Ten thousand people from 86 countries have descended upon Poznan, Poland, for yet another United Nations meeting on climate change. It’s the annual confab of the nations that signed the original United Nations climate treaty in Rio in 1992. That instrument gave rise to the infamous 1996 Kyoto Protocol on global warming, easily the greatest failure in the history of environmental diplomacy.

Al Gore himself descends on Wednesday to personally bless the conclave’s work product — which, based on past history, we can be assured will range somewhere between flawed, fraudulent, and downright farcical.

Kyoto was supposed to reduce global emissions of carbon dioxide below 1990 levels during the period 2008–2012. But, since it was signed, the atmospheric concentration of this putative pollutant continued to rise, pretty much at the same rate it did before Kyoto. Incidentally, even if the world had lived up to the letter of the Kyoto law, the effect on global temperature would have been too small to measure.

The purpose of the Poznan meeting is to work out some type of framework that goes “beyond Kyoto.” After completely failing in its first attempt to limit carbon dioxide emissions internationally, the U.N. will propose reductions even greater than those Kyoto required. Kyoto failed because it was too expensive. Anything “beyond” it will cost that much more, and is even less likely to succeed.

Besides, the world cannot afford any expensive climate policies now. Economic conditions are so bad that carbon-dioxide emissions — the byproduct of our commerce (not to mention our respiration) — are likely falling because of the financial chill, not the climatic one. Indeed, a permanent economic ice age would likely result from any mandated large cuts in emissions.

And, before proposing an even harsher treaty, the U.N. ought to pay attention to its own climate science. It regularly publishes temperature histories from its Intergovernmental Panel on Climate Change (IPCC), which was formed in the late 1980s with the express charge of finding a scientific basis for a global climate treaty.

Since Kyoto in December 1996, a very funny thing has happened to global temperatures: IPCC data clearly show that warming has stopped, even though its computer models said such a thing could not happen.

According to the IPCC, the world reached its high-temperature mark in 1998, thanks to a big “El Niño,” which is a temporary warming of the tropical Pacific Ocean that occurs once or twice a decade. El Niño years are usually followed by one or two relatively cold years, as occurred in 1999 and 2000. No one knows what really causes these cycles but they have been going on sporadically for millennia.

Wait a minute. Starting an argument about global warming in 1998 is a bit unfair. After all, that’s starting off with a very hot temperature, followed by two relatively cool years.

Fine. Take those years out of the record and there’s still no statistically significant warming between 1997 and 2007. When a scientist tells you that some trend is not “significant,” he or she is saying that it cannot mathematically be distinguished from no trend whatsoever.

More importantly, there’s not going to be any significant trend for some time. Assume, magically, that temperatures begin to warm in 2009 at the rate they were warming before the mid 1990s, and that they continue to warm at that rate. The world has to warm in such a fashion through 2020 before there’s a significant trend reestablished in the data. That’s a full quarter century for any discernable trend of global warming to emerge.

That, however, is not what the U.N.‘s own models show. The IPCC’s latest (2007) compendium on climate used 21 different climate models to forecast the future, and subjected each to different “storylines” (in the U.N.‘s parlance) for global emissions of carbon dioxide. They are there for the world to see, on page 763 of the volume on climate science. Not one of them predicts a quarter century without warming — even under a scenario in which emissions increase more slowly than they already are.

The U.N.‘s own climate models have failed barely a year after they were made public. They have demonstrated a remarkable inability to even “predict” the present. Will 10,000 people in Poznan somehow ignore this?

They shouldn’t. Instead they should be thankful. The lack of recent and future warming almost certainly means that the ultimate warming of this century is going to be quite modest. And they should keep in mind that expensive policies to fight a modest climate change will only worsen the cold snap currently affecting the global economy.