GARBAGE IN, GARBAGE OUT

A first look at the climate model computer codes:

As the leaked messages, and especially the HARRY_READ_ME.txt file, found their way around technical circles, two things happened: first, programmers unaffiliated with East Anglia started taking a close look at the quality of the CRU’s code, and second, they began to feel sympathetic for anyone who had to spend three years (including working weekends) trying to make sense of code that appeared to be undocumented and buggy, while representing the core of CRU’s climate model.

One programmer highlighted the error of relying on computer code that, if it generates an error message, continues as if nothing untoward ever occurred. Another debugged the code by pointing out why the output of a calculation that should always generate a positive number was incorrectly generating a negative one. A third concluded: “I feel for this guy. He’s obviously spent years trying to get data from undocumented and completely messy sources.”

Programmer-written comments inserted into CRU’s Fortran code have drawn fire as well. The file briffa_sep98_d.pro says: “Apply a VERY ARTIFICAL correction for decline!!” and “APPLY ARTIFICIAL CORRECTION.” Another, quantify_tsdcal.pro, says: “Low pass filtering at century and longer time scales never gets rid of the trend – so eventually I start to scale down the 120-yr low pass time series to mimic the effect of removing/adding longer time scales!”

It’s not clear how the files were leaked. One theory says that a malicious hacker slipped into East Anglia’s network and snatched thousands of documents. Another says that the files had already been assembled in response to a Freedom of Information request and, immediately after it was denied, a whistleblower decided to disclose them. (Lending credence to that theory is the fact that no personal e-mail messages unrelated to climate change appear to have been leaked.)

Maybe the codes are not as sophisticated as we have been led to believe.