Does Global Warming Affect Hurricanes?
Summarizing the Debate on Warmer Waters and Tropical Storms
Hurricane Katrina hit the US coast in 2005 becoming one of the deadliest and costliest hurricanes in recorded history. She also intensified the global warming debate as scientists pointed towards her gales as evidence of global warming’s destruction. Although scientists tend to agree that there have been an increased number of hurricanes over the years and that those hurricanes seem to be stronger, the reason as to why remains unclear.
More Hurricanes and the Global Warming Debate
Even before Hurricane Katrina hit, scientists had been predicting an increase in strong hurricanes. In July 2001 Hillary Mayell of the National Geographic wrote the article “Major Hurricanes Predicted to Increase in Years Ahead”. She quoted scientists from NOAA as saying hurricanes had been increasing since 1995 and more were expected for the next 30 years. However, where this article cited a natural cycle as the reason for the hurricane increase, in September 2005 Mark Henderson of The Times Online wrote “Global warming linked to increase in hurricanes”. Henderson noted that Katrina-strength hurricanes had become twice as common over the past thirty-five years.
How Hurricanes Form Over the Ocean
Scientists are still studying the exact mechanisms by which hurricanes form however they do know that warm moist air is essential. As NASA explains in its clearly titled webpage “How Do Hurricanes Form?”, these tropical cyclones typically form over the ocean near the equator. As air over the ocean warms from the sun’s energy, the air rises creating an area of low pressure below. Wind swirls in to fill the low-pressure area also becoming warm and moist. As the warm air rises it cools to form large clouds. These clouds continue to grow and swirl in the wind to become a hurricane.
Global Warming Affects Hurricanes
Mark Henderson connects the increase in hurricanes to global warming by noting that hurricanes need warm air to form and that ocean surface temperatures have increased by 0.9 degrees Fahrenheit (0.5 C) over the past 35 years. Bryan Walsh echoes a similar connection in his September 2008 Time Magazine article “Is Global Warming Worsening Hurricanes?”. He cites Kerry Emanuel, an MIT meteorologist, as saying that a hotter ocean will lead to greater evaporation and more intense hurricanes. Emanuel’s colleagues believe that a sea surface temperature increase of 1 degree Celsius should increase the number of Katrina-size storms by 31%.
Global Warming Does Not Affect Hurricanes
Scientists are not unanimous on connecting hurricanes to global warming. NOAA scientists Gabriel Vecchi and Thomas Knutson say that the observed increase in hurricanes is not due to more hurricanes but rather better monitoring in “How well do we know the historical cyclone record?” at the Geophysical Fluid Dynamics Laboratory site. BBC News’ Mark Kinver goes on to cite Thomas Knutson in his May 2008 article “’Fewer hurricanes’ as world warms”. Knutson’s weather models actually show that there could be fewer hurricanes in the future. Meanwhile, in the August 2009 New York Daily News article “Research to rock you like a hurricane” Eitan Gavish reports that the increase in hurricanes is similar to an increase 1,000 years ago. Scientists involved in that study believe a natural cycle and global warming could both be involved.
BNC101
Global Warming May Increase Hurricane Destruction
|
What do you think about this article?
Comments
More in Science & Nature
Latest Articles