And extremely bad logic! (Extreme Weather).

• Author: Michaels, Patrick J.
• Position: Government officials are incorrectly labelling all extreme weather changes as global warming

This summer's floods in Europe were an unmitigated tragedy, as is the ongoing severe drought plaguing the eastern United States. In 1998, Hurricane Mitch killed roughly 10,000 in Central America. Annually, floods in China force thousands from their homes. And the list goes on.

These disasters all have something in common. In every case, a senior and responsible government official blamed them on global warming; in each case, they were wrong. But in no case have I heard the United Nations counter such misstatements. It is time for this to change, for exaggerations of the threat of climate change only serve to cheapen the environmental ethic.

Alas, much of the current rhetoric can be justified by United Nations documents. In 1995, in its Second Assessment Report on climate change, the Intergovernmental Panel on Climate Change (IPCC), of which I am a member, wrote: "Warmer temperatures will lead to a more vigorous hydrological cycle; this translates into prospects for more severe droughts and/or floods in some places and less severe droughts and/or floods in other places."

This unfortunate statement allows any official to blame any drought, storm or flood on global warming. Critics of global warming extremism, including myself, waxed apoplectic, because this 1995 IPCC statement even allows weather that is more normal than average to be caused by global warming. It was a truly universal and therefore scientifically meaningless statement. This criticism apparently worked, for no similar text appears in the IPCC 2001 Third Assessment Report.

Nevertheless, the statement has had its effect upon a citizenry who is, in general, poorly educated about environmental matters. So it's time to set the record straight:

Tropical cyclones. Several scientists, notably Christopher Landsea of the United States National Oceanic and Atmospheric Administration's Hurricane Research Division, have demonstrated that there is simply no global trend in the frequency of tropical cyclones (hurricanes, typhoons, and tropical storms). Even more interesting is an apparent drop in the annual average wind maximum measured in storms in the Atlantic Basin (see Figure 1). This was published by the IPCC, but a Nexis-Lexis search of news stories reveals that not one United Nations official has ever noted its existence.

Also, the computer models that scientists often rely on for projecting the future climate under an enhanced greenhouse effect simply exhibit no consensus on tropical...