An increase in moisture generates more clouds, which blocks UV and causes negative feedback.

The inability of climate models to simulate clouds is one of the primary reasons they aren't reliable.

Oh please.

Let me see if I have this right.
Warmer air can hold more moisture.
Since there is more moisture in the air, it is warmer.
So human induced CO2 must be the cause.

What kind of science is that?

I don't believe climate scientists really know whether increased moisture in the atmosphere is a positive or a negative feedback. It depends on whether that extra moisture increases the cloud cover or not, and that's something that's still not handled correctly by the current climate models.

Reply: That is a valid concern Tom as I can personally attest to cloud cover issues by the models in my daily forecasting. Brett

I wonder if NOAA will start preannouncing records soon? Their climate models have been proven reliable and there is really no reason for them to wait to the end of the period to announce that this (month/year/decade) was the warmest in history.

In response to some comments, as a climate scientist: Yes, more moisture in the air can increase cloud cover, however, not all cloud cover has a cooling effect. High clouds have a warming effect actually because they still allow radiation to reach the surface, but they themselves radiate out to space at a very cold temperature because of their elevation. Thus, the net down is greater than the net up.

Additionally, in response to Boondocks: warmer air holds more moisture, yes. Water vapor is a greenhouse gas, similar to CO2. In fact, water vapor is the strongest and most prevalent greenhouse gas. Without it, our planet would be inhabitable. Solar radiation balances alone would leave our planet 33 C cooler, thus water vapor is the important balancing mechanism. Thus, more water vapor = more greenhouse warming, which in turn leads to more water vapor.

I've been reading this blog for quite some time, and I am disheartened by the negative bent it has toward climate change. This post, for example, is confusing to someone who is unfamiliar with atm. physics. Present all the facts or don't present anything at all.

...natural variability in climate just can't explain this moisture change.

Let me get this straight, if exactly the same moisture profiles and associated variables did have a natural cause, then these computer models would not give the same answer. Have I got that right?

Verily, these climate models are shiftie beasties.

natural variability in climate just can't explain this moisture change. The most plausible explanation is that it's due to the human-caused increase in greenhouse gases.

i.e. the author has no clue what is causing this.

NASA Science News for September 18, 2007

Last week in Boulder, Colorado, scientists converged on the "Living With A Star" workshop to share the latest research in solar physics. At one point, nearly 200 participants sat slack-jawed as they watched a new movie recorded by Japan's Hinode spacecraft showing a sunspot emerging from the depths of the sun. The newborn spot resembled nothing less than a swimming planet-sized trilobite.

Ref: A trilobite is an extinct 3 lobed marine arthropod of the Paleozoic era.

Goes to show you, what scientists thought they knew about sun spots was not actually correct. The study of science is always evolving. Amazing!

See for yourself.

http://science.nasa.gov/headlines/y2007/18sep_trilobite.htm?list1040802

I don't think anybody has any idea of how these awesome video clips relate to global climate change, but I share Rich's appreciation for the dramatic video.

Wow!

High clouds have a warming effect actually because they still allow radiation to reach the surface, but they themselves radiate out to space at a very cold temperature because of their elevation. Thus, the net down is greater than the net up.

Mike,

The effect you are describing (high clouds causing warming) is due mainly to the fact that they absorb and radiate some IR downwards at night, which a clear sky won't do. High clouds during the day tend to cool temperatures at the surface - as every skier knows. Once a high cloud comes over, temperatures can cool substantially on the slopes. The cloud goes away and it warms up right away.

In �Inconvenient Truth� is a chart with several instances where the temperature and CO2 go up �together� and then down �together�. What we are not told is that the temperature goes up first and the CO2 follows. If the increase in CO2 caused a significant increase in the �greenhouse effect� the temperature would go even higher, causing more CO2 and more water vapor, which would raise the temperature even more - culminating in a heating death spiral. It didn�t happen. Eventually, the temperature went back down and the CO2 concentration followed.

Mike,

I'm not familiar with solar radiation balances, what is that exactly?

This article states that the additional .41 kg per meter squared is caused by the additional warming caused by CO2, CH4, etc, when the strongest evidence to support that is a "very highly likely" that stems from these scientists' belief that natural influences cannot be the cause.

I'd like to know how an additional 2 Watts per second per meter squared increase in solar irradiance can be disregarded when there are nearly 254 billion square meters facing the Sun at all times? That energy must go somewhere. A .15% increase to 300 Kelvin is .45 Kelvin.

With your experience, what would you say is the cause for the one degree increase we have seen since the end of the Little Ice Age?

Regards,

Steve

Mike,
High clouds can act as both as a negative or positive feedback mechanism. Durng daylight hours, even high level cirrus stratus will decrease the amount of insolation. During the night, cirrus can also dampen the amount of radiative cooling in some situtations. Of course, you may not always notice this, as in the mid-latitudes cirrus stratus normally preceeds frontal systems. In many cases strong low level warm air advection will raise the ambient air temperature despite the presence of thick overcast skies.

Where cirrus stratus could have a big effect is in the tropics, where insolation is at its strongest. BTW, it is the tropics, where, because of its constant warm temp, there is also the greatest density of water vapor (as measured in grams of WV/ kilogram of dry air). It is the tropics that not only have the greatest amount of insolation (as measured in Watts per/sq metre), but also the greatest amount of GHGs. If there was to be an increase in high level cirrus or even mid level alto-stratus, there would be an attendent "cooling" of tropical air masses.

Hi Guys,

Vapor in rain out. hhmmm
Well it looks like this ones got some problems. Please see the link.

http://climatesci.colorado.edu/2007/04/05/evaporation-is-equal-to-precipitation-on-the-global-scale-implications-to-the-conclusion-on-a-claimed-increase-of-atmospheric-water-vapor/

Mike:

I believe you have focused on my lead-in and not my point. Which is, pointing out one indicator that the atmosphere is warming does not demonstrate that anthropogenic CO2 is the impetus of that warming.

Brookline(mass)Tom,

It wasn't the clips themselves that relate to global climate silly, but rather the fact that scientists are still learning about that big fireball in the sky, which effects global climate. Up until 6 moths ago, we didn't have as much detailed information and 3-d imagery of the sun as we do now. They were not completely accurate with the solar physics aspect behind the theory of sun spot generation. Hence the reason I stated that the very science used in understanding not only the sun but our own planet is always evolving. Sorry you couldn't connect the dots. Don't stereotype everyone in the same category as you. I am sure some will see the relevance.

Did anyone see or hear anything about the meteorite coming that landed in Peru before it happened? We didn't even hear a peep about something so obvious as an incoming meteorite. But in our own arrogance, we think that we have everything figured out, don't we? We are still learning is the point. It may be difficult for someone such as yourself to accept the fact that maybe we don't know everything. The truth is Tom, we will never know everything, for sure, until we die. This is why we call some of OUR logical explanations, theories.

Go Pats ;)

JP and Patrick Henry,

High clouds do block radiation, however, because they are typically above 500 mb they are very cold (as the atmosphere cools as you increase in height). Now, assume for a moment that the cirrus clouds are approx. 230K. This means that they are radiating out to space [ sigma*(230)^4 ] Watts/m2. Now, if the cloud weren't there, then space would only see the Earth which is much warmer, say 290K. That means the cloud is radiating out sigma*(60^4) W/m2 LESS radiation than Earth. Thus, the planet is giving OFF much less heat. Now, assume without the cloud that approx. 200 W/m2 of the sun's original energy made it to Earth. The presence of the cloud perhaps reduces that figure to 180 W/m2. Thus, the change in downward energy is only 20 W/m2. As you can see, simple physics explains how high clouds act to WARM the planet, no matter the time of day.

Now, Steve, just to clarify, Watts per second per square meter is not the correct term, as Watts = Joules per second. I digress. I don't understand your question. Are you saying that the sun outputs an additional 2 W/m2 than it has in the past? Or that it goes through cycles? Please clarify.

-MIke

mike,

i too am disheartended by the lack of integrity by those that claim they can predict future climatic conditions 50 years from now to within a hundredth of a degree, or as in the case of the above article, use remote sensing techniques to calculate a 2% change in global atmospheric moisture content for the past twenty years, then even worse claim without any evidence, its man's fault...to further give me the blues, is the crowd of scamsters going around profiting off these doom and gloom scare tactics at the expense of the most vulnerable...keep your chin up, little buckaroo, i just read that some real scientists are going to try and lasso the AGW LIE with a scientific integrity world conference in a couple of days, convened because of gross misrepresentations in climate modeling...here comes the real science rodeo, and AGW is in for a rough ride...have a nice sunny warm day, it will brighten your climatic outlook!!!

Also, JP, your claim that the tropics contain the highest levels of GHGs is not true. Please refer to the following plots:

http://instaar.colorado.edu/sil/images/co2rug_490px.jpg

As you can see, CO2 levels are highest in the Northern Hemisphere winter. In the Northern Hemisphere. As explained by plant respiration.

Also, JP, your claim that the tropics contain the highest levels of GHGs is not true. Please refer to the following plots:

http://instaar.colorado.edu/sil/images/co2rug_490px.jpg

As you can see, CO2 levels are highest in the Northern Hemisphere winter. In the Northern Hemisphere. As explained by plant respiration.

Page 40 of the Technical Summary of the IPCC Physical Science Basis contains the following statements.

Tropospheric water vapour is increasing (Figure TS.8). Surface specific humidity has generally increased since 1976 in close association with higher temperatures over both land and ocean. Total column water vapour has increased over the global oceans by 1.2 +- 0.3% per decade (95% confidence limits) from 1988 to 2004. The observed regional changes are consistent in pattern and amount with the changes in SST and the assumption of a near-constant relative humidity increase in water vapour mixing ratio. The additional atmospheric water vapour implies increased moisture availability for precipitation.

Upper-tropospheric water vapour is also increasing. Due to instrumental limitations, it is difficult to assess long-term changes in water vapour in the upper troposphere, where it is of radiative importance. However, the available data now show evidence for global increases in upper-tropospheric specific humidity over the past two
decades (Figure TS.8). These observations are consistent with the observed increase in temperatures and represent an important advance since the TAR. {3.4}

Chapter 9 deals with understanding and attributing climate change. It does not contain a section dealing with water vapor. However, section 9.5.4 deals with precipitation and contains the following statement.

Greenhouse gas increases are also expected to cause enhanced horizontal transport of water vapour that is expected to lead to a drying of the subtropics and parts of the tropics (Kumar et al., 2004; Neelin et al., 2006), and a further increase in precipitation in the equatorial region and at high latitudes(Emori and Brown, 2005; Held and Soden, 2006).

The truth is Tom, we will never know everything, for sure, until we die.

No doubt.

There is a staggering amount of information that we don't know about metallurgy, aerodynamics, and even basic physics. Yet most of us still get on airplanes -- even though they sometimes crash. Each time we do, we implicitly accept the reality that our "theories" about flight are reliable enough, and our knowledge about the science of flight is complete enough, that we willingly trust that we'll arrive safely at our destination. That trust is well-placed the overwhelming majority of the time.

There will, thankfully, always be new science to explore in almost any field we choose. That is why, in my opinion, it is so offensive to artificially inflate uncertainty about material that is, in fact, already settled.

As fascinating as the video is that you posted, it has no discernible relevance to the science of global climate change. Similarly, the recent Peruvian meteorite hit is fascinating -- especially because of the apparent atmospheric anomalies in the immediate area -- and still has no discernible relevance to global climate change.

Thanks for the great clip, however. It does illustrate, rather marvelously, the inspiring appeal of good solid science.

A little more of the science.

Water vapor in the atmosphere generally decreases with elevation. Above a certain elevation (the tops of clouds) the atmosphere is so cold that water vapor can not exist as anything other than ice and ice does not stay up in the atmopshere very well.

On the other hand, CO2 and CH4 are well mixed at all elevations of the atmosphere. However, there has been a generally increasing amount of CO2 and CH4 due to human causes.

What is being found, is that over time water vapor is reaching greater and greater elevations of the atmosphere. This makes sense because it is at the higher elevations where CO2 and CH4 are providing additional warming.

sammyk, perhaps you misunderstood. I'm upset that there are still so many people out there who would turn a blind eye to science and say GW isn't real. Nobody is predicting climate conditions 50 yrs from now to within a hundredth of a degree. Nor does anyone claim to know exactly what will happen. There is, however, surmountable evidence that humans are causing global climate change, and for you to say that us scientists, who are conducting REAL research, and are not gathering our "facts" from the "media", are just making it all up, is absurd, reprehensible and irresponsible. How can you say that we claim, "WITHOUT EVIDENCE" that it's man's fault. You want evidence? There is plenty of evidence. Do some research instead of listening to the views of a select few naysayers. For the benefit of science, find a reliable source for your information, instead of the media, and a weather site. Because we all know meteorologists are NOT climatologists.

Mike,

The energy balance of the atmosphere is fixed. On average, as much energy arrives as leaves every day. If this wasn't true, the temperature of the atmosphere would change dramatically.

During the day, cirrus clouds lower the temperature at the surface markedly. People who live at dry, high-altitude locations are well aware of this. Here in Colorado on a calm day with full sun, it can be quite comfortable even at temperatures well below freezing. However, a few cirrus clouds roll over and on goes the jacket. Everyone here understands this. It happens because cirrus clouds block a lot of short wave radiation.

At night, the opposite effect happens. There is little short wave radiation coming in, and some of the long wave radiation gets reflected or emitted downwards towards the ground. Nights with high clouds can be much more comfortable in the winter.

The numbers you are "assuming" above are probably incorrect if they don't match direct observation. Perhaps cirrus clouds absorb or reflect a lot more short wave radiation than you are assuming? This will cause the clouds to warm more and the surface to warm less. Your math doesn't seem to be taking this into account.

One problem I have with some climate modelers is that they seem to be very fond of math, to the exclusion of simple qualitative analysis - like watching water go down a bath or having an apple fall on their head. I have been involved with several multi-billion dollar boondoggles which could have been rescued by some simple back of the envelope calculation.

As per your graph of CO2 - I think you are ignoring the large amounts of methane and H20 coming out of jungles. What altitude was that CO2 measured at?

Sammy K,

Why are you disheartened by climates models's claims that they can predict the climate 50 years in advance? What is your beef with the models?

"just read that some real scientists are going to try and lasso the AGW LIE with a scientific integrity world conference in a couple of days, convened because of gross misrepresentations in climate modeling...here comes the real science rodeo, and AGW is in for a rough ride"

Wow, I thought the Republican National Convention was supposed to convene in September 2008? I guess they're getting a head start.

This conference will be interesting. When quacks peer-review each other, there's no telling what asinine theories will come out of this...LOL.

Allright Patrick Henry and Mike. Both of your arguments are prima facie convincing ($0.25 word alert), but I just don't know enough in orderto tell which of you is more correct. For those of you who are well-versed in atmospheric physics, which is it? Do high clouds cause net warming or net cooling, or is it sometimes one and sometimes the other? Brett, do you know?

Reply: In my experience it depends what type of high clouds you are dealing with and the percentage of cloud cover in the sky, but in a general sense I would lean toward the warming idea near the surface, at least across the countryside. But, if you are in a city or on a small island where you typically do not radiate at night due to the heat island effect/maritime influence, the high clouds probably have little impact in keeping it warmer at night, and probably have a slightly higher effect in keeping it cooler during the day. I don't think there is one simple answer to this, just too many factors to plug in. Brett.

Great post, Mike. It's nice to have an actual climatologist here talk about things, rather than the armchair climatologists on this blog who think they're experts because they own a physics textbook and are good at using Google.

I've said it once and I'll say it again. The type of "proof" demanded by deniers, which would require having thousands of Planet Earths in a test tube and the ability to inject each of them with CO2 to see what happens, is not only unrealistic, but it's unnecessary. Our success as a species -- heck, even our success as individuals -- is largely due to our ability to identify, analyze and mitigate risks. If every risk had to be "proven" in order for actionable decisions to be made, we'd be in serious trouble.

Science has not only shown that AGW is possible, but it's probable. The threshold has far exceeded what is required for actionable measures to be taken. This is why most people have moved past the argument of "Is it real?" and towards figuring out what to do about it. I've learned that it's pointless arguing about whether AGW is 'real' with the right-wing noise machine. My energy is better-served debating solutions, and I hope this blog has more posts about potential solutions.

If something occurs that fundamentally changes our understanding of climate science, we will need to re-evaluate. However, nothing like this is on the horizon. And praying that the next solar cycle will be weak, or that the PDO will switch to negative tomorrow, or that the Earth's orbit will magically tilt, simply doesn't help your case when attempting to disprove AGW.

Mike; Mark;
When you REAL scientists doing REAL research come up with even one shred of actual proof, we MAY find your rantings credible.
Until then you are just more oil salesmen peddling silly theories. We have heard it all before.
Same story, different tune.
We have lots of evidence to show the earth was created in six days by some magician. Do we have proof? No.
Until there is proof is it just a theory; nothing more.
And history very adequately shows that scientific consensus means less than nothing.
The majority of the scientific community will always follow the popular funding.
Scientists are not stupid, and they gotta eat too.
I fundamentally don't believe you!!!!!!

---High clouds have a net warming effect---

This seemed to be verified after 9-11. Jets were grounded and there were no contrails. A young meterorologist told me night-time temperatures dropped .5 degree at USA recording stations. This would seem to demonstate the warming effect of contrails is short term. Has anyone else heard what the young meterorologist told me, and are the effects of contrails included in models?

Reply: I did not hear that. Brett

Brett, I very much appreciate the debate your site makes possible.

Caleb

Mike,
Water vapor is by far the greatest greenhouse gas 96% of all GHGs), and the Tropics contain the most water vapor. Ergo, you will find the highest concentration of GHGs in the Tropics.

Also direct measurements of surface temps with and without high level cirrus prove beyond a doubt that high level cirrus blocks incoming solar radiation (daylight hours), and hence the temperatures cool. Any professional weather observer can tell you that.

If for some unknown reason the entire earth were blanketed by a thick shroud of cirrus-stratus at, say 300mb level, and it remained there for 6 months, could you guess what would happen to global temps? I can tell you know one would be worrying about AWG.

When quacks peer-review each other, there's no telling what asinine theories will come out

Mark,

Well said. I guess that is how things like this happen.

Britain set to enjoy another sizzling summer .... (Met Office) Forecasters expect above-average temperatures and warn that weather changes will grow worse
http://observer.guardian.co.uk/uk_news/story/0,,2052500,00.html

Today is the last day of summer. High temps in London averaged 69F this summer. The maximum temperature for the summer was a "sizzling" 82F, There were only three days which made it to 80F.

2007 to be hottest year ever, says Met Office
http://www.theregister.co.uk/2007/01/04/phew_what_a_scorcher/

These Met forecasts came out a few months before the Met declared that their models were inadequate and global warming was on hold until 2009.

Didn't the IPCC tell us in April that the "science is settled?"

Mike,

Are you suggesting that Meteorologists are unqualified to determine if clouds cause warmer or colder temperatures? That climate modelers somehow know better?

Astonishing arrogance on your part.

Caleb,

You forgot to mention the other half of the study. i.e. high clouds cause the inverse. Warmer nights and cooler days.

The 9/11 study showed that removing contrails resulted in a large increase in the daily temperature range - in other words warmer days and cooler nights.
http://www.bbc.co.uk/sn/tvradio/programmes/horizon/dimming_qa.shtml

Are you saying that the sun outputs an additional 2 W/m2 than it has in the past? Or that it goes through cycles? Please clarify.

Thanks for correcting the per second statement. Yes, nearly 2 Watts. NASA says solar irradiance has gone up by .05% every decade for the last three decades. 1366 Watts muiplied by .0015 gives 2.049 additional Watts. This was not attributed to the 11 year cycle. The cycle continues as the increase occurs.

Funny thing is the NASA spokesperson who annouced this says it is insignifigant. I am asking how an extra 40 quadrillion Watts a day is insignifigant.

Mike,

Can you point me to a reliable place to get info? I have little need for models that simply attribute the warming to CO2 because someone doesn't think 40 quadrillion Watts is signifigant.

Thanks,

Steve

hey cb & mikey,

thanks for the response...first, mike, as a climate scientist, you should be well schooled in earth's variable climate history...you should be well aware that man has only been around for a short period of time...the idea that a miniscule change in a life sustaining gas drives climate change is ridiculous considering how large the other factors are... i do read other articles other than the national enquirer, like those that suggest co2 increases are a response, not cause of temperature change...as a climatologist, you should also be aware, that mathematical models of the globe using human recorded temperature values is quite suspect, error prone and unreliable... without these models, all we are left with is theory, conjecture, maybe's and guesses...i appreciate your jab about i only listen to media, weather blogs, and naysayers because i fired a shot at you climate dudes, however, as a climate scientist, perhaps you should consider how & what caused earth's historic temperature variability before the word anthropogenic was invented...serioulsy, how and why did it change when us bipeds were'nt around...what caused the little ice age?...what caused the big ice age?...what caused the periods of warm between the two?...what caused earth's variable temperature before that?...it wasnt a few parts in a million of co2, it was a big ball of fire that burns hotter sometimes, interacting with a big ball of iron coated mostly with water, that explodes thru little cracks in it every once in awhile, and these two big balls swirling around each other at different places at different times and every not so often, get pelted be little balls of iron and ice that can cause big changes in climate...evidence man is causing climate change?...i see no evidence, when taken in contex with the other plausible causes, heck you can put us all on hawaii...have you ever stared up at the stars and pondered the vastness of it all? pondered how lucky we are its warm enough to survive in all that cold that surrounds us?...what i do see is alot of money being spent, some if it dubiously, trying to prove we are really bad guys trying to live comfortably and i am "DISHEARTENED" some want to change that for the worse, especially to the detriment of the most vulnerable...what i do see, however, is a lot longer time when climate changed without us...not only was it hotter than it was today, but also much colder...the past is the key to the present and the future, not some computer generated fairytale...the earth's climate is cyclic, variable and you give us humans we too much credit about influencing it...if you havent noticed, this climate game has gone political because of money and power and it wont just effect your pocketbook, but strengthen those who think our lifestyle is a shame...i disagree with that philosophy, not because i think i'm shortsighted, but because i like to think i listen to all sides of the argument...since the argument has gone political, i am, in my opinion, looking out for the best interest of my grandchildren, by raising my voice in dissent of AGW...i concede, my opinion is probably worth as much as you just paid for it, but i'm a "denier" i guess, until you climate dudes can prove to me otherwise...a good start would be if brett, using a climate algorithm, can tell me who will win the superbowl this year and what the gametime temperature will be to say within +/- one degree...have a nice sunny warm day, its a good thing...i enjoyed the discourse :)

An estimate of the change in solar flux at the surface of the earth for Madison, Wisconsin at 13:00 GMT on December 1, 1989 was calculated using Equation 18. For this time period, a 45.3% difference in cirrus cloud cover resulted in a change of 58.18 Wm seen at the surface of the Earth. The magnitude of this error was approximately 14 times greater than the effects due to the doubling of CO2, 4 Wm. Obviously an incorrect cloud cover will have an important effect on both the radiative balances occurring in the atmosphere and the models simulating the radiative and dynamical structure of the Earth's atmosphere. Even though Equation 18 does not incorporate the Earth's surface albedo or absorption by atmospheric gases, it does show the need for the accurate simulation of cirrus clouds and their global coverage.

http://lidar.ssec.wisc.edu/papers/ww_thes/node10.htm

CO2 is a cooling agent (dry ice). When water vapor is introduced to the CO2 gas in the upper levels, the gas dissolves within the H2O(gases are water soluble.)

The cooling effect creates condensation, returning the now cooled water and dissolved CO2 back to the earth in the form of carbonic acid, carbonates and bicarbonates. Ever notice how the air feels cooler when it rains? This is not coincidence. This is nature doing it's balancing act.

The carbon in carbon dioxide is returned to earth as carbon and recycled. Do you think humans invented recycling? Please. The earth has been doing it forever. We cannot destroy the earth. Ourselves yes, the earth no.

JP,

I'm sorry, but you're being absolutely foolish. One of the commets indicated a study that people did after 9-11 which showed that cirrus clouds (contrails) have a net warming effect.

OF COURSE cirrus clouds block downwelling solar radiation. We are not all idiots, we understand that when a cloud is in the sky it blocks radiation. What you are forgetting, perhaps because YOU ARE NOT A SCIENTIST, is that the Earth also gives off heat as it is a blackbody. Thus, the balance is maintained. Downwelling solar radiation MUST equal upwelling TERRESTRIAL radiation, in order for the Earth to maintain a balance. Here is the equation:

F*(1-R) = sigma*T^4 + GHG effect, where F is the downwelling solar radiation, defined as 1342/4 (the solar constant, divided by the area of Earth exposed to the sun at any given moment), R = Earth's albedo, currently ~0.30, sigma = 5.89 x 10^-8, T = Earth's effective temperature and GHG effect = sigma*(Ts^4 - T^4) where Ts = Earth's actual surface temperature.

Now, Earth's radiation balance is maintained at the top of the atmosphere because this is where incoming radiation is received, and outgoing radiation is released. If a cloud were up there, naturally incoming radiation would decrease. However, outgoing radiation would increase dramatically more, because clouds at that elevation are very cold.

You are being arrogant for assuming that you know more about radiation balances because you live in Colorado where you can feel the effects of cirrus clouds. Obviously nobody else in the country has cirrus clouds, ever. Second, you are right in understanding that clouds block the sun. What you do not understand, probably because you don't wish to, is that clouds are cold at that elevation. The Earth is warm. With a cloud in between Earth and space, the last thing space sees is the cloud, which is radiating terrestrial radiation at a VERY cold temperature. Thus, the net OUTGOING radiation is smaller than the net INCOMING radiation. It's physics, dude. But I'm glad you can ski. And that you have cirrus clouds. We are all jealous.

Now, lower clouds have the exact opposite effect. Because they are close to the surface, their temperature is the same as Earth. Thus, they radiate out to space at a very similar temperature to Earth. However, they BLOCK a lot more incoming radiation. So, in this case, outgoing radiation stay the same, but incoming radiation decreases dramatically = net cooling.

-Mike

As a follow-up, when I say "warming" effect I do not mean that when a cirrus cloud comes overhead it WARMS up the surface. What I mean is that the overall radiation balance (as viewed from space) is positive, indicating a gradual warming trend. Perhaps the reason people on this blog don't understand this is because they haven't studied atmospheric physics, in which case they should not be debating climate science. Any idiot can tell that when solar radiation is reduced, the surface temp. decreases. What they don't understand is that global temperatures are controlled by Top-of-Atmosphere (TOA) radiation balances. A negative balance = cooling, a positive balance = warming. I do understand the confusion though.

I'm sorry, my last post addressed to "JP" should have been addressed to "Patrick Henry"

Mike,

because YOU ARE NOT A SCIENTIST

Darn, all those years in grad school wasted for nothing. Did you learn to use capital letters an insults in your science program?

Perhaps you missed my earlier quote from someone who has actually measured the effects of cirrus clouds, rather than the theoretical arm-waving which some modelers are so fond of. I'll repeat it again in a post clearly labeled with the keyword "Mike" at the top.

An estimate of the change in solar flux at the surface of the earth for Madison, Wisconsin at 13:00 GMT on December 1, 1989 was calculated using Equation 18. For this time period, a 45.3% difference in cirrus cloud cover resulted in a change of 58.18 Wm seen at the surface of the Earth. The magnitude of this error was approximately 14 times greater than the effects due to the doubling of CO2, 4 Wm. Obviously an incorrect cloud cover will have an important effect on both the radiative balances occurring in the atmosphere and the models simulating the radiative and dynamical structure of the Earth's atmosphere. Even though Equation 18 does not incorporate the Earth's surface albedo or absorption by atmospheric gases, it does show the need for the accurate simulation of cirrus clouds and their global coverage.

http://lidar.ssec.wisc.edu/papers/ww_thes/node10.htm

No Mike, I do not live in Colorado. And I spent the better part of 15 years as a professional weather forecaster and weather observer on 4 different continents. Someday you may wish to forecast surface temperatures for a 24 hour period (at hourly intervals), and see what unforecasted cirrus-stratus cloud cielings can do to your forecast. It's enough to ruin your day.

Reply: I used to do that 24-hour interval forecasting too, about 15-18 years ago for utility companies. It wears on you quickly. Brett

No Mike, I do not live in Colorado.

I suspect that JP submitted this before Mike's self-correction was posted -- Mike's comments were directed at PH, not JP.

I'm so glad we have climate scientists that use the term "dude". It must be gnarly to be a SCIENTIST.

As JP suggested, consider a world covered with cirrus clouds for an extended period of time. Mike's stated view of the world is that cirrus is basically transparent to SW and opaque to LW radiation, and that the cirrus tops are cold - so they emit less radiation back into space.

If all these things were true, the temperature of the earth would quickly become like Venus, as very little heat could escape. Obviously this is not the case, and as JP pointed out temperatures would actually decline if the earth was covered with clouds.

The upshot being that the energy balance of the atmosphere has to be conserved and there are other mechanisms allowing heat to escape which Mike is not accounting for properly.

As JP suggested, consider a world covered with cirrus clouds for an extended period of time. Mike's stated view of the world is that cirrus is basically transparent to SW and opaque to LW radiation, and that the cirrus tops are cold - so they emit less radiation back into space.

If all these things were true, the temperature of the earth would quickly become like Venus, as very little heat could escape. Obviously this is not the case, and as JP pointed out temperatures would actually decline if the earth was covered with clouds.

The upshot being that the energy balance of the atmosphere has to be conserved and there are other mechanisms allowing heat to escape which Mike is not accounting for properly.

Any idiot can tell that when solar radiation is reduced, the surface temp. decreases.

Mike,

Can any idiot tell that when solar radiation is increased, surface temps increase?

Can any idiot tell that when temps rise and fall with CO2 levels staying the same that it wasn't CO2 that altered the temperature?

Can any idiot tell that when the Earth experiences a ONE degree increase in temps that follows a very harsh time when temps were ONE degree cooler, that this is a good thing, not some catastrophe?

Perhaps we should employee idiots instead of climatologists to "study" the climate.

Regards,

Steve

.A model the Anthropogenic Global Cooling crowd should get their hands on.