From NCAR:
Future warming likely to be on high side of climate projections, analysis finds
November 08, 2012
BOULDER—Climate model projections showing a greater rise in global temperature are likely to prove more accurate than those showing a lesser rise, according to a new analysis by scientists at the National Center for Atmospheric Research (NCAR). The findings, published in this week’s issue of Science, could provide a breakthrough in the longstanding quest to narrow the range of global warming expected in coming decades and beyond.
NCAR scientists John Fasullo and Kevin Trenberth, who co-authored the study, reached their conclusions by analyzing how well sophisticated climate models reproduce observed relative humidity in the tropics and subtropics.
The climate models that most accurately captured these complex moisture processes and associated clouds, which have a major influence on global climate, were also the ones that showed the greatest amounts of warming as society emits more greenhouse gas into the atmosphere.
“There is a striking relationship between how well climate models simulate relative humidity in key areas and how much warming they show in response to increasing carbon dioxide,” Fasullo says. “Given how fundamental these processes are to clouds and the overall global climate, our findings indicate that warming is likely to be on the high side of current projections.”
The research was funded by NASA.
Moisture, clouds, and heat
The world’s major global climate models, numbering more than two dozen, are all based on long-established physical laws known to guide the atmosphere. However, because these relationships are challenging to translate into software, each model differs slightly in its portrayal of global climate. In particular, some processes, such as those associated with clouds, are too small to be represented properly.
The most common benchmark for comparing model projections is equilibrium climate sensitivity (ECS), or the amount of warming that eventually occurs in a model when carbon dioxide is doubled over preindustrial values. At current rates of global emission, that doubling will occur well before 2100.
For more than 30 years, ECS in the leading models has averaged around 5 degrees Fahrenheit (3 degrees Celsius). This provides the best estimate of global temperature increase expected by the late 21st century compared to late 19th century values, assuming that society continues to emit significant amounts of carbon dioxide. However, the ECS within individual models is as low as 3 degrees F and as high as 8 degrees F (, leaving a wide range of uncertainty that has proven difficult to narrow over the past three decades.
The difference is important to reconcile, as a higher temperature rise would produce greater impacts on society in terms of sea level rise, heat waves, droughts, and other threats.
Clouds are one of the main sticking points, say the NCAR authors. Although satellites observe many types of clouds, satellite failure, observing errors, and other inconsistencies make it challenging to build a comprehensive global cloud census that is consistent over many years.
However, satellites perform better in measuring water vapor, and estimates of the global distribution of relative humidity have become more reliable. Relative humidity is also incorporated in climate models to generate and dissipate clouds.
Fasullo and Trenberth checked the distribution of relative humidity in 16 leading climate models to see how accurately they portray the present climate. In particular, they focused on the subtropics, where sinking air from the tropics produce very dry zones where most of the world’s major deserts are located. The researchers drew on observations from two NASA satellite instruments — the Atmospheric Infrared Sounder (AIRS) and Clouds and Earth’s Radiant Energy System (CERES) – and used a NASA data analysis, the Modern-Era Retrospective Analysis for Research and Applications (MERRA).
The seasonal drying in the subtropics and the associated decrease in clouds, especially during May through August, serve as a good analog for patterns projected by climate models.
“The dry subtropics are a critical element in our future climate,” Fasullo says. “If we can better represent these regions in models, we can improve our predictions and provide society with a better sense of the impacts to expect in a warming world.”
Accurate humidity yields higher future temperatures
Estimates based on observations show that the relative humidity in the dry zones averages between about 15 and 25 percent, whereas many of the models depicted humidities of 30 percent or higher for the same period. The models that better capture the actual dryness were among those with the highest ECS, projecting a global temperature rise for doubled carbon dioxide of more than 7 degrees F. The three models with the lowest ECS were also the least accurate in depicting relative humidity in these zones.
“Because we have more reliable observations for humidity than for clouds, we can use the humidity patterns that change seasonally to evaluate climate models,” says Trenberth. “When examining the impact of future increases in heat-trapping gases, we find that the simulations with the best fidelity come from models that produce more warming.”
The authors focused on climate models used for the 2007–08 assessment by the Intergovernmental Panel on Climate Change. The next-generation models being used for the upcoming 2013–14 IPCC assessment were found to behave in a similar fashion, as described in a preliminary analysis by the authors in a supplement to their paper.
“In addition to providing a path forward and focus for improving models, results strongly suggest that the more sensitive models perform better, and indeed the less sensitive models are not adequate in replicating vital aspects of today’s climate,” write the authors in the paper.
About the article
Title: A Less Cloudy Future: The Role of Subtropical Subsidence in Climate Sensitivity
Authors: John Fasullo and Kevin Trenberth
Journal: Science
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
J Martin says:
November 9, 2012 at 11:41 am
Gail Combs,
You’ve probably read these, but in case you haven’t….
_______________________________
Thanks much I had not seen those from ChiefIO but he is spot on.
Until the politicians realize the economy is just like a horse the country is going to stay deep in horse manure and keep sinking. A horse won’t move until you loosen the reins (regulations) and if you beat it (punitive taxes/fines) it will just go backwards. Beat it even more and it will rear and flip over backwards (rebellion).
DGH says:
November 9, 2012 at 3:13 am
Dr. Trenberth is a Nobel Laureate (shared) with IPCC 2007. He is listed in more Who’s Who’s than I can count and has “many appearances on national and local television programs and news.” Did you know that one of his papers has been cited 766 times?!
He is a very big deal. Just ask him. http://www.cgd.ucar.edu/cas/Trenberth/trenberth-cv.html
Now how about a little respect.
**************************************************************************************************
Firstly, He is not a Nobel Laureate, see the statements from the Nobel committee recently about Michael Mann’s similar claim (easily found).
Secondly, “He is listed in more Who’s Who’s than I can count” – a certain dictator in Germany also has been mentioned many times.
Thirdly, “many appearances on national and local television programs and news.” – so has Jimmy Savile, so what?
Fourthly, “Now how about a little respect.” – see the response from Arkell v Pressdram, again easily found.
SteveT
Matthew R Marler says:
November 9, 2012 at 12:55 pm
….There is no fundamental reason why they can not do that. No model does it very well now for very far in advance, but there is no reason to think that some model might be accurate enough and reliable enough if enough work goes into its development and testing.
____________________________
As long as there are political forces shaping those models – the need to blame humans for climate change – the models will continue to be garbage.
At this point the emphasis should be on trying to determine the different things that effect the climate. Instead the emphasis is on trying to bury anything that might show that CO2 is not the driving force in the climate. There is plenty of evidence of that right here on WUWT.
RE my post at 3.20 pm
Perhaps you will have realised by now that the sarc tag is necessary, owing to a fair number of trolls around.
Apologies for my earlier reply, I came back to my PC and hadn’t refreshed posts submitted since I loaded the article several hours earlier and hadn’t caught up.
Steve T
richardscourtney – In multiple posts here (including this one) you claim comparing model outcomes is nonsense, and by extension that Fasullo and Trenberth cannot support their suggestion for higher climate sensitivity using those model comparisons.
Yet in another post you wax rhapsodic about Spencer and Braswell using the very same technique, comparing model predictions to observations to gain insight into climate sensitivity.
I believe the proper terms for these two posts, and your arguments therein, are internally inconsistent and confirmation bias.
Or is there another explanation why S&B’s use of this technique is (in your opinion) appropriate, and F&T’s use of the same method is not?
Richardscourtney, the assassin.
Note the “service” provided by RC on WUWT. He posted the following:
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
richardscourtney says:
November 9, 2012 at 10:33 am
Jeff and JJ:
Thankyou for drawing attention to the error by KR.
In common with most regular readers of WUWT, I skip over posts by KR because I don’t want to waste time on them. However, in this case his error is not only blatant but is also offensive to our host. And, importantly, it clearly shows the validity of posts by KR so it needed to be pointed out for the benefit of people who may be tempted to take his posts seriously.
Richard
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
KR had indeed made an error and then very promptly apologized for it and corrected it. Then this
guy, richardscourtney, uses the opportunity to do further damage to KR. I don’t know anything about KR but have learned a lot about Sir Richardscourtney and have come to think he is an assassin – in the sense that he does his best to undermine the credibiltiy of anyone he fears might not be a fellow anti AGW er.
So now when I scan through WUWT, I try to see who Richardscourtney is trying to trash today on that thread. Then I look up the posts of that person and invariably find that person to be someone with real knowledge of science!!!!
How can this have any credibility? As far as I can see, on the Internet, the lastest Mars lander program has found that the Martian atmosphere has 95.3% CO2 and 210 ppm water vapour. Its average temperature is estimated at -63 degrees Celsius which is 6 deg C less than the modelled temperature for a greenhouse gas free atmosphere. That is right. Negative 6 deg C global warming for 95.3% CO2 !
So where is the greenhouse gas global warming? Hidden in the oceans – there are none ?
Interestingly, the First Assessment Report by the IPCC gave Mars as having 10 deg C greenhouse gas warming and this has not been retracked in any of the later reports that world leaders reply upon for their decisions. Perhaps the IPCC is not interesting in providing any information that conflicts with their aim of ever-increasing economic and political power.
Matthew R Marler says:
One of the goals is to improve the model inputs sufficiently so that the model outputs begin to have demonstrable accuracy and reliability. This is a step toward that goal.
No it isn’t. It isn’t a step toward anything other than their predetermined political endpoint. Nothing here improves any model, it just puts a fig leaf over the assertion that the models that make the predictions they like should be preferred over the models that make the predictions they don’t like.
Flaming elephants.
@Steve Thatcher
Many thanks for acknowledging my later posts where I was forced to admit that “He is a very big deal. Just ask him” was meant as sarcasm.
No doubt it should be easy for you to find a troll on this blog. Usually the troll is the first commenter to illustrate Godwin’s Law.
Matthew R Marler says:
November 9, 2012 at 12:55 pm
There is no fundamental reason why the models can not be improved.
But there is a fundamental limit to how much they can be improved.
Let’s say the Forcings model, with currently recognized forcings accounts for 50% of climate variability, then that is the limit of the predictive accuracy of a model that embeds the theory and recognized forcings.
The real problem with the models is the CO2 forcing is fixed and has been for 20 years and other forcings are varied primarily to maintain the CO2 forcing and produce half-way accurate hindcasts.
Of course, this (not changing the CO2 forcing) cannot continue indefinitely, but as long as it does, model forecasts will get progressively worse.
Strange how they keep saying more heat will lead to more humidity that will lead to more heat and more humidity and…
Somehow they never manage to remember that more humidity leads to a long hard cold rain…
“It’s a hard rain, a-gonna fall”…
http://chiefio.wordpress.com/2011/04/03/perspective-on-rain-and-heat/
Every afternoon during a Florida summer, it gets warm mid day, then the convected moisture makes a nice tropical thunderstorm in the afternoon and brings cooler air. Like clockwork, I could look out my office window at rain after lunch. Sometimes, but not always, ending before the drive home…
More heat just drives the rain cycle faster and dumps that heat to space faster.
http://chiefio.wordpress.com/2011/07/11/spherical-heat-pipe-earth/
It doesn’t ‘build up’ and it doesn’t lead to higher temperatures. It leads to LOWER temperatures as the heat is taken to altitude and dumped making things like rain and hail that fall to earth.
Anyone who says more heat and humidity will lead to higher temperatures has no clue how heat and humidity work in weather, need to spend some time in the tropics, and needs a refresher course on the difference between heat and temperature… Oh, and they need to write on the blackboard 10,000 times “I will not forget Enthalpy”…
Oh, never mind all that; just force them to stand in the (tropical?) rain for a few weeks…
Could be things will warm some after the end of the current 30-yr cold spell. CO2 will have soared by then as people try to keep from dying of hypothermia, (and may try to take the credit). Making all that lovely CO2 will have been MUCH more expensive than necessary, though, because of Twisty Trenberth and the others desperately demanding we take CAGW as the Null.
KR:
I copy all of your egregious and mendacious post at November 9, 2012 at 4:20 pm so it cannot be said that I am not addressing anything out of context.
Like all your posts it is fallacious, misleading and offensive. It says
1.
I have NOT said, “comparing model outcomes is nonsense”.
I repeatedly point out – with evidence – that the climate models do not emulate the climate system of the real Earth and, therefore, the models do not indicate climate behaviour of the real Earth.
2.
I have NOT said, “Fasullo and Trenberth cannot support their suggestion for higher climate sensitivity using those model comparisons”.
I have said the simple truth that indications of “climate sensitivity” by use of climate models indicates the behaviour of the models and NOT the behaviour of the Earth’s climate system.
3.
S&B do NOT use the “same method” as F&T.
S&B compared climate model outputs to empirical data and the comparison shows the models are wrong. F&S compared outputs of climate models as a method to assess the Earth’s climate behaviour. Simply,
(a) S&B did something called science: i.e. they assessed the outputs of the climate models by comparison with empirical data of real world climate behaviour.
but
(b) F&S did something called pseudoscience: i.e. they assessed real world’s climate behaviour by comparison with outputs of the models which do not emulate the real world’s climate system.
4.
I could not care less about what you say you believe.
Your beliefs are as irrational and untrue as Grimsrud’s.
5.
You make a false and untrue assertion about my “opinion” based on your false and untrue claim that S&B use the same method as F&S.
I am willing to accept your false an untrue assertions are merely another example of your lack of reading comprehension (which has already embarrassed you in this thread).
Richard
ericgrimsrud:
I enjoyed the laugh you provided with your post at November 9, 2012 at 4:36 pm. Thankyou.
I write to ask a question which is not about science so you don’t need worry that it will tax your abilities.
How did you “look up” the troll who posts anonymously as KR and so “find that person to be someone with real knowledge of science”?
Richard
Moderators:
My reply to Grimsrud has gone in the ‘bin’. Please retrieve it.
Richard
Reply: OK. -ModE
Jeez, Gail, take a pill. The post was a mixture of hyperbole, irony, and then a switcheroo to a valid conclusion opposite to those of Trenbumpf et al. You should be applauding a clever post, not nattering about it.
Amusingly, the actual sensitivity falls below the bottom number on the vertical scale (1).
All of the climate model studies must be meaningless, if, as I understand, the models are anchored to the proposition that increased atmospheric CO2 concentration causes an increase in the global temperature. Actual data on the relationship between CO2 concentration and temperature is on the Web site for the “World Data Centre for Greenhouse Gases” run by the World Meteorological Organisation, to be found at :
http://ds.data.jma.go.jp/gmd/wdcgg/
The data covers 348 locations across the globe and each location contains annual files of meteorological conditions and atmospheric gas concentrations over many decades. A detailed study of the hourly temperature and CO2 concentration for the years 1996 to 2006 inclusive for Barrow, Alaska, reveals the interplay between the two variables. Daily averages over the 11 year period ( one Sun cycle ) gave a correlation coefficient of -0.74, that is, as CO2 concentration increases, temperature decreases and visa versa. Cross correlation of the data set gave a maximum correlation of +0.83 for a 153 day lag of CO2 behind temperature.
What does this mean? It is simply the seasonal variation in temperature, climate and life, controlled by the 12 month passage of the Earth around the Sun. At Barrow, as the temperature rises from a minimum of about -27 degrees Celsius through about -8 deg C, the biological life cycle begins with a flourish as life forms suck up atmospheric CO2. That causes the CO2 concentration to fall rapidly, reaching a minimum when the temperature is at about its maximum – the exact opposite of the behaviour proposed by the atmospheric greenhouse gas warming conjecture. Then as the temperature falls, life forms die, generating CO2 and causing its atmospheric concentration to rise.
Note that the temperature increase initiates the biological life cycle which, in turn, causes the CO2 concentration to rise and then fall. That is, the Sun, via temperature, is the prime mover of the atmospheric CO2 concentration. The plants and animals have known it for millions of years yet we accept the pronouncement of some clown on two legs who says “No, it is increasing CO2 in the atmosphere that is causing the temperature to rise”.
A study relating annual increments in both surface temperature and CO2 concentration from six locations across the globe gave a correlation coefficient of 0.1051 from 144 yearly observations. This small positive correlation merely reflects the above explanation that changes in the incoming Sun’s radiation cause both temperature and CO2 concentration to change. There is simply no basis in the data for the claim that increased CO2 concentration is causing a rise in temperature.
Eric Grimsrud said “So now when I scan through WUWT, I try to see who Richardscourtney is trying to trash today on that thread. ”
Eric, as you sit beside your warm “carbon-neutral” pellet stove in 10F degree Montana winds and think of ways to make heat more expensive for ordinary Americans without pellet or wood stoves, think about this. Each American should be trying to make life better for their fellow Americans. People like Richard Courtney have been doing that for decades by educating them on why they should reject the copy and pasting of climate catastrophism by people like yourself and KR, and instead pay attention to the research that points to the beneficial effects of a small amount of warming.
KR and yourself deserve all the scorn you get for your superficiality. As KR demonstrated above and subsequently apologized, you are quick to jump on any trivial error to avoid talking about important issues in detail. KR to his credit came back with a less trivial although still incorrect argument. You seem to be content to wallow in triviality and admit it by saying you simply “scan” through the threads to see who RSC is “trashing”.
Unfortunately it is you who are trashing. My modest suggestion is to read the threads and comments in detail and try to comment on something on-topic.
The thing about this global warming nonsense is that those pushing it are largely governments and their agencies that support the UN and its IPCC. As long as they continue to have the upper hand controlling the global warming agenda, and the money that flows its way, we are forever going to see more alarmism packaged every which way it can. By now, everyone must realise that real science on climate is irrelevant… political science on climate is what matters.
After that great comment by @Bevan, how about this:
Just by sitting in front of my computer i’m causing the CO2 to go up in this room by breathing and causing the temperature to go up(from body heat and because i turned the heater on ).Seems like i got rising CO2 and temperature.Must be a bad thing,can’t have much of that going on……WUWT?
Thanks for the interesting articles and comments
eric1skeptic,
Excellent post, I could not write it better. I could not have even written it as well.
Grimsrud is a site pest, incessantly arguing his hypocritical nonsense even as he consumes fossil fuels for his own convenience. He is an unhappy iconoclast who feels it necessary to take hypocritical positions cloaked in ‘green’ ideology. The day he gives up his motor car and his fossil fuel-provided electricity is the day he will begin to attain some credibility. Until then, he is just a crank.
DB, thanks. I originally thought you were German or other foreign national due to the umlaut. But then I realized you are a patriotic American.
“Given how fundamental these processes are to clouds and the overall global climate, our findings indicate that warming is likely to be on the high side of current projections.”
“However, because these relationships are challenging to translate into software, each model differs slightly in its portrayal of global climate. In particular, some processes, such as those associated with clouds, are too small to be represented properly.”
“Clouds are one of the main sticking points, say the NCAR authors. Although satellites observe many types of clouds, satellite failure, observing errors, and other inconsistencies make it challenging to build a comprehensive global cloud census that is consistent over many years.”
Hmm…ya think clouds are the Achilles heel of the models so processes associated with clouds are too small to be represented – and this isn’t a problem. Clouds are the sticking points! Gee they are easy to see and determine cover. Do ya think satellite failure, observing errors and other inconsistencies could be another way of saying they aren’t giving you what you want them to, especially in albedo. One inconsistency is that when a cloud comes over on a sunny day it cools things off.
richardscourtney
F&T 2012 compares model outputs to the Atmospheric Infrared Sounder (AIRS) and Clouds and Earth’s Radiant Energy System (CERES) satellite data on atmospheric water vapor – empirical data. Perhaps you haven’t read the press release at the top of this thread? Because that _is_ quite clear.
You have praised S&B 2011, heaped insult on F&T 2012, for using the same basic method of comparing models to observations and considering the climate sensitivities of those models against their correlation with observations. Both have then drawn their conclusions about climate sensitivity based on that correlation. The distinction between your opinions of these two works is the very definition of confirmation bias.
You have in addition phrased your opinions in running argumentem ad hominem, a string of insults, a near rant. While I have, over time, come to expect that logical fallacy from you, I would point out to others that insults do not substitute for facts. If you have the facts and data to support your opinions, insults are not necessary – they in fact imply a lack of evidence.
—
What I’ve noted here is that your opinions on those two papers are completely self-contradictory – which indicates (IMO) that you are not basing your opinions on the evidence, but on some other criteria entirely. I will refrain from speculating as to what those criteria may be.