Saffir-Simpson Hurricane Scale Warns of Logarithmic Increase in Property Damage from Category 4 and Category 5 Storms
Posted Jan 14 2009 5:05pm
The Saffir-Simpson Hurricane Scale measures local peak gust velocities of wind
in meters per second. A relatively weak, category 1 hurricane has wind gusts of
around 30 meters per second. Major hurricanes, which I refer to as killers,
begin at around 50 meters per second and run off the Saffir-Simpson scale at 100
meters per second.
If ever you have watched live news coverage of a hurricane as it approached land
fall, you may have noticed that meteorologists always raise warnings about
staying out of harm’s way but seem to twitch whenever discussing storms which are category 3 or above. Why is this? As Dr. Amanda Staudt of
the National Wildlife Federation shared with attendees of the Hurricane Science
for Safety Leadership Forum, increases in wind speed between category 3 and 4
equal roughly 10% but the reality of materials science is that such an increase
equals a 50% increase in property damage.
In other words, movement between categories on the Saffir-Simpson Hurricane
Scale is linear but increases in property damage from major storms are
How does this horrible news relate to global warming? Thanks to the brilliant
work of Professor Kerry Emmanuel of the tropical meteorology group at the
Massachusetts Institute of Technology, we know that there is a direct
correlation between sea surface temperatures in the Atlantic basin and the wind
speed of hurricanes. Indeed, Professor Emmanuel has plotted a graph of the power
dissipation index of hurricanes in relation to sea surface temperatures going
back more than 40 years and the linkage is clear.
Pages 5, 6 and 7 of Dr. Staudt’s presentation are the most compelling but I
encourage you to read the whole thing. Dr. Staudt was gracious enough to grant
me access to her file and it is
I have stated very clearly here on Keyboard Culture that global warming
exacerbates the formation and strengthening of hurricanes but admit that a
modicum of dissent within the scientific community exists regarding this
connection. What no longer is open to debate in the hallowed halls of
atmospheric science is the correlation between sea surface temperatures and
general hurricane strength. What we also know for sure is that, measured
globally, the increases in mean temperatures which we are causing through the
reckless burning of fossil fuels carry water temperature right along with them.
The connection of A to B to C is sadly all too easy.