Or Is Global Warming Just An Easy Scapegoat?

Yesterday I posted a commentary on how Hurricane Katrina should be a wakeup call for global warming. After writing it, I found this column by James Glassman, basically saying all these people screaming about how global warming caused Katrina are full of crap (e.g. RFK Jr., the Germans, French, etc.).

So instead of relying on intuition and speculation, I went to the National Hurricane Center website and found all of the annual US hurricane data from 1851-2004. I put together the charts below that basically prove James is right. It might not be much consolation to the victims in the South, but nothing about recent hurricane activity is abnormal, nor does it exceed what's happened in the past - we are actually in a period of relative calm compared to the time between 1850-1950 (though it looks like we are leaving that period of calm as part of a natural cycle, as meteorologists have been telling us).

The first chart takes the sum of the Saffir-Simpson intensities (the Category 1-5 rating) for every hurricane that hit the US in the given year. For example, if two hurricanes hit the US in 2005, one being a Category 2 and the other being a Category 3, the total intensity for that year will be 5.

The second chart shows simply the number of hurricanes hitting the US each year.

Both charts show that the past 30 to 40 years have been periods of relative calm. While both the number and intensity of hurricanes are now trending upwards, we are still below the average from the 1850-1950 time period.

I do not think we can conclusively say whether this is just part of a natural cycle or if it is being caused by humans; however, I think it shoots a hole in the arguments of those who are claiming we are experiencing some sort of man-made cataclysm.

The caveat - note these data only track hurricanes landfalling in the US, not all of the hurricanes forming in the Atlantic. Some may take issue with that, however, if we are talking in terms of weather patterns that threaten human life and our economy, I think we must consider the total environment taken together, i.e. if changes to our climate are pushing more hurricanes out to sea, then clearly the threat from hurricanes is lessened.