At the bottom it is a marketing problem. See, if you describe global warming as a robust ongoing academic debate, then when you start proposing seriously expensive regulations to take it on, the opposing party will say "Whoa, whoa -- all of these impressive PhDs think it isn't really happening, so how about we wait a while to see how things shake out and save the money?"

So the decision was made that the robust academic debate couldn't be allowed to exist, because that would provide cover to The Bad Guys (TM). Thus there needed to be a Consensus on climate, something which could be referred to as the authoritative Voice of Science. It needed to be international, both because science is international and because a major portion of the intended office of the argument keeps offices in Europe as opposed to America. (Global warming is pretty much a dead letter elsewhere else: Africa is too poor to care, China and India are getting too rich on high-polluting industries to care about the issue except to the extent it allows them to wring concessions out of the First World, etc) Hence, the IPCC.

Now, the IPCC doesn't matter two hills of beans for science. The papers say what they say. But the IPCC, as the official Voice of Science, has quite a bit of sway in corridors of power, such as European governments and your local newspaper's editorial board. The ready made The Science Is Settled narrative worked at what it was supposed to do: marginalized as "deniers" and deviants anyone who questioned The Science, and paved the way for expensive interventions against climate change.

The problem with marketing, though, is that eventually you have to deliver on what you're selling... and delivering on infallibility is pretty hard. Perhaps recognizing this, some scientists (like the illustrious Phil Jones, climatology heavyweight and editor of a section in the last IPCC report) have gone to some lengths to avoid being seen as losing on issues of fairly minor import.

And, as so often happens, it turns out the coverup did more damage than the original lapse. I mean, paleoclimatology: hard to understand. Statistics behind hockey sticks: hard to understand. Impropriety of deleting data to avoid other scientists from seeing it: not too hard to understand.

OK, this post seems a little out there. Right now you're proposing a massive global academic conspiracy to hide the "truth" of climatology. Do you have a citation for such a large scale cover-up?

Personally, I don't think there is an explicit conspiracy. But I do think there is a bit of group think in climate science due to the fact that many people who choose to study Environmental Science are also environmentalists. It's a conflict of interest when your primary researchers are also passionate green activists. So, when one scientist says to another "here's my research and data, don't let any of those knuckle-dragging skeptics get a hand on it, I'm going to see if we can deny their FOI requests", the other scientist goes along with it. Summed over hundreds of such acts, an us-versus-them true-believer culture can produce the same effects as an explicit conspiracy.

The Implausible Conspiracy has got to be one of the all-time top strawman arguments.

Consider: hot dogs are sold in packs of 12, and hot dog buns are sold in packs of 8. When you run out of hot dog buns you have hot dogs left over and buy more buns. When you run out of hot dogs, you have buns left over so you buy more hot dogs.

Somehow the makers of hot dogs and hot dog buns manage to get this done without decoder rings, secret handshakes, ominous chanting, or ritual sacrifice.

(see also http://xkcd.com/140/)

It is certainly not a strawman argument. The problem with conspiracy theories is that they often fail in a number of ways: Occam's Razor and falsifiability especially. One of the problems with the AGW conspiracy theory is that it supposes that academics all over the world are actively suppressing evidence to the contrary.

The other problem with your hot dog system is that it's not a conspiracy theory. It was quite likely that the actual arrangement happened entirely by accident. Once there, the manufacturers just decided it wasn't in their best interests (profit) to change. To make the same argument about AGW you would have to argue that there is a huge benefit to climatology supporting AGW -- enough to not only convince the academic departments of every major university to go along with it, but also some kind of silencing of the morally grounded climatologists. Instead it seems that disproving the AGW theory would prove quite a nice feather in the cap of any recently hired associate professor at a major university.

I'm not saying that all of this is impossible. What I am saying is that this requires extraordinary evidence for such an extraordinary claim.

You're not making sense.

If the IPCC wrote that elephants can fly, that would not have any impact on the state of climate research or on the state of elephants. It would just mean that the IPCC report was wrong.

Mistakes in the IPCC report only means the conclusions of the IPCC report could be wrong (if they are bad enough). It can never alter the state of the studies that the IPCC references. They can be right or wrong just like any other studies.

And the article posted makes a pretty convincing case that these mistakes were not in any way central to the conclusions of the IPCC.