A question of accuracy - US COOP temperature data

I came across an exchange at WUWT today. It was on yet another WUWT article about global surface temperature. The article itself avoided the obvious big picture and honed in on the detail (archived here). (The obvious being that global surface temperatures are rising very rapidly as CO2 emissions increase.) But that's not what this article is about.

What I'm writing about is in the comments. The exchange was about US temperature data, (which for some people is the same as global temperature data. The USA, believe it or not, comprises only a small proportion of the world's surface.). This topic seems to occupy the hive mind of WUWT to an inordinate and unwarranted degree.

Denier Weirdness: Desperately searching for denialist tidbits at WUWT

Anthony Watts is lashing out at all and sundry. He is desperate to find some remnant from past history that will prove that the world isn't getting hotter (archived here).

Today he's stretching way back to July 1936 in the USA. He's absolutely convinced that July 1936 was the hottest month on record in the contiguous USA. And he may be right. Who knows.

Anthony reckons that back in July 1936 the average temperature for the contiguous USA was 76.8°F. In July 2012 it was only 76.77°F. At least according to the latest NOAA data he found.

Not only that, but he's found proof, PROOF - in black and purple and white - that NOAA adjust past temperatures. Oh, golly gosh. Would you believe they adjust past temperatures downwards. Two years ago it was 77.4°F in July 1936 and now it's only 76.8°F. Not only that but they adjust recent records downwards, too. In July 2012 two years ago it was 77.6°F and now the record shows it as 76.77°F.

If there's one thing that Anthony Watts cannot abide it's change. Especially change to his most treasured possession, the average temperature in the contiguous USA for the month of July 1936. How dare anyone adjust the record. Who cares if there were time of observation corrections to be made. Who cares if someone decided to add some new data unearthed from some old ledger. The record is sacred and must not be touched at penalty of a blog article at WUWT.

Anthony's given up looking for hotter years, now he's down to months. Won't be long before it's weeks, then days, then minutes, then seconds.

Imagine the poor chap fifteen years from now, sweltering in the latest heat wave. He'll be hunched over paper records from the 1930s whimpering, "I know it's here. It's got to be here somewhere. I'm sure that one day in 1936, somewhere in the USA must have been hotter than today." You could almost feel sorry for the man if you didn't know he was such a shady character with a shameful record of unethical behaviour.

This is from the USA records, just in case you thought the USA was getting colder and was heading for an ice age. The average temperature for the entire year (not just one month) in 2012 was higher than any year in the 1930s. It was hotter than the hottest year in the 1930s. I've put a line across for comparison. The hottest year in the 1930s was 1934. But it was hotter again in 1998 and 2006 and much hotter still in 2012.

Data Source: NOAA

But it's not the "hottest" that's so important. It's the overall trend. Look at all those warm years bunched up together to the right of the chart. Keep your eye on that end as time goes by.

There were a few warmer than average years in the first half of the twentieth century in the USA. 1921, 1931 and 1934 stand out as being very warm years by comparison with the rest of the century.  After the 1950s it got colder for a bit, though nearly not as cold as some of the earliest years in the instrumental record. Since the early 1980s it's just kept getting warmer, with only one or two cooler years. The last time there was a year colder than the twentieth century average was almost twenty years ago in 1996. The last couple of decades is almost a solid block of warmer years. Quite different to the twentieth century and earlier.

And while Anthony has his nose buried in the 1930s in the USA, this is what's been happening in the rest of the world.

Data sources: NASA GISTemp, NODC/NOAA Ocean Heat, U Colorado sea level, PIOMAS Arctic Ice

From the WUWT comments

The comments are pretty ordinary. Mostly they are just wailing that raw temperature records are adjusted. It's probably fair to say that most WUWT-ers are conservatives and conservatives don't like change of any kind.

NotAGolfer doesn't know what he's talking about but he's memorised the words of the meme he's meant to parrot and says:

June 29, 2014 at 3:39 pm
Anthony, wake up! It’s intentional. They are trying to make it appear that the warming trend is greater than it is. It’s beyond obvious. Do you still believe Clinton didn’t inhale?

Pamela Gray makes a more sensible comment for a change and says:

June 29, 2014 at 4:50 pm
On the other hand, this is kind of like the TSI/SSN data series. There are, as we have discussed, different reconstructions and observations that differ from one data set to another. The fact that it is being corrected is a matter of scientific correction. Not necessarily evidence of wrong doing.
Could this be a good sign when dealing with a very horrible set of measuring issues?

Lawrie Ayres complains that the keepers of the records are all warmists except for the Russians and Chinese (oh how sentiment has changed since the 1950s):

June 29, 2014 at 5:16 pm
The BoM in Australia has been fiddling the books for ages in order to arrive at “the hottest summer ever” and when an audit was about to take place cancelled that system and started another which was just as fraudulent. We do have a new government with a representative that’s a real scientist. He has been calling for another audit and will probably get it as many Coalition members are skeptics. The whole land based temperature system is in disarray as the keepers of the records all seem to be warmists except for the Russians and Chinese.

Lawrie might be interested in these charts of temperature trends in Russia and China, which aren't immune from warming any more than the rest of the world:

Source: Berkeley Earth

NOAA and temperature data - it must be a conspiracy.

Update: Nick Stokes of Moyhu has written two articles that demonstrate what would happen if Anthony Watts had his way and stations with no data were ignored completely. See here and here. Anthony Watts might change his tune if he read them.

Sou 3:22 pm 1 July 2014 AEST

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This article is about the kerfuffle that erupted between a bunch of science deniers. It all started when Steve Goddard accused NOAA and NASA of "fabricating data" (archived here).  The lie was spread all over the right wing media. Politifact and Climate Crocks among others pointed out he was wrong. Steve didn't explain how the two agencies did this. All he did was put up an animated chart that he claimed showed that the US temperature was warmer in the 1930s than at any time since. He wrote:

Prior to the year 2000, NASA showed US temperatures cooling since the 1930′s, and 1934 much warmer than 1998....Right after the year 2000, NASA and NOAA dramatically altered US climate history, making the past much colder and the present much warmer. The animation below shows how NASA cooled 1934 and warmed 1998, to make 1998 the hottest year in US history instead of 1934. This alteration turned a long term cooling trend since 1930 into a warming trend.

Steve doesn't say what data was "fabricated". Why should he? He's not a fact checker. Quite the opposite. He's in the denial business of making up stuff to stop any action to mitigate global warming.

This article is another one that's too long :( Click read more if you're on the home page.