We all know that statistics themselves don’t lie, but the people who use statistics may intentionally or unintentionally do so. A Tweet late yesterday by Eric Holthaus (@EricHolthaus) was the most recent example to catch my eye.
With the Atlantic Ocean region bustling with intense hurricanes at this time, it would be easy for some people to draw an incorrect conclusion from Holthaus’ data (Fig. 1) – i.e., that intense hurricane activity is escalating. But that’s not necessarily what is happening.
While Holthaus’ initial post was misleading (and implied that NOAA data supported the trend line), it is important to recognize that the hurdat (hurricane data) values are the “best” historical hurricane data that scientists may have. However, hurdat contains known errors and omissions and is only as good as the observations that were used to generate the data set. Holthaus continued with additional comments and a link to the Geophysical Fluid Dynamics Laboratory (GFDL) suggesting that climate change was either the culprit now or would soon be the culprit – “Additional context: There was likely undercounting pre-1960. We expect more Cat 5’s in the future, if not already.”
First, research conducted by some scientists (e.g., Ryan Maue, Matt Bolton, and myself) indicates that the long-term global hurricane trend is “steady” and that hurricanes are not becoming more intense. Then, one must recognize that there has been a dramatic change in global observing and forecasting systems since the mid 19th century.
In fact, it wasn’t until the latter part of the 1800’s that hurricane warning offices were established and it wasn’t until the mid 20th century before the National Hurricane Center was created. Hurricane hunter aircraft were not employed until the 1940’s and the first weather satellite didn’t arrive on the scene until 1960. Since 1960, satellite observation systems have evolved to be highly powerful, high frequency, and high resolution observing tools (Fig. 2). These satellites can now see entire ocean basins; in earlier years, point ship and island reports were all that meteorologists had available. To say that “There was likely undercounting pre-1960,” would be an understatement.
The bottom line is that the data table and reference links offered by Eric Holthaus are misleading. Such data and associated statistics need to be viewed with a consistent (or at least a clearly stated discussion of the) data and how it was obtained. Apples must be compared to apples!
© 2017 H. Michael Mogil
Originally posted 9/19/17
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