Guest essay by Dan Travers
On Thursday, March 13, 2014, the U.S. National Climactic Data Center switched to gridded GHCN-D data sets it uses to report long term temperature trends – with a resulting dramatic change in the official U.S. climate record. As seems to always happen when somebody modifies the temperature record, the new version of the record shows a significantly stronger warming trend than the unmodified or, in this case, discarded version.
The new dataset, called “nClimDiv,” shows the per decade warming trend from 1895 through 2012 for the contiguous United States to be 0.135 degrees Fahrenheit. The formerly used dataset, called “Drd964x,” shows the per decade warming trend over the same period to be substantially less – only 0.088 degrees. Which is closer to the truth?
As will be illustrated below in the side by side comparison graphs, the increase in the warming trend in the new data set is largely the consequence of significantly lowering the temperature record in the earlier part of the century, thereby creating a greater “warming” trend.
This particular manipulation has a long history. For an outstanding account of temperature record alterations, tampering, modifications and mutilations across the globe, see Joseph D’Aleo and Anthony Watts’ Surface Temperature Records: Policy-Driven Deception?
It should be noted that the 0.088 degree figure above was never reported by the NCDC. The Center’s previous practice was to use one data set for the national figures (nClimDiv or something similar to it) and a different one for the state and regional figures (Drd964x or something similar). To get a national figure using the Drd964x data, one has derive it from the state data. This is done by taking the per decade warming trend for each of the lower forty-eight states and calculating a weighted average, using each states’ respective geographical area as the weightings.
The chart below shows a state by state comparison for the lower forty-eight states of the per decade warming trend for 1895-2012 under both the old and the new data sets.
In the past, alterations and manipulations of the temperature record have been made frequently and are often poorly documented. See D’Aleo and Watts. In this instance, it should be noted, the NCDC made considerable effort to be forthcoming about the data set change. The change was planned and announced well in advance. An academic paper analyzing the major impacts of the transition was written by NOAA/NCDC scientists and made available on the NCDC website. See Fenimore, et. al, 2011. A description of the Drd964x dataset, the nClimDiv Dataset, and a comparison of the two was put on the website and can be see here.
The relative forthcoming approach of the NCDC in this instance notwithstanding, looking at the temperature graphs side by side for the two datasets is highly instructive and raises many questions – the most basic being which of the two data sets is more faithful to reality.
Below are side by side comparisons under the two data sets for California, Maine, Michigan, Oregon and Pennsylvania for the period 1895-2009, with the annual data points being for the twelve month period in the respective year ending in November. The right-side box is the graph under the new nClimDiv dataset, the left-side box is the graph for the same period using the discarded Drd964x dataset. (The reason this particular period is shown is that it is the only one for which I have the data to make the presentation. In December 2009, I happened to copy from the NCDC website the graph of the available temperature record for each of the lower forty-eight states, and the data from 1895 through November 2009 was the most recent that was available at that time.)
I will highlight a few items for each state comparison that I think are noteworthy, but there is much that can be said about each of these. Please comment!
California
Left: Before, Right: After – Click to enlarge graphs
- For California, the change in the in datasets results in a lowering of the entire temperature record, but the lowering is greater in the early part of the century, resulting in the 0.07 degree increase per decade in the Drd964x data becoming a .18 degree increase per decade under the nClimDiv data.
- Notice the earliest part of the graphs, up to about 1907. In the graph on left, the data points are between 59 and 61.5 degrees. In the graph on the right, they are between 56 and 57.5 degrees.
- The dips at 1910-1911 and around 1915 in the left graph are between 57 and 58 degrees. In the graph on the right they are between 55 and 56 degrees.
- The spike around 1925 is above 61 degrees in the graph on the left, and is just above 59 degrees in the graph on the right.
Maine
· The change in Maine’s temperature record from the dataset switch is dramatic. The Drd964x data shows a slight cooling trend of negative .03 degrees per decade. The nClimDiv data, on the other hand, shows a substantial .23 degrees per decade warming.
· Notice the third data point in the chart (1898, presumably). On the left it is between 43 and 44 degrees. On the right it is just over 40 degrees.
· Notice the three comparatively cold years in the middle of the decade between 1900 and 1910. On the left the first of them is at 39 degrees and the other two slightly below that. On the right, the same years are recorded just above 37 degrees, at 37 degrees and somewhere below 37 degrees, respectively.
· The temperature spike recorded in the left graph between 45 and 46 degrees around 1913 is barely discernable on the graph at the right and appears to be recorded at 41 degrees.
Michigan
- Michigan’s temperature record went from the very slight cooling trend under Drd964x data of -.01 degrees per decade to a warming trend of .21 degrees per decade under nClimDiv data.
- In Michigan’s case, the differences between the two data sets are starkly concentrated in the period between 1895 and 1930, where for the entire period the temperatures are on average about 2 degrees lower in the new data set, with relatively modest differences in years after 1930.
Oregon
· Notice the first datapoint (1895). The Drd964x dataset records it at slightly under 47.5 degrees. The new dataset states at slightly over 45 degrees, almost 2.5 degrees cooler.
· The first decade appears, on average, to be around 2.5 degrees colder in the new data set than the old.
· The ten years 1917 to 1926 are on average greater than 2 degrees colder in the new data set than the old.
· As is the case with California, the entire period of the graph is colder in the new data set, but the difference is greater in the early part of the twentieth century, resulting in the 0.09 degrees per decade increase shown by the Drd984x data becoming a 0.20 degree increase per decade in the nClimDiv data.
Pennsylvania
· Pennsylvania showed no warming trend at all in the Drd964x data. Under the nClimDiv data, the state experienced a 0.10 degree per decade warming trend.
· From 1895 through 1940, the nClimDiv data shows on average about 1 degree colder temperatures than the Drd964x data, followed by increasingly smaller differences in later years.
DR says: April 29, 2014 at 3:53 pm
“As observed by Steven Goddard, there have been massive adjustments for Michigan temperatures.”
They aren’t massive adjustments to the same data. They are different datasets with a different mix of stations. You just can’t compare regional averages unless they use anomalies.
“He who controls the present controls the past.
He who controls the past controls the future”
Big Brother is alive and well in the present day.
Thanks for the link to your source code Zeke. I’m interested in you breakpoint and kriging logic and whether it’s applicable to sea-level and precipitation trends. Any thoughts? Personally I use R, but I should be able to muddle through your matlab code.
Given the fact that so many sites have so many unique characteristics and given the long term quality of the data, the simplest approach is the one most likely to give an accurate idea of what is happening in the long run. Not interested in weighted averages, etc. What is the trend for maximum temperatures for all stations, unadjusted. Possibly an urban heat island adjustment will be required, but even that should be avoided if possible, by excluding stations that are found in built up areas that weren’t previously built up.
@ur momisugly Nick Stokes
Utter nonsense. NCDC claims this past winter/spring in Michigan was warmer than 4 other winters while we are looking at record ice.
The ice tells the truth on the Great Lakes and inland lakes for that matter as well. NOAA is adjusting the raw data. It doesn’t matter if their reasoning is “peer reviewed”, it is an impossible physical occurrence that it can be warmer yet have hugely more ice area on the Great Lakes. Stop obfuscating. If you use a base period of 1901-2010 and the “anomaly” is higher in 2014 than 4 other years, that means it was warmer in 2014. The adjustments are there for anyone to see.
Michigan has some of the better rated weather stations in the country. I want you to explain how Spring 2014 can be warmer than 4 other years when the total ice of all the Great Lakes, not just Superior, is at all time record highs.
To adjust temperatures upward in 2014 is a load of bullshit and as far as I’m concerned it is a concerted effort by a few in control of how and why it is done to fit their political master’s narrative while they themselves are political activists, including one man that on his own bio page claimed he had a PhD, and didn’t, and is now in charge of it all.
You still have not explained how Michigan can have record ice even today, yet it is supposedly warmer than four other years. It is entirely accomplished by adjustments to the raw data.
omnologos says: April 29, 2014 at 8:04 am
This of course being completely pointless, since we all agree that the USA is only 3% of the planet ((c) J Hansen)
And apparently misses the whole point of the article:
Which is about adjustments to historical temperature records, not about whether USA temperatures are indicative of global warming.
Mark Bofill says:
There’s nothing there worth replying to. The comment you refer to isn’t an argument about facts. The first part is a critique of skeptics’ strategy, the second an undirected reading list including a disgraceful and unsubstantiated ad-hom against Monckton. Re (1), there is no central skeptical command directing strategy, so everyone does what they like, and good on them. Re (2), it isn’t our job to read an open-ended list of general material (least of all an ill-mannered and abusively presented one) and construct Mosher’s argument for him. Let him put a clear concise argument up and there will be people willing to look at it.
DR says: April 29, 2014 at 5:52 pm
“I want you to explain how Spring 2014 can be warmer than 4 other years”
I’d like you to give your evidence for saying that it isn’t. NCDC has at least added up the data. I can’t see that you’ve done anything like that. In fact, in one place you’re saying winter was fifth coldest – here it’s spring.
What I was saying about Goddard’s plot is that it doesn’t show the effect of adjustments at all. It shows the mean of different sets of stations. It looks like the first one he calculated himself. There could be some difference due to adjustments, but you can’t tell until you account for the effects of latitude etc.
AJ,
I suspect kriging would be useful for both (or at least more useful than other spatial interpolation techniques). As far as breakpoint detection goes, it really depends on the structure of ihomogenities in the data, as well as the underlying “true” field. Pairwise homogenization approaches tend to work well when the underlying field is smooth and well correlated over distance, or the field is very densely sampled, such that you can easily identify localized biases without removing real signals through false positives (ala GHCN with some arctic stations). It also works well when inhomogenities tend toward larger step-changes, and less well (though its still useful) when they are gradual trend biases or lots of small breaks. This paper by Williams et al looks into cases when homogenization does and doesn’t work for temperature records, which should help a bit: ftp://ftp.ncdc.noaa.gov/pub/data/ushcn/papers/williams-etal2012.pdf
It might also be useful to do some tests on synthetic data with different known inhomogenities added, to see how well different methods perform.
Well, when the rate of warming declines despite higher carbon concentrations, they’ll have to account for that moderating trend in their models.
Nick Stokes,
I caught them red handed lying
In February we had snow, 3 to 6 inches of snow. Enough snow to bury my feet in and it was reported as RAIN!
Don’t tell me it was because of different weather stations or micro climate or what ever because I am close enough to that darn weather station that I can walk, through the snow, to it.
Oh and when I told them I caught them lying they readjusted the data to say we had 0.37 inches of snow but above freezing temps. You CAN”T BURY YOUR FEET IN 0.37 inches of snow and I do not get 3 inches of ice on my water tanks when the temperature is ‘Above Freezing’
Also ‘Adjustments’ are not needed at the weather station in question because it is only about a decade old.
THEY LIED! And the raw data was ‘adjusted’ before it was 24 hours old.
AJ says: @ur momisugly April 29, 2014 at 4:35 pm
Thanks for the link to your source code Zeke. I’m interested in you breakpoint and kriging logic and whether it’s applicable to sea-level and precipitation trends. Any thoughts?…
>>>>>>>>>>>>>
On Krigging:
http://www.geostatscam.com/index.htm
(Several articles listed on left)
I find the whole Mosher/Zeke/Stokes fusillade amusing SOP for them. They all miss the point by focusing on minutiae.
The main point to remember: all national temperature averages are a mathematical construct, with choices made by the creator of the construct. Some constructs are closer to reality than others, but none of them match reality exactly.
Let’s assume that they are correct and the past was cooler and the past warming trend is correct.
Since the present warming trend is flat, the total temperature record is very good evidence that the affect of increased CO2 levels is cooling.
Sometimes it isn’t necessary to do anything, maybe we should just let them dig a deeper hole.
@Nick Stokes
Has the freezing temperature of water changed? Come on Nick, you’re a smart guy. Explain how there can be more ice than ever recorded on the Great Lakes in January-March, yet 2014 is still warmer than 4 other years recorded in Michigan during the same period.
You said there are no massive adjustments, but of course in ‘Nick Stokes’ speak, massive could mean anything from zero to infinity. Yet, there are the before and after charts at the beginning of the thread and somehow in your mind there is no massive adjustment while it stares you in the face.
I’m sure if Anthony or someone would post Michigan’s weather station siting quality ratings, they will be higher than most other states, yet a 100+ year trend of -.010/decade turned into +.21/decade in just a few years time by the geniuses who figured out people were complete idiots that kept thermometer records.
Anthony,
I’ve lived in Michigan my entire life, 1/2 mile from Lake Huron. As one who has been ice fishing since 5 years old, in the next 57 years it didn’t take a lot of brain power to figure out that when temperatures go above freezing and the sun gets higher in the sky, the ice melts. Throw in some rain and it goes away quickly. Instead it remained very cold and continued to snow. Our heating bills speak for themselves and can be lowered by making it colder in the house, but water cannot change its freezing temperature.
Virtually nobody I know living in Michigan remembers such a cold winter and extended ice fishing season. Spring 1960 was colder than 2014? Not a chance. I just find it incredulous looking at the “new and improved” Michigan temperature records NCDC spews out can be taken seriously. I don’t care how many peer reviewed approvals Mosher/Stokes/Zeke references, THE ICE DOES NOT LIE. My mother is 93 years old this July; lived in Michigan her whole life.
There is no other state in the country that can validate/invalidate temperature data by simply looking at the ice. Seriously, these adjustments are absurd, even the 2009 version is a joke. My mother is 93 and would ask what school taught you the last ten years in Michigan were warmer than the 1930’s.
http://stevengoddard.files.wordpress.com/2014/04/screenhunter_253-apr-17-06-04.gif
“A) when you add more stations, you will find the past is cooler than previously estimated.
B) when you add more stations, you will find that the present is warmer than you think.” SM quote
How does that tie in with the mass altering individual station records!!!???
Mike Jonas – excellent point.
Steve Mosher – I don’t understand how it automatically follows that, if the past was cooler than the present, and you then add more stations from the past to the existing records, that this will cool the past further. As a thought experiment, what if there was an extra 100,000 stations out there which we haven’t yet added the records from? Would the past be cooled every time we added another batch? How large would the temperature adjustment be, by the time they were all added?
Has anyone thought about starting a change log (spreadsheet), showing each change, date, effect of the data, and agency making the change?
DR says: April 29, 2014 at 7:29 pm
“Explain how there can be more ice than ever recorded on the Great Lakes in January-March, yet 2014 is still warmer than 4 other years recorded in Michigan during the same period.”
Again, how about some actual data? That’s what NCDC was looking ta.
Here’s Alpena/Phelps, right on the shore of Lake Huron. GHCN V3 unadjusted data. And yes, March was cold. Av -6.7°C.
But how about March 1885: -10.3°C. Or 1960: -8.2°C. Here’s the ten coldest:
1885 -10.3
1960 -8.2
1883 -8.0
1888 -7.7
1923 -7.0
1926 -6.9
1877 -6.8
1887 -6.8
2014 -6.7
Gail Combs says “I caught them lying …”
Perhaps the NWS reported “Water Equivalent” rather than snow depth insofar as snows are greatly different in the former.
After seeing this it’s impossible to deny that global warming is the result of man’s hand. 😉
1) What is the margin of error in the measurement? Is it less than 0.01 F? If not, we cannot say if the trend is flat or positive or negative.
2) Are the data adjusted to account for UHI? Large towns can 1 to 3 C warmer than surrounding rural area.
So, can anyone falsify Moshers claims by doing what he suggests, and coming up with a different answer?
Nick Stokes: GHCN V3 unadjusted data.
Methinks I should have said a bit more about my thoughts at 1:09 PM. It is clear that way back in 1892 the Weather Bureau was concerned with UHI and how to deal with it in area records. The report clearly states that corrections have been made and that the result is that the urban temperatures are substantially the same as in the nearby rural areas. It is not clear whether ‘corrections’ means physical location of the instruments, but it could just as well mean ‘adjustments’ to the readings, done on an ad hoc basis by persons unknown. It is not beyond imagination that current ‘corrections’ are being inflicted on numbers that were already ‘corrected.’