So when I happened to read a widely published Associated Press article in May about a scientist from the Geophysical Fluid Dynamics Laboratory of the National Oceanic and Atmospheric Administration who had changed his view on the link between global warming and hurricane frequency, it seemed like something worth exploring further.

As reported in Ara Trembly's lead article for this edition of E&S/Specialty Lines Extra, the new NOAA view argues against the notion that any recent tropical cyclone can be traced to global warming.

Further, and perhaps of more interest to participants in the property-casualty insurance market, the view suggests--based on computer simulations through the end of the century--that warming might actually decrease hurricane frequencies globally over the long term.

Personally, one element of the AP story that had actually piqued my interest was the identity of the researcher, Tom Knutson of Geophysical Fluid Dynamics Laboratory of the National Oceanic and Atmospheric Administration, and another scientist, Kerry Emanuel of the Massachusetts Institute of Technology, who argued against his new view. Both had participated on a panel of experts convened by one of the cat modeling firms--RMS--in 2006 to help the Newark, Calif.-based firm develop a new five-year view of hurricane activity.

RMS, of course, was not alone. In the wake of criticisms that cat models had underestimated hurricane activity in 2004 and 2005, the modeling firms put out these shorter-term views to replace 100-year models and reflect a higher observed frequency of hurricanes in recent years.

"The increased frequency and severity of hurricane activity in the Atlantic Ocean Basin, as observed since 1995, are driven by higher sea surface temperatures in the tropical North Atlantic and by associated changes in atmospheric circulation," RMS wrote in a typical statement, suggesting a high degree of certainty about cause of observed activity.

Given the new level of uncertainty in the scientific community, it seems reasonable to ask about possible insurance implications of the current thinking. Should cat models now change to reflect a new view of the world? Will insurance prices go down?

As reported in Ara's article, representatives of modeling firms are now voicing just as much as uncertainty as GFDL scientists about the link between global warming and hurricane activity--and about the likely long-term frequency of hurricanes.

Peter Dailey, director of Atmospheric Science at AIR Worldwide in Boston, told Ara: "There is now a near consensus that global air temperatures are increasing, [but] no consensus on how this has affected the temperature of the world's oceans"--the Atlantic, in particular.

Christine Ziehmann of RMS added: "It is not clear what effect global warming is having, and will have, on the frequency, intensity and geographical distribution of hurricanes in the Atlantic basin."

Computer models suggest that global warming should, in the long term, lead to less frequent tropical cyclones globally, but they're "less clear about hurricane activity in individual ocean basins," she said, noting that some indicate increased long-term frequencies and some decreased long-term frequencies of Atlantic storms.

I haven't juxtaposed the 2006 statements with current comments to highlight discrepancies between them. In fact, as Ara pointed out when I pressed him to investigate insurance implications of what seems like a changed view of hurricane frequency, a careful reader may conclude that nothing has changed to alter model assumptions.

After all, the latest statements about potentially lower frequencies refer to global long-term trends--over multiple decades--not five years in the Atlantic Basin, he noted. In addition, RMS's 2006 press release disclosed that the experts convened by the firm held "different climatological perspectives on the underlying causes of elevated hurricane activity."

But more casual readers are bound to ask questions. Without old press releases at their fingertips to compare exact phrases word for word, what most of us recall is that modelers told us warming was producing more hurricanes--which hiked their model results, and property rates went up along with them.

Despite the fact that hurricane levels were at record-high levels, with no major storm making landfall, critics focusing on consumer issues rather than insurer strength and solvency are likely to start putting modeling firms and insurers on the hot seat again--this time not asking why models are underestimating losses, but why they are overestimating them.

Such questions are already being raised. The July 1 edition of The Wall Street Journal, for example, ran a page one article, "Insurers Criticized For New Rate Models."

I asked Ara to give RMS a chance to address potential questions--focusing first on the question of whether the firm's view has changed since 2006, when an official said its expert panel "agreed unanimously that a forward-looking view of risk should reflect a higher probability of landfalling hurricanes than represented by long-term historical averages."

RMS responded: "The views of RMS remain based on the most up-to-date scientific evidence and reflect the current range of expert opinion within the hurricane research community.

"It is clear there has been an increase in the annual frequency of hurricanes in the Atlantic basin since 1995, and that estimates of hurricane numbers over the next five years based on a simple average of frequency since 1900 are likely to be too low. Similarly, the proportion of strong hurricanes has increased since the 1970s such that a simple average since 1900 will also tend to underestimate the proportion of Category 3-to-5 hurricanes over the next five years.

"There is currently no consensus among researchers about whether these changes in frequency and intensity are caused by global warming or natural cycles in climate.

"Computer models of the effect of global warming on tropical cyclones project many decades into the future and so do not directly apply to hurricane activity in the recent past or near future."

Another relevant question to ask may be how short-term models can even hope to be reliable when there's now little consensus over the longer term?

Related questions about the appropriate uses of short-term models have been asked before--by Karen Clark, founder of AIR, and now president and chief executive officer of Karen Clark & Company.

Even back in the days when she was president and CEO of AIR, she told NU that she worried about wild swings in insurance premiums that would occur if insurers relied on short-term models for pricing purposes, suggesting that short-term views be used only for short-term decisions, like how much reinsurance to purchase next year. (See related article, NU, March 13, 2006.)

Going forward, only one thing seems certain--the models will never give a perfect view of storm activity, leaving modelers to blame users, and users to blame models for inaccuracies in rates and shortfalls in capital that emerge as a result.