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Saturday, January 23, 2016

Desperate Deniers Part 3: Rud Istvan mixes up GISTemp data versions

Sou | 1:11 AM Go to the first of 4 comments. Add a comment
This is Part 3 of the Desperate Denier series, following the announcement that 2015 smashed the record for the hottest year. A numerically-challenged disinformer called Rud Istvan is blaming the hot planet on Dr Thomas Karl  from NOAA and Dr Gavin Schmidt from NASA (archived here).

Deniers have been swiping at NOAA ever since it updated its data set to include a heap more weather station records over land, and switched to an updated version of sea surface temperatures. Thing is, in Part 1 of this series, I showed how the trend for the NOAA data set is virtually identical to that of three other main datasets. In fact if you look at the trend since 1971, which was the last time there was a change in the trend, NOAA has the second lowest trend.




Rud mixes old and new versions of GISTemp


Rud can't keep track of numbers or data set versions (archived here). He pulls a single year, 2014, from a previous version of GISTemp and tries to compare it with a different year, 2015, from an updated version of GISTemp. That's not something a scientist would do, but then Rud Istvan isn't a scientist, he's a science denier. He wrote about what he called a 0.1C "jump" - but that's because he's comparing the old version of GISTemp with the new. He made a big deal out of the fact that the new version had a higher 2014 temperature than the old version, writing:
The 2014 degrees C GISS anomaly is plainly 0.64C (not given in the PR text).
And further down he wrote how "alarming" it is that GISTemp uses the latest version:
This is alarming anthropogenic global warming. But it isn’t caused by CO2. It is obviously just government ‘scientists’ altering ‘official’ temperature records. A 0.1C jump in what the 2014 GISS anomaly supposedly is, manufactured during 2015. It is notable only because of the media ballyhoo that NOAA and NASA created, which they cannot now erase. 

Everyone should know that if you are comparing two different periods, they need be from the same set of data. You can't compare a number representing one time period from one data set with a number representing a different time period from another data set.

You can compare:
  • one data set with another to see the difference between data sets, and 
  • one period from one data set with the same period from another data set, to see the difference between data sets.
However you can't pluck out a single period from one data set and try to compare it with a different period from another data set and claim you are comparing like with like. You aren't. Yet that's just what Rudd Istvan did. He's either a woefully ignorant denier or a disinformer. (And going by his track record, probably both.)

NASA's GISS has a page that lists all the updates to the temperature analysis. Back in July last year, GISS shifted from the old version 3b of ERSST to the updated version 4. Instead of comparing the 2014 anomaly from the latest version with the anomaly for 2015, Rud compared the anomaly from the old version with the 2015 number from the latest version, making a complete fool of himself in the process.



Comparing GISTemp versions


In case you think the updated version is hugely different from the previous, it isn't. Here are charts comparing data sets. GISTemp as at June 2015 and GISTemp as at January 2016, which is after it started using the latest operational version of ERSST.

Figure 1 | Global mean surface temperature from 1880 to 2014 - GISTemp old version and updated version. Data source: GISS NASA

The long term linear trend is the same for both versions, a long term rise of 0.67 C a decade.

Below is the difference it made to the period from 1970, around the time of the latest trend change:

Figure 2 | Global mean surface temperature from 1970 to 2014 - GISTemp old version and updated version. Data source: GISS NASA

Because there was almost no change to the earlier decades, and in some of the recent decades the updated version is slightly warmer, there is a slight difference to the trend from 1970 as long as you go to three decimal places (or four if you are looking at the trend per year). The latest version has a trend of 0.172 C a decade, and the older version a trend of 0.165 C a decade. Deniers are up in arms. They don't want scientists to update their data sets, or at least only if the result is cooler, not warmer temperatures.


Double standards of deniers - no protest at UAH cooling


The following demonstrates the double standards of Rud Istvan and other deniers. The only improvements permitted in deniersville are improvements that lower the recent temperatures. There have been no protests from climate conspiracy theorists about the changes to the UAH lower troposphere (air temperature) data set, even though the UAH changes made a much bigger difference than the changes to GISTemp. Look at the chart below:

Figure 3 | Global mean atmospheric temperature (lower troposphere) from 1979 to 2015 - UAH old version and updated version. Data source: UAH

Remember, the change to GISTEmp made a difference of 0.007 C a decade, using the trend from 1970. The change to UAH resulted in a difference of 0.024 C a decade, using the trend from 1979 (when the satellite record begins). I calculated the difference for the same period, 1979 to 2014 for GISTemp, and it was even less. A mere 0.002 C a decade, as shown in the chart below. (I couldn't extend GISTemp to the end of 2015 because the new version replaced the previous version.)

Figure 4 | Global mean surface temperature from 1979 to 2014 - GISTemp old version and updated version. Data source: GISS NASA

That's not what happened with UAH. Below is a chart showing the difference the UAH update made for the period from 1979 to 2014 (using the same period for comparison). The difference in trend is much larger, mainly because of the fairly large drop in the most recent years. Pre-update the trend was 0.11 C/decade and post-update it was 0.14 C/decade. A much larger change than for GISTemp:

Figure 5 | Global mean atmospheric temperature (lower troposphere) from 1979 to 2014 - UAH old version and updated version. Data source: UAH


If you're sick of looking at charts, how about a table for comparison. The UAH trend difference between recent versions is an order of magnitude (of reverse sign) greater than that for GISTemp.




From the WUWT comments


Early on in the comments Nick Stokes tried to get some honesty out of Rud, but failed.
January 21, 2016 at 4:29 pm
Werner Brozek gave a much more thorough account of the change here, with actual numbers for the years. And it shows what happened. The ERSST update changed the 1951-1980 anomaly base, and made a shift of about 0.06°C to current temperatures. All recent years shift up; the order of top years remains the same, until you get back to 1998 (fourth in 2014), which drops a few places.

Instead he got Rud, as ristvan, insisting that GISTemp shouldn't have updated the dataset with an improved version. It looks as if Rud didn't understand what Nick said:
January 21, 2016 at 5:05 pm
So, NS, it is OK with you that the ballyhooed 2014 anomaly is raised by 0.1C in the ballyhooed 2015 presser? I think not. And that was the sole subject of this post, which you avoid.

Nicholas Schroeder wants gravity deniers and flat earthers and so forth to be given equal coverage in the media with gravity believers and round-earthers.
January 21, 2016 at 4:35 pm
Has anyone considered using the FTC’s “fairness doctrine” to force the MSM to provide equal coverage to our skeptical point of view?

dbstealey confesses (again) that he's a conspiracy theorist of the utter nutter kind. (He's the chap who thinks that Pope Francis is a KGB sleeper agent).
January 21, 2016 at 6:33 pm (excerpt)
...Pretty much everyone found in the Climategate emails demonstrates that they’re in it for the money, status, political power, travel, etc. Find me comments they’ve made expressing real skepticism of AGW. Yes, there are a few; but very few. They are far outnumbered by the connivers who’ve buried their scientific skepticism under piles of grant loot.

Scottish Sceptic doesn't "believe in" any of the temperature data, going by this comment (since all the data sets tell the same story)
January 21, 2016 at 5:02 pm
NASA temperature “data” has less credibility than some lunatic political party massaging bogus stats to prove some idiotic policy.

Enough is enough. You get the picture. Climate science is a hoax, or so says WUWT.

From the HotWhopper archives

4 comments:

@whut said...

Rud is a world-class know-it-all, rivaling Wonderin'Willis. I think he has three e-books out on "if-only-they-would-listen-to-me" topics.

He does have a point with his arguments supporting fossil fuel depletion as a critical problem, which is based on simple math, but I think he is over-reaching with respect to his understanding of climate science. He's a corporate suit, so likely surrounded by yes-men, but just pronouncing his opinions doesn't work well on the internet.



Harry Twinotter said...

He appears to have got the 2014 figures wrong, anyway. I was suspicious when he included an unrelated chart, and plucked one of the figures out of the air.

I think he was deliberately deceiving his readers.

Tony Banton said...

Admits his error and then says ....

"The post’s conclusion stands uncorrected."

Johnny Vector said...

Oh, Scottish Sceptic doesn't like NASA data, eh?

Wait, what's this? "The best measurement of global temperature come from the satellites" (from an earlier blog post of his).

I guess he doesn't know that it's NASA that built, launched, and operates the satellites.