Archive for the ‘policies’ Category

Finding bugs in GISTEMP

As part of our work, it is natural that we find problems with the GISTEMP code.  All code has bugs, and there are few better ways to find them than by analysing the code in detail for re-implementation.

To date, we have found:

  • a bug in STEP0, in reading the last decimal place of  USHCN temperature records, which made a very small difference to the GISTEMP results;
  • a problem in STEP2, whereby the rounding behavior in some Fortran implementations could cause an infinite loop;
  • a collection of problems in STEP5, all basically down to a problem in using sorted indexes with an unsorted array, which didn’t make any difference the the final results.

We have found a number of other problems with the code – this project would not exist if the GISTEMP code were perfect – but these are the only places in which the actual semantics of the code definitely differ from the intentions of the programmer. (more…)

Sceptics are welcome

Our project goals are well-defined:

1. To produce clear climate science software;
2. To encourage the production of clear climate science software;
3. To increase public confidence in climate science results;

The following are not project goals, and will not form part of the project:

1. To pick fights and flame wars with sceptics and/or denialists;
2. To judge or arbitrate in climate science;

I am not a scientist and I didn’t set up the project to make  judgements about climate science.  By doing ClearClimateCode I hope to  help actual climate scientists to do actual climate science, and to help others to trust the results.

My personal beliefs on some aspects of climate science are pretty well-documented (if you make the reasonable and correct guess that I  am the Nick Barnes who sometimes hangs out on blog comment threads): I am certain that anthropogenic global warming is real and a serious global crisis.  And those  beliefs form a strong motivation for me to start and take part in this  project.  But this project is not intended to be a platform for promoting those beliefs.  The blogosphere is full of places to vent  views about these subjects; this is not one.

In particular, the project welcomes sceptics to take part: write code, read code, criticise code.

If you truly doubt the climate science consensus and are (therefore rightly) alarmed at moves for critical public policy to be based on that consensus, then I expect you are keen to discover and publicise the truth about the global temperature record.  Working on the project will allow you to do that.  Please, join the mailing list, download the code, work with us.

(this important post is partly cut-and-paste from a message I sent last year to the project mailing list)