Why Hurricanes Are Getting Worse: And Why They Will Get Better

As we study nature, we find all things to be cyclical in some way. The sun and moon, human and animal menstruation, ants, and trees are just sum of the things that change and change back. Among others are natural disasters that can be "timed" by their recurring frequency, whether that frequency is frequent (yearly) or rare (millions of years between events).

The natural disasters in question occur yearly, seasonally, cyclically, and come to us in the form of strong circular storms with winds that destroy and kill. Hurricanes, unlike other disastrous events-earthquakes, volcanoes, and asteroids-hit the continental United States with frightening regularity. In fact, we can safely say every August, September, and October, at least one will sweep up from the African coast, cross the Caribbean, and strike land from Florida to Texas.

Every year, when the mid-Atlantic waters warm, hurricanes come. And now scientists believe they know the secret to this mysterious consistency. The eye of the storm in this case is not Hurricane Dean, the latest monster, but Atlantic Multidecadal Oscillation (AMO for short), a theory raising debate throughout the scientific world.

What is AMO?

Atlantic Multidecadal Oscillation is a long term, durational change in the ocean's surface temperature. Deep below the waves, the water is a constant temperature depending on its depth, but near the surface where the sun shines, water temperature is at the whims of weather, the sun, the seasons, cool and warm water currents from the north or south respectively, and possible global warming factors.

The AMO theory states that, outside of the yearly seasonal changes in temperature from cold (in winter), and warm (in summer), the Atlantic Ocean goes through periods where the warm surface temperatures in the summer are warmer than usual. The ocean may go through ten to twenty or even thirty years of warmer than average temperatures before slipping back into a normal or cooler period. AMO may also be the cause of drought periods in North America and Europe, along with periods of heavy rainfall.

There are two sides to the AMO from a scientific standpoint dealing with global warming. Some believe global warming is causing the high level of strong storms, while others believe AMO is exaggerating the effects of global warming.

Why is this normal cycle outside of global warming?

The normal cycle is evident by the fact that fewer hurricanes struck America in the 1970s and 1980s than the three decades before, stretching to the 1930s and the 1990s and 2000s. If global warming was the culprit, there would be a more consistent stretch of high octane storms. Each year would be worse than the last due to the worsening affects of global warming.

Global warming proponents point to the rise in moderate storms, or more named storms each year than in previous years. AMO does not affect the number of storms in a given year so much as it affects moderate storms becoming Category 5 strength, which means there is much room for global warming to play an important part in creating more named storms. The two events may even work side by side to create a higher number of powerful storms.

Scientific data, especially satellite imaging, is a very recent human achievement. Before Man went into space, we had no idea how many storms formed each year unless they struck densely populated land or at least crossed a ship with a captain who reported the event. We certainly don't have reliable statistics of hurricanes from two or three hundred years ago. Who knows what kind of storms hit the American Indians before Columbus came to the New World?

Being awash in cat five storms isn't our future. If the AMO proponents are correct, and looking at the strong hurricane seasons of 2004 and 2005, and the very weak 2006 season, we may have already hit the peak and may be in the beginning stage of a ten or fifteen year (if not a twenty or thirty year) cycle of lower ocean temperature, and consequently lower impact storms.

The warm periods seem to end in very dramatic fashion. The Galveston hurricane in 1900, killing thousands of unaware citizens, tipped off a cool period from 1900 until 1925. Hurricane Camille in 1969 tipped off a cool period from 1970 to 1994. And in the year and a half since Katrina devastated New Orleans, we've had very few hurricanes, or even tropical storms. It's much too early to predict that the ocean temperature will cool soon, but the trend is obvious. It's not a matter of if, but of when.