global warming: salvaging fact from heaps of BS

[jryan]

Actually, my first inclination was that the US was measuring US temperatures and the UK was measuring UK temperatures, however, since you did not cite a source (and your image came from imageshack), I could not find out more.

 

What is the source of the data presented in your graphs? I'd like to see for myself what was being measured, what methods were used, and what those pictures you posted truly represent (that is, of course, if they represent anything useful at all, or if they are perhaps some random persons scribblings).

 

The charts are marked with the source data. The only unaccounted for line is the red line in the second chart, which is a linear phase out smoothing done by Steve McIntyre over at CA. You really should read the CA site as all McIntyre is doing over there is checking statistical modeling and researching the core data to ensure that it is sound.

 

These are things that climatology should be doing for itself, but it apparently isn't since it took 30 years to pickup on the biases, and another 30 to finally admit that the original correction was almost as wrong as the uncorrected data. And it still appears to be quite wrong today.

 

Thompson metioned in the Nature article that his finding have no appreciable effect on the overall climate trend... what he fails to metion is that that limited effect has more to do with the scope of his study than on the actual problem he found. His study looked at just a few years in the middle of the bucket to intake change over which took at least 70 years (first account of intake method rather than bucket was in 1926). So saying it had no appreciable effect is really just saying that his study had an insignificant scope.

 

Also, her eis something else worth considering in this mell of a hess.... in Arctic ships, the engine intakes were warmed by low pressure steam to prevent ice from forming.... yet I see no documentation to indicate that this was ever adjusted for.

 

And finally, McIntyre has also turned up documetation verifying that Canadian and Japanese fleets had converted to intake completely as of 1970, whereas they were counted as buckets (they were in the "unknown" so were lumped into buckets). So there data is wrong....

 

It would seemto me that at this point the SST is no longer a reliable or precise data set. I can't see trusting any models that continue to use data that is derived from SST or uses SST explicitely.

 

I am still waiting for a list of models that don't use SST in some fashion... be it in a secondary fashion using GISSTEMP or HADCRUT, or using SST specifically. I am fairly certain the list would be incredibly small as it would have to be a study that is concerned with Global temperatures, but not concerned with the temperatures of 70% of it's surface.

 

Stratosphere and Troposhere studies, maybe? I can't imagine a surface temp study that wouldn't have used GISSTEMP or HADCRUT.

Edited June 6, 2008 by jryan

[bascule]

It would seemto me that at this point the SST is no longer a reliable or precise data set.

 

That's a pretty broad statement to make based on a fairly limited set of problems.

 

I can't see trusting any models that continue to use data that is derived from SST or uses SST explicitely.

 

There are models which use the circulation of ocean heat rather than just trying to model the atmosphere/ocean interface with SST alone.

 

I am still waiting for a list of models that don't use SST in some fashion

 

Coupled atmosphere-ocean GCMs (AOGCMs), such as HadCM3 and GFDL CM2.X, do not rely on SST for modeling the atmosphere/ocean interface.

[jryan]

That's a pretty broad statement to make based on a fairly limited set of problems.

 

That's a fairly broad statement based on a study of very limited scope.

 

 

There are models which use the circulation of ocean heat rather than just trying to model the atmosphere/ocean interface with SST alone.

 

Could you explain that bold bit? I understand that few studies use only SST, but whatever SST is used in (tuning or averages) is adversely effected by the problems in the data.

 

 

 

Coupled atmosphere-ocean GCMs (AOGCMs), such as HadCM3 and GFDL CM2.X, do not rely on SST for modeling the atmosphere/ocean interface.

 

Thanks for the direction. I'll go take a look at those... do they really model the ocean without ever using ocean temps??

[bascule]

That's a fairly broad statement based on a study of very limited scope.

 

Indeed! Thanks for... backing me up?

 

Could you explain that bold bit? I understand that few studies use only SST, but whatever SST is used in (tuning or averages) is adversely effected by the problems in the data.

 

I think you're making a mountain out of a molehill. I don't know if or how SST is used as model inputs for AOGCMs so I'm the wrong person to ask, however the atmospheric/ocean interface is modeled, rather than relying on model inputs alone.

 

Thanks for the direction. I'll go take a look at those... do they really model the ocean without ever using ocean temps??

 

The models use ocean heat, not surface temperatures.

[JohnB]

The models use ocean heat, not surface temperatures.

And they are calibrated against what exactly for their hindcasts?

 

Don't you think a reworking of the temp record for the second half of the 20th C that may drop the trend from .11⁰/decade to around .06⁰/decade is a major change? Given that AR4 puts the GHG forcing at roughly half the rise? And half the rise might have just disappeared?

 

On the plus side, models have always had trouble with the 1940-1970 cooling and now they don't have to account for it. You for one have often pointed out that the models can't model the trend without including GHG forcing. Where do they stand now?

 

On the minus side the Solar models come back into play. They couldn't account for the mid century cooling either and were generaly thought inaccurate and discredited. With the cooling gone, the Solar models now have a much better fit to the temp record than they did.

 

I predict this will have far reaching effects.

 

Just as an aside, I've been following this on a number of blogs and came across this gem of a post at Dot earth.

The technology already exists to make our homes energy free in all areas of the planet where the solar insolation exceeds 1,500 kwh/m2.

(Post 30)

 

I love this one too;

The surface temperatures at Antarctica are cooling slightly. The climate models already predicted this effect — it is not something new and wonderful. One reason for the cooling is that the hot air is going up and out of the ozone hole into the upper troposphere. Once the ozone hole closes up, Antarctica will begin to warm as well.

No wonder this poster went to RC to ask Gavin's help.

 

From the thread content I would also say that all of our resident "Bush Haters" are only beginners in the art.

Edited June 5, 2008 by JohnB
multiple post merged

[jryan]

Indeed! Thanks for... backing me up?

 

No, the limited effect shown in the Nature study are completely due to it's limited scope, not on the findings themselves. As a matter of fact, the change to the temperature record for that very limited time scale is very large.

 

And there is good evidence that this error discussed in that study is actually applicable to a larger time scale as there are similar and numerous attribution errors that persist long past 1945.

 

Not the least of which is the baseless assumption made in previous adjustments that the temperature measurements of "unknown method" in the Hadley data were all done by buckets.

 

I think the simple solution at this point would be to go back into the Hadley SST data and just remove all measurements of "unknown method". There is no good way to statistically fix these entries.

Edited June 6, 2008 by jryan

[bascule]

And they are calibrated against what exactly for their hindcasts?

 

OGCMs are calibrated against SST and sea ice data

 

Don't you think a reworking of the temp record for the second half of the 20th C that may drop the trend from .11⁰/decade to around .06⁰/decade is a major change? Given that AR4 puts the GHG forcing at roughly half the rise? And half the rise might have just disappeared?

 

I'm afraid I don't know what you're talking about...

 

On the plus side, models have always had trouble with the 1940-1970 cooling

 

No? That's entirely explicable based on radiative forcing inputs due to a decrease in volcanic activity (resulting in lower levels of sulfate aerosols) and increased solar activity.

 

On the minus side the Solar models come back into play. They couldn't account for the mid century cooling either and were generaly thought inaccurate and discredited.

 

Huh?

 

No, the limited effect shown in the Nature study are completely due to it's limited scope, not on the findings themselves. As a matter of fact, the change to the temperature record for that very limited time scale is very large.

 

Perhaps you'd care to fill me in here a little better, as I don't know what you're citing.

 

Can you provide a paper? Particularly a publically accessible one?

 

And that said: AOGCMs are calibrated against GHCN data, not SST directly.

Edited June 6, 2008 by bascule
multiple post merged

[SkepticLance]

From bascule

 

"On the plus side, models have always had trouble with the 1940-1970 cooling

 

No? That's entirely explicable based on radiative forcing inputs due to a decrease in volcanic activity (resulting in lower levels of sulfate aerosols) and increased solar activity."

 

bascule, If you double check your figures, I think you will find that is not so. Sulfate reduction had been close to linear for a period that well precedes the cooling. No change there. Solar activity as shown by sunspots remained relatively stable over that period, except for normal cycles, and cannot be used to explain the cooling.

[bascule]

bascule, If you double check your figures, I think you will find that is not so. Sulfate reduction had been close to linear for a period that well precedes the cooling. No change there. Solar activity as shown by sunspots remained relatively stable over that period, except for normal cycles, and cannot be used to explain the cooling.

 

No? Sorry. Here's THE GRAPH again:

 

[JohnB]

OGCMs are calibrated against SST and sea ice data

And if the SST temps have been adjusted to high for the last 50 years, how does this effect the calibration?

I'm afraid I don't know what you're talking about...

In the standard format, temps rose from 1900-1940 due to natural causes. From 1940-1970 there was a drop in temps, then after 1970 the temps rose again at roughly .11⁰/decade. Okay, I've rounded off the years a bit, but you see what I mean. So the 20th C temp graph can be roughly divided into 3 sections: Rise, Fall, then rise again. A fair bit of the drop can now be attributed (apparently) to incorrect adjustments to the SST data.

 

The abstract for the Nature paper is here. Thompson appears to work from the assumption that there was a complete changeover from buckets to inlet measurements by the late 1960s. The graph jryan posted above is from Kent et al 2007 and shows clearly that this is not the case. The upshot is that if the mid century cooling turns out to be an artifact of biases in the measuring system then the 20th C will not be divided ino 3 parts any more. It will instead be a century of steady, roughly linear rise.

 

Removal of the mid century cooling means that rather than temps rising at .11⁰/decade for the last 30 years, much of the latest rise is moved to the 1945-1970 period. So rather than accelerated warming in the second half of the 20th C, we now have a linear rise of .06⁰ for each decade.

 

This effects climate models because they are calibrated to the .11⁰ rise for recent times. If the rise/decade is found to be only half that figure, then they perforce need recalibration.

 

IPCC AR4 uses the .11 figure also and attributes roughly half the rise per decade to GHG, or around .06⁰/decade. What happens to this idea if the rise is found to only be .06/decade in total? What is the flow on effect re sensitivity to CO2 doubling?

 

This is all relatively new and I don't know that anyone knows the full implications yet. TBH I've been reading so many different things lately I'm not even sure where I got the .11 figure from, but it sounds about right. Right now the estimates for the decrease in trend run from 15% to 50%. The change effects NMAT, SST, HADCRUT and I expect GISSTEMP.

Here's THE GRAPH again:

And here's the IPCC. You notice the graph shows increasing negative forcing due to Sulfate aerosols. (It's that squiggly purple line at the bottom.) But the IPCC AR4 says;

The most recent study (Stern, 2005) suggests a decrease in global anthropogenic emissions from approximately 73 to 54 TgS yr–1 over the period 1980 to 2000

Sulfates are not long lived, most are gone in a few years. Can you please provide a reference as to how decreasing the sulfate pollution emissions increases the negative forcing? Aside from that the graph comes from Wiki, not something we normally accept as a referencable source. Further it is from a section called "Global Warming Art". Art? Is this the level of proof now for AGW?

 

If you want to believe the models are right, that's fine, but how about some cites to back it up? Merely repeating "The models are right" is a mantra, not a debate on science. I gave two links on the previous page demonstrating flaws in the models and except for Realclimates argument (which I showed to be flawed) your side have yet to provide a rebuttal. Can I therefore conclude that there is no good rebuttal and the models are agreed to be flawed?

[jryan]

No? Sorry. Here's THE GRAPH again:

 

 

There are several problems with that chart....

 

 

First, the "observed" line is now demonstrably wrong.

 

Second, the forcings models shown are themselves produced in part from the istrumental data. The solar forcings took a hit because they seemed to not be able to account for the cooling of the first half of the 20th century. This led to a reduction in it's evaluated forcing ability.... ie. increased solar activity existed during an observed cooling, therefor solar forcing must be weak.

 

We now know that the period that reduced the modeled solar forcing didn't actually exist. So the the solar forcing model needs to be redone.

 

Finally, all of those forcing models need to be recalculated, actually...

 

That graph no longer applies to the real world. Actually, it never did, apparently.

[swansont]

No? That's entirely explicable based on radiative forcing inputs due to a decrease in volcanic activity (resulting in lower levels of sulfate aerosols) and increased solar activity.

 

Wouldn't both of these result in warming? The graph shows a decrease in forcing from both, which would be from an increase in volcanic activity and decrease in solar.

 

First, the "observed" line is now demonstrably wrong.

 

Then please demonstrate it.

[jryan]

Then please demonstrate it.

 

You mean "please demonstrate it once Bascule offers the source of the graph" right? Bascule made an arbitrary argument which was equally arbitrarily refuted. Though I am very certain that once Bascule offers up the study that created that graph we will see that the "observed" line uses SST data in it's average (probably pre-adjusted HADCRUT)

 

So I guess you can hope that Bascule's graph was done after the Nature article if you want. But I won't.

[JohnB]

Swansont, as I noted in my previous post, the graph is not from published literature. Quote from Wiki:

This figure was created by Robert A. Rohde from published data and is incorporated into the Global Warming Art project.

The Wiki article claims it is based on Mehl et al 2004 and Jones and Moberg 2003. Link.

Then please demonstrate it.

I would think that onus of proof would be on those offering an artists rendition as evidence. Wouldn't you?

[swansont]

This figure was created by Robert A. Rohde from published data and is incorporated into the Global Warming Art project.

 

I don't see how that makes this "not from published literature." If the data were published, then it is a graph of published data. If it's wrong, I would like a link to what's wrong about it, rather than an (currently) empty claim.

[bascule]

First, the "observed" line is now demonstrably wrong.

 

Then please, demonstrate it.

 

Second, the forcings models

 

I'll stop you right there. The forcings aren't modeled, they're model inputs.

 

shown are themselves produced in part from the istrumental data.

 

Yes, and using them to perform an accurate reconstruction of the historical climate provides a test.

 

We now know that the period that reduced the modeled solar forcing didn't actually exist. So the the solar forcing model needs to be redone.

 

Finally, all of those forcing models need to be recalculated, actually...

 

And again, you don't know what you're talking about... they're not models. The GMST is modeled, not the forcing inputs.

 

That graph no longer applies to the real world. Actually, it never did, apparently.

 

Game, set, match! Err, no...

 

once Bascule offers up the study that created that graph we will see that the "observed" line uses SST data in it's average (probably pre-adjusted HADCRUT)

 

The graph was created using the DOE Parallel Climate Model as part of Meehl et al (2004)

 

Wouldn't both of these result in warming? The graph shows a decrease in forcing from both

 

Yes, my bad, the explanation I gave was for early 20th century warming, not the mid century cooling.

[jryan]

I'll stop you right there. The forcings aren't modeled, they're model inputs.

 

This is a matter of pure sematics. A time scale chart of qualitative forcing data is based on numerous inputs determining what the forcing was at any given point in time. Since hitorically the data was not collected we have to determine historical forcing by modeling the environment in which the forcing is to be evaluated.

 

If your chart simply showed the CO2 ppm then you would have a point. But the derived forcing value of historic CO2 concentrations is as modeled as the models it is derived from.

 

 

Yes, and using them to perform an accurate reconstruction of the historical climate provides a test.

 

Unless, as in this case, the instrumentation data is inaccurate, then it is used to inaccurately reconstruct historical climates.

 

And again, you don't know what you're talking about... they're not models. The GMST is modeled, not the forcing inputs.

 

See the first response. If a given value is determined based on modeled data, then the value is modeled. You could similarly say that "global temperature" is a real thing and not a model... but global temperature in the 1700s is modeled.

 

In the same fashion, tree ring temperature proxies are modeled, and are used as inputs into other models.

 

The qualification of being "used as input into a model" does not mean it isn't modeled itself.

 

Game, set, match! Err, no...

 

Er... why?

 

 

 

The graph was created using the DOE Parallel Climate Model as part of Meehl et al (2004)

 

I will look into those... though they aren't very transparent. I can't access their data without an account.

 

I don't see how that makes this "not from published literature." If the data were published, then it is a graph of published data. If it's wrong, I would like a link to what's wrong about it, rather than an (currently) empty claim.

 

This is an interesting statement considering this previous thread:

 

http://www.scienceforums.net/forum/showthread.php?t=31720&page=3

[bascule]

Unless, as in this case, the instrumentation data is inaccurate, then it is used to inaccurately reconstruct historical climates.

 

Except the reconstruction wasn't inaccurate, which leads me to question your premise... care to defend it instead of making vague, blanket statements?

[jryan]

Except the reconstruction wasn't inaccurate, which leads me to question your premise... care to defend it instead of making vague, blanket statements?

 

There is nothing vague about my statement. The instumental data is inaccurate, therefore the reconstructions that use the data are inaccurate.

[bascule]

There is nothing vague about my statement. The instumental data is inaccurate, therefore the reconstructions that use the data are inaccurate.

 

What data, how flawed was it, and how much did it affect the reconstructions? That stuff is kinda important

 

For example, a flaw in the data used by GISS for their surface temperature analysis did cause an inaccurate reconstruction of the GMST, but the inaccuracy was only ~0.003°C.

 

http://data.giss.nasa.gov/gistemp/2007/

 

Data Flaw

 

Finally, we note that a minor data processing error found in the GISS temperature analysis in early 2007 does not affect the present analysis. The data processing flaw was failure to apply NOAA adjustments to United States Historical Climatology Network stations in 2000-2006, as the records for those years were taken from a different data base (Global Historical Climatology Network). This flaw affected only 1.6% of the Earth's surface (contiguous 48 states) and only the several years in the 21st century. As shown in Figure 4 and discussed elsewhere, the effect of this flaw was immeasurable globally (~0.003°C) and small even in its limited area. Contrary to reports in certain portions of the media, the data processing flaw did not alter the ordering of the warmest years on record. Obviously the global ranks were unaffected. In the contiguous 48 states the statistical tie among 1934, 1998 and 2005 as the warmest year(s) was unchanged. In the current analysis, in the flawed analysis, and in the published GISS analysis (Hansen et al. 2001), 1934 is the warmest year in the contiguous states (not globally) but by an amount (magnitude of the order of 0.01°C) that is an order of magnitude smaller than the uncertainty.

 

Edited June 6, 2008 by bascule

[SkepticLance]

To bascule

 

Your graph does NOT explain the pattern. There was a temperature rise from 1910 to 1940 - a drop from 1940 to 1976, and then another rise. Greenhouse gases explain the final rise, but the fall is unexplained by your graph.

 

In your graph, sulfate forcings drop from 1905 to the present, rather than over the period of cooling, while your rather debatable solar forcings show little effect over the cooling period.

 

I see nothing, and no combination, in your graphs to explain the 1940 to 1976 cooling.

[swansont]

 

This is an interesting statement considering this previous thread:

 

http://www.scienceforums.net/forum/showthread.php?t=31720&page=3

 

I see you continue to miss the point about that exchange.

 

To bascule

 

Your graph does NOT explain the pattern. There was a temperature rise from 1910 to 1940 - a drop from 1940 to 1976, and then another rise. Greenhouse gases explain the final rise, but the fall is unexplained by your graph.

 

In your graph, sulfate forcings drop from 1905 to the present, rather than over the period of cooling, while your rather debatable solar forcings show little effect over the cooling period.

 

I see nothing, and no combination, in your graphs to explain the 1940 to 1976 cooling.

 

There's also volcanic activity

[John L]

If you all REALLY want to know what the future is going to be like, all you have to do is just travel to SpaceWeather.com, and check out the sunspot activity, on a daily basis. Yesterday, there was a tiny spot, that did not even get numbered. Today?

 

The sun is blank--no sunspots. Credit: SOHO/MDI Notice the date in the address window.

 

Gentlemen, and ladies :wink: , we are still currently at the trailing end of Sunspot Cycle 23, which is long overdue to have been over,.........but it isn't. And the reason why it isn't is because there is no 'ginned-up' activity on the sun. The sun is Dead, with regard to activity. And it is FACT that a tranquil sun, means that the plant Earth, will become a cooler Earth.

 

This period of tranquility has been going on since 2005, and it usually takes around 4-7 years for the change, ever so slightly, to be felt here on our planet. Forget the current hot spell, but look at the rest of the last few months, and it is aparent that we are not heating up, but rather the opposite.

 

If solar scientists are correct, and Sunspot Cycle 23 continues on for another year, the cooling period will accelerate. Yet, this is exactly what has been forecast. This graph shows a history of the last two complete 178.8 year solar cycles, and also projects outward the next one, and as you can see, Sunspot Cycle 24 is going to be a Real Dud, activity wise. In fact, it will be almost an absense of a sunspot activity.

 

The sun is blank--no sunspots. Credit: SOHO/MDI

 

In other words, forget about AGW, it's the Sun that is the REAL diciding factor, and although it may not be all that much, it is enough to make a real difference in global temperatures. Personally, I believe we are headed for another little ice age by 2030, like another Dalton Minimum. Then where will Algore be?

 

As for the term "Climate Change", so what? Climate is ALWAYS changing, and if you think things are bad with a warm planet(which I contend is much better), just wait until a cooler climate wrecks havoc on the agriculture belts of the planet. Global cooling is the ABSOLUTE WORST thing that could happen to we humans. Trust me on this one. :wink:

 

What we should REALLY be worried about are Impactors from space. Why aren't you AGW True Believers all vexed about the threat of Asteroids and especially Comets? If you take the time and just study the latest Clovis Comet theory, you will see that a comet does not have to actually strike the earth to cause mass extinctions, and totall disruption. And we are constantly struck, with a major strike occuring about every thousand years. THERE is where you guys should be worried.

 

And speaking of Clovis Comet, that's why I'm Really here..............................

[iNow]

In other words, forget about AGW, it's the Sun that is the REAL diciding factor

From a very very high level, yes, the sun drives climate. However, we cannot forget about AGW just for that reason, and I call your attention to the following:

 

 

 

Nature - No solar hiding place for greenhouse sceptics

 

Sun not to blame for global warming.

 

A study has confirmed that there are no grounds to blame the Sun for recent global warming. The analysis shows that global warming since 1985 has been caused neither by an increase in solar radiation nor by a decrease in the flux of galactic cosmic rays

 

 

NATURE article in .pdf --> http://www.auger.org.ar/Auger_Sur/PDF/Nature%20July%202007.pdf

 

This paper is the final nail in the coffin for people who would like to make the Sun responsible for present global warming.

 

 

 

 

 

 

An additional problem is that the temperature change leads, not lags, solar activity changes earlier in the 20th century.

 

 

 

Solar variability certainly plays a minor role, but it looks like only a quarter of the recent variations can be attributed to the Sun.

 

Global Warming -- Research Issues

 

 

 

 

 

 

 

 

 

 

 

 

 

I've found a wealth of knowledge at the following, so perhaps you can catch yourself up too!

 

 

 

RealClimate - Recent Warming But No Trend in Galactic Cosmic Rays

RealClimate - A critique on Veizer’s Celestial Climate Driver

RealClimate - The lure of solar forcing

RealClimate - Did the Sun hit record highs over the last few decades?

RealClimate - Another study on solar influence

 

 

[T']here is not much evidence pointing to the sun being responsible for the warming since the 1950s.

[JohnB]

Swansont, I have no idea if the graph is accurate. My point is that it is an artists rendition that is claimed to be based on data. It is up to those making the claim to prove their case. If someone wishes to provide graphs from Meehl et al and Jones and Moberg et al I will happily concede the point. Until then it can only be described as "a pretty picture" rather than "evidence".

 

I also note that it is indeed inaccurate re forcings. The graph shows increasing negative forcings for sulfates when sulfate emmissions (and levels) have been dropping. This cannot be reconciled with the IPCC data shown above, therefore the graph is wrong. (Unless someone can point to a paper showing how decreasing sulfate levels lead to increasing negative forcings.

 

Bascule,

The graph was created using the DOE Parallel Climate Model as part of Meehl et al (2004)

Could you please show where in that paper the forcings are defined quantitativly? Quick answer, they are not. The reference to forcings leads here. I quote from the abstract:

In addition to the five individual forcing experiments, an additional eight sets are performed with the forcings in various combinations. The late-twentieth-century warming can only be reproduced in the model with anthropogenic forcing (mainly GHGs), while the early twentieth-century warming is mainly caused by natural forcing in the model (mainly solar).

There is no mention here of using actual measured values. (Something that I have asked for before.) Loose translation of the first sentence above: "We did 1 run using our estimate of each individual forcing, then 8 runs where we varied our estimates." Wanna bet they compared each run to the climate record before varying the estimates? I'm willing to be wrong here as the actual paper is behind a paywall, so if someone can provide the methodology used in the paper (with quotes) I'll concede the point.

The GMST is modeled, not the forcing inputs.

More correctly stated as "The GMST is modelled, not the forcing inputs, which are estimates only."

how much did it affect the reconstructions? That stuff is kinda important

It certainly is, Ollie. Please compare these two following graphs of GMST.

Hansen 1995;

and Hansen 2005;

You'll note the differences are a bit more than .003 degrees. Which of these should you calibrate the models to?

 

John Goetz over at CA used the Wayback Machine to recover earlier versions of GISSTEMP and prepared a comparison of how many times historical monthly data was changed in the datasets. Here is his result;

Anybody comparing anything to GISSTEMP had better quote the day they d/loaded the data there are that many changes.

I posted a graph earlier showing the Raw/Adjusted difference for Wellington NZ to demonstrate that many of these adjustments are not trivial in size. In another thread linked to on page 2 I showed that the raw data shows no warming in New Zealand at all, but the adjusted data does. I mean look at the curve. Do you really believe that the temps were right in 1880, then got out by a degree and a half by 1915 then miraculously gradually got it right again in the 1915-1930 period?

 

So which data is right, raw or adjusted? Is the adjustment correct? GISS don't sat why they adjust data from certain staions or comment on the magnitude of the adjustments. You want to claim the data is fine? Then find the place in the US that regularly has 60+⁰ temps that Atmoz found in the CRU data. Either there have been new US temp records set or there is something wrong with the data, they can't both be right.