WASHINGTON, DC -- Since I last wrote in this space a month ago ("Bye-Bye Kyoto,'' October 8), there have been several new body blows to the global warming crusade.

First, Europe has confessed that it is struggling to meet its Kyoto emission reduction targets, even with stagnant economies and stable population. While the European Union is supposed to reduce greenhouse gas emissions by eight percent below 1990 levels by the year 2008 to 2012, the European Environment Agency announced last month that recent trends suggest emissions will only fall by 4.7 ercent. The foot dragging has started.

The European Parliament is delaying the first reading of the legislation designed to regulate emissions trading. Spain, Portugal, and Greece are demanding that the level of their contributions to developing nations for greenhouse gas emission reduction be reduced.

Next, the U.S. Senate voted down by 55-43 the attempt of Sen. John McCain and Sen. Joseph Lieberman to drag the U.S. into the Kyoto Protocol through the back door. The McCain-Lieberman "Climate Stewardship Act'' would have imposed CO2 emission limits on wide swaths of the American economy supposedly for the modest cost of $20 per capita. No one bought it, even at this bargain-basement price.

But the biggest developing story of the last month concerns the famous "hockey stick'' graph of world temperatures in the 20th century that has been the linchpin of climate alarmism. Working from an elaborate reconstruction of climate history for the last 1,000 years, climatologist Michael Mann reported in 1998 that world temperatures in the second half of the 20th century were the highest on record. The graph of temperatures showed a discernable uptick in the shape of a horizontal hockey stick.

Mann's graph was prominently displayed by the UN's influential 2001 report on climate change. But now two Canadian statisticians have cast serious doubt about Mann's hockey stick.

Writing in the web journal Energy and Environment (http://www.multi-science.co.uk/ee_openaccess.htm), Stephen McIntyre and Ross McKitrick reviewed Mann's source data and concluded that Mann's calculations are wrong. McIntyre and McKitrick conclude that once data processing errors are corrected, the temperature record shows that the medieval warm period around the 1500s was warmer than the 20th century. This finding coincides with the work of Harvard's Sallie Balliunas and others that shows temperatures were warmer in the Middle Ages than today.

Mann has replied with some bitterness that McIntyre and McKitrick have used an incomplete dataset and are engaged in a "political stunt.'' McIntyre and McKitrick have reproduced the full e-mail exchanges with Mann and his assistants refuting Mann's claims. An ugly, full-scale scientific dispute looks to be commencing. It will turn on arcane knowledge of advanced statistical techniques that will be hard for the layperson to follow. The defensiveness of Mann's replies suggests something is amiss, however.

Either his results can be replicated, in time-honored scientific fashion, or they cannot. Already several observers are drawing a parallel to the scandal over historian Michael Bellesiles work on guns, wherein a formal inquiry found he had falsified and manipulated data in a fraudulent way. Stay tuned: the supposed smoking gun of global warming may have been loaded with blanks.