[StBernard] Behind the hurricane hype
westley at da-parish.com
Thu Aug 26 22:33:59 EDT 2010
Behind the hurricane hype
Aug 26, 2010 10:13 EDT
climate change | global warming | hurricanes
The fifth anniversary of Hurricane Katrina, coupled with the mild hurricane
Danielle tracking toward Bermuda, turns thoughts toward cyclones.
In May, before the current Atlantic hurricane season began, forecasts were
for Armageddon. This year's hurricane season could be "very active" (Jane
Lubchenco, head of the National Oceanic and Atmospheric Administration) or
"very very active" (CNN) or "a hell of a year" with "quite high" numbers of
intense storms (William Gray, head of the hurricane prediction center at
Colorado State University).
What has actually happened so far? A below-average season of two hurricanes,
neither one intense.
The totals should change, though. September can be the peak month for
Atlantic hurricanes. But three of the last four years have shown
below-average hurricane activity in the Atlantic, and 2010 is shaping up as
another below-average season.
What's going on here? Wasn't global warming supposed to spawn ultra-monster
hurricanes? That's what Al Gore started claiming five years ago. Similar
assertions have been heard from other quarters, too.
Of course, just because Al Gore says something doesn't mean it's untrue. So
what is going on?
The media loves predictions of deadly hurricanes. Each spring NOAA, CSU and
other organizations issue hurricane forecasts; in recent years nearly all
such forecasts have been alarming; the alarming forecasts are played up. If
hurricane season ends without calamity, there are never follow-up stories
noting the predictions were wrong, because newspapers and newscasts want to
feature the next spring's alarming predictions.
The media loves hurricanes, period. Hurricanes make great television! Fierce
winds, lapping waves, correspondents in heavy rain gear shouting to be
heard. Plus because hurricanes take days to form, there's time to put
newscasting resources in their paths: good luck positioning cameras in the
path of a tornado. I don't think it is too cynical to say that cable news is
rooting for destructive hurricanes, though rooting for a kind of Hollywood
fantasy hurricane which causes widespread cinematic-quality destruction but
doesn't kill anyone.
Predictions are worthless. The below mini-chart shows the
pre-hurricane-season predictions of NOAA and CSU, followed by actual
results. (I use the upper bound for NOAA, which sometimes issues vague
predictions such as "three to seven" hurricanes, which is like predicting,
"the Dow Jones will either rise or fall." I use the seasons-start
predictions by CSU, which has a sneaky habit of altering its forecasts once
the season is nearly over and most of the trend is already known.)
NOAA CSU Actual
2004 8 hurricanes, 3 intense. 8 hurricanes, 3 intense. 9 hurricanes, 6
2005 9 hurricanes, 5 intense, 8 hurricanes, 4 intense. 15 hurricanes, 7
intense. (This was the year of Katrina and Rita.)
2006 10 hurricanes, 6 intense. 9 hurricanes, 5 intense. 5 hurricanes, 2
2007 10 hurricanes, 5 intense. 9 hurricanes, 5 intense. 6 hurricanes, 2
2008 9 hurricanes, 5 intense. 8 hurricanes, 4 intense. 8 hurricanes, 5
2009 7 hurricanes, 3 intense. 5 hurricanes, 2 intense. 3 hurricanes, 2
2010 14 hurricanes, 7 intense. 10 hurricanes, 5 intense So far: 2
hurricanes, neither intense.
Note that in the six years before the current season, only two of the 12
major predictions turned out to be correct. Since the likely numerical range
of hurricanes is fairly small - the 50-year average is six hurricanes, three
intense - you'd think some predictions would be right by sheer chance.
Instead the leading experts in the field have been wrong on 10 of their last
12 projections, and are on track to be totally wrong this year.
Predictions get attention anyway. Last year Colorado State analyzed its
predictions and for the last 25 years discerned only a "modest" improvement
over simply predicting every season would be average. As best I could
determine, no major media outlet covered the release of this report showing
that hurricane predictions are a complete waste of everyone's time.
The sillier the prediction, the better. Colorado State has gotten press for
this website, which claims to generate a scientific likelihood of hurricane
landfalling by U.S. county. The page offers absurdly hyper-specific
predictions, such as a "18.7 percent probability" that a hurricane will
strike Harrison County, Mississippi, this year, or a "2.4 percent
probability" that a hurricane will cross Essex County, New Jersey. Numbers
such as these are gibberish, not science - since what's to the right of the
decimal point cannot possibly have statistical significance, and what's to
the left is pure guesswork. But the pseudo-science feel makes for a nice
source of stories for local newscasters. ("Researchers Say Hurricane Might
Hurricanes have been awful long before artificial global warming. The
extremely strong Great Hurricane of 1780 killed about 27,500 people, at a
time when the Western Hemisphere was far less populous - and when artificial
greenhouse gas emissions were not a factor. The Category Four Galveston
hurricane of 1900 killed 8,000 people, and occurred when greenhouse gas
levels in the atmosphere were much lower than today. The 1938 Long Island
hurricane left 800 dead and $4.6 billion in property damage (stated in 2010
dollars), also occurring before coal and oil use could have altered nature.
Hurricanes don't show any pattern clearly linked to greenhouse gases. A
terrible hurricane year (2005) or an eerily quiet year (2009) doesn't prove
anything one way or the other. Nor does the larger trend. For the last 60
years, decade-by-decade averages have been roughly the same. A good summary
But you should still worry. Just because climate change hasn't yet caused
more or stronger hurricanes does not mean they will not happen. The evidence
for climate change is strong. If sea surface temperatures are the key to
hurricanes, as some researchers think, then hurricanes should get worse,
because sea surface temperatures are rising. Then again, climate change
might make cold fronts less cold, while reducing the difference between
high- and low-pressure areas, and those factors could reduce hurricane
incidence or intensity.
This 2005 paper by a researcher at the National Center for Atmospheric
Research, published just before Katrina, takes the view that rising
sea-surface temperatures will cause stronger hurricanes and also more rain.
This 2009 paper, from a researcher affiliated with the same organization,
takes the view that hurricane activity will decline in a warmer world.
This recently released study, from the Geophysical Fluid Dynamics Laboratory
at Princeton - gotta love that name - splits down the middle, forecasting
that climate change will increase hurricane activity but slowly, requiring
decades or longer. (The Princeton paper is also a rare example of presenting
scientific information in a way intended to be comprehensible and
Perhaps the Princeton paper would cause you to think, "If hurricanes won't
get worse until 2050, then I don't need to care about this." You do.
One of the big questions of global warming is whether there will be tipping
points - natural thresholds that cause climate change to accelerate. If the
Princeton paper's view is correct, by the time the tipping point for
hurricanes is reached, it will be too late to reverse the effect - because
greenhouse gas levels in the air will be too high.
Bottom line: instant-doomsday hurricane panic isn't supported by science.
But greenhouse gas regulation is.
More information about the StBernard