General AGW discussion thread

[Ari Jokimaki]

Recently I looked at Lindzen & Choi (2009) (LC09 from hereafter). Here are some of my thoughts and couple of thoughts of others:

1. The study is limited to tropics.

2. They mention:

Originally Posted by LC09

The anomalies include a semiannual signal due to the temporal aliasing effect that needs to be eliminated [Trenberth, 2002]. The relevant sampling error of the tropical monthly ERBE data is about 1.7 W m–2 for SWR and 0.4 W m–2 for OLR [Wielicki et al., 2002a, b]. This spurious signal, particularly in the SWR, can be removed in a 36-day average, reducing the SWR error to the order of 0.3 W m–2.

So, they know that there is a false signal in the data, and they know how to eliminate it. Nevertheless, their action is not to correct the data:

Originally Posted by LC09

However, in this study, the 36-day average was not applied because we wish to relate monthly SSTs to monthly ERBE TOA fluxes.

They may relate the monthly values all they want, but with the false signal in the data, the comparison doesn't mean much.

The fun doesn't stop here, though. They have just said that they are not correcting the data because they want to compare monthly values, but then they say anyway:

Originally Posted by LC09

Instead, the moving average with a 7-month smoother was used for the SWR anomalies alone;

They left data uncorrected because they don't want to mess monthly values, but then they go ahead and mess them for one dataset? And they do it by using strange value of 7 months, which they don't explain. They do say that they are later going to show that this smoothing doesn't affect their results. But later they show it by comparing it to equally strange smoothing values of 3 and 5 months. Let us also emphasize this: they only smoothed one dataset out of the three they are using.

3. The study is limited to short time variations (from few months to less than 2 years), of which they use only 9. They don't study long time response at all. They say:

Originally Posted by LC09

Simple calculations as well as GCM results suggest response times on the order of decades for positive feedbacks and years or less for negative feedbacks [Lindzen and Giannitsis, 1998, and references therein].

Assuming that this claim is correct, by limiting their study to timescales of years or less, they are focusing their study only to the feedbacks they are claiming to be negative. In other words, they are not even trying to study positive feedbacks by their own words.

4. Their model selection is strange:

http://julesandjames.blogspot.com/20...-and-choi.html

See also the response to this comment:
http://www.realclimate.org/index.php...comment-134494

I'll quote the relevant section there:

Additionally, AMIP runs are known to have very counter-intuitive behaviour when it comes to surface energy fluxes (for instance, an oceanic warm anomaly caused by atmospheric anomalies in the real world is associated with an anomalous downward flux of heat - however in an AMIP run, the flux anomaly is upwards (completely opposite)).

So, in certain conditions the model runs LC09 used are known to behave exactly the opposite to real life.

5. Let's also remember that in earlier paper on the same subject Lindzen used old dataversion even if new one was available (note also the interesting comment of Rob Dekker about this new paper):

http://chriscolose.wordpress.com/200...mate-feedback/

[Ivan Viehoff]

Originally Posted by William

You can fool some of the people some of the time, you can not fool all of the people all of the time.

The question is not if the planet is cooling but how much and how quickly it will cool.

Is the Earth Cooling?
http://www.metoffice.gov.uk/corporat...ratures_09.pdf

Indeed, you aren't fooling me, William. Especially not with the boring weather anecdotes. Lovely warm weather we've been having here recently, but that's not interesting either. We have discussed to death with you how vacuous weather anecdotes are.

Once again you quote articles that don't support you. The Met Office's headline is that recent data shows +0.07C/decade (+/- 0.07), a confidence interval that is all non-negative. The +/-0.07 bit indicates how much statistical uncertainty you get by considering short runs of data. I thought you'd learned a bit about statistics from your last lot of posts, but it seems you've forgotten it all.

Further down the article, they point out that models that can fully explain the recent slow down still predict 2C warming over the century.

If you'd taken time to read the recent run of posts, including a discussion of articles pointing out that only cherry-picking will find you cooling in the recent data, you might have realised your ammo was wet.

[Ivan Viehoff]

Originally Posted by William

This is what to look forward to as the planet cools. Drought in Africa and Asia ...

Interestingly drought in Africa and Asia (and various other places) is also an expected consequence of the planet warming.

The reality is that any change in climate changes the distribution of rainfall, so there are bound to be extensive populated areas suffering more drought than previously, whatever the change is. This is an argument for trying to maintain climate stability - the earth has been populated on the expectation of recent climate, and it is damn costly adjusting to a new climate, even if the new climate actually, in its totality, is beneficial.

But if the planet does cool back to what it was, say, in the 1970s, that ought to be good, because it should restore the rainfall in places like the Sahel: in other words, less rain, but more rain where people live.

You were pointing to stuff back in the 70s about people warning about global cooling. I'm actually old enough to remember that stuff, and I think we all had a good giggle about it at the time, it wasn't mainstream science but it made for fun journalism. I had some post a little while back pointing to how there were always warnings from whacky minorities of global cooling every time the temperature ceased to have its secular upward trend. It may even have been in response to one of your posts.

What short memories we have.

[Trakar]

Originally Posted by mugaliens

Correction: The issues as you stated them were most certainly raised in the paper. If you feel they were not, it's up to you to restate your issues in a manner which clearly communicates something different that what you have already communicated.

If you don't understand what I've stated, and would like me to explain in more detail my comments and why they are important to properly understanding the paper at hand, I will be happy to do so. If the above is your attempt at such a request, it is awfully convoluted and unclear

Look, Trakar - this isn't some stupid power struggle. I responded to your comments as you wrote them. Nothing more, nothing less, and certainly nothing personal.

Curiously, I had never considered issues of power struggles, whatever that means under the circumstances of a messageboard discussion, but perhaps you could explain to me how and why such would/could occur? I only ask you since it seems to be an issue that concerns you. I'd certainly hope that there are not any personal issues or commentary being flung about as that is completely out of place in a discussion of issues on a science board.

The issue is anthropogenic global warming. With your permission, let us continue along that line.

I never left that line

As I stated earlier, it's not my claims we're examining. It's the conclusions of the paper.

Have you finished reading it, yet?

The paper's assertions are straight-forward, the interpretation of those claims, the validity of their findings, and the potential implications of these conclusions are the only reason one discusses any paper. If you don't understand the paper, what its findings are based upon (data and methodologies applied) and how all of this impacts or effects the current and established understandings then there is very little to talk about.

I don't read minds or divine publications, therefore I obviously finished reading the paper before I began commenting upon it, ...but what happened to talking about the paper, not casting aspersions in a personal manner?

[mugaliens]

Originally Posted by Trakar

If you don't understand what I've stated, and would like me to explain in more detail my comments and why they are important to properly understanding the paper at hand, I will be happy to do so.

By all means, do so. But begin with the paper, please. Several times you've demanded I restate the paper in my own words. Were I to do so it would look much like the paper, so let's skip that wasteful step and get to the contents of a short 6-page paper.

If the above is your attempt at such a request, it is awfully convoluted and unclear.

Apparently, you're unwilling to discuss the paper at all, or you'd have done so by now. This and your other comments are stalls.

So long, Trakar.

[SolusLupus]

Originally Posted by mugaliens

By all means, do so.

[...]

So long, Trakar.

"Please do it! By the way, I won't listen to you."

[Trakar]

Originally Posted by mugaliens

By all means, do so. But begin with the paper, please. Several times you've demanded I restate the paper in my own words. Were I to do so it would look much like the paper, so let's skip that wasteful step and get to the contents of a short 6-page paper.

I have never asked you to restate the paper in your own words, I have asked you to tell me in your own words what elements of the paper you feel significantly add to or contradict what specific elements of current mainstream scientific understandings. This should be a relatively simple and straight-forward process, if you understand the current science and understand in what ways you feel that the paper significantly supports or contradicts that science. I can't understand why you seem to find this such an onerous request?

Apparently, you're unwilling to discuss the paper at all, or you'd have done so by now. This and your other comments are stalls.

It's you who have refused to address any significant issue I've raised with the paper, and you refuse to even state in what way you feel that this paper is important or addresses issues of import to climate science.

So long, Trakar.

When you feel like you understand the paper well enough to discuss it and your understandings in relation to it, please return. Likewise, I shall be happy to post Lindzen/Choi's responses to my queries when they get back to me. In the meantime, if anyone else would like to discuss the paper I will be happy to share my impressions and understandings.

[William]

Originally Posted by Ivan Viehoff

Interestingly drought in Africa and Asia (and various other places) is also an expected consequence of the planet warming.

The reality is that any change in climate changes the distribution of rainfall, so there are bound to be extensive populated areas suffering more drought than previously, whatever the change is. This is an argument for trying to maintain climate stability - the earth has been populated on the expectation of recent climate, and it is damn costly adjusting to a new climate, even if the new climate actually, in its totality, is beneficial.

But if the planet does cool back to what it was, say, in the 1970s, that ought to be good, because it should restore the rainfall in places like the Sahel: in other words, less rain, but more rain where people live.


What short memories we have.

Hi Ivan,

Have you heard the term abrupt climate change? Every thought about what causes the cyclic series of abrupt climate changes in the paleoclimatic record? Glacial/interglacial cycle?

During the glacial cycle, the planet is colder and drier (Does that make sense more rainfall when the planet is warmer, less when it is colder?). 1/3 of the Amazon tropical forest was covered by savana, during the glacial period. The region where I live was covered by a 2 kilometer thick ice sheet. (The biosphere shrinks when the planet is colder and expands when the planet is warmer.) The glacial/interglacial cycle has happened 22 times before. The interglacial periods are short, around 12 kyrs. The glacial periods are long, around 100 kyrs.

This current interglacial period the Holocene was interrupted by the abrupt Younger Dryas cooling period 12800 years ago that lasted for about 1000 years. During the Younger Dryas period the North Atlantic froze each winter to the latitude of mid-Spain. The Younger Dryas cooling period is only one of series of abrupt cooling periods that occur with periodicity of around 6000 years to 8000 years.

When the North Atlantic freezes the UK climate is no longer moderated by the ocean. I would suspect winters were colder then.

Let's await more data and papers.

[Stroller]

Originally Posted by Trakar

Regardless, even if it is sheer speculation, I'd be interested in the reasoning and mechanism you propose for as a linkage that results in the correlation between cumulative sunspot counts and millisecond day length variation.

The two graphs show different correlations.

The first is the correlation between the historical sea surface temperature data and a curve generated from a combination of a cumulative sunspot count above and below the level determined as the oceanic equilibrium value, and the changes in Earth's length of day.

The second is the anti-correlation which is discovered when comparing the changes in Earth's length of day to the vertical or 'z-axis' motion of the solar system centre of mass relative to the solar equatorial plane.

There have been quite a few studies done in the past which have found quite strong correlations between the motions of the planets (Particularly Jupiter) and sunspot numbers.

There is also a strong correlation between changes in the Earth's length of day and the multidecadal changes in atmospheric angular momentum. The timings of the inflexions of these multidecadal changes also match the changes in oceanic positive and negative temperature phases, particularly the NAO, the AMO and the PDO.

I am attempting to pull together these disparate phenomena to see if they have a bearing on the cyclic fluctuations we see in global temperature.

It is speculative at the moment, because the physical mechanisms by which the disposition of the planets might affect sunspot production and changes in length of day is elusive. Nonetheless, I think it's a worthwhile line of enquiry, because a lot of phenomena seem to relate to it, and I believe they will turn out to have important effects on Earth's climate.

If we can get a handle on the magnitude of these effects, we would then be in a better position to subtract them from the temperature history, and from the residuals, get a better idea of what effect, if any, changes in the levels of trace gases in the atmosphere might have on climate.

Seem reasonable?

[Stroller]

From ‘the Age of Wonder’ by Richard Holmes

“From further afield there came reports of climate change: huge sheets of thawing pack ice were sighted off Greenland, melting snowcaps seen in Alpine mountains, and unprecedented river spates and flooding were recorded throughout Europe. Banks (President of Royal Society) was not disposed to panic at these strange phenomena.’ Some of us flatter ourselves that our Climate will be improved and may be restored to its ancient state, when grapes ripened in Vineyards here’” [p383]

Then, polar explorer William Parry recorded a latter meeting with Banks before attempting the North West Passage: “…he opened the map which he had just constructed and in which the situation is shown, of that enormous mass of ice which has lately disappeared from the Eastern coast of Greenland…” [p395]

The first was in 1815, the second in 1819

[Atraveller]

Originally Posted by Ivan Viehoff

You were pointing to stuff back in the 70s about people warning about global cooling. I'm actually old enough to remember that stuff, and I think we all had a good giggle about it at the time, it wasn't mainstream science but it made for fun journalism. I had some post a little while back pointing to how there were always warnings from whacky minorities of global cooling every time the temperature ceased to have its secular upward trend. It may even have been in response to one of your posts.

What short memories we have.

Actually I am old enough to remember that time too...

I also know there was data that did support a slight cooling variability in the temps. (What was hilarious was some journalists who extrapolated a coming ice age.)

I would also propose that that slight cooling cycle was due to Anthropogenic Global Cooling. Up to the mid '70s lead was a standard additive to all automotive fuels - add to that the lack of laws regulating what could be dumped into the atmosphere. The number of aerosols humans dumped into the atmosphere could have had a global impact on the weather.

The clean air act reversed that trend...

[Stroller]

Ari and Trakar may (or may not) be interested in Dr Roy Spencer's comments on the Lindzen-Choi paper.

http://www.drroyspencer.com/2009/11/...eedback-study/

There is some worthwhile discussion of it at Luboš Motl's "the reference frame" blog:
http://motls.blogspot.com/2009/11/sp...dzen-choi.html

Be careful how you interpret what Spencer means by positive climate sensitivity.

There are also some excellent and well informed posts on a discussion at
http://wattsupwiththat.com/2009/11/0...eedback-paper/

Including some by Spencer himself.

[Stroller]

And it looks like dear old Trenberth is getting a clue in line with what I've been saying about increased solar energy absorption in the latter C20th. We'll get there eventually...

http://www.cgd.ucar.edu/cas/Trenberth/2009GL037527.pdf

Abstract:
“Global climate models used in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) are examined for the top-of-atmosphere radiation changes as carbon dioxide and other greenhouse gases build up from 1950 to 2100. There is an increase in net radiation absorbed, but not in ways commonly assumed. While there is a large increase in the greenhouse effect from increasing greenhouse gases and water vapor (as a feedback), this is offset to a large degree by a decreasing greenhouse effect from reducing cloud cover and increasing radiative emissions from higher temperatures. Instead the main warming from an energy budget standpoint comes from increases in absorbed solar radiation that stem directly from the decreasing cloud amounts. These findings underscore the need to ascertain the credibility of the model changes, especially insofar as changes in clouds are concerned.”

[Ari Jokimaki]

Originally Posted by Stroller

Ari and Trakar may (or may not) be interested in Dr Roy Spencer's comments on the Lindzen-Choi paper.

I would be interested to see your answer to this question you have been ignoring:

So, Stroller, why are you claiming that Hansen et al. are reproducing 1940-1970 cooling in their model runs by aerosol forcing, when they cannot reproduce it in their model runs, are not even trying to do it by aerosols, and explain it by natural oscillation anyway?

[Trakar]

Originally Posted by Stroller

Ari and Trakar may (or may not) be interested in Dr Roy Spencer's comments on the Lindzen-Choi paper.

http://www.drroyspencer.com/2009/11/...eedback-study/

I, for one, always find Spencer's comments interesting. Usually, at least of late (the last decade or so), and especially when in reference to areas outside his own narrow specialty, more entertaining than intriguing, but what the heck, he seems to be happy to have someone listen to what he has to say and doesn't really care what inspires them to listen.

There is some worthwhile discussion of it at Luboš Motl's "the reference frame" blog:
http://motls.blogspot.com/2009/11/sp...dzen-choi.html

Be careful how you interpret what Spencer means by positive climate sensitivity.

By what measure do you deem this "worthwhile"?

There are also some excellent and well informed posts on a discussion at
http://wattsupwiththat.com/2009/11/0...eedback-paper/

Including some by Spencer himself.

Again, by what measures do you qualify "excellent" and "well informed"?

[Trakar]

Originally Posted by Stroller

And it looks like dear old Trenberth is getting a clue in line with what I've been saying about increased solar energy absorption in the latter C20th. We'll get there eventually...

http://www.cgd.ucar.edu/cas/Trenberth/2009GL037527.pdf

Abstract:
“Global climate models used in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) are examined for the top-of-atmosphere radiation changes as carbon dioxide and other greenhouse gases build up from 1950 to 2100. There is an increase in net radiation absorbed, but not in ways commonly assumed. While there is a large increase in the greenhouse effect from increasing greenhouse gases and water vapor (as a feedback), this is offset to a large degree by a decreasing greenhouse effect from reducing cloud cover and increasing radiative emissions from higher temperatures. Instead the main warming from an energy budget standpoint comes from increases in absorbed solar radiation that stem directly from the decreasing cloud amounts. These findings underscore the need to ascertain the credibility of the model changes, especially insofar as changes in clouds are concerned.”

Not sure if this is due to misunderstanding, or misrepresenting, this paper. My rather quick read through of the paper seems to indicate that Trenberth is analyzing and discussing the results of global climate models and extending these results to the late 21st century effects. The paper clearly states that the absorbed solar radiation has decreased through the middle to late 20th century due to aerosols and clouds, and that this has masked the enhanced greenhouse-induced warming to date. It’s expected to continue to do so through to about the mid-21rst century when we should experience a marked increase in absorbed solar radiation driving significant additional warming. Now if this is your position, then I've completely misunderstood what you were saying and trying to establish. Please help me to reconcile your position and my understanding of Trenberth's paper?

[Stroller]

Originally Posted by Ari Jokimaki

I would be interested to see your answer to this question you have been ignoring:

You ignore mine, I ignore yours. Seems equitable to me.

[Stroller]

Originally Posted by Trakar

by what measures do you qualify "excellent" and "well informed"?

The ones I have developed for myself. If you don't agree, that's fine.

[Gillianren]

Originally Posted by Stroller

The ones I have developed for myself. If you don't agree, that's fine.

How can we agree or disagree if we don't know how you developed them?

[Stroller]

Originally Posted by Gillianren

How can we agree or disagree if we don't know how you developed them?

So much interesting stuff to think about. So little time for dealing with rubbish.

[Trakar]

Originally Posted by Stroller

So much interesting stuff to think about. So little time for dealing with rubbish.

I concur.

[Ari Jokimaki]

Originally Posted by Stroller

You ignore mine, I ignore yours. Seems equitable to me.

It's always tactics like this. Reminds of the time when you all of a sudden started accusing me of ignoring your question when I just had answered it explicitly.

Well, we can sum up the situation so that Stroller made claims about Hansen et al. paper and looking at the paper strongly suggested that Stroller didn't even look at the paper when making those claims. It is not the first time that has happened either.

[mugaliens]

Originally Posted by Gillianren

How can we agree or disagree if we don't know how you developed them?

Oh, gee, I dunno, Gillianren.. Perhaps you should review his posts in which he detailed the links, the data, the explanations...

Just a thought.

[Stroller]

http://wattsupwiththat.com/2009/11/1...-tv-interview/

I wonder if Ari could furnish us with a translation of this Finnish news article.

[Trakar]

Originally Posted by mugaliens

Oh, gee, I dunno, Gillianren.. Perhaps you should review his posts in which he detailed the links, the data, the explanations...

Just a thought.

Sometimes it helps to understand what one is talking about, before jumping into other's conversations. Case in point, Gillianren's comment is directed at asking Stroller about how he came up with the qualifiers "excellent" and "well informed." If you have access to posts in which Stroller "detailed the links, the data, the explanations..." in regards to his methodology of determining excellent and well informed, please provide them as evidently Stroller himself has forgotten about them.

just a thought

[Stroller]

Nothing is forgotten, just ignoring the snark and drivel. When something I see as substantive or interesting is said on the thread, I'll respond.

[SolusLupus]

It's "snark" and "drivel" to ask how you came to a conclusion on a topic?

No wonder none of these discussions go anywhere; asking you to substantiate your claims or explain your conclusions about a topic is considered a bad thing.

[Trakar]

Originally Posted by Stroller

Nothing is forgotten, just ignoring the snark and drivel. When something I see as substantive or interesting is said on the thread, I'll respond.

Always good practice as well as invaluable advice.

[mugaliens]

Originally Posted by Trakar

If you have access to posts in which Stroller "detailed the links, the data, the explanations..." in regards to his methodology of determining excellent and well informed, please provide them...

I have the same access to them as you, Trakar. Personally, I prefer the Page Up button on my keyboard, but you may, of course, use whatever method you prefer.

...as evidently Stroller himself has forgotten about them.

Originally Posted by Stroller

Nothing is forgotten...

Apparently not.

[Trakar]

Originally Posted by mugaliens

I have the same access to them as you, Trakar. Personally, I prefer the Page Up button on my keyboard, but you may, of course, use whatever method you prefer.
.

You seem to be lying.

Please link the posts where Stroller details his method of determining his qualifications for "excellent" and "well informed"