| Global Warming is a term denoting a gradual warming | | | | over cooler water and have weakened over warmer |
| of the Earths average temperature. The term has | | | | water. There may be a small "boost" to a hurricanes |
| become synonymous to the Earths warming | | | | strength as it moves over the Gulf Stream, if upper air |
| exclusively due to man-made effects, especially | | | | wind profiles do not change much. Some of the |
| carbon dioxide. Carbon dioxide concentrations have | | | | computer generated hurricane models have this bias |
| increased from 300 parts per million to 384 parts per | | | | built in and will rapidly strengthen a tropical cyclone if |
| million since 1900, with the most accelerated increase | | | | predicted to go over a warm pool of water. |
| during the past 40 years. Some scientists have drawn | | | | The recent upturn in tropical cyclone activity was |
| the conclusion that the increase in the Earths average | | | | predicted long before Global Warming became a |
| temperature (about 1°F since 1975) is essentially | | | | household name. The tropical |
| solely based on man-made activities such as the | | | | Atlantic has been known to vary in cycles, and this |
| burning of fossil fuels, biomass burning, and | | | | recent upturn was expected. If you were to compare |
| deforestation. | | | | the period from 1900 to about 1950, with the 1950s until |
| Causes of Global Warming | | | | now, you would find an actual decrease in the |
| The Earths atmosphere is made up of different gases. | | | | average number of hurricanes and their intensity. It also |
| Nitrogen makes up 78% of the total composition, | | | | is noted that the upswing in hurricane numbers over |
| Oxygen 21%, Argon 1% and traces gases .1%. Carbon | | | | the past ten years or more has been only in the North |
| dioxide makes up most of the volume of the rare | | | | Atlantic basin. Other hurricane formation regions have |
| gases. Water vapor varies from almost 0% over the | | | | not shown this same trend. |
| deserts to 4% over the oceans. Water vapor, carbon | | | | The Effects of Global Warming on Hurricanes: |
| dioxide, methane, ozone, and nitrous oxide are the | | | | Summary |
| gases of interest since these are the greenhouse | | | | There has been a noted increase in the number of |
| gases. Greenhouse gases can reradiate heat or trap | | | | hurricanes in the Atlantic Ocean, Caribbean Sea, and |
| heat absorbed by the Earth from the sun. Water | | | | Gulf of Mexico since the mid-1990s. The long term |
| vapor is by far the largest mechanism for heat | | | | average is that ten tropical storms will form per year,of |
| retention out of the greenhouse gases. | | | | which about six will become hurricanes. Since the |
| In the past, the Earths orbital eccentricity, variance of | | | | mid-1990s the average has been fifteen tropical |
| the tilt and wobble have led to periods of warmer | | | | storms, of which eight have become hurricanes. There |
| weather. Even though the solar energy from the sun is | | | | has also been an upward trend in the concentration of |
| considered a constant, a slight change could cause | | | | the greenhouse gas carbon dioxidedue to mans |
| temperature fluctuations. Recently, Mars has also | | | | activities over the past 100 years. During this time, |
| shown a decrease in ice coverage without | | | | hurricanes have gone through cycles where they have |
| greenhouse gas changes. The cause for the reduction | | | | been more numerous, such as the cycle that we are in |
| in aerial coverage is unknown. | | | | now. Some scientists have drawn a one to one |
| In summary, there are three mechanisms which would | | | | correlation between the Earths temperature increase |
| cause global warming, or in other words allow for a | | | | and the number of hurricanes and their intensity. As |
| warming of the Earths average temperature. These | | | | we have noted, the number one factor in tropical |
| are: (1) solar energy variance, (2) gradual changes in | | | | cyclone intensity is related to the atmospheric wind |
| the Earths orbit, tilt, and wobble, and (3) greenhouse | | | | shear profile. There is even some research that |
| gas changes. It is difficult to calculate what percentage | | | | suggests that higher temperatures couldactually |
| of the recent warming could be attributed to human | | | | increase the wind shear profile resulting in a decrease |
| activities. We can eliminate changes in the Earths orbit, | | | | in hurricane activity. The upward cycle in hurricane |
| tilt, and wobble causing a temperature increase since | | | | numbers is expected to continue for several more |
| these are long term effects. | | | | years. If this trend were to continue for a considerably |
| What are the Effects of Global Warming on | | | | longer period, only then could one draw a conclusion |
| Hurricanes? | | | | that warmer temperatures have played some part to |
| There is a common misconception that since the global | | | | cause an increase in tropical cyclone formation. |
| temperature has increased, hurricanes also must | | | | Rich Johnson - Expert Hurricane Forecasts | Travel |
| increase in number and intensity. The primary factor in | | | | Resources |
| the ability of a hurricane to strengthen or weaken is | | | | Rich is a Certified Broadcast Meteorologist with 25 |
| the wind shear profile of the atmosphere - not water | | | | years of weather forecasting and television |
| temperature. It always has been warm enough in the | | | | experience. His expertise is in tropical meteorology |
| tropics to produce hurricanes. This temperature | | | | forecasting hurricanes. His website |
| equates to a sea surface temperature of about | | | | TropicalWeather.net is dedicated to helping travelers |
| 80°F. If you study the behavior of hurricanes you | | | | cope with tropical weather. |
| can find cases where hurricanes have strengthened | | | | |