The IPC Vice-Chairman responded to a recently revealed error in a report they produced with the following: "I don't see how one mistake in a 3,000-page report can damage the credibility of the overall report..." Except that this wasn't a small minor error. This was a big climate change prediction. This was a huge result: The Himalyan Glaciers are either going to be here or not in 30 years time. How did no one check and catch this?
Having some experience producing reports involving the results of detailed calculations I do feel some sympathy for members of the IPC. You can review and check a document over and over as many times as you want and still there will be errors. But after reviewing a document a certain number of times (or by a certain number of people) the errors left that people find are not only few but they are minor.
Certainly with a 3000 page report probably involving numerous participants is a recipe for at least a couple errors. I would think that they would have a thorough review process in place to catch errors like this one.
The question is, why did such a huge glaring error go unnoticed? This wasn't a decimal point error on a figure on page 2459. This was a prediction no doubt used by policy makers to justify public policy positions.
I believe it's clear that the IPC has to suck it up and deal with the fact that there is something seriously wrong with their system and subsequently something seriously wrong with the reports they're producing if they can't even predict whether or not it's likely that the Himalayan glaciers will be here in 30 years time.
A mistake like that one is not a small typo. It's a big boo boo that's indicative of the quality of report they have produced.