Hurricanes Are Inevitable

We are only just beginning to appreciate the significance of hurricane effects on our biological resources. As we learn more from scientists about the frequency with which hurricanes can occur, the systems they affect, and how they interact with the evolution of our coastal ecosystems, we can better prepare ourselves and our environment for their onslaught.

Hurricanes have long affected the Atlantic and gulf coasts of North America. We can find chronicles of the storms in the New World experiences of Christopher Columbus and throughout the period of colonial settlement. Evidence is also imbedded in the growth rings of trees and in coastal geologic deposits, and it tells us that these storms have struck our coastlines with regularity. (Figure 22)

Figure 22 - Tracks of cyclones in the Gulf of Mexico this century.
NATIONAL BIOLOGICAL SERVICE * SOURCE: AMER. SOCIETY FOR OCEANOGRAPHY, 1982 & NATIONAL WEATHER SERVICE, 1982-1988

For instance, return times-how frequently hurricanes strike an area-along the northern gulf coast can average from five to 20 years, depending on location. Before 1995, the deadly nature of these storms had faded from the public consciousness because, even though Louisiana had been hit by other recent storms, the previous 25 years had been relatively inactive. The inactivity, however, seems to be changing.

Recent studies of hurricane activity and global weather patterns seem to indicate that hurricane activity comes in cycles of roughly 20 years. Meteorologists predicted 1995 to be one of the most active years for tropical storms in the last 50 years, and indeed by mid-October, a near-record 18 tropical storms and hurricanes had been named and tracked. Although these storms missed Louisiana that year, future storms will inevitably come this way. Most climatic computer models suggest a period of increased activity and a tendency toward stronger storms as we approach the new century.

Statistics compiled from storms this century indicate that while the number of deaths per hurricane decreased over time (Table 2), the costs of hurricane damage increased. In 1992, Hurricane Andrew was listed as the costliest natural disaster to occur on U.S. soil; total damage assessment for the storm was about $27.2 billion, but only 60 lives were lost.

How is it that the cost of storms has increased over the years while their deadliness has decreased? One reason is that people are building and living in coastal areas much more so than in the past, and these areas are the ones hit hardest by hurricanes. Over half the nation lives and works in coastal counties, which represent only about 10 percent of the U.S. land mass. At the same time, however, the advent of aerial reconnaissance and satellite imagery has warned people about the approach of such storms, leading to prompt evacuations and a reduction in deaths. But we still have much to learn before we can understand whether human activities in the coastal zone are making these ecosystems more vulnerable to hurricane effects.

< Previous Page | Next Page >