A catastrophic heat wave appears to be closing in on the Intergovernmental Panel on Climate Change. How hot is it getting in the scientific kitchen where they've been cooking the books and spicing up the stew pots? So hot, apparently, that Andrew Weaver, probably Canada's leading climate scientist, is calling for replacement of IPCC leadership and institutional reform.

If Andrew Weaver is heading for the exits, it's a pretty sure sign that the United Nations agency is under monumental stress. Mr. Weaver, after all, has been a major IPCC science insider for years. He is Canada Research Chair in Climate Modelling and Analysis at the University of Victoria, mastermind of one of the most sophisticated climate modelling systems on the planet, and lead author on two recent landmark IPCC reports.

For him to say, as he told Canwest News yesterday, that there has been some "dangerous crossing" of the line between climate advocacy and science at the IPCC is stunning in itself.

Not only is Mr. Weaver an IPCC insider. He has also, over the years, generated his own volume of climate advocacy that often seemed to have crossed that dangerous line between hype and science.

It is Mr. Weaver, for example, who said the IPCC's 2007 science report -- the one now subject to some scrutiny -- "isn't a smoking gun; climate is a battalion of intergalactic smoking missiles."

He has also made numerous television appearances linking current weather and temperature events with global warming, painting sensational pictures and dramatic links.

"When you see these [temperature] numbers, it's screaming out at you: 'This is global warming!"

Mr. Weaver is also one of the authors of The Copenhagen Diagnosis, an IPCC-related piece of agit-prop issued just before the recent Copenhagen meeting.

The Copenhagen Diagnosis is as manipulative a piece of policy advocacy as can be found, filled with foreboding and alarming assessments. Described as "an interim evaluation of the evolving science," it was an attempt to jump-start decision-making at Copenhagen. It failed, perhaps in part because one of the authors was U.S. climate scientist Michael Mann, who plays a big role in the Climategate emails.

That Mr. Weaver now thinks it necessary to set himself up as the voice of scientific reason, and as a moderate guardian of appropriate and measured commentary on the state of the world's climate, is firm evidence that the IPCC is in deep trouble. He's getting out while the getting's good, and blaming the IPCC's upper echelon for the looming crisis.

In the language typical of an IPCC report, one might say that the radiative forcing created by Climategate and Glaciergate strongly suggest this is very likely to bring about cataclysmic melting of the organization within the next portion of the current decadal period. The words "very likely" in IPCC risk assessment terms mean a 90% or greater probability that something will happen. As it looks now, the IPCC is burnt toast and unless it is overhauled fast there's a 90% probability the climate-change political machine is going to come crashing down.

Mr. Weaver's acknowledgement that Climategate -- the release/leak/ theft of thousands of incriminating emails from a British climate centre showing deep infighting and number manipulation -- demonstrates a problem is real news in itself. When Climategate broke as a story last November, Mr. Weaver dismissed it as unimportant and appeared in the media with a cockamamie story about how his offices had also been broken into and that the fossil-fuel industry might be responsible for both Climategate and his office break-in.

The latest IPCC fiasco looks even more damaging. In the 2007 IPCC report that Mr. Weaver said revealed climate change to be a barrage of intergalactic ballistic missiles, it turns out one of those missiles -- a predicted melting of the Himalayan ice fields by 2035 -- was a fraud. Not an accidental fraud, but a deliberately planted piece of science fiction. The IPCC author who planted that false Himalayan meltdown said the other day "we" did it because "we thought ... it will impact policy makers and politicians and encourage them to take some concrete action."

Mr. Weaver told Canwest that the Himalayan incident is "one small thing" and not a sign of a "global conspiracy to drum up false evidence of global warming." We shall see. It is a safe bet that there have been other tweaks, twists, manipulations and distortions in IPCC science reports over the years. New revelations are inevitable. Now is a good time to get out of the kitchen. Mr. Weaver is the first out the door.