Photo courtesy GISuser.com and licensed by Creative Commons.

Taking a cue from recent research into tornadoes and global warming, I set out on a journey over the weekend to discover if a link exists between total hurricane strike count and global warming as well as hurricane strike intensity and global warming.  I’ve graphed the results of my study below.

Before getting into the results, however, I must point out a few things.  First, the hurricane data used for this study is from the National Weather Service’s site here and the temperature variance data is from NASA’s GISS website, which is the responsibility of Dr. James Hansen.  The temperature variance data is global while the hurricane data is U.S.-based, but seeing as how the United States takes up a major chunk of the northwestern part of the globe, I feel this study is valid, especially since it covers well over 100 years.

The first graph depicts total hurricanes strikes by decade when compared to global temperature, going back to the 1881-1890 decade.  As you can see, global temperatures have shown a relatively smooth increase since the beginning chart period on this graph with a little larger jump beginning in the 1971-1980 time period.  During this same reporting period, however, you can clearly see a downward-trending total hurricane strike plot line, with some wild variations at times.  A few items to note:  The 1921-1930 decade showed an increase in temperatures, but a severe dip in the number of overall hurricane strikes but the following decades showed levelling-off of temperatures and a spike in total hurricane strikes.  So do hurricane strikes follow temperature?  The two decades beginning in 1971 show both an increase in temperature as well as an increase in hurricane strikes but, if you look further down the timeline, you’ll see that in the first half of this decade, temperatures moved significantly higher while hurricane strikes dropped precipitously.  Conclusion?  There is no real link between total hurricane strikes and global temperatures.

Now I know some of you followers of Gore out there remember him saying that storm intensity will increase due to global warming and Katrina was the poster child for such an event (which was a Category 3 at the time of land fall, by the way - hardly the most powerful storm to strike the U.S.).  I did some research on intense hurricanes as well and found similar results.

This graph is even worse if you’re a global warming believer.  The hurricane strikes plotted on this graph are only Category 3, 4 and 5 but the global temperature variance data is the same.  The same statistics are true as shown in the total hurricane strikes vs. average global mean temperatures graph except even more conclusive.  The 1921-1930 decade still clearly shows an increase in temperatures but a drop in hurricane strikes, while the 1941-1950 period shows both an increase in temperatures in addition to an increase in intense hurricane strikes.  But look at the graph from about 1990 onward.  Global temperatures show a significant increase in variance while intense hurricane strikes stayed the same or decreased, even to the point of becoming an inverse correlation when compared to temperature in the first half of this decade.  Conclusion?  There’s no direct link between increases in global temperature and increases in intense hurricane strikes.