I woke up this morning to a bunch of Twitter notifications saying I had been mentioned. I looked at them, and I found I had been brought up in a discussion beginning with this tweet:
— Steve Goddard (@SteveSGoddard) December 17, 2014
Because someone thought they remembered me having written about the subject. I haven't. I'm not sure why they thought I had, but as I said in one of my responses:
— Brandon S? (@Corpus_no_Logos) December 17, 2014
Which isn't really true. I find the subject itself, changes made to temperature records, quite interesting. What I find completely boring is the incessant stream of stupid discussions about the subject. As an example, while both the tweet which started the thread, and another tweet by Steven Goddard right after it:
— Steve Goddard (@SteveSGoddard) December 17, 2014
Blame Gavin Schmidt (@ClimateofGavin) for the changes which were made, Schmidt had absolutely nothing to do with it. Schmidt works for NASA's GISS which does produce the temperature series being referred to in those tweets (such as this graph Goddard complains about). However, GISS gets its input data (called GHCN) from another organization, the National Climatic Data Center (NCDC).
If the NCDC changes its GHCN data set, that will change GISS's temperature series even if GISS does nothing new. That's what happened here. The GHCN data series changed, and Steven Goddard blamed Gavin Schmidt because of his involvement with GISS even though GISS had no involvement in the change.
That sort of thing is stupid. It's also incredibly common in these discussions. Steven Goddard, one of the main people starting these discussions, routinely says wrong and deceptive things. I've written about such a couple times, but he does it all the time. For some reason, a lot of people don't seem to mind. They don't even seem to mind the constant stream of abuse and invective he hurls based upon fabricated claims, a point which makes one of today's tweets about me rather amusing:
— Andy Mac (@AndyMeanie) December 17, 2014
Which makes it seem abuse is fine so long as it is directed at the right people. Regardless, I don't see how one could hope to have a meaningful discussion about changes to temperature series in this sort of environment. It's a shame. The topic is interesting. There's far more to it than people like Goddard suggest. For instance, Goddard complains about GISS's changes to the Reykjavik temperature series, showing this graph as the previous version:
He doesn't explain where that graph comes from though. It's worth some discussion. If you go to the GISS page for its previous version, you'll find three different options as to what data set to use. If you search for Reykjavik under the first, "raw GHCN data+USHCN corrections," you'll find four different entries. That's because there are four different series which get combined into a single series.
Under the second data set, "after combining sources at same location," you'll find the graph Goddard uses:
But that's not the official GISS result. GISS applies adjustments to its data. We can see the result for Reykjavik with those adjustments included in the third data set, "after cleaning/homogeneity adjustment" in this graph:
As you can see, the GISS adjustments used to warm the earlier portions of the Reykjavik temperature record. Goddard likes to talk about how adjustments add "artificial" warming trends, but he doesn't tell you the adjustments to this record used to add an "artificial" cooling trend. In fact, he doesn't even show you what the record used to look like after those adjustments were made.
But that was in the past. Perhaps we shouldn't care too much about it. What's going on now at GISS is far more relevant. To see what's going on now, we can look up the Reykjavik location on GISS's current results page. Again, there are three data sets. However, the first one no longer gives a list of four series (because of a change in how the NCDC processes its GHCN data). Because of this, the first two data sets give the same result for the Reykjavik location:
There is clearly a significant change. This change, however, is caused entirely by changes to the GHCN data set/methodology. It exists before GISS applies any adjustments to the data. It's certainly troubling a warming trend was added to this location, but you can't blame it on GISS or Gavin Schmidt when they had nothing to do with it.
That point is emphasized by an examination of how GISS does adjust the Reykjavik location. Previously, GISS introduced a cooling trend to it. Now, this is what happens when GISS adjusts the data:
Once again, GISS warms the earlier portions of the Reykjavik series. In the earlier version, doing so added a cooling trend. In the current version, doing so reduces a warming trend. In both cases, GISS adjusts the data in the opposite direction of global warming.
Steven Goddard would have you believe a specific, named individual (Gavin Schmidt) at GISS fudged with the Reykjavik series to add artificial warming because he didn't like what it showed. The reality is GISS has consistently adjusted the Reykjavik record to reduce global warming.
It would certainly be interesting to examine why the Reykjavik and Alice Springs temperature series have changed. I would love to talk about it. It's just a waste of time if people like Steven Goddard are going to set the level of discussion.