Hurricanes

Total words: 1097

Hurricanes are the most destructive storms on the Earth. Their waves have wiped out entire communities and forever altered coastal landscapes. Their winds humble even the sturdiest of man's structures; their torrential rains transform gentle streams into raging rivers. By definition, global warming is the increase in the average temperature of the atmosphere, oceans, and landmasses of the planet Earth. Since its existence, the planet has warmed and cooled various times. The question that arises is whether these two are related in any way. Scientists today are trying to find whether there exists a trend between increasing temperatures caused by global warming and the intensity and frequency of hurricanes.

In order to understand the relationship between hurricanes and global warming, we need to understand what hurricanes are, what causes them, and how they are measured. Hurricanes are usually born in the tropics region due to one main reason - warm water is their fuel. They usually begin over the warm tropical waters of the North Atlantic Ocean near the equator and usually appear in the late summer or early fall when see temperatures are at their highest ("Global Warming and Hurricanes"). While tornadoes can create stronger winds, they only last for a few hours. Hurricanes, on the other hand, can last for weeks and as a result cause more damage. Hurricanes measured by Saffir-Simpson Scale which ranges from Category 1 - the lowest intensity hurricane to Category 5 - the highest intensity hurricane (Buckley 136).

Global warming is responsible for warmer temperatures over all. Various sources make evident how much the earth's temperature has increased. It has been observed that the ten warmest years since 1860 have all been since 1980 (Union of Concern Scientist 59). The US National Climate Data Center has reported that, "warmest year in the warmest decade in the warmest century of the last millennium was 1998. The second and third warmest years on the record were 1997 and 1995. There is now little doubt that our planet warmed substantially during the 20^th century - by 0.5 °F (0.25 °C) a decade..." (Pearce 6). NOAA scientists used more than 5.1 million profiles of ocean temperatures since to the 1950s and have found that "the top 1,000 feet of the world's oceans warmed by about 0.5 °F in the last half of the twentieth century" (Sheets 266). Since warm oceans are the source of energy for hurricanes, and since water temperature is one of the factors used to determine how intense a hurricane might be, it would suggest that warmer temperatures would lead to more intense hurricanes. Now that there is an idea of what global warming is and what its consequences are, the most important question can be answered - where there is a relationship between hurricanes and global warming.

Yes there is. Recent studies are beginning to show that global warming might be making hurricanes more powerful. As we know that hurricanes get their energy from warm tropical seas and due to global warming, these seas are getting warmer resulting in more energy for intensifying hurricanes. During the past year, there were two studies published suggesting that the intensity of hurricanes is increasing more than we might know. The first study was done by Kerry Emanuel of MIT. In 1987, Emanuel theorized that if the tropical sea surface temperature increase by 1°C, the maximum wind speed of hurricanes would also increase by 7%. Since then, studies have shown that to be true. The result of his study shows that the "energy released by the average hurricane had increased by 50-80% over the past 30 years. Wind speeds had increased by 15% and the storms were lasting longer, as intense ones trend to do" (Year in Science).

Another point to consider is whether the intensity of hurricanes is increasing with time.

Evidence shows that hurricane activity world wide has increased maximum wind speed and in duration. The energy released by an average hurricane has also increased by about 70% in the past 30 years. Correspondingly, there has been a 15% increase in the maximum wind speed and a 60% increase in a storm lifetime (Emanuel).

Now that it has been proved that there is a link between higher ocean temperatures and hurricanes, there are questions whether hurricanes will increase in frequency or intensity in a warmer world, with higher wind speeds and greater precipitation. "Scientists do believe that global warming will result in more intense hurricanes, as increasing sea surface temperature provide energy for storm intensification". The number of storms that occur in 2004 was the third highest number in the 1950-2004 time periods. The 2005 season was expected to be more active than 2004 and may become have been the most active season on the record ("Global Warming and Hurricanes").

The article, "A Climate in Conundrum" confirms the fact that the hurricanes of 2005 were a result of global warming. It is believe that the ocean played an important role in the "rapid and sustained intensification" of many of the storms in 2005. Oceanographers suggested that the waters in the Gulf of Mexico were unusually warm resulting in plenty of stored energy that would encourage the formation of intensified storms (Halverson 23).

From the statistics presented, it can be seen that global warming doesn't directly cause hurricanes, but it does contribute to the increase in their intensity and frequency. This can be compared to the analogy of cigarettes and occurrence of lung cancer. As the article Year in Science mentions about smoking not a major cause of lung cancer but does increase the frequency of lung cancer. Similarly, global warming can't be pointed as the sole reason for hurricanes. But it does increase the chances of hurricanes. This means that global warming as a cause of more hurricanes cannot be ignored. In order to develop a better picture of a situation, more in depth studies need to be done in order to figure out how much of an effect global warming really does on hurricanes.

Works Cited

Buckley, Bruce, Edward J. Hopkins, and Richard Whitaker. Weather: A Visual Guide. Buffalo: Firefly Books Ltd., 2004.

Sheets, Dr. Bob, and Jack Williams. Hurricane Watch. New York: Vintage Books, 2001.

"Hurricanes and Global Warming". The Pew Center on Global Climate Change. 25^th March, 2006. <http://www.pewclimate.org/hurricanes.cacfm>.

Union of Concerned Scientists. "The Theory of Global Warming Is Scientifically Credible". Ed. James Haley. Opposing Viewpoints: Global Warming. California, 2002.

Pearce, Frank. Global Warming: A Beginner's Guide to Our Changing Climate. New York: DK Publishing Inc., 2002.

"Year in Science". Dicover Magazine. Jan 2006. 4^th March, 2006

<http://www.discover.com/issues/jan-06/cover/>.

Halverson, Jeffrey B. "A Climate Conundrum". Weatherwise. Mar/Apr 2006. 19-23