On Friday, the United Nations’ Intergovernmental Panel on Climate Change (IPCC) is going to release its much-anticipated fifth “scientific assessment” of global warming. Like its 2007 predecessor, the document will be a ready poison pill for those contemplating political suicide.

Each iteration of this document becomes the reigning go-to document for climate pests, including legislatures and governments. For example, the fourth version was cited repeatedly by the U.S. House of Representatives as the putative factual basis for its 2009 cap-and-trade legislation, which passed that body on June 26 of that year.

Three days later, Rasmussen’s generic congressional ballot switched from Democrat to Republican, and it remained there continuously through the Democrats’ electoral debacle of 2010, when they lost 65 seats and their majority. Virtually every close race was lost by a Democrat who had voted for the legislation.

Meanwhile, U.S. Senate staffers noticed the polls and wisely counseled their bosses to make sincere noises but no law. In the fall, every close Senate race was won by a Democrat.

The carnage in Australia has been even more serious. In 2009, when the Labor party ran the country, Australia’s Liberal (i.e., conservative) party leader, Malcolm Turnbull, was thrown out on his ear because of his support for cap-and-trade, and he was replaced by Tony Abbott, who is now Oz’s new prime minister. Turnbull was fond of quoting the IPCC’s authoritative “consensus” on climate change.

Two years ago, Labor prime minister Kevin Rudd was deposed for implementing his cap-and-trade program (pretty much the same one that cost Turnbull his Liberal leadership) and replaced by Labor’s Julia Gillard, who vowed to scrap his program and also to never impose the alternative, a tax on carbon-containing fuels.

When I asked Mr. Rudd, after running into him in the men’s room at Washington’s tony Café Milano, why he did what he did, he got all huffy, saying for all to hear: “My scientists told me, I say, my scientists told me that this is a terribly important problem.”

Those “scientists” would include the Aussies on the IPCC, where their membership is as disproportionate to the country’s population as is its quadrennial haul of Olympic medals.

Unfortunately, after the 2010 parliamentary election, the Green party held the balance of power in a divided senate, and it agreed to support Gillard only if she went back on her promise to steer clear of a carbon tax. She did, and is no longer prime minister. In June of this year she was removed as party leader, and earlier this month, in an election that was largely a referendum on global-warming hysteria, Labor was completely thrashed in the lower house, while also handing the Liberals a working coalition in the senate.

All these losers have the IPCC to thank, and any politician foolish enough to rely on their new report is likely to join their ranks.

The IPCC is really in a pickle. Not only can it be blamed for the lack of any effective (unnecessary) national climate policy, but it is about to produce a report that is going to be obsolete the minute it is published.

Over the years, the IPCC has behaved like a treed cat. Instead of closing its eyes and scurrying to the ground, it climbs onto even higher and thinner branches, while yowling ever louder. How does it back down from a quarter-century of predicting a quarter of a degree (Celsius) of warming every decade, when there’s been none for 17 years now?

In fact, as I demonstrated in a recent presentation to the American Geophysical Union, the reigning suite of climate models has now officially failed, with the difference between them and reality now statistically significant at the 1‑in-20 level.

Since the beginning of 2011, at least 16 separate experiments published by nearly 50 researchers show that the “sensitivity” of temperature to carbon dioxide that is characteristic of the IPCC’s climate models is simply too high. “Sensitivity” is the amount of temperature change expected for a nominal doubling of atmospheric carbon dioxide.

The new IPCC assessment calls sensitivity “the single most important measure of climate response” because changes in global mean surface temperature are what drive other changes, like sea-level rise. If you blow the sensitivity, you also blow every forecast of what is supposed to happen because of climate change.

Historians tell us scientists are reluctant to abandon their overarching worldviews. The New York Times’ Andrew Revkin wrote in February that there is even greater than normal reluctance to admit to a lower sensitivity “because the recent work is trending towards the published low sensitivity findings from a decade ago from climate scientists best known for their relationships with libertarian groups.” Call me nameless.

So the IPCC has three options:

  • 1. Vote at week’s end to “not accept” the latest report and start over;
  • 2. Note the recent findings and include a prominent disclaimer directing readers to substantially discount anything they say about the effects of future climate change; or
  • 3. Do nothing and mislead the world. Again.

Bet on Door No. 3, with the corollary that whoever legislates or promulgates climate policies based upon the new report will be putting his political career in very serious jeopardy.