We should all study the ocean circulations more to understand polar trends in temperatures while we also factor in soot levels and ozone holes. All have equal but opposite effects on the different polar temperatures.
Although we will never observe a uniform global warming trend we can still observe the real threat which is a steady global climate change Perminant Climate change has occurred now due to AGW. The change is now being driven by the affected natural systems, something that has its own drivers and source of fuel.

Remember the Titanic turned away from the threat and the dangers only got worse. We are turning away slightly but we will turn just as slowly.

Is it worth noting that we're on pace to enter a La Nina season this year? (Obviously, it's just one instance...)

Reply: that is noted in the piece. Actually, it is officially a La Nina now. Brett

And I had done an hellish thing,
And it would work 'em woe:
For all averred, I had killed the bird
That made the breeze to blow.
'Ah wretch!' said they, 'the bird to slay,
That made the breeze to blow!'

Nor dim nor red, like God's own head,
The glorious Sun uprist:
Then all averred, I had killed the bird
That brought the fog and mist.
'Twas right', said they, 'such birds to slay,
That bring the fog and mist.'

The fair breeze blew, the white foam flew,
The furrow followed free;
We were the first that ever burst
Into that silent sea.

Down dropt the breeze, the sails dropt down,
'Twas sad as sad could be;
And we did speak only to break
The silence of the sea!

All in a hot and copper sky,
The bloody Sun, at noon,
Right up above the mast did stand,
No bigger than the Moon.

Day after day, day after day,
We stuck, nor breath nor motion;
As idle as a painted ship
Upon a painted ocean.

Water, water, everywhere,
And all the boards did shrink;
Water, water, everywhere,
Nor any drop to drink.

The very deep did rot: O Christ!
That ever this should be!
Yea, slimy things did crawl with legs
Upon the slimy sea.

About, about in reel and rout
The death-fires danced at night;
The water, like a witch's oils,
Burnt green, and blue and white.

And some in dreams assured were
Of the spirit that plagued us so;
Nine fathom deep he had followed us
From the land of mist and snow.

And every tongue, through utter drought,
Was withered at the root;
We could not speak, no more than if
We had been choked with soot.

Ah! well-a-day! what evil looks
Had I from old and young!
Instead of the cross, the Albatross
About my neck was hung."

The Rhyme of the Ancient Mariner
Samuel Taylor Coleridge

Brett,

Do not believe there has been only 30 years of data. Rather, the last 30 years of data have on average been at exceptional levels indicating stronger El Nino conditions than historic norms.

Reply: correct, it is the way this data was collected the past 30 years. There are ENSO records go much farther back, but obviously retreived through different methods.
--------------------------------------------------

As most everybody should know, greenhouse gases increase the ability of the atmosphere to hold moisture. There is of course an upper limit to how much moisture the atmosphere can hold. That is the atmosphere can not hold more than 100 percent relative humidity.

The Walker Circulation is driven by differential in atmospheric moisture content. Greenhouse gases rise the humidity of the atmosphere the most where the humidity is the lowest to begin. So, the eastern pacific, which generally has lower humidity than the west, has seen a greater increase in humidity. Thus, the differential moisture content between east and west pacific has lowered and thereby the Walker Circulation is weaker and El Nino stronger.

So, in theory, Greenhouse Gas Global Warming is part of the cause. However, quantifying how much of the strengthening El Nino conditions are due to Greenhouse Gases and how much are due to natural variation is beyond me to quantify without at least a million dollars, a super computer and a year or two.

Andrew-
So you know exactly how to quantify the effects though, given your required tools("a million dollars, a super computer and a year or two")? If so enlighten me please, I'm rather skeptical.

Andrew sez:
As most everybody should know, greenhouse gases increase the ability of the atmosphere to hold moisture.

Greenhouse gases do not directly have anything to do with the amount of moisture in the atmosphere, of course. Increasing the temperature of the atmosphere increases the amount of moisture that can be held there, but the relationship of greenhouse gases to the temperature is indirect and many other things (solar cycles, ocean circulation, volcanic activity, cloudiness, ...) affect the temperature as well.

Andrew also sez:
There is of course an upper limit to how much moisture the atmosphere can hold. That is the atmosphere can not hold more than 100 percent relative humidity.

Of course, the amount of atmospheric moisture that 100% humidity represents also depends on the temperature. As the temperature increases, 100% humidity represents greater and greater moisture. There's no inherent upper limit to the amount of moisture that could be in the atmosphere - the higher the temperature, the higher the specific humidity can rise.

This recent paper is relevant, although the Walker Circulation is not mentioned.

This related Tsonis et al paper is more on-point, but I'm not sure how it relates to the Vecchi et al paper Brett linked or to what the Australians think is happening. But in the time-hallowed spirit of small boys poking sticks into wasp nests, by all means let's heat up the atmosphere and see what happens.

Tsonis yet again, this time on the subject of small boys, sticks and wasps: "[G]lobal warming has resulted in an increase of randomness in the climate system."

Hi Brett,
thank you for showing an interest in this work. Just thought i would clarify the situation a little bit.

For the SOI we had data extending back to 1876. We examined running 30 year averages - one value for each 30 year block. The lowest value occurred during the most recent 30 year period i.e. in 1977-2006. We also examined the degree to which the difference in the mean before and after 1977 is unusual but shall refer your readers to the paper if they are interested in such technical details. Its a short note so I'd encourage people to read it!

We also examined Darwin MSLP separately. As you know Darwin MSLP is sometimes used as an index for ENSO in its own right. Darwin MSLP exhibited its highest 30-year value on record during 1977-2006.

This strongly suggests that Walker Circulation weakened to record levels in 1977-2006. To test this hypothesis we examined changes in zonal (east-west) windstress averaged across the Pacific. We used ERA40 and NCEP reanalyses to do this. We recognise that the reanalyses have inaccuracies but they are best available as far as i am aware. This data is also much shorter than SOI. Nevertheless it exhibited its lowest 30 year magnitude (corresponding to weakest trade winds) during - you guessed it - the period 1977-2006.

We also used the SOI to define El Nino and La Nina events: if June-Dec SOI>5 we called it a La Nina year, if the June-Dec SOI

We then went on to discuss these findings in light of previous work (e.g. Vecchi et al. and other studies discussed in recent IPCC report) pointing out that some climate models exhibit a weakened Walker Circulation in response to global warming.

Finally, note that some of the media stories written about the article have different conclusions to the paper itself!

Thanks again.

Regards,
Scott Power

Reply: Scott, thank you very much for clearing things up in regards to the post. We greatly appreciate your feedback! Brett Anderson (moderator)

Great Response from Dr Scott Power!

------------------------------------------

Question for Brett,

Is there a direct link for the paper?

Reply: I will look. I would hope so. Brett

Scott,
In tracking ENSO events or ENSO related weather/climate phenomenon I've always preferred the Multivariate ENSO Index (MEI http://tinyurl.com/2xohac). It takes into account not only Pacific SSTs, but also east-west and north-south wind components, ambient air temperature and cloudiness. In the short time that I followed ENSO using the MEI (5 years or so), it appears that it gives a more complete picture of the climate trends associated with ENSO. Do the Austrailians ever reference the MEI?

WIth the exception of the 1999-2001 strong La Nina event, the MEI has primairily been anchored in a positive departure state (.7 to 1.2). This seems to coorelate with the long term Austrailian drought. Thanks

Scott:

Interesting work as a case study. I'm curious though, why link this to GW? Why not to some other issue? And then to state that human induced forcing is likely contributing seems a bit dramatic.

Why also the use of single data points representing 30 year blocks of time? Why not deal with it as a running data point. It seems as though the study is tailor made to exploit the most recent changes in lieu of looking at all of the data. I do appreciate the comment that the data from the past is suspect but the beat available. I would guess this would apply to the SOI as well.

TomP

Andrew says a lot of things that are simply false or cannot be verified.

Ask him how CO2 and CH4 become "more important" as altitude increases.

News Flash

James Hansen is funded by billionaire liberal fanatic George Soros. Anyone surprised?

http://ibdeditorial.com/IBDArticles.aspx?id=275526219598836

Should I take this moment to whine about Hansen's political affiliation and who funded him?

Nope, his work speaks for itself and it has proven him to be a hack and a phony. He wrote models in the 70's to predict GC and years later built models to predict GW.

His new line of work might be to make a model that can predict anything you want it to.

Regards,

Steve

TomP and Steve,

CO2 and CH4 enhance the ability of the atmosphere to hold water vapor in the upper portions of the troposphere where the water vapor level would be much lower if not for the warming ability of CO2 and CH4.

If you would like to understand the science of GHG and water vapor better, then review the following paper on the subject.

http://www.gfdl.noaa.gov/~ih/papers/hydro_revised.pdf

or starting at page 271 of the following.

http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch03.pdf

Andrew,

You obviously have not learned that I read the links you post and you have obviously continued to not read them yourself :) What gives? I am astonished that someone who touts their profession, degree, and Alma Mata would be so sloppy.

I retract, I am not astonished that someone who touts their "credentials" would be so sloppy.

The first paper simply ATTRIBUTES the increased warmth we have seen to CO2 and is based on a model that assumes a CO2 doubling. Doubling from when is not indicated. It mentions the high troposphere, but says they are interested in the LOWER troposphere and talk much about HORIZONTAL movement of water vapor. Temperature determines the ability to hold water vapor not a GHG.

The second paper only says it is LIKELY more water vapor is present and attributes it to temperature, not GHG. The amount of increase is extremely minute and when one factors in that heat ALWAYS travels from hotter to cooler, it makes little difference. There is so little air and moisture at those altitudes that a 1 to 5% increase is basically moot. It is -50 C for Christ's sake.

At this point I have determined your credibility from your sloppy posts and will from now on simply assume you have not read the links you provide. If you want to get your point across, you should spell it out in your own words. I have no time to read IPCC BS.

Instead of simply parroting the IPCC, try to understand a little about thermodynamics, weather nor climate exists without it.

Regards,

Steve

Steve,

I do not know why you are attacking me.

A while back somebody had questioned my credentials in physics. I responded to that person what they were. IIRC, I only mentioned it once. You are now making it out as if I am flouting it. Sorry, but that is not the case.

I have also made it clear that I am learning climate science as I go. This is not my field of specialty and only a recent hobby. However, I understand the underlying science fairly well.

Perhaps it bothers you that I already have a fair understanding of the subject.

Or perhaps it just bothers you that greenhouse gases unequivocally contribute to global warming.

Either way, the sciene of greenhouse gases are what they are. Attacking me will not change it.

The IPCC represent the state of the science for global warming. It has been subject to multiple peer reviews for many years. It is too bad if it does not support your political views. The fact that you dismiss it out of hand only goes to show me where you are at with respect to accepting the truth.

Also, it is unfair for you to claim that some of what I post is not true. I make my best effort at making every post as correct as possible. However, if you feel there is a specific error, please let me know. I will freely admit to any mistakes.

Hey Steve,

I found it, I found it, I found it!

A very good paper identifying human induced changes in atmospheric moisture content.

In other words, the paper shows how recent increases in water vapor are consistent with increases in greenhouse gases, which we all know have come from human activities.

More specifically, the paper shows that water vapor increases did not come from solar forcing or recovery from the Mt Pinatubo eruption.

It is a very recent article and was published by the National Academy, a peer reviewed publication.

Here is the free link.

http://www.pnas.org/cgi/reprint/104/39/15248

Conclusion from the paper.

Detection and attribution studies have now moved beyond temperature only analyses and show physical consitency between observed temperarure, moisture, and circulation changes. This internal consistency underscores the reality of human effects on climate.

Good find, Andrew. In fact, an excellent find. It will be fun to watch McIntyre et al respond.

How about it, Brett? This paper is peer-reviewed, it's freely available, I don't see any immediate holes, and it offers a reasonably well-supported conclusion. Our contrarians and denialists have been asking for "proof" rather repeatedly here -- is this it?

Sounds like a thread-starter to me.

Of course there were a relatively higher number of El Ninos from the late 1970s through at least the 90s. Positive Phase PDO began in 1979! And guess what, now thet PDO seems to either just moved into Negative Phase, or is in the throes of it, La Nina will probably dominate the next 20 - 30 years .... imagine that!

RE: Posted by Scott Power | September 26, 2007 7:33 AM

The truth is, that because prior to the 1970s, ENSO was not really understood, the observation of it was not specifically done .... certainly, not like it is done today. Therefore, in order to understand what was happening ENSO wise prior to then, proxies and reconstructions must be used. The truth is, really really do not know what the true baseline of ENSO phases and strengths, let alone PDO phases and strengths, explicitly were prior to full knowledge of ENSO (not to mention PDO).

Hadley Cell slowdown - certainly, versus what was the case during the period 1940-1979 it may well have weakened. We can only infer what the long term variability has been. Let us make a promise to ourselves to revisit this whole thing once we have had solid negative phase PDO for at least 10 years.

Sorry, I wanted to correct an error. In my most recent (currently pending) pose, I wrote Hadley Cell instead of Walker Circulation. Related but not identical.