The great thing about old magazines is that once published, they can’t be adjusted. Jo Nova has a great summary of some recent work from occasional WUWT contributor Frank Lansner who runs the blog “Hide the Decline” and what he found in an old National Geographic, which bears repeating here. – Anthony
Human emissions of carbon dioxide began a sharp rise from 1945. But, temperatures, it seems, may have plummeted over half the globe during the next few decades. Just how large or how insignificant was that decline?
Frank Lansner has found an historical graph of northern hemisphere temperatures from the mid 70’s, and it shows a serious decline in temperatures from 1940 to 1975. It’s a decline so large that it wipes out the gains made in the first half of the century, and brings temperatures right back to what they were circa 1910. The graph was not peer reviewed, but presumably it was based on the best information available at the time. In any case, if all the global records are not available to check, it’s impossible to know how accurate or not this graph is.
The decline apparently recorded was a whopping 0.5°C.
But, three decades later, by the time Brohan and the CRU graphed temperatures in 2006 from the same old time period, the data had been adjusted (surprise), so that what was a fall of 0.5°C had become just a drop of 0.15°C. Seventy percent of the cooling was gone.
Maybe they had good reasons for making these adjustments. But, as usual, the adjustments were in favor of the Big Scare Campaign, and the reasons and the original data are not easy to find.
Above: Matthews 1976, National Geographic, Temperatures 1880-1976
Now compare the 1935-1975 decline for the same area – the entire Northern hemisphere – presented by CRU/Brohan 2006:
Source: http://www.metoffice.gov.uk/climatechange/science/monitoring/CR_data/Monthly/HadCRUGNS_3plots.gif
And when the old and the new are overlaid…hey where’s the decline?
Above: The blue line is the adjusted CRU average from 2006, overlaid on the 1976 Nat Geo graph.
If temperature sets across the northern hemisphere were really showing that 1940 was as hot as 2000, that makes it hard to argue that the global warming that occurred from 1975 to 2000 was almost solely due to carbon, since it wasn’t unusual (at least not for half the globe), and didn’t correlate at all with our carbon emissions, the vast majority of which occurred after 1945.
The US records show that the 1930’s were as hot as the 1990’s. And the divergence problem in tree rings is well known. Many tree rings showed a decline after 1960 that didn’t “concur” with the surface records. Perhaps these tree rings agree with the surface records as recorded at the time, rather than as adjusted post hoc? Perhaps the decline in the tree rings that Phil Jones worked to hide was not so much a divergence from reality, but instead was slightly more real than the surface-UHI-cherry-picked-and-poorly-sited records?
Esper – Tree ring widths declined from 1940-1975. Records after 1960 are sometimes ignored because they don’t fit the “temperature record”. (All timeseries were normalized over the 1881–1940 period. RCS, regional curve standardization; TRW, tree-ring width.) Thanks to ClimateAudit. (Link below)
Steven McIntyre discusses the Esper data here.
Frank Lansner also discusses the data from Scandinavia, which originally showed that temperatures were roughly level from mid-century to the end of the century, but that the large decline from 1940 to 1975 was…adjusted out of existence. (My post on that here).
Scandinavian Temperatures: 25 data series combined from The Nordklim database (left), compared to the IPCC’s temperature graph for the area.
Frank points out that while the older graph is not peer reviewed, the modern data sets are also not peer reviewed, so even if the papers they are published in are peer reviewed, it’s meaningless to claim this is significant when the underlying data can be adjusted years after its collection without documentation or review.
The CRU has an FAQ on their datasets, and it includes this comment on the accuracy of the hemispheric records:
In the hemispheric files averages are now given to a precision of three decimal places to enable seasonal values to be calculated to ±0.01°C. The extra precision implies no greater accuracy than two decimal places.
Do I read that correctly? After an adjustment that may be in the order of 0.34°C, the accuracy is ±0.01°C?
At the time when there was a Global Ice Age Scare, this graph appeared in Newsweek.
Newsweek: Global Temperatures 1880-1970 (NCAR)
Either 70% of the decline has been hidden in the years since then, or the climate scientists at the time were exaggerating the decline in order to support the Ice Age Scare (surely not!).
Full references available on Frank Lansner’s & Nicolai Skjoldby’s Blog. Stanley is derived from an NAS document. Mathews from National Geographic.
Thanks to Frank for his good work.
Brohan 2006 is linked here, with a pdf.
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OT – Judith Curry interview:
“[Q] Are you saying that the scientific community, through the IPCC, is asking the world to restructure its entire mode of producing and consuming energy and yet hasn’t done a scientific uncertainty analysis?
[A] Yes. ….”
From the April 2010 issue; published online March 10, 2010
http://discovermagazine.com/2010/apr/10-it.s-gettin-hot-in-here-big-battle-over-climate-science/article_view?searchterm=michael%20mann&b_start:int=0
Jiggery Pokey. Zounds!
=============
There is a simple, obvious explanation: the data from the National Geographic article was collected using older, less accurate instruments.
What evidence do you have that this explanation is wrong?
(Note that I am not arguing this explanation is right. I am offering it as a hypothesis and asking you to disprove it.)
It’s anecdotal, but this would jibe with what Russian friends told me. Victims in the Siberian labor camps in the 1930s were buried in the thawed zone on top of the permafrost layer. When attempts were made to exhume them a half-century later the thawed zone was thinner and the bodies were frozen into the permafrost.
[post excerpts and links, not whole articles. ~ ctm]
wolfwalker (20:15:50) :
“There is a simple, obvious explanation: the data from the National Geographic article was collected using older, less accurate instruments.”
Are you serious wolfwalker? So 1976 temperatures measured in 2006 are more accurate than 1976 temperatures measured in 1976, because they now have more accurate instruments. How does that work?
Who would have been at NCAR at the time the Newsweek article had/printed their graph (presumably, with permission)?
Any records exist from that time period?
.
.
wolfwalker (20:15:50 says:
“There is a simple, obvious explanation: the data from the National Geographic article was collected using older, less accurate instruments.”
Are you suggesting that the CRU measurements taken in 1910 were done on modern, accurate instruments?
You don’t suppose we’ve been shined then do you? I am incontrovertibly stunned.
Gold star Frank, thank you.
1976, wasn’t that the peak of the ice age is coming hoax, we will all die unless we cover the polar ice caps with carbon black to stop the ice age from coming was in vogue.
I have been around too long the hoaxes are running together in my head. But they seem to cycle between the ice age is coming, we are all going to die, and the planet is going to melt, we are all going to die. What would have happened if we had melted the ice caps in 1976?
That brings up a really good question, how accurate were thermometers around 1900? Do we even know?
Sorry,
thank you too Jo, I was simply so shocked that I forgot my manners…
or maybe it was all that wool over my eyes.
Speaking of old articles. I’ve often seen mentioned an OMNI Magazine (March 1984) interview with Roger Revelle and his thoughts on AGW. I have an original copy of the magazine and was wondering if anyone at WUWT, or anyone else like a scanned copy of the article?
Just trying to help.
Which lays to rest the idea that scientists are logically rational. Just look at how imaginative and creative scientists can be in adjusting the historical record. What was once a minor cyclical variance has been adjusted to present an alarming nonstop temperature rise.
You too can become a modern Chicken Little.
The wolfwalker appears to be implying that CRU’s adjustments bring the earlier instrumental temperatures in line with more accurate modern ones. I believe however that if he were to do some research he’d find that the modern ones are in fact less accurate.
This is a good post, I would love to see the tree rings over laid on the old graft here,
http://hidethedecline.eu/media/Northern%20hemisphere%20temperatures/NHNatGeo76small.jpg
there is evidence to go after the fraud.
Tx ctm for your work on WUWT.
Tim L
The NEWSWEEK article is available here:
http://www.denisdutton.com/newsweek_coolingworld.pdf
We now know both how they hid the decline and where they hid it…
Tarpon:
I don’t think the 1970’s “ice age” thing was a hoax. It actually makes a lot more sense than the current warming scare if you start looking at more than a few thousand years of climate history.
I think both are in part a result of science too often thinking in too short of a time span and then applying linear trends to the data. We see the same logic applied to the post-1998 trend by some skeptics too.
When one looks at the data for the last 100K years it becomes really obvious that 0.5 C up or down is not an issue. If we look at 1 million years it is even more obvious that not only are modern temperature swings (and even those throughout recorded human history) insignificant, but that we are in for a big drop – soon!
“Realign the incline.”
So when did the time-of-observation bias revisions begin? Is that part of the reason for the difference between the two charts?
The overlay of Matthews (1976) and CRU (2006) is a fascinating figure.
Both Fahrenheit and Celsius were developing reasonably accurate mercury thermometers during the mid seventeen hundreds. I go back far enough that we did dangerous experiments in high school physics lab that would never be allowed today; among them, we made our own mercury in glass thermometers that compared well in accuracy to our certified lab thermometers. If a bunch of dumbass kids could manage, I’m sure the technicians of the eighteenth century could manage.
cheers
Who’s tree rings these are, I think I know,
They’re hidden deep beneath the snow,
A great snow job that plunders much,
Claiming ground it cannot touch,
And when the time has come at last,
To prove their point and hoist the mast,
To fly the flag of “PROOF” – but wait!
Their arrogance has sealed their fate.
Their proof’s been lost, where is it now?
Computers cannot model clouds?
And what’s that scraping sound I hear?
The wheels are off? We cannot steer?
Doesn’t matter – we’ll just flap our arms,
Take to the sky, sound the alarm!
Whats that down there? What was that sound?
Ack! Those skeptics shot me down!
Don’t they know that I know best?
They don’t need to test my tests!
Oof! I’ve landed. Here they come.
There’s no escape. The truth has won…
.
.
©2010 Dave Stephens
Climate heresy – No net global warming since 1940!
Could this ancient heresy be gaining favour?
Say it’s not so, Phil, say it’s not so!
_________________________________
http://icecap.us/index.php/go/joes-blog/is_this_the_beginning_of_global_cooling/
Wednesday, September 17, 2008
Is This The Beginning of Global Cooling
By Allan MacRae
Many scary stories have been written about the dangers of catastrophic global warming, allegedly due to increased atmospheric concentrations of the greenhouse gas carbon dioxide (CO2) from the combustion of fossil fuels. But is the world really catastrophically warming? NO. And is the warming primarily caused by humans? NO.
Since just January 2007, the world has cooled so much that ALL the global warming over the past three decades has disappeared! This is confirmed by a plot of actual global average temperatures from the best available source, weather satellite data that shows there has been NO net global warming since the satellites were first launched in 1979.
See larger image here.
http://icecap.us/images/uploads/uah7908.JPG
Since there was global cooling from ~1940 to ~1979, this means there has been no net warming since ~1940, in spite of an ~800% increase in human emissions of carbon dioxide. This indicates that the recent warming trend was natural, and CO2 is an insignificant driver of global warming.
Quote from the article: “Many tree rings showed a decline after 1960 that didn’t “concur” with the surface records.”
CRU apologists have claimed on at least two sites I’ve monitored that “Hide the decline” (in the infamous CRU leaked e-mail) does not refer to temperature. If true, then exactly what does the “decline” refer to if not temperature? They make the denial, but never explain themselves.
Just goes to show when measuring temperature,
Raw apples should stay with raw apples and raw oranges with raw oranges.
It’s not a punch cocktail, unless someones got some rum and some pineapples.
But seriously both data sets, proxy and thermometer can be looked at side by side and a bigger picture emerges. Proxies in their nature as pointed out by Anthony many times are subject to other influences other than temperature alone.