A Citizen Science Choice: Obfuscate or Illuminate
Welcome Real Climate readers. The bare link to this website in the post Doing it yourselves probably left a little too much unanswered. So let me lay out a short introduction.
One early criticism was the lack of the availability of the actual ‘code.’ Despite the fact that the methods were generally described in publicly accessible publications, the lack of the ability to examine the actual code lent itself to an attack on the ‘transparency’ of the methods. GISS responded with the release of GISTEMP in 2007. But CRU left itself vulnerable to this criticism which eventually led to the vexatious barrage of FOI requests sent against them.
Despite the availability of the GISTEMP code (partly due to an unfamiliar FORTRAN code base and what is frankly poor code documentation), questions and criticisms continued to be raised about the methods used to create the global anomaly charts. This began to turn around in the beginning of 2010 when a variety of technical bloggers began to write their own code to create these charts. While the similarities and differences between each of these approaches and those of the “majors” (GISS/CRU/NOAA/JMA) remains of interest, these independent and individual efforts largely corroborated the results of the institutional products. There was nothing deceptive being hidden in the code. Some of these efforts are listed below. Skeptical Science recently posted a summary: Assessing global surface temperature reconstructions
The “Clear Climate Code” project, which includes Nick Barnes and Dave Jones, refactored the GISTEMP code into python, uncovering some minor bugs, which were then corrected in the official GISTEMP code.
With the ‘methods’ question pretty much answered, there remains questions about the data. The major source of 20th century land temperatures is the Global Historical Climate Network (GHCN). This CLIMAT (pdf) based data set was compiled from multiple data sources in the early 1990s and refreshed in 1997 as “Version 2” from over 30 different sources, but was then put on ‘automatic’ with updates occurring as various National Weather Services (NWS) reported current records via a Global Telecommunication Network (GTN). This method of updating current records has led to a decrease in the number of overall stations in GHCN with current records. The overall drop in stations has led to related claims that changes in the frequency of high latitude, high altitude, rural stations, and stations based at airports have biased the data set.
While various players spar over possible impacts of the declining number and change in distribution of the current GHCN stations, an alternate approach was suggested by Dr. Schmidt in Nov 2009 to develop a SYNOP temperature data set. With the seed of an idea set, I finally found the correct data source and proceeded to download and process the Global Summary of the Day (GSOD) data.
The GSOD data appears to be a summarized version of the Integrated Surface Hourly (ISH) (which is also called the Integrated Surface Database (ISD)). It is very sparse prior to 1950 and thus is not good for century long studies. On the other hand, after 1992, GSOD contains data from well over 10000 surface stations where GHCN drops to less than 2000. Along with Nick Stokes and Zeke Hausfather, we have begun comparing and contrasting the GSOD data with GHCN.
My work with the GSOD is still preliminary and there remain unexamined quality issues. Nevertheless, early results seem to corroborate the results obtained with the GHCN data set. It should be noted that the GSOD data that I and others have been working with is filtered to create a GHCN-style inventory and to pass through GISTEMP quality and homogeneity checks. Here are links to some of my posts with GSOD.
GSOD does not ‘answer’ all the questions. It offers an alternative to those concerned about declining stations numbers or a biased decline in GHCN. Other efforts are needed to address concerns such as station siting, instrumental bias, or UHI. Some of these are more amenable to a citizen science approach than others.
I’m going to take a turn on the soapbox.
Some seem to see science as a method to separate “Truth” from “Falsehood.” But those who believe that have only a passing acquaintance with the history of science. Science, in my view, is a progression of approximations each better than the previous (with frequent forkings and occasional dead-ends). For some, for those who seek to obfuscate, it is enough to point to issues in a particular line of scientific inquiry and declare that approach “false.” For others, for those who seek to illuminate, it is important to quantify the net effect of those issues and to, when possible, provide improved alternatives. Whenever reading a criticism of a scientific approach ask yourself these two questions:
1. Has this critic been able to quantify the effects of the issue they raise?
2. Has this critic suggested a better approach to the problem?
If the answer to these two questions is “No”, then it might be worth taking a moment to wonder why.