Here is a link to an earlier report on the same subject published by the National Academy. It used data from 1988 to 2006.

http://www.pnas.org/cgi/content/full/104/39/15248

And then it's cloudy more, due to the higher moisture content, which in turn blocks the suns energy better, in turn cooling everything back down. It is vaguely possible that this is a natural method by which the earth cools itself. Most of the research Svensmark has done, regarding nucleation and the suns energy seems to indicate more clouds lend to cooler temps, while the reverse is also true. This would also lend to the cyclical theory.

All of svensmarks papers, most notably the one introducing his theory on cloud cover and the solar flux and the parallels between the two, are at this website..
http://www.dsri.dk/~hsv/

Even if you disagree with him, it is a fascinating read an you might learn something.

Regards, Elliot

Sounds like more and more powerfull hurricanes to come with an increase of warmer moisture. Sounds like it would trap more heat like the greenhouse gasses do.

I'm sure this will elicit some snipes, but I've noticed here (around the Great Lakes) that it has been more humid than it used to be. Mind you, this IS NOT a scientific statement, but just my observations and my opinion. It used to get humid early in the day, then taper off as the day wore on in the summertime and was hardly humid at all in the winter. Now it's very humid all summer AND winter. I'm not going to comment on what's to blame because frankly I don't know, but the climate around here sure seems different to me...heck, Lake Superior is (or soon will be) 12 inches below it's average level...

Maybe the warmer conditions are evaporating the lakes like a pot of water on a stove and adding more moisture to the air! ;-)

Again, these are only my (TOTALLY unscientific) observations, so please don't attack me anti-Global Warming folks. Seeing these attacks around here is why I've kind of stopped reading this blog...although Brett does an awesome job!

I don't see it cloudier. I have looked at US satellite imagery many times this Spring and summer and it appears there's been a paucity of cloud cover. A moister atmosphere is not necessarily a cooler one. As for the sources of higher atmospheric humidity, mankind is among them by way of heavy industrial use of water irrigation, pools, cleaning etc. There is no question in my mind that Man is augmenting the natural level of humidity.

The previous post by "anonymous was actually me I just forgot to type in my name, I guess. My apologies.
Regards, Elliot

I have an interesting thought that I would like you all to critique. While pondering how much a 2.2% increase in humidity would mean in mass it occurred to me that figuring out how much CO2 contributes to Greenhouse Effect percentage wise can be done by calculating how much more energy water vapor can hold compared to CO2.

Here's my reasoning. There is about 13 trillion tons of water vapor in the atmosphere at any given moment. I get this number from a study I read that says if all the humidity were to drop to the ground at once it would rain 1 inch over the entire surface of the planet.

Sphere area = (pie)(r squared)(4) The surface of the planet is 5.083 quintillion centimeters squared.
Volume of 1 inch of rain over surface of planet = (area)(depth) The volume is 12.910 quintillion cubic centimeters = 12.910 billion cubic meters.
1 cubic meter of water weighs 1 metric ton. So there are 12.910 trillion tons of water in the atmosphere at any given moment.

That is 17.2 ( I erred in a previous post where I had parroted that it was 70 times more abundant ) times the amount of CO2 at 750 billion tons. The specific heat of CO2 is .846 and Water Vapor is 2.08 so Water vapor's heat capacity is 2.46 times that of CO2. So water vapor in the Earth's atmosphere has 42.3 times the heat capacity as CO2.

So if we assume that Water Vapor and CO2 are the only GHG's the percentage value for CO2 out of 100% would be X + 42.3X = 100% or 2.3%.

At 280 ppm CO2's mass would be about 500 billion tons so it would only account for about 1.5% of the GHE.

I am aware there are other GHG's, but they only subtract from Water Vapor and CO2. So CO2's role cannot be more than 2.3% of the greenhouse effect.

Does this make sense?

Elliot,

RealClimate has a blog with a bunch of comment on some of Svensmarks work and the cosmic ray topic.

http://www.realclimate.org/index.php/archives/2006/10/taking-cosmic-rays-for-a-spin/

I have not studied it extensively. However, my impression is that the central problem is that there has been no significant trend in cosmic rays since the 1950s and in particular since the mid 70's that could explain our current global warming.

Natural GW Steve wrote

it occurred to me that figuring out how much CO2 contributes to Greenhouse Effect percentage wise can be done by calculating how much more energy water vapor can hold compared to CO2.

No: as soon as an individual molecule warms up it'll exchange its extra energy very quickly with other molecules in the atmosphere by collision.

Andrew-
It is the trend in solar irradience that has been noted as nonexistent. During the length of a solar cycle the irradiance varies on the order of +/- percent which is too little to demonstrate any major effect on the climate. After realizing this Svensmark began to look at other factors such as cosmic flux.
I don't really have time to string together a bunch of quotes and my various explanations at the moment, so I will make my case and reply to you in greater detail later tonight or in the morning. I hope to get the chance to read through the site you posted. It is a very interesting theory at any rate and certainly one that should be explored. The link that I posted earlier has several of his papers on it. If you get the chance you should definetely read through the third one "cosmic rays and the earths climate".

Regards,
Elliot

Hi guys,

Andre, See this . No further comment.

http://science.nasa.gov/headlines/y2006/10may_longrange.htm

Stephen V,

as soon as an individual molecule warms up it'll exchange its extra energy very quickly with other molecules in the atmosphere by collision.

Correct, in a manner of spaeking, bringing that particular volume of matter to the same temp.

I am speaking of the specific heat capacity of the molecule and how much (mass) of each type of molecule.

If it takes a gram of CO2 10 seconds to raise the temp one degree then it will take a gram of water vapor with the same energy source 24.6 seconds to raise the temp one degree. It also absorbed 2.46 times the energy.

My point is that the amount of water vapor in the atmosphere at any given moment has 42 times the heat capacity as CO2 because of mass and specific heat.

The amount of matter and the specific heat is quite signifigant. It determines how much energy can be absorbed and for how long it will take to cool.

Any thoughts?

Steve

Natural GW Steve:-

I don't think the specific heat capacity of individual atmospheric gases is the issue here. At the very most, it might have a sub-microscopic impact on how quickly the atmosphere reaches a new equilibrium temperature in response to an external forcing, but not on the equilibrium temperature itself.

Suggested reading:

http://www.realclimate.org/index.php/archives/2007/08/the-co2-problem-in-6-easy-steps/

I have not seen the data yet. Can someone tell me if the increase in water vapor pressure has led the increase in atm CO2 since, say 1930, or followed it? This may be impossible to unravel, because water could be both a cause and a effect of warming, one of Jim Hansen's positive feedbacks.

Elliot,

I was wondering if you could elaborate a little on your statement, "During the length of a solar cycle the irradiance varies on the order of +/- percent which is too little to demonstrate any major effect on the climate."

I've been having some neat discussions involving the graph of solar irradiance shown at:

http://www.junkscience.com/Greenhouse/irradiance.gif

That graph shows that since 1950 the 11-year-cycle has been pretty stable, but before that there was a rise. The low points of the current 11-year-cycle are higher than the high points of prior cycles. Could a change as large as this demonstrate a major effect on the climate?

I hadn't even considered cosmic rays. I just read that they increase as sunspots decrease. I've only started to read Svenmark's papers at http://www.dsri.dk/~hsv/ and you are right. They are fascinating. But then, this whole subject is fascinating.

I don't think the specific heat capacity of individual atmospheric gases is the issue here. At the very most, it might have a sub-microscopic impact on how quickly the atmosphere reaches a new equilibrium temperature in response to an external forcing, but not on the equilibrium temperature itself.

Huh? :) Amazing. Your understanding of thermodynamics is lacking.

Issue? It is simply calculating how much energy two different substances can absorb based on mass and specific heat capacity.

Please read your second sentence, if that still makes any sense you need to go back to school and please don't vote.

Regards,

Steve

Caleb-

When svensmark started doing research to look at the possible link between solar activity and temperature change he first looked to the solar irradiance and its change. Throughout the solar cycle it appears that it only changes by about a tenth of a percent either way. That is about .2 w/m-2, which is less than the estimated change necessary for the temperatures to rise such as they have. This change would appear to be to small to account for the warming that is/might be taking place. It is after this that he begins to look for mechanisms that would provide for the temperature raise, in direct response to the changes in solar activity. He realized that clouds behaved as both an insulator to the earth at the high levels, and a mechanism of cooling at the lower levels. (cirrus like clouds keep things warmer, while thick ones such as stratus help keep temps cooler) The substance of his research has been dealing with how changes in the suns activity correspond to cloud formation and thus temperatures on Earth. His paper does an infinetely better job explaining this than I do, but I'll give it a try....

Given the amount of cooling attributed to clouds forcing, (17-30 w/m-2) any impact solar activity has on cloud formation would be extremely significant in terms of global temp change. It appears that monthly variance in cloud cover correlates very nicely with change in solar flux. Solar flux is the rate at which solar rays impact the earth's atmosphere and it has been shown that the rate is determined by both solar wind and the earth's magnetic field. With the changes in solar flux observed over the last solar cylcle, it appears that the change in cloud forcing is on the order of .5 w/m-2 which at the estimate of 1 degree C per w/m-2 change accounts for about half a degree C change in temperature which is very similar to what has occured. Effectively, it is observed that during a solar cycle the change in cloud cover, in response to the change in the suns irradiance is enough to cause about a half a degree temperature change.

The only way that we have to attempt to recreate solar irradiance levels in the past, that was documented is the amount of sunspots. Given how closely sunspot # coincides with change in irradiance it is reasonable to use similar correlation to compare historical sunspot data, to the probable irradiance of the time. Svensmark goes into several well known periods of abnormally cold and warm spells, including the maunder minimum which occured around 1700. This period had incredibly few sunspots, and thus theoretically had a very low level of irradiance. It seems, per his research, that activity of the sun and the change in irradiance has a considerable effect on our climate.

It must be remembered, as he points out, though, that even though this appears to be a major factor, the change in climate won't follow any single forcing mechanism perfectly as it is a medley of so many processes. There is also an interesting correlation noted in the concentrations of various atoms (Be10) and the overall temperature. This could be very indicative of the effect cosmic rays have on our atmosphere.

This link will take you directly to his paper explaining his theory on cloudiness and our climate.
http://www.dsri.dk/~hsv/SSR_Paper.pdf

Regards, Elliot

The solar forcing has been well studied and does not not account for today's warming trends. The anthropogenic paradigm has evolved for over a century now and has shown to be successfully explanatory and predictive with high confidence, and while some uncertanties in specifics remain, and some solar ideas are still being pushed, the foundation for AGW is remarkably solid.

It is well known now that solar changes since about 1950 have a very minimal forcing, and maybe even negative (solar irradiance also declined from 1960 to about 1990 from Gilgen et al 1998; Stanhill and Cohen, 2001) and just a few references on this subject.
http://www.pnas.org/cgi/reprint/104/10/3713
http://www.nature.com/nature/journal...ture05072.html
http://www.ucar.edu/news/releases/20...ghtness.shtml#
http://www.pubs.royalsoc.ac.uk/media...pa20071880.pdf
http://www.mpg.de/english/illustrati...lease20040802/

Regarding Svensmark et al., there is no trend in the Cosmic ray flux or explanatory trend in cloud cover, and there are a lot of unproven leaps in the hypothesis. Even if it has validity (or the solar forcing) you cannot add the "something else" and somehow subtract the CO2 forcing- the radiative nature of CO2 is well understood and its warming influence as a function of absorbtion and re-radiation of longwave energy. If there is another influence, you add to the CO2, you don't "replace" CO2.

The forcing chart is given in the AR4 for the relative role of humans and specific factors:
http://www.greenfacts.org/en/climate-change-ar4/images/figure-spm-2-p4.jpg

Chris,

For some odd reason all five links you gave resulted in "Page Not found," when I tried to access them. (One said so in German.)

You had best re-do them, or appear to be someone pretending to have links who actually has no support for their ideas.

The link to "greenfacts" did work, but was only a IPCC chart involving radiative forsing.

Would you please explain what your concept of radiative forsing is?

You will note the chart does not include plain, old water vapor. Haven't many complained this makes the impression generated by the chart more or less meaningless?

Chris,

I was able, at last, to download the first link you gave. The other four still don't work. If the fault lies in my computer, forgive me.

The paper will take some time to study, however the tital, "Solar Influence On Climate During The Past Millenium: Results From Transient Simulations With the NCAR Climate System Model," suggests a computer model was used.

As I'm sure you know, skeptics tend to downplay the results obtained by computer models, for some computer predictions made in the late 1990's have already proven incorrect.

Can you spare me the trouble of reading this paper tonight, (I'd rather watch baseball,) by telling me if this particular model could back-predict the Maunder Minimum?

If a computor model can recreate the Maunder Millimum without involving less energy coming from the sun, then indeed I think the sun's influence on climate change can be down-played.

I have seen no such model, and therefore continue to wonder about the sun's role.

Strange...

http://www.pubs.royalsoc.ac.uk/media/proceedings_a/rspa20071880.pdf (if it doesn't work google "Lockwood and Frohlich 2007" and top link works)

http://www.nature.com/nature/journal/v443/n7108/abs/nature05072.html
(if it doesn't work this is Foukal et al.,2006- Nature 443, 161-166 doi:10.1038/nature05072)

http://www.pnas.org/cgi/reprint/104/10/3713 (this link should work, you don't get a error screen you get a begin download screen- if not it is from Ammann, Caspar et al. (2007) which you can get at reference #3 on wikipedias article on "global warming")

try here for the max plank reference (the one you got in german)- http://www.mpg.de/english/illustrationsDocumentation/documentation/pressReleases/2004/pressRelease20040802/ (if not google "How Strongly Does the Sun Influence the Global Climate?" 4th link down from the Max Planck Institute)

A radiative forcing is an external perturbation on the Earth's climate system. Water Vapor is not a forcing mechanism, but rather a feedback (meaning that it is a maintainer of temperature, but doesn't in itself force a climate change without it responsing to something else)