IPCC Chapter 8 of the 2007 Physical Science Basis Report.
For models to simulate accurately the seasonally varying pattern of precipitation, they must correctly simulate a number of processes (e.g., evapotranspiration, condensation, transport) that are difficult to evaluate at a global scale.
Since the TAR, there have been few assessments of the capacity of climate models to simulate observed soil moisture. Despite the tremendous effort to collect and homogenize soil moisture measurements at global scales (Robock et al., 2000), discrepancies between large-scale estimates of observed soil moisture remain.
Glaciers and ice caps, due to their relatively small scales and low likelihood of significant climate feedback at large scales, are not currently included interactively in any AOGCMs.
There is a very simple solution when the data is insufficient. Use a model. Which is based on insufficient data.
It is very hard to quantify water vapor in the atmosphere. Its concentration changes continually with time, location and altitude. To measure it at the same location every day, you would need a hygrometer, which in earlier days made use of the moisture-sensitivity of a hair, and by now of for instance condensators. A vertical profile is obtained with a weather balloon. To get a global overview, only satellite measurements are suitable. From a satellite, the absorption of the reflecting sunlight due to water vapor molecules is measured. The results are pictures of global water vapor distributions and their changes. The measurement error, however, is still about 30 to 40%.
There is a very simple solution when the data is insufficient. Use a model. Which is based on insufficient data.
Every problem has a solution which is simple, easy, and wrong.
In the case of water vapor, not only is the distribution poorly understood, related cloud cover and how it effects planetary temperatures is poorly understood.
The daylight is uncomfortably bright for eyes so long in the dark.
There's models, then there's supermodels. Those are VERY pretty, very expensive, high maintenance, and don't do anything really useful. But they're pleasing to the eye, so I suppose there's utility in that.
The Canadian Centre for Climate Modeling and Analysis located at the University of Victoria in British Columbia submitted five runs of its climate model CanESM2 for use in the fifth assessment report of the International Panel on Climate Change (IPCC). The climate model produces one of the most extreme warming projections of all the 30 models evaluated by the IPCC. (See Note 1.) The model badly fails to match the surface and atmosphere temperature observations, both globally, regionally, as presented in six graphs.
If the models fail, it's not because Reality got it wrong.
When opinion and reality conflict - guess which one is going to win in the long run.
JLawson wrote:There's models, then there's supermodels. Those are VERY pretty, very expensive, high maintenance, and don't do anything really useful. But they're pleasing to the eye, so I suppose there's utility in that.
The Canadian Centre for Climate Modeling and Analysis located at the University of Victoria in British Columbia submitted five runs of its climate model CanESM2 for use in the fifth assessment report of the International Panel on Climate Change (IPCC). The climate model produces one of the most extreme warming projections of all the 30 models evaluated by the IPCC. (See Note 1.) The model badly fails to match the surface and atmosphere temperature observations, both globally, regionally, as presented in six graphs.
If the models fail, it's not because Reality got it wrong.
There is another problem. Chaos. Not chaos in reality (although there is that). Computer generated chaos from the "initial conditions" problem. To get a handle on that you need to do at least 20 runs and more like 100. They really can't tell with 5 runs if they have captured mostly outliers or the central tendency of the model.
Engineering is the art of making what you want from what you can get at a profit.
JLawson wrote:There's models, then there's supermodels. Those are VERY pretty, very expensive, high maintenance, and don't do anything really useful. But they're pleasing to the eye, so I suppose there's utility in that.
The Canadian Centre for Climate Modeling and Analysis located at the University of Victoria in British Columbia submitted five runs of its climate model CanESM2 for use in the fifth assessment report of the International Panel on Climate Change (IPCC). The climate model produces one of the most extreme warming projections of all the 30 models evaluated by the IPCC. (See Note 1.) The model badly fails to match the surface and atmosphere temperature observations, both globally, regionally, as presented in six graphs.
If the models fail, it's not because Reality got it wrong.
The large errors are primarily due to incorrect assumptions about water vapor and cloud changes. The climate model assumes that water vapor, the most important greenhouse gas, would increase in the upper atmosphere in response to the small warming effect from CO2 emissions. A percentage change in water vapor has over five times the effect on temperatures as the same percentage change of CO2. Contrary to the model assumptions, radiosonde humidity data show declining water vapor in the upper atmosphere as shown in this graph.
Now here is a supermodel:
Engineering is the art of making what you want from what you can get at a profit.
JLawson wrote:There's models, then there's supermodels. Those are VERY pretty, very expensive, high maintenance, and don't do anything really useful. But they're pleasing to the eye, so I suppose there's utility in that.
The Canadian Centre for Climate Modeling and Analysis located at the University of Victoria in British Columbia submitted five runs of its climate model CanESM2 for use in the fifth assessment report of the International Panel on Climate Change (IPCC). The climate model produces one of the most extreme warming projections of all the 30 models evaluated by the IPCC. (See Note 1.) The model badly fails to match the surface and atmosphere temperature observations, both globally, regionally, as presented in six graphs.
If the models fail, it's not because Reality got it wrong.
There is another problem. Chaos. Not chaos in reality (although there is that). Computer generated chaos from the "initial conditions" problem. To get a handle on that you need to do at least 20 runs and more like 100. They really can't tell with 5 runs if they have captured mostly outliers or the central tendency of the model.
Did it really matter? The results showed warming, that was all that was important.
Gotta keep the money coming, and you don't get that by saying "Hey, our models show something odd - there's not going to be much warming for the next decade."
When opinion and reality conflict - guess which one is going to win in the long run.
JLawson wrote:There's models, then there's supermodels. Those are VERY pretty, very expensive, high maintenance, and don't do anything really useful. But they're pleasing to the eye, so I suppose there's utility in that.
Now here is a supermodel:
Let's see...
VERY pretty? Check
VERY expensive? Insufficient information to determine.
High maintenance? Obviously not in the clothing department.
Utility? Dubious, possibly negative - notice how she's not monitoring the fishing line.
But very pleasing to the eye! I'd say that's one successful model!
When opinion and reality conflict - guess which one is going to win in the long run.
MSimon wrote:The most important greenhouse gas is only known to an error range of 30% to 40%? That can cover up a LOT of CO2.
No it can't. First of all it's rarely thick enough to completely obscure the outgoing IR; so the CO2 can act on what escapes. Second of all, they're mixed together, so even if there was enough water in the whole atmosphere to completely obscure it, the CO2 would still act in the atmosphere on the IR that had not yet made it far enough for the water to obscure it. Third, water vapor only stays in the air for days; CO2 lasts centuries. So the same CO2 molecule will reroute many, many photons, whereas a given water molecule only a few. And last, CO2 has a major absorption band at 4µm close to the Earth's radiation peak where water has a gap.
Do you actually know any physics?
We need a directorate of science, and we need it to be voted on only by scientists. You don't get to vote on reality. Get over it. Elected officials that deny the findings of the Science Directorate are subject to immediate impeachment for incompetence.
Schneibster wrote:Third, water vapor only stays in the air for days;
Given that water constantly evaporates somewhere on Earth, why does it matter how long an individual molecule stays in the atmosphere? Surely it's the average concentration that matters, not the identity of molecules in the air at any given moment.
Schneibster wrote:Third, water vapor only stays in the air for days;
Given that water constantly evaporates somewhere on Earth, why does it matter how long an individual molecule stays in the atmosphere? Surely it's the average concentration that matters, not the identity of molecules in the air at any given moment.
No, it means the concentration of water vapor varies wildly, and constantly, whereas the concentration of CO2 varies only slowly and not by much.
We need a directorate of science, and we need it to be voted on only by scientists. You don't get to vote on reality. Get over it. Elected officials that deny the findings of the Science Directorate are subject to immediate impeachment for incompetence.
Teahive wrote:That doesn't mean there can't be a long-term trend for the average concentration of water vapor.
But there isn't.
Maybe you've noted this mysterious phenomenon where water falls from the sky.
We need a directorate of science, and we need it to be voted on only by scientists. You don't get to vote on reality. Get over it. Elected officials that deny the findings of the Science Directorate are subject to immediate impeachment for incompetence.
Teahive wrote:That doesn't mean there can't be a long-term trend for the average concentration of water vapor.
But there isn't.
Maybe you've noted this mysterious phenomenon where water falls from the sky.
So because rain exists there can be no change in the average concentration of water vapor in the atmosphere, ever.
Makes sense. Not.
It is worse than that. To make CO2 the devil gas the modelers need more water vapor in the atmosphere. So the prediction is for more water vapor Caused by CO2 heating. "Water vapor amplification" is the term.
Schneibster has falsified the models. - Well done sir.
Engineering is the art of making what you want from what you can get at a profit.
Just so we see how dumb this whole thing about water vapor is:
Water vapor contains latent heat of vaporization. So even when the water vapor is the same temperature as the air, it still contains heat. This is the major complication of water vapor.
Now, theoretically, clouds reflect some of the heat back out to space before it gets to the ground; and theoretically higher surface temperatures mean more clouds; and some real geophysicists who are of the iconoclast predilection point out that this is a possible negative feedback that would tend to cool the surface down. Unfortunately this probably isn't a very big feedback; first, solar panels produce more than half their power under clouds or fog, indicating that even clouds reflect less than half the energy. Second, snow under clouds or fog reflects much less light since it receives much less; and that is further attenuated trying to go back through the clouds again, and increasing the heat retained. So clouds over ice or snow increase heat retention. Third, CO2 is there all the time. Clouds come and go, and so does humidity. And finally, the more clouds there are, the more rain there is; and the more rain there is, the more heat gets taken out of the atmosphere. But remember, that heat goes directly into the water where it falls on water, and that means more evaporation and more clouds, and that's heat that doesn't make it to space. It just gets stored in the water vapor again. Which means more water vapor, which means more warming.
Have fun guys. They're still working this out, quantifying each phase. They have most of them, and they believe all the most important ones; and so far they've been right. Furthermore, they think the oceans are more important than any potential inaccuracies in their approximations of water vapor behavior, because they can contain hundreds of times more heat (a not unreasonable guess), and they're mostly working on the O in AOGCM just now. But it turns out that heat in the ocean is the most important unknown factor in the water cycle. So they have to have accurate ocean models before they can finally work out the last details of water vapor. If you actually took me seriously and attempted to analyze the hot mess in the paragraph above this one, that's what you'd find out.
So actually, your thread title is incorrect; you should have omitted "vapor."
But the trends are unmistakable and eventually, no matter how long it takes for the heat to percolate through this maze, if you keep seeing the same heat going in and less coming out, it's gonna get hotter, that's conservation of energy. Energy doesn't just disappear, and if you hear me call climate deniers cranks, that's why: you're denying the First Law of Thermodynamics, the Law of the Conservation of Energy. And the satellites say less is coming out. That's really the problem. And remember this: we only know where some of the heat is going. That just about has to mean it's going into the ocean, and we currently have less knowledge of that than we would prefer and are working hard on it. It's currently the biggest unknown and the place real climate science iconoclasts are focusing their attention, along with the rest of the climate scientists. Anyone carrying on about CO2 "fibers in the atmosphere" (I'm not kidding, one of you actually quoted that as if it means anything) or trying to insert uncertainty with clouds just doesn't know what's going on period.
We need a directorate of science, and we need it to be voted on only by scientists. You don't get to vote on reality. Get over it. Elected officials that deny the findings of the Science Directorate are subject to immediate impeachment for incompetence.
