Hurricanes and global warming

Hurricanes and Global Warming

The 2005 season saw the largest number (27) of named storms (sustained winds over 17 m s -- 1) and the largest number (14) of hurricanes (sustained winds over 33 m s -- 1), and it was the only year with three category 5 storms (maximum sustained winds over 67 m s -- 1) (Anthes, et al., 2006). This has provided a strong incentive for researchers to better understand the relationship between tropical storms, hurricanes, and global warming. The costs of storms such as Katrina are in the hundreds of billion dollars and could potentially become more commonplace since the climate is a state of rapid warming.

Human activities have resulted in the emission of greenhouse gases (GHGs) and well as changing land use patterns. Greenhouse house gases accumulate in the atmosphere and increase the amount of heat trapped by the sun due to the properties of the GHGs. Land use patterns have resulted in a situation in which many heavily wood areas such as forests have been cleared for farm land among other uses. Trees and other vegetation helps soak up much of the carbon that is in the atmosphere and converts carbon dioxide into oxygen which indirectly reduces the greenhouse gas concentration.

The effects on global warming on storms has been somewhat downplayed recently in the media although the relationship is not fully understood. The idea has been presented that global warming does not have any significant relationship with hurricanes and other storm systems. However, this is misleading because there may be important aspects of the potential relationship are overlooked or downplayed. Furthermore, this could make society more vulnerable to hurricane damage and therefore, even though there is still a high level of uncertainty, researchers should take the potential relationship between climate change and storm frequency and intensity seriously.

Global and tropical atmospheric temperatures near the Earth's surface as well as in the atmosphere are increasing which also increases the amount of water vapor (Anthes, et al., 2006). Most researchers believe this is due to anthropogenic warming and the effects of this warming. It is well-known that tropical cyclones form over warm water and it is the heat in the water from which they get their energy. Therefore it is reasonable to believe that warmer waters could increase hurricane intensity and activity. Warmer waters would translate into more energy to fuel the tropical cyclone and make their effects more pronounced. There is also evidence that global warming is contributing to changing circulation patterns.

Sea level rise due to warmer conditions which melts glaciers and sea ice can have a number of implications for the Earth's storm patterns. Many climate models have suggested that with warmer temperatures there would be higher wind speeds in hurricanes. In fact, one study shows a 70% increase since the mid-1970s of an index of hurricane activity related to the total power dissipation, which is proportional to the cube of the maximum wind speed, integrated over the lifetime of the storm (Anthes, et al., 2006). Therefore such a relationship would have significant implications for society on many levels. One such implication would be building codes and ensuring that vulnerable areas are able to withstand stronger storms with higher wind speeds. There are also implications for storm surges because these are likely to grow stronger as well.