I was working on a general report yesterday, but in checking background for it, I discovered this recent missive from Dr. Hansen. I suppose when your agency is the “odd man out”, you feel a need to explain yourself. Note the difference in November 2010 global temperature anomaly metrics:
UAH: 0.38 GISS: 0.74°C
Yes, I’d try to explain that too. I’ll have another post on this, but for now, here’s GISS report verbatim as it appears here. – Anthony
GISS Surface Temperature Analysis
2010 — Global Temperature and Europe’s Frigid Air
By James Hansen, Reto Ruedy, Makiko Sato and Ken Lo
Figure 1:
(a) January-November surface air temperature anomaly in GISS analysis, (b) November 2010 anomaly using only data from meteorological stations and Antarctic research stations, with the radius of influence of a station limited to 250 km to better reveal maximum anomalies. (View large PDF)Figure 1(a) shows January-November 2010 surface temperature anomalies (relative to 1951-80) in the preliminary Goddard Institute for Space Studies analysis. This is the warmest January-November in the GISS analysis, which covers 131 years. However, it is only a few hundredths of a degree warmer than 2005, so it is possible that the final GISS results for the full year will find 2010 and 2005 to have the same temperature within the margin of error.
As described in an in-press paper at Reviews of Geophysics (see summary PDF) that defines the GISS analysis method, we estimate a two-standard-deviation uncertainty (95 percent confidence interval) of 0.05°C for comparison of global temperatures in nearby recent years. The magnitude of this uncertainty and the small temperature differences among different years is one reason that alternative analyses yield different rankings for the warmest years. However, results for overall global temperature change of the past century are in good agreement among the alternative analyses (by NASA/GISS, NOAA National Climate Data Center, and the joint analysis of the UK Met Office Hadley Centre and the University of East Anglia Climatic Research Unit).
Figure 1(b) shows November 2010 surface temperature anomalies based only on surface air measurements at meteorological stations and Antarctic research stations. In producing this map the radius of influence of a given station is limited to 250 km to allow extreme temperature anomalies to be apparent. Northern Europe had negative anomalies of more than 4°C, while the Hudson Bay region of Canada had monthly mean anomalies greater than +10°C.
The extreme warmth in Northeast Canada is undoubtedly related to the fact that Hudson Bay was practically ice free. In the past, including the GISS base period 1951-1980, Hudson Bay was largely ice-covered in November. The contrast of temperatures at coastal stations in years with and without sea ice cover on the neighboring water body is useful for illustrating the dramatic effect of sea ice on surface air temperature. Sea ice insulates the atmosphere from ocean water warmth, allowing surface air to achieve temperatures much lower than that of the ocean. It is for this reason that some of the largest positive temperature anomalies on the planet occur in the Arctic Ocean as sea ice area has decreased in recent years.
The cold anomaly in Northern Europe in November has continued and strengthened in the first half of December. Combined with the unusual cold winter of 2009-2010 in Northern Hemisphere mid-latitudes, this regional cold spell has caused widespread commentary that global warming has ended. That is hardly the case. On the contrary, globally November 2010 is the warmest November in the GISS record.
Figure 2(a) illustrates that there is a good chance that 2010 as a whole will be the warmest year in the GISS analysis. Even if the December global temperature anomaly is unusually cool, 2010 will at least be in a statistical tie with 2005 for the warmest year.
Figure 2: Global surface air temperature anomalies relative to 1951-1980 mean for (a) annual and 5-year running means, and (b) 60-month and 132-month running means. In (a) the 2010 point is a preliminary 11-month anomaly. Green vertical bars are two-standard-deviation error estimates, as discussed in our Reviews of Geophysics paper. (View large PDF)
Figure 2(b) shows the 60-month (5-year) and 132-month (11-year) running-mean surface air temperature in the GISS analysis. Contrary to frequent assertions that global warming slowed in the past decade, as discussed in our paper in press, global warming has proceeded in the current decade just as fast as in the prior two decades. The warmth of 2010 is especially noteworthy, given the strong La Nina that developed in the second half of 2010. The La Nina, caused by unusually strong easterly equatorial winds, produces the cool anomalies in the tropical Pacific Ocean as cold upwelling deep water along the Peruvian coast is blown westward along the equator.
Figure 3: Temperature anomalies relative to 1951-1980 for the European region defined by 36°N-70°N and 10°W-30°E. (View large PDF)
Back to the cold air in Europe: is it possible that reduced Arctic sea ice is affecting weather patterns? Because Hudson Bay (and Baffin Bay, west of Greenland) are at significantly lower latitudes than most of the Arctic Ocean, global warming may cause them to remain ice free into early winter after the Arctic Ocean has become frozen insulating the atmosphere from the ocean. The fixed location of the Hudson-Baffin heat source could plausibly affect weather patterns, in a deterministic way — Europe being half a Rossby wavelength downstream, thus producing a cold European anomaly in the trans-Atlantic seesaw. Several ideas about possible effects of the loss of Arctic sea ice on weather patterns are discussed in papers referenced by Overland, Wang and Walsh.
However, we note in our Reviews of Geophysics paper in press that the few years just prior to 2009-2010, with low Arctic sea ice, did not produce cold winters in Europe. The cold winter of 2009-2010 was associated with the most extreme Arctic Oscillation in the period of record. Figure 3, from our paper in press, shows that 7 of the last 10 European winters were warmer than the 1951-1980 average winter, and 10 of the past 10 summers were warmer than climatology. The average warming of European winters is at least as large as the average warming of summers, but it is less noticeable because of the much greater variability in winter.
Finally, we point out in Figure 3 the anomalous summer warmth in 2003 and 2010, summers that were associated with extreme events centered in France and Moscow. If the warming trend that is obvious in that figure continues, as is expected if greenhouse gases continue to increase, such extremes will become common within a few decades.
A copy of this webpage text is also available as a PDF document.
Reference
Hansen, J., R. Ruedy, Mki. Sato, and K. Lo, 2010: Global surface temperature change. Rev. Geophys., in press, doi:10.1029/2010RG000345.
Contacts
Please address media inquiries regarding the GISS surface temperature analysis to Ms. Leslie McCarthy by e-mail at Leslie.M.McCarthy@nasa.gov or by phone at 212-678-5507.
Scientific inquiries about the analysis may be directed to Dr. James E. Hansen.
Got to laugh everytime I hear s omething from Hansen.
Just keep in mind that most of this “warming” they are speaking of is primarily in the minimum temperatures during nights and not in maximum’s that occur in the afternoons. There are few things on this Earth, but maybe to decrease insects, that mind it being a fraction or maybe one degree warmer in the nighttime. Add in the UHI and that seems to sum up GISS’s global average “blood-red we are all going to die” temperatures to me. Their mouths are where the real hot air resides. Too bad some call them objective scientists.
Looks like the AO is heading for even greater negative territory if recent predictions bring fruit. In this case, frozen fruit.
http://www.cpc.noaa.gov/products/precip/CWlink/daily_ao_index/ao_index_mrf.shtml
Add to that our La Nina and you get gobs and gobs of cold coming from all directions compared to no more greenhouse warmth than you can get sitting in a pool filled with ice next to a 40 watt nightlight (and I am being generous). It appears natural weather pattern variation is kicking butt against anthropogenic global warming. If Hansen wants to continue betting on some future warming, it’s a fool’s bet.
I wonder if Hansen can explain this:
http://chiefio.wordpress.com/2010/12/10/does-rain-call-giss-liars/
Those are some mighty interesting graphs.
Theo Goodwin says:
December 12, 2010 at 4:43 pm
steven mosher says:
December 12, 2010 at 1:11 pm
R. Gates
‘“In short, claiming “natural variability” as a cause in no explanation at all as science is all about finding the reasons behind that variability.”Thanks. This seems to be a particularly hard point for some to get. ‘
Apparently, a harder point to get is that we sometimes do not have a clue what the “reasons behind the natural variability” are. When we do not, we have a duty to say so.
######
you still dont get it. Natural variation is not an explanation. It’s the admission of ignorance. Science has some clues as to why the temperatures goes up and down. to test that you can only do 1 thing. Write equations. And then test those equations. In the begining they will be simplistic and inaccurate. One strives to make them more accurate. They are never perfect. Ever.
To reduce the earth’s climate to a single figure – a global annual average temperature – is fatuous in the extreme. Hansen at al are clutching at straws.
I think that people who do not understand base periods in anomaly calculations should be careful what they are saying. There is nothing wrong or sinsister about the GISS selection of the base period. People who think there is are welcomed to re run GISS with a DIFFERENT base period. In fact, GISS allows you to do this. I did an exhaustive study of the base period. Selecting different base periods and calculating the rates of warming. Answer. It doesnt matter, except in this small way: You want to maximize the number of stations that pass the quality test. The quality test is this: a station must have 15 years of data (CRU) in the base period to qualify as a station.
In any case, if you take all the stations and search for the period where you get the maximum number of stations reporting you will see two things>
1. if you do this on a global basis you will pick the 30 year period of 1953-1982.
2. if you want to maximize stations in the southern hemisphere you will select
1961-1990.
Very simply, both 1951-1980 and 1961-1990 are defensible choices. If anybody wants to suggest a different period, go ahead. Suggest a period and suggest a HYPOTHESIS to test.
“changing the period to 19xy-19zy will change the global trends in the following way”
If you select any other periods you will get a SPARSER selection of data and a noiser signal, and the answer wont change. You’ll just be less confident in it.
It is singularly annoying for people to focus on the NON problems when there are real problems that need attention.
Paul Coppin: “Climatology is “the study of climate” There is only one “climatology” There are no other “climatologies””
“Climatology” is common parlance among researchers in the sense of the ‘average meteorological (or oceanography etc) values in a place for a period of time’. Example uses in these papers:
http://www.agu.org/pubs/crossref/2010/2010GL043680.shtml
http://etd.library.miami.edu/theses/available/etd-04192008-124713/
http://etd.library.miami.edu/theses/available/etd-04192008-124713/
http://journals.ametsoc.org/perlserv/?doi=10.1175/JAS-3323.1&request=get-abstract
http://www.agu.org/pubs/crossref/2004/2004GL019961.shtml
http://www.bom.gov.au/amm/docs/2004/shaik1_hres.pdf
http://www.cima.fcen.uba.ar/~carolina/ictp1877/sinclair_1996.pdf
ftp://ftp.etl.noaa.gov/user/cfairall/wcrp_wgsf/pubs/cronin_EOS_205_02.pdf
http://journals.ametsoc.org/perlserv/?doi=10.1175/JAS-3323.1&request=get-abstract
ftp://ftp.etl.noaa.gov/user/cfairall/wcrp_wgsf/pubs/cronin_EOS_205_02.pdf
http://linkinghub.elsevier.com/retrieve/pii/0967064596000355
http://journals.ametsoc.org/doi/pdf/10.1175/JPO2720.1
http://crosbi.znanstvenici.hr/datoteka/456407.Palmer_etal_JClim_1992.pdf
http://www.agu.org/pubs/crossref/2008/2008GL035984.shtml
And another example; the link to this page is titled, by the University of Reading’s Department of Meteorology as ‘Maidenhead Climatology’:
http://www.met.reading.ac.uk/~brugge/maidenhead_climate.html
If you search in the top right bar for ‘climatology’ you will see many more example uses.
‘Warmer than climatology’ is a simpler way of saying ‘warmer than the average temperatures in this region for this time period’.
old engineer; did you follow Anna V’s comments on anomalies, running through the thread linked below?
New peer reviewed paper shows just how bad the climate models really are
i.e. We have been bamboozled with anomalies, and worse, with global average anomalies. – Anna V (December 6, 2010 at 10:03 pm)
E.M.Smith says:
December 12, 2010 at 5:27 pm
This is a splice artifact being dressed up as an anomaly.
So it’s a create an incline splicing instead of a hide the decline splicing?
“Pamela Gray says:
December 12, 2010 at 9:00 pm
Looks like the AO is heading for even greater negative territory if recent predictions bring fruit. In this case, frozen fruit.
http://www.cpc.noaa.gov/products/precip/CWlink/daily_ao_index/ao_index_mrf.shtml”
Thanks for pointing that out Pamela.
One of my propositions is that the AO is susceptible to both oceanic effects from below and solar effects from above.
Currently we have the sun recovering a little from the recent minimum so I was unsure whether the AO would become less negative as a result or whether the effect on AO of the slightly more active sun would be offset by the developing La Nina causing the tropical air masses to contract.
It appears that the latter is the case, at least so far.
Stephen Wilde says:
December 12, 2010 at 9:35 am
“Doesn’t that all suggest that more open water in the Arctic Ocean actually vents heat to space faster rather than encouraging global warming from reduced albedo and more insolation into the Arctic waters ?”
You continue to be among the best commenters here IMO.
Absolutely correct that ice-free water loses heat much faster than ice-covered water. Transport of latent heat of vaporization is halted. Ice cover insulates the water below from wind and wave mixing with the air, stops convective cooling, largely stops conductive cooling, and blocks radiative cooling.
The albedo change is insignificant above the arctic circle for two reasons. First of all the reflectivity of water increases as the angle of incidence decreases. With such a low angle of incidence in the arctic open water is nearly as reflective as sea ice. Secondly the insolation is tiny to begin with due to the low angle of incidence – you can’t heat something unless you have energy to heat it with.
So it absolutely correct to say that the more ice-free the artic is the better it performs as a radiator. This amounts to a negative feedback. As the tropics warm and the heat is transported to the pole it melts ice and makes a less resistive path for that heat to be radiated into the frigid black cold of outer space.
The south pole is a different story as it is covered by a continent so there’s no way for the warm air and water circulating down from the tropics to reach the sweet spot for radiative transfer to space. It isn’t such a good radiator to begin with and doesn’t get better when there is more heat to remove.
So I agree with the climate boffins that Arctic sea ice extent is good evidence of warming but I strongly disagree on the nature of the feedback it represents. It is clearly a negative feedback whereas the climate boffins, in their desperate search for the missing amplification, contend it is a positive feedback that turns very desirable modest warming at higher northern latitudes predominantly during the night and winter months into a nighmarish scenario of rapid sea level rise.
Steven Mosher: I have seen you allude to people missing the “real” issues several times on WUWT.
Could you not just spell out what you think are the problems we should be focusing on?
“Hansen is using an outdated base period”
Whether or not there is a standard base period (as per the WMO) makes absolutely no difference to the discussion at hand. There is no “correct” base period – all that matters is that a common base period is used to compare temperature datasets. The statement, “UAH: 0.38 GISS: 0.74°C,” shows a lack of this essential understanding, and claims of an “outdated base period” represent a clear diversionary tactic with no relevance to the matter at hand.
Surface temperature datasets and satellite temperature datasets measure different things, and there have always been (and always will be) specific months where they diverge more than other months. However, the overall agreement between all temperature datasets for the longterm trend is very robust. Quibbling over whether this month or that is higher or lower is a complete strawman. The longterm trend is strongly positive, no matter how you look at it. If the GISS temperature record didn’t exist, our understanding of the planet’s temperature would be unchanged.
REPLY: “The statement, “UAH: 0.38 GISS: 0.74°C,” shows a lack of this essential understanding, and claims of an “outdated base period” represent a clear diversionary tactic with no relevance to the matter at hand. ”
Umm, sorry, no you are wrong about that. You see if they used a more recent base period, then this graph, the most widely cited one on AGW on the planet, would have a different look to it. It’s all about presentation for public consumption. GISS knows what they are doing, by keeping the 1951-1980 base period for anomaly calculation, they ensure that their graph is always offset more than every other metric, and thus appeal to the people who subscribe to the CAGW worries. An again I say: You can’t trust a man who uses his public paid position to protest, getr himself arrested, and then be the gatekeeper of data.
And then there’s this:
I assume from your tone that you are OK with post facto adjustment of data? Would wellesley.edu tolerate such a thing?
I see you have a website that says “what Climate Deniers fear most”. How professional of you to denigrate others with that distasteful term that is just another way of saying “holocaust deniers”. How sad for you Mr. Griffith that your “explanations” start with such disgust. Again would wellesley.edu tolerate such a thing?
Let’s find out. – Anthony
You know what they say about some old folks who forget to come in out of the rain.
Well, there’s this warming climate dude we all know….
As we keep saying the key metric is ocean heat content not surface temperature. I cannot find recent ARGO results. Can anyone help.
Check out Tamino’s (Open Mind) most recent post in response to this one. He plots GISS and UAH using the same base. They are highly concordant. The main difference is that UAH shows greater highs and lows in response to El Nino and La Nina respectively. Apart from that difference they are difficult to tell apart. Since NASA would like to make comparisons of its own data across the years, this seems like a reasonable reason for keeping the same base period. The main point in making comparisons between different data sources is to compare the fluctuations, and not the magnitude of the anomolies.
Rhoda R says:
December 12, 2010 at 12:06 pm
I think Mr.Vulcevic has succinctly described his theory above:
vukcevic says:
December 12, 2010 at 12:17 pm
(Though we, like birds walking on a 200,000 volts wire just ignore it and keep on singing ) 🙂
This is just another example (for the umpteenth time) that Tamino shows why Anthony shouldn’t be doing these type of analyses. Global warming skepticism or not, there is absolutely no excuse for the mathematical laziness displayed in this post. The claim that a reference period is ‘outdated’ for computing an anomaly is even more startling. Let’s start being skeptical of everyone, not just those who disagree with our pre-conceived notions.
Yeah I think that Watts should clearly point out at the beginning of the title that they have different baselines. If not I think the article should be retracted.
Well, Tamino has made a good job on explaining that you cannot compare the GISS and UAH temperature datasets unless you use the same base period:
http://tamino.wordpress.com/2010/12/13/odd-man-out/
But one thing more:
Yes in November we have:
UAH: 0.38 GISS: 0.74°C
But in SEPTEMBER:
UAH: 0.60 GISS: 0.55°C
Yes in September UAH temperatures were warmer than GISTEMP ones, and this despite that the UAH baseline temperature is higher than the GISTEMP one.
In effect, with the uniformed baseline, Tamino found that UAH temperatures were HIGHER than GISTEMP ones!
http://tamino.files.wordpress.com/2010/12/baseline.jpg
http://tamino.files.wordpress.com/2010/12/base12.jpg
Clearly 2010 is a very warm year, the hottest so far in the GISTEMP record and also , together with 1998, the hottest in the UAH record.
And remeber that the 1997-1998 event was a Super El Niño, while the 2009-2010 event was just a moderate-to-strong El Niño. The fact that 2010 and 1998 are so far equally warm indicates that the world has warmed in these years.
That is , there is an obvious warming trend.
I said:
“The fact that 2010 and 1998 are so far equally warm indicates that the world has warmed in these years.”
Equally warm in the UAH dataset, of course. Warmest ever in the GISTEMP one.
Anthony says:
Hardly. The Y axis values would be different. The anomalies would still be the same relative to each other, the plot would be the same, and the trend would still be the same.
Oh, the error bars might be wider, which would mean that the alternative choice of baseline was a poorer one.
Surely you know all this? So what guided your choice to omit?
By omitting adjustment for baselines, you make the UAH and GISS anomalies appear much more different than they actually are. If your agenda is counter-propaganda rather than illumination, then you are doing an admirable job.
REPLY: “The Y axis values would be different.”
Exactly, and November’s GISS value, the one everyone is yelling about, would be different (higher or lower) depending on the base period used . – Anthony
Thank you for your comments R. Gates and Dave Wendt.
Just a technical detail, R. Gates, you say: “The water vapor (King of the GH gases) in the clouds will usually keep the temps higher than if there was clear skies and no cloud cover. Now, just because we can’t see the CO2 molecule in the same way we can often see water vapor, ”
Actually water vapor consists of just individual gas molecules of H2O and this is just as invisible as CO2, even if the relative humidity is 99%. It is only when individual gas H2O molecules coalesce to form tiny droplets of liquid H2O that they become visible as clouds or fog.
However you raise a very interesting point in that clouds keep temperatures warm. This is true. However if there were no clouds, how much difference would 390 ppm CO2 make versus 280 ppm CO2, ie Is it significant or not worth worrying about relative to the effect of clouds at night?
Dave, you say “One need only look at the Moon or similar bodies, down to satellites in orbit, which without atmospheres are much colder than the Earth on their dark sides, but also much hotter on their sunlit sides.” Is the “hotter on their sunlit sides” because any atmosphere “conducts” heat away? It would seem to me that greenhouse gases would actually hinder the movement of heat away from a hot surface since they absorb certain wavelengths and re-radiate about half back to Earth. Does this make sense?
Mr. Watts,
The matter that you put forth is that the GISS temperature anomaly for November 2010 is “the odd man out”. Your contribution is to compare the temperature anomalies of this month from both UAH and GISS. As these numbers do not use the same base period, they clearly cannot be compared at face value. When compared using a common base period (1980-1999), the November temperatures are UAH: 0.38 GISS: 0.50°C. Yes, GISS is higher for November, but not nearly as high as the incorrect comparison that you present to your readers.
Let’s go back to January 2010. When using the same base period we get UAH: 0.64 GISS: 0.46°C. Now, UAH is higher. It is clear that on a month-to-month basis, different temperature datasets show disagreements. However, what matters most to the larger discussion is obviously the long-term trend: all temperature datasets agree that the world is warming. If we look at the 5 major temperature datasets from 1979 through 2009, they produce the following decadal trends:
HadCRUT3: 0.158, GISS: 0.165, NOAA: 0.163, UAH: 0.128, RSS: 0.153°C/decade. Of this group UAH is definitely the “odd man out”, although if you include 2010 through November it brings UAH up considerably. The big picture is this: if the GISS analysis never existed, our understanding of global temperatures would be fundamentally the same.
Now to your assertion that the “most widely cited” graph on AGW “would have a different look to it” if using a different base period. Starting with the monthly data, I’ve recreated the GISS figure using the 1951-1980 base as well as the 1980-1999 base period. The trend is identical and the scale is identical, only shifted. I’m not sure how you think the choice of base period has significantly altered the discussion or understanding of global warming – it hasn’t. I am amazed that you accuse NASA of trying to deceive people by their inconsequential choice of base period, when you have just deceived your own audience by incorrectly comparing anomalies that use different base periods. Also, if we overlay the UAH data using the same base period, the overall conclusion remains the same. (If included, the UAH average for 2010 so far is off the scale.)
You have yet to correct your comparison for the November 2010 UAH and GISS data, nor have you actually addressed that it is entirely incorrect to compare them using different base periods. Instead, you have talked about how using an “outdated” base period somehow makes James Hansen even more scandalous, that the GISS dataset is fundamentally flawed (without mentioning that it is corroborated by all the other datasets), and you have tried to smear me by suggesting that by labeling somebody a “climate denier”, I am labeling them a holocaust denier. The first two points do not surprise me, but the third is insulting, absurd, and inappropriate to the conversation that we should be having.
REPLY: You are right about #3 you shouldn’t be using the word “denier” as it is in fact insulting. May I suggest you take it off your website to prove that you are on the level? – Anthony
If you raised the baseline, thereby lowering the anomaly value, the results would still be the same – the value for November would have the same relationship to every other anomaly in the GISS record and the trend wouldn’t change. Similarly, the UAH values would have the same relationship to UAH anomalies if they changed their baseline. The problem here is that you have not noted that the baselines are different, and therefore you are comparing apples to oranges. If you want to compare apples to apples:
UAH 0.38 GISS 0.46 (adjusted to match baselines)
The correct difference is 0.08C, instead of 0.36C. Omitting the baseline adjustment magnifies the difference 6-fold.
GISS explain their choice of baseline (they even point it out in the parts you cited), as does UAH. When GISS compare their anomalies with other data sets, they adjust baseline accordingly. So does UAH. So should anyone comparing them.
The public is generally not aware of the actual anomalies, and the only people that compare anomalies across data sets are the small number of climate bloggers and their followers. It would take no more than two sentences to amend the oversight in your post.
(One of the) GISS explanation for choice of baseline:
http://pubs.giss.nasa.gov/docs/2010/2010_Hansen_etal.pdf
GISS first began publishing on the temperature record in 1981. Their baseline choice was then the most recent 30 years. All they have done since is be consistent, and you surmise a strategic intent. There is no good reason (only political ones) for them to use an alternative baseline.
Similarly, UAH have not changed their 20-year baseline choice, even though they now have 30 years of data. They, too, have published values and graphs based on the initial climatology, and they also seem to think it practical to keep the baseline consistent.
Two sentences is all it would take Anthony. Will you not shed some light in your post?
REPLY: Actually yes, but not right now, as this post was bait for a social experiment, hoping to gather lots of comments to use in the next story, and you are all doing a splendid job. Tamino went after it too, but that’s generally predictable anytime GISS is mentioned, and he and many of you have provided what I need. All this covered in the next post on this, probably sometime around the end of December. Thanks for playing! – Anthony