Hurricane Sandy left in its path some impressive statistics. Its central pressure was the lowest ever recorded for a storm north of North Carolina, breaking a record set by the devastating "Long Island Express" hurricane of 1938. Along the East Coast, Sandy led to more than 50 deaths, left millions without power and caused an estimated $20 billion or more in damage.

But to call Sandy a harbinger of a "new normal," in which unprecedented weather events cause unprecedented destruction,...