What was done
A long-held prediction of climate alarmists is that the frequency and intensity of extreme weather events will increase as a result of CO2-induced global warming.  We have long contended that this prediction is not supported by real-world data of the past few decades, during which time climate alarmists claim the world experienced unprecedented warming (see the articles we have reviewed under the heading Weather Extremes in our Subject Index).  In the present study, temporal fluctuations in U.S. freezing rain occurrences were examined at 161 first order weather stations over the period 1949/50 to 1998/99, providing insight into whether or not the history of this phenomenon supports the climate-alarmist position or our contrary contention.

What was learned
Out of the 161 stations examined, 9 exhibited a statistically significant increasing trend in the number of winter freezing rain-days, 20 exhibited a statistically significant decreasing trend, while the vast majority (82%) exhibited no significant trend.  In further examining the data, the authors found that the national freezing rain-day frequency "generally decreased through the first 40 years of the record before leveling off at values near the long-term average during the 1990s."  These several results led Changnon and Bigley to conclude that there has been "little change in the frequency of freezing rain days across most of the United States" over the past 50 years.

What it means
Although there have been year-to-year and decadal-scale oscillations in the annual number of freezing rain-days in the United States, recent numbers are about the same as the 50-year average.  Thus, it would appear that there is nothing extreme or unusual about the current level of occurrence of this particular weather phenomenon, which finding represents just one more example of the superiority of our contention that real-world data fail to support climate-alarmist predictions of warming-induced increases in extreme weather events.