated?'
My working hypothesis is that the planned World currency, a mix of the Euro and the Amero, plus perhaps the hypothetical 'Ausso' [hence the letter from DC to Gillard on 22 July last year congratulating her introduction of the carbon tax] was to have been based on the income stream from the new taxation system based on individual carbon budgets, a Marxist/Fabian political wet dream.
To justify this, the IPCC has for 30 years been creating a fake scientific justification. The real clue is the claim by Hansen in 1981 that we have 33 K present GHG warming. No professional scientists could have stated this because lapse rate warming comes to ~24 K meaning the IPCC's claims are exaggerated by a factor of ~3.7 from this issue alone.
Convolve it with the 2.7 times exaggeration of heat input to the system from the fake 'back radiation' claim, and the exaggeration rises to a factor of ~ 10. Yes, that's right, for political purposes, the IPCC has made the scare 10 times too high. Very convenient isn't it that 2.7 x 3.7 is an order of magnitude?
I suggest we use the words of an equally eminent climate scientist, Kevin Trenberth, who in 2007 said:
"In fact there are no predictions by IPCC at all. And there never have been. The IPCC instead proffers “what if” projections of future climate that correspond to certain emissions scenarios. There are a number of assumptions that go into these emissions scenarios. They are intended to cover a range of possible self consistent “story lines” that then provide decision makers with information about which paths might be more desirable. But they do not consider many things like the recovery of the ozone layer, for instance, or observed trends in forcing agents. There is no estimate, even probabilistically, as to the likelihood of any emissions scenario and no best guess.
Even if there were, the projections are based on model results that provide differences of the future climate relative to that today. None of the models used by IPCC are initialized to the observed state and none of the climate states in the models correspond even remotely to the current observed climate. In particular, the state of the oceans, sea ice, and soil moisture has no relationship to the observed state at any recent time in any of the IPCC models. There is neither an El Niño sequence nor any Pacific Decadal Oscillation that replicates the recent past; yet these are critical modes of variability that affect Pacific rim countries and beyond. The Atlantic Multidecadal Oscillation, that may depend on the thermohaline circulation and thus ocean currents in the Atlantic, is not set up to match today’s state, but it is a critical component of the Atlantic hurricanes and it undoubtedly affects forecasts for the next decade from Brazil to Europe. Moreover, the starting climate state in several of the models may depart significantly from the real climate owing to model errors. I postulate that regional climate change is impossible to deal with properly unless the models are initialized.
The current projection method works to the extent it does because it utilizes differences from one time to another and the main model bias and systematic errors are thereby subtracted out. This assumes linearity. It works for global forced variations, but it can not work for many aspects of climate, especially those related to the water cycle. For instance, if the current state is one of drought then it is unlikely to get drier, but unrealistic model states and model biases can easily violate such constraints and project drier conditions. Of course one can initialize a climate model, but a biased model will immediately drift back to the model climate and the predicted trends will then be wrong. Therefore the problem of overcoming this shortcoming, and facing up to initializing climate models means not only obtaining sufficient reliable observations of all aspects of the climate system, but also overcoming model biases. So this is a major challenge."
[Venting]
Few people would argue that Richard doesn't engage in a straightforward way, and that where he does elect to comment, he does so truthfully.
Could we please accept that it's a tactical error to constantly demand that he tells everyone he might be in some way accountable to that they're liars and / or idiots?
Spending your time doing that is a certain route to frittering away your influence, irrespective of what it does to your career prospects.
We know that the Met Office seasonal forecasts based on their models have been completely wrong. We know that climate models did not predict the lack of warming over the last decade. More recently, many new papers have found evidence to support the influence of solar activity on our climate. I could go on...
Climate scientists obviously do not understand all the factors that influence climate and some of these are clearly powerful enough to negate the effect of CO2.
Models based on incomplete understanding and dubious assumptions are no basis for policymaking.
To the Secretary of State for Energy and Climate Change,
From Julia Slingo
"Our climate models only incorporate factors which we think we understand to a reasonable degree. We stubbornly refuse to acknowledge possible contributions from other factors such as cosmic rays despite a growing body of evidence that their influence on climate may be significant. Instead, forcings which might properly be attributable to these other factors are attributed to carbon dioxide. As this attribution results in a sensitivity of climate to carbon dioxide which is greater than that suggested by radiative theory, models postulate a strong positive feedback from water vapour. No empirical evidence for this has ever been found, whereas contradictory empirical evidence exists such as the missing stratospheric hotspot. Hindcasting of the resultant models then produces more past warming than has actually occurred, so aerosol fudge factors have been incorporated to damp this down. As can be seen, our models have been cobbled together with the express goal of blaming carbon dioxide for climate change.
The value of climate models lies in their predictive ability. No climate model has ever come close to correctly predicting the climate. Consistently, a more accurate prediction can be obtained by superimposing a sine curve on to an upward trending straight line.
However, we are confident that you will still keep supplying us with research funding. This confidence is based on the knowledge that you are scientifically illiterate and, more importantly, that you will continue to close your ears and minds to non-consensus scientists who would present a proper “due diligence” examination of the science. We are the gatekeepers.
Of course, it is easy to persuade you with messages of doom. What could be better for a politician than an excuse to strut around the world stage, exercising power and pretending to save the world."
(BTW, I don't exclude the possibility that mydogsgotnonose may be correct.)
mrsean2k: 'Could we please accept that it's a tactical error to constantly demand that he tells everyone he might be in some way accountable to that they're liars and / or idiots?'
[Snip - O/T]
"No scientist should support fake science"
I doubt anyone would disagree with that, but I don't see that it means we can decide what someone else's actions should be.
Could everyone please calm down and keep on topic.
noselesscanine,
there's a difference between slowly moving to the centre and the 'postal' moment where someone tells their employers they're all fakes, liars and fraud. I'd rather have a groundswell of scientists in good positions who are on the side of truth but relatively keeping quiet (for now), than a bunch of ex-scientists on the dole with their dignity, but their previous roles filled by more brainwashed fools.
The time will come, but only once the groundswell is there.
'Is this a DAGW which I see before me?'
Stuck-record has it spot-on...
How can she POSSIBLY know that 'all factors which influence climate' have been taken into account..?
Apart from the fact that these models would have been produced by human beings making crude assumptions, there are all the 'known unknowns' - not to mention the 'unknown unknowns'...
I bet the models don't take into account 10% of what actually affects climate - but the politicians wouldn't want to hear that, would they..?
I have provided what I believe to be the most important things policymakers should know about models on previous threads. The top one, worth repeating until someone reads it relates to the fallacy contained in this sentence by Slingo:
To even consider making such a statement your model should first and foremost have verifiable predictive abiltity. Not "backcasting", or "historical simulation" or something similar, but proper forecast ability as in into the future, time not experienced yet etc.
Slingo is being highly misleading to leave that out, in fact to imply otherwise (that simulating pat climate is sufficient) as she appears to have in that extract.
Re DAGW
I am sorry to report that that acronym has already been taken by Drummers Against Global Warming. See here.
CAGW it remains. If Anthropogenic Global Warming wasn't meant to be 'Catastrophic', then what are we doing here fretting about it?
The first rule of 'people who want an answer' is to keep asking different people until one gives you the answer you want. Orgs like the Met Offfice know that if they keep giving the 'wrong' answer, i.e. we don't know all the factors, the models are crap are forecasting, this problem may not be numerically computable in a finite time... then the govt, NGOs, the purse-holders.... will move onto the next one who will give them the answer.
Journos use this technique all the time, and so do politicians with an ideology to peddle. The Met office probably have the view that if someone's going to get the money for saying the unprovable, it may as well be them.
Computer modelling of complex systems is notoriously difficult to do, and does not have a good track record. We know that the complexity of the climate system is such that predictive models of the kind we use for weather forecasting support are inevitably incompetent when it comes to forecasting the climate. Much of what we do in weather forecasting involves deductions from features which already exist, such as a weather front, or from their evolution over relatively short periods – typically a few hours to a few days. Beyond these timescales, innumerable disturbances which may well have begun at space scales too small for our models to capture, will be taking their turn in producing new features that will dominate the weather. When our observational systems detect those features, our forecasting cycle begins again. Without this frequent checking against observations, we know these models will inevitably diverge dramatically from the real system. We therefore cannot hope to extrapolate them to produce climate forecasts in the same way. [7]
The best we might hope to do is provide illustrations of various hypotheses by including them in our models (e.g. giving CO2 a role in driving climate which it does not appear to have had in the past), and looking for results which survive averaging out over large numbers of model runs. So far, this has not been very encouraging. [9]
Giving CO2 a relatively prominent role at current levels in our models leads to increased temperatures in parts of the troposphere which have not been observed, and the models have of course failed to account for the recent flattening-out of global mean temperature, nor have they produced results as impressive for CO2 as the correlations between cosmic ray intensities and various weather phenomena linked to airborne water droplets. Simple extrapolations of known climate cycles have also beaten the projections of computer models as published by the IPCC. Accordingly, we advise severe caution in using these models for any practical purpose relating to climate. [12]
Instead, guidance should be sought from observation-based reconstructions of past climate over say the past 1000 years to get an indication of the range of weather conditions it would be prudent to make contingency plans for as and when we are able to afford them. In what we hope will be the very long term (more than a thousand years from now), it seems more likely than not that the present interglacial will come to an end, and so we anticipate our descendants in that future will have to cope with ice sheets over appreciable parts of what is currently called the industrially developed world. From our more comfortable place in the Holocene, we can but wish them well, and in the meantime take what steps we can to strengthen our understanding of nature and benefit from the remarkably inventive ingenuity of mankind. [15]
[n] = number of sentences so far
Hengist,
'...Is this a DAGW which I see before me?...'
..its (hockey stick) BLADE toward my hand...?
Slingo's three assertions are False, False, and False. Her credibility should be at zero.
Hengist,
I don't remember the "which" being in my copy... but then there seemed to be so many witches... and my memory might be failing... didn't they also say 'hubble, bubble BOIL and trouble'?
All western governments run ponzi schemes. All western governments are in debt up to their eyeballs. Electorally impossible to raise new direct taxes. Get together, create a good scare, soon they can add a tenner to plane ticket, a few quid on the road fund licence for the wrong kind of emissions, all sorts of other bits and pieces here and there, it all adds up, electorates'll probably swallow it if its sold hard enough, keeps the show on the road, the day of reckoning at bay.....sounds ridiculous, sadly, it probably isn't.
mrsean
I agree. Dr Betts is out on a thin enough limb as it is, and just because he might be right won’t necessarily translate into instant popularity. Probably the reverse.
sHx
Pretty much covers it, except Thrasyllus got some of his predictions right. That led Tiberius to put too much faith in his predictions. The result was Caligula. I wonder what Caligula will come out of the DAGW?