By Steven Goddard
I recently had the opportunity to attend a meeting of some top weather modelers. Weather models differ from climate models in that they have to work and are verified every hour of every day around the planet. If a weather model is broken, it becomes obvious immediately. By contrast, climate modelers have the advantage that they will be long since retired when their predictions don’t come to pass.
Weather and climate models are at the core very similar, but climate models also consider additional parameters that vary over time, like atmospheric composition. Climate models iterate over very long time periods, and thus compound error. Weather modelers understand that 72 hours is about the limit which they can claim accuracy. Climate modelers on the other hand are happy to run simulations for decades (because they know that they will be retired and no one will remember what they said) and because it provides an excuse to sink money into really cool HPC (High Performance Computing) clusters.
But enough gossip. I learned a few very interesting things at this meeting.
1. Weather modelers consider the realm of climate calculation to be “months to seasons.” Not the 30 year minimum we hear quoted all the time by AGW groupies. That is why NOAA’s “Climate Prediction Center” generates their seasonal forecasts, rather than the National Weather Service.
2. The two most important boundary conditions (inputs) to seasonal forecasts are sea surface temperatures and soil moisture. No one has shown any skill at modeling either of those, so no surprise that The Met Office Seasonal forecasts were consistently wrong.
For example, just a few months ago the odds of La Niña were considered very low. Compare the December forecast with the May version. How quickly things change!
SST modeling capabilities are very limited, and as a result seasonal weather forecasts (climate) are little more than academic exercises.
Oh and by the way, Colorado will be exactly 8.72 degrees warmer in 100 years. But they can’t tell you what the temperature will be next week.
“If I don’t understand it, it must be simple.”
– Dilbert Principle
In the top picture, which boxer is weather and which one is climate? What do readers think?
carrot eater
If you have something specific to say technically, I’d like to hear it. But when people start quoting terminology they learned earlier in the day, it is pretty much of a turn off.
When your model does not get the cloud distribution right but in the end the temperature fits, does this not give you the feeling that it might be right for the wrong reasons?
Maybe it means clouds are not as important as you think.
“weather prediction is an initial value problem, and climate is a boundary value problem” – carrot eater
Why imagine that things divide so neatly? Isn’t it more likely that both weather prediction and climate prediction are both initial and boundary value problems?
PDA, there is a big difference between random events (coin tosses) and chaotic events (climate). Get back to us when you understand the difference.
Steve, IMHO the two fighters is a bad analogy. I see no relationship to weather and climate. Climate basically contains weather. A better analogy would be a large team of fighters vs. a single fighter on the team.
Carrot said:
“use physics to make some estimates of how climate may change over the long term in response to changes in the energy flows into and out of the system.”
Reasonable, but then your model must expand to consider the factors in changes in the sun, and whether these factors are uncoupled to the thing predicted. Each iteration of modeling that observes external factors to the model must expand to include those factors, or your model is aliased garbage. The wonderful thing about lab-scale experiments is they can be uncoupled from multiple factors and controls can be used, but the earth??? The statement that if you can’t predict the weather you can’t predict “climate” is a completely valid viewpoint: If you don’t understand energy distribution changes over a small time, how can you assume they will react in your predicted manner indefinately? The assumption that a warmer sun leads to a warmer climate may be valid for a small window: How large, how long and how high? What factor that leads to a change in the sun also has a terrestrial effect uncoupled to irradiation? Who the [snip] knows? Who’s bothering to find out?
Saying: CO2 and solar insolation both went up, and so did temperature, means instantly that prexisting models F(CO2)=delT and F(SI)=delT are both incorrect, and instead you must have F(CO2,SI)=delT or you are wrong, and even then you’re probably still wrong, because you can’t uncouple delT from any other factors. I think the objection at the moment is: F(CO2)=delT is too simple to be any sort of credible science. I agree.
/general rant (again)
Also, to have a model you must have a thing which is defined. All these completely ridiculous analogies here, subjective definitions and feel-good probability similies suggest that climate is a simple concept, some summation of some amount of particular types of weather over time which can be predicted to behave a particular way according to limitations established during the experiment. “Skeptics” point out ice ages and warm periods to suggest that what we call “climate” is really a dynamically-limited snapshot of a much larger and varied dataset which encompasses any current delT across all testable regions and that assuming “climate” should fit into that snapshot indefinately into the future is ignorant, and that concluding
F(CO2)=delT is 1) true 2) dominant 3) indefinite is also ignorant. Where’s the valid argument to this?
The “Climate” I see described here realistically amounts to no more than the energy distribution of a TINY (couple of miles) shell around one enormous, complex gravity producing electromagnetic body floating in an unbelievably enormous soup of radiation, gravity and magnetic fields. F(CO2)=delT IS retarded. Get over it.
I saw somebody suggest you could mix cream in a cup of coffee and this was some analogy to climate. What utter trash is that? Splash that coffee on top of a table, put one drop of cream somewhere in the puddle, turn the lights on and off, put in a few fans, hit the table with a hammer a few times, freeze it, thaw it, stir it around with a wire brush once or twice, grow some Sea-Men in it, kill them off, let mold take over, stir the mold around, start clearing some of the mold here and there, drop a giant firecracker in it and then at the very very end of your experiment, add some warm grains of sand to represent cities and take 5 measurements of cream concentration in various locations, then use these five measurements to predict the concentration of cream correctly across the whole puddle after you add one more drop and repeat the above process. Hey, look, coffee analogy that is exceedingly more complex and accurate to reality and still fails miserably to describe external factors comprehensively.
Climate science as a valid scientific discipline is stunted and aborned by AGW scare tactics and the world is a poorer place for it.
blockquote cite=”Dan says:
July 1, 2010 at 5:56 am
Hi Steven,
Let’s make a bet. I’ll bet you that the average temperature in the United States in July 2100 will be warmer than the average temperature in January 2100. If I’m wrong, I’ll give you $100. If I’m right, you give me $1. (What a deal!)
Do you accept? If you’d like this bet to be a bit more tangible, we can change the year to 2015, or any other year of your choosing. According to your logic, accepting this deal should be a no-brainer, since you’ve claimed that prediction of climate variables and weather variables are mathematically equivalent.
Let me know. Thanks!
Dan
“>
I think you’ll find that January colder than July in the northern hemisphere due to Earth’s orbit around the Sun and the axial tilt of the Earth WRT the orbital plane.
A weather forecast is what you are expected to remember.
On Sunday you are expected to say “It’s raining, but they said on Friday it was going to be sunny”
A climate forecast is what you are expected to forget.
On October 31st 2013 you are not expected to say “There is still ice in the Arctic, but they said seven years ago it was going to be Ice Free.”
The difference is that the weather forcaster will still be working at the same job when their predictions are falsified, whereas the climate forecaster will likely have already died of old age when their predictions are falsified.
Found in: PDA on July 1, 2010 at 5:33 am
By the circumstantial evidence I’d say the word has gone out to take out Steven Goddard. Since “PDA” is known here, time to break out a mask, which turned out to be a lousy one. You recognized him so now the mask is off but he’s going ahead anyway.
Seems like they’re using the plan they started using at the “Amazing Grace” thread, complain about his credentials, complain about his posting name being fake, and keep working him down until he feels he has to defend himself by declaring where his degrees are from, where he works, maybe they’re hoping he’ll skip to the chase and just give his real name and save them the effort of the tracking down. Then they can stick his name on the list and destroy him professionally.
Heh, “PDA” linked to a one-entry new blog where he doesn’t even use the name found here, of which the domain has an anonymous registration. And while there is complaining about Steven being “anonymous”… Hey look, it’s carrot eater! Yup, got a real party going on here now. 🙂
Nigel Harris
The orthodoxy always gets upset when their position of power is threatened by outsiders.
Team AGW is behaving more and more like the 16th century Catholic Church. Can you imagine the catastrophe which would occur if word got out that the earth is not the centre of the Universe?
The Climate Model Paradox:
If climate physics is “settled” science why are all climate models not identical? If it is not settled how can a computer projection based on unknown climate physics give remotely usable output?
Where is Leif when you need him, he thinks computer models cannot be programmed to get the results that you want. If most climate scientists think like him it is likely they are all computer illiterate.
RE: The silly seasonal argument,
Saying that the winter months will be colder than the summer months in the northern hemisphere is based on observational data since man recorded such things. No need to model something you can look up in the farmers almanac. Yes of course we now know why based on the orientation of the Earth to the Sun, none of which has anything to do with being able to correctly predict or project the temperature of those months in the future.
The problem with those who never studies computer science is they think “close-enough” results from a model are accurate, they are not they wrong (right in the sense that the model did exactly what it was supposed to, wrong in that they do not match reality). Why they are wrong (do not match reality) is a guessing game and cannot be determined on a computer. Wrong results (do not match reality) are worthless.
Virtual reality can be whatever you want it to be and computer climate models are just that, they are the code based on the subjective opinions of the scientists creating them. The real world has no such bias.
andrew adams
If you vary clouds in radiative transfer models by 5%, you get a huge difference in the resultant surface temperature. Think about the difference in afternoon (or nighttime) temperature on a cloudy day.
RW
You should get on the phone with NOAA’s “Climate Prediction Center” right away and tell them that based on your understanding of the definition of climate, they have no business doing seasonal forecasts.
I bet you will get a really positive response.
@R. Gates says:
July 1, 2010 at 11:51 am
“The energy from the sun is certainly the major supply of energy on earth, but for example, the Milankovitch cycle is not the sun per se, as the sun is not changing its output significantly, but it is the Earth’s eccentricity, axial tilt, and precession that are changing. So some distant alien astronomer trying to predict the Earth’s longer term climate by studying the small variations of just the total solar irradiance would fail miserably if they didn’t take the Milankovitch cycles into account”
The energy from the Sun is certainly the only supply of energy on earth. And as temperature change follows the large changes in solar wind velocity (and hence geomag` recordings) and not TSI, then you can regard Milankovich cycles as curious proxy for solar variation. As well as orbital cycles cannot explain the shift from 41kyr to c.100kyr glaciation cycles, and should not produce a `saw tooth` shaped feature on the rapid rise out of deep glaciation.
I feel that Climate pushes Weather around, so I go with the big guy being Climate.
The Earth isn’t the center of the universe? Things look pretty spread out in all directions to me. What would Dr Hawking say?
@Enneagram says:
July 1, 2010 at 12:37 pm
{R.Gates
Both have chaotic dynamic elements}
“Chaos’ explanation, or rather, justification, appears where knowledge is lacking.
Knowledge is not so hard to attain than hard to accept.
Pitagoras with his simple monochord attained it, how about you?”
Yes, weather events and temperature deviations can be (and are being) forecast way in advance from predictable changes in the solar signal. Nothing chaotic in terms of `without cause` or `random` that I can note. I understood chaos to mean change, the weather nearly always does that fortunately.
PDA says:
July 1, 2010 at 5:33 am
[…]
Weather is chaotic and unpredictable. Climate is weather averaged out over time.
Common quality of chaotic systems is they tend to be self-similar at any scale. If we Define weather a a phenomena lasting 15 minutes and climate as a phenomena lasting 30 years, weather seems erratic when viewed over a period of a week, like wise climate will seem erratic when viewed over a period of a millenia. Additionally whether a phenomena erratic and unpredictable, or it is chaotic are two separate issues.
Ulric Lyons says: July 1, 2010 at 5:53 pm
“I understood chaos to mean change”
I do not think that chaos means change. I think that is in closer to a Brownian motion contribution to a system.
I understand chaos as an attribute of a system; it is a collection of unrelated or seemingly unrelated events that have a visible effect on the system but no known or predictable underlying cause.
Given a long enough sample of the externally visible changes in a system that contains a chaotic group of contributors one can project the next few samples. Since the chaotic contributors may be completely unrelated and not share any common cause, their contributions to the system can not be anticipated and therefore the reliability of any projection of the future state of the system beyond the immediate next few samples is as best a guess, the error bars quickly overwhelm the projection.
Modeling a system that contains a large collection of chaotic contributors is very difficult.
Tom in South Jersey
Yes, team AGW has convinced themselves that the world depends on their belief system. The same delusions as the fanatics of every generation and every culture.
One other attribute of chaotic systems that some folks seem to misunderstand is that changes can happen fast. There may be long periods of stability and then many fast changes. We see this in both weather and climate at different scales.
Just like a change in weather often brings changes in a day or less, big changes in climate could lead to ice age conditions in a few decades. That makes predictions of events in 2100 silly at best … dishonest at worst.
@paul jackson says:
July 1, 2010 at 6:30 pm
“Given a long enough sample of the externally visible changes in a system that contains a chaotic group of contributors one can project the next few samples….
Given a long enough sample of the externally visible changes in a system that contains a chaotic group of contributors one can project the next few samples. Since the chaotic contributors may be completely unrelated and not share any common cause, their contributions to the system can not be anticipated and therefore the reliability of any projection of the future state of the system beyond the immediate next few samples is as best a guess,”
Yes, weather events and temperature deviations can be (and are being) forecast way in advance from predictable changes in the solar signal.
And from an accuracy currently of 49/52 weeks per year correct for temperature deviations from normals, and with an understanding of temperature/precipitation relationships at different seasons, it is possible to not only do very exacting climatic temperature forecasts, but also the all important hydrology factors, ie. flood/drought cycle mapping.
tonyb:
it must have been Scott himself that truncated that quote-not me.
I wasn’t making a specific accusation, just pointing out that there was more context.
KD Knoebel:
Since “PDA” is known here, time to break out a mask,
I’m “known here?” Under a name I’ve never posted with before? Awesome! Sorry I haven’t blogged more, but please feel free to come over and comment.
I only tweaked “Steven Goddard” about his pseudonymity as a way of responding to Anthony’s hypocrisy about “anonymous cowards.” I made a number of substantive comments too, “KD Knoebel.” Did you read them? Do you have any response, or is attempting character assassination all you’ve got?
By the way, where’s your blog? Where’s your WHOIS registry, what’s your online record? Or is creepy webstalking only for people you disagree with?
paul jackson:
Common quality of chaotic systems is they tend to be self-similar at any scale.
You are saying “chaotic systems” but you mean “fractals.” It might be cool around here to just redefine scientific concepts on the fly, but that doesn’t mean it makes any sense.
Andrew30:
I understand chaos as an attribute of a system; it is a collection of unrelated or seemingly unrelated events that have a visible effect on the system but no known or predictable underlying cause.
Ditto. You could try reading about chaos, or you could just keep groping around in the dark. Your choice!
Ulric Lyons said:
“The energy from the Sun is certainly the only supply of energy on earth…”
_________________
Quite untrue. There are several more, and so I don’t think you’ve thought this through very well, but let me give you a hint: Think Madame Curie. Here’s another hint: Think of Eyjafjallajokull. So when our spacecraft leave the Earth and travel deep into space where the influence of the sun’s energy is even less, or non-existent, then we rely on the first of these non-solar sources of energy (it being too impractical to take small volcanoes onboard a spacecraft)
But in general, I don’t deny the major role that the sun plays in the Earth’s climate, but I also am not blind to the other factors. The weathering of rock for example and geological processes such as volcanoes are completely independent of solar output but have major influences on the composition of our atmosphere and in creating the GHG forcing that we enjoy and the subsequent climate, without which, we’d all be, well…nonexistent.
stevengoddard says:
July 1, 2010 at 7:14 pm
Tom in South Jersey
Yes, team AGW has convinced themselves that the world depends on their belief system. The same delusions as the fanatics of every generation and every culture.
_______________
Well, I guess I currently am part of this “team AGW” (at least 75% of me), and I am certain that world (both natural and man made) could give a rat’s ass about my belief systems. I look around and see fanatics on both sides of this issue– a fanatic being someone who absolutely will never change their paradigm no matter what facts are presented to them because it is an emotional bond they have with their beliefs, not a rational one. I have no such attachment, and could easily change my beliefs given rational evidence to do so.
@R. Gates says:
July 1, 2010 at 7:31 pm
Ulric Lyons said:
“The energy from the Sun is certainly the only supply of energy on earth…”
_________________
Quite untrue. There are several more, and so I don’t think you’ve thought this through very well, but let me give you a hint: Think Madame Curie. Here’s another hint: Think of Eyjafjallajokull.
__________________________
So if the Sun were to `switch off`, x billion people huddle round a handfull of active volcanoes and some nuclear reactor cores as planet Earth ice balls?
R. Gates
All of the heat being generated in the earth is ultimately from radioactive decay, including that coming out of volcanoes. But that is a tiny amount compared to what the earth receives from the sun.