Regular readers here will recognize that the "Greatest Scientific Fraud Of All Time" is the world temperature data tampering fraud, by which the guardians of the world surface thermometer temperature records seek to convince you that dangerous global warming is occurring by making downward "adjustments" to earlier year temperatures and hoping you won't notice.  To read Parts I to XVII of the series, go to this link, where you will find the prior 17 posts arranged in reverse chronological order.

The last post in the series was August 14, 2017.  There's a reason for the hiatus from then until now.  It's because after a big El Niño and high temperatures in 2016, the El Niño dissipated, and temperatures came down somewhat in 2017.  With temperatures failing to hit anything that could be plausibly characterized as records, NASA and NOAA took a break from their monthly breathless press releases proclaiming the current month or quarter or whatever to be the "hottest ever."  However, the year ended on December 31, and at that point they had to say something.  Here's the NOAA Global Climate Report -- Annual 2017.  I would describe it as rather energetically spinning:

The monthly global land and ocean temperatures at the start of 2017 were extremely warm, with the first four months each ranking as the second warmest for their respective months, behind the record year 2016. Of particular note, the global land and ocean temperature for the month of March 2017 was 1.03°C (1.9°F) above the 20th century average—this marked the first time the monthly temperature departure from average surpasses 1.0°C (1.8°F) in the absence of an El Niño episode in the tropical Pacific Ocean. 

And even that energetic spin is rank amateurism compared to what we find at Bloomberg news in a January 18 article titled "Earth’s Relentless Warming Sets a Brutal New Record in 2017."   "Relentless warming" and a "brutal new record"?  Wait a minute, I thought the temperature went down from 2016?  And indeed it did.  Read on, and you will learn that, despite the headline, what they mean by a "brutal new record" is a record "in the absence of El Niño":

2017 [was] the third-hottest on record. The only years to exceed it—2015 and 2016—occurred amid a powerful El Niño weather pattern that ripped heat from the Pacific Ocean into the atmosphere. In the absence of El Niño, the swelter of 2017 was unprecedented.

Do you think, as I do, that when these people tell you something like "there was an absence of an El Niño in 2017," that you would be wise to check?  Here is the NOAA page that records monthly what is called the "MEI":  Multivariate ENSO Index.  "ENSO" is the "El Niño Southern Oscillation."  This is the most comprehensive measure of whether there is or is not an El Niño at a given point in time.  Zero is neutral, and the index varies between about +3 (very strong El Niño) and -3 (very strong La Niña).  The peak of the MEI in the very strong El Niño year of 2016 was +2.227 in January.  In 2017, the MEI started out very slightly negative at -.055 in January through -.08 in March, and then suddenly had a powerful spike to +1.455 in May and +1.049 in June.  Only after September did it turn modestly negative at -.449, reaching -.576 in December.  Sure looks like 2017 was at least a modest El Niño year, although not as strong as 2016; an El Niño, but no record temperatures.  

Now let's look at the latest news on the subject of downward adjustment of early-year temperatures.  Remember that the (highly accurate) satellite temperature records only extend back to 1979.  When NOAA and NASA talk about "hottest year ever" they are referring not to these highly accurate records, but rather to records from a network of surface thermometers, extending back into the 1880s or so.  But those are the records that they have been "adjusting" to make the past cooler, and thus make the recent temperatures appear to be warmer.

Neither NOAA nor NASA has even provided sufficient information to enable outsiders to replicate what they are doing in "adjusting" the earlier temperatures downward.  However, they have from time to time offered purported explanations.  One of those explanations is that at certain stations they have changed the "time of observation," and therefore the earlier temperatures at these stations need to be adjusted so that they are comparable with more recent observations made at a different time of the day.  It sounds plausible on its face -- but can they give us actual examples where the specific adjustment they have made can be justified?

One of the diligent independent investigators who has called NOAA out on many previous occasions is Paul Homewood of the website Not a Lot of People Know That.  Homewood has once again caught NOAA red-handed in a completely unjustifiable temperature adjustment, this time from Ithaca, New York -- home of Cornell University.  What's more, the Ithaca records from 1949 to date specifically state that they are made at 8:00 AM.  Thus, no possibility that the adjustments could be justified by change of time of observation.  

Here is Homewood's January 26 post titled "TOBS [Time of Observation] at Ithaca."   The annual average temperature for the year 1949 was 49.5 deg F.  Here's a screenshot of the raw data captured by Homewood:

The 49.5 deg F for Ithaca for 1949 is way in the lower right.  For 2016, NOAA's annual average temperature for the same Ithaca station read at the same time of day was 48.0 deg F.   This is a link to NOAA's 2016 data.  You'll have to scroll down a way to find Ithaca temperature data.  But anyway, 48.0 deg F is a full 1.5 deg F lower than the 49.5 deg F of 1949.  The temperature has gone down, not up -- at least if you compare the original readings for 1949 to the data currently reported for 2016.

But what about the data for this area that make their way into the surface temperature records that support those "hottest year ever" claims that NOAA and NASA regularly release?  Those data have of course been subject to large "adjustments."  Here is a link to NOAA's "Climate at a Glance" information, with surface temperature data going from the late 1800s to 2017.  They don't break these data down to an individual small town like Ithaca, but you can get the small region in which Ithaca is included, namely "New York State, CD10, Central Lakes," that is, the Finger Lakes region of upstate New York.  And the answer is, for that small region, the 1949 annual average temperature was 48.6 deg F, and for 2016 it was 48.7 deg F.  Instead of going down by 1.5 deg F, the temperature went up by 0.1 deg F!  How could that possibly have happened?

Perhaps you might think, this must just be a quirk of the Ithaca station, and the other stations in the small region must have had temperature increases that outweighed the Ithaca decline when the region average was calculated.  Homewood has the answer for that as well.  His post includes temperature graphs for other main stations in the region -- Auburn, Geneva, and Hemlock -- including "unadjusted" and "adjusted" GHCN data in each case.  All of these stations show massive downward adjustments of the temperatures in the earlier years, generally in the range of about 1 deg C (which would be 1.8 deg F), or even more.  For example, here is the graph for Geneva:

By the way, 1 deg C, or 1.8 deg F, is approximately the entire amount of the claimed warming of the past century that is regularly trotted out to support the narrative that "the earth is warming."  Go through the prior seventeen posts in this series, and you will find dozens of other examples of downward adjustments of earlier year temperatures in approximately the same magnitude.  No one who has looked into this can find any significant examples of adjustments going in the other direction.

There is more on region CD10 at another recent (January 25) post by Homewood, titled "New York’s Temperature Record Massively Altered By NOAA."   This post contains extensive data for all the stations in that region, both unadjusted and adjusted.  Homewood decides to compare January temperatures in two particular years, 1943 and 2014.  Key quote:

On average the mean temperatures in Jan 2014 were 2.7F less than in 1943. Yet, according to NOAA, the difference was only 0.9F.  Somehow, NOAA has adjusted past temperatures down, relatively, by 1.8F.

No one get any kind of satisfactory explanation out of NOAA or NASA as to what is going on.  In Part II of this series back in July 2014, I reported on comparable early-year downward temperature adjustments discovered in the state of Texas by Homewood, in Kansas by Anthony Watts of the Watts Up With That website, and in Maine by Joseph D'Aleo of the ICECAP website.  Those reports led Politifact to put some questions in writing to NOAA.  They received a response, the gist of which was "our algorithm is working as designed" -- without any information as to how or why the specific adjustments were made, nor any access to code or methods to enable the adjustments to be replicated.  

At this point it is becoming an embarrassment to the Trump administration that they have not gotten anyone in place at NOAA or NASA who has started to get to the bottom of this.