|Extreme weather, extreme hype
Comments to pages 94 - 116 in Cool it.
Chris Mooney criticises Lomborg´s chapter on hurricanes here.
FLAW OF OMISSION
Page 95: "It makes three strong and specific points".
Flaw: Lomborg refers to a summary
statement on tropical cyclones and
climate change issued by the World Meteorological Organization in
November 2006. This summary contains not three, but ten clearly
formulated points. But Lomborg cites only the first three
these points - which happen to fit his overall agenda - and
leaves out those that do not fit him. Most importantly, he omits
the point stating that scientists agree that we should expect a
rise in peak wind-speed as the sea surface warms. Instead, he
focuses on the point stating that "The recent increase in
societal impact from tropical cyclones has been largely caused by
rising concentrations of population and infrastructure in coastal
regions." Few scientists would oppose against this
statement, but Lomborg claims that this is all there is to it -
as if we had to choose whether damages were due to denser
infrastructure or to
increasing wind speeds, instead of admitting
that both factors contribute in tandem, and that the intensity of
cyclones is expected to rise in the future, wherefore the
necessary protective measures will be ever more costly -
especially as there is at the same time a rising of sea level.
Page 95: "When Al Gore tells us that . . . it is incorrect".
Flaw: Lomborg refers to a summary
statement on tropical cyclones and
climate change issued by the World Meteorological Organization. He
focuses on point 1 in this statement, that a detectable human-caused
signal is controversial, but he omits the following points:
"6. It is likely that some increase in tropical cyclone peak wind-speed
and rainfall will occur if the climate continues to warm. Model studies
and theory project a 3-5% increase in wind-speed per degree Celsius
increase of tropical sea surface temperatures.
7. There is an inconsistency between the small changes in wind-speed
projected by theory and modeling versus large changes reported by some
Point 6 says that a human-caused signal is likely to appear in the
future, and point 7 says that unexplained increased wind-speeds have
been observed already. Therefore, when Gore says that "global warming is making hurricanes more
powerful", he is right. this is considered a deliberate flaw, as Lomborg
has read points 6 and 7, but neglects them.
Page 100 bottom and note 507: " . . . or almost twice the damage of
Flaw: The source given for this statement
is NOAA 2006c. But according to this source, the economic costs of the
Great Miami hurricane would today have been $ 90 billion, which is only
20 % higher than the estimate given in the same source for Katrina ($75
billion). The figure cited by Lomborg for the Great Miami hurricane
originates form another source, Pielke et al. 2007.
Page 100 bottom : "Had it hit today, it would have caused damage of
about $100 billion . . ".
Flaw: Lomborg´s source, Pielke et
al. 2007, gives a figure of $78 billion. "
FLAW OF OMISSION
Page 100 bottom, note 509: In the note: "Notice that both hurricanes .
. . caused many deaths . . ".
Flaw: The important omission is that
hurricane Katrina caused the death of 1,200 - 1,300 people, making it
the second most fatal hurricane after the Galveston hurricane.
Estimates for the Great Miami hurricane range from 373 to 800 dead.
That better warning systems today would have evacuated much of the city
is at odds with what actually happened when Katrina struck in 2005.
Page 101, figure 29:
Flaw: The figure is taken from Pielke et
al. 2007, but the columns for 1900 and 1915 are considerably higher
than in the source.
Page 102 top: "Katrina ranks third at $81 billion."
source (Pielke at al. 2007) which is used here, has the following
estimates of damages: Galveston $72 -78 bn, Great Miami $140 - 157 bn,
and Katrina $81 bn. So Katrina ranges second, not third. Although
Lomborg states at the bottom of page 100 that the Galveston hurricane
would have cost $100 today, he gives no source for this claim. It must
be added that we are talking about hypothetical damages, and that the
calculation of these depends inter alia on the economic growth rate
from 1900 to 1925, which is not precisely known. But when
Lomborg´s source has Katrina ranging as second, it is a
manipulation to write without any reservation that it ranges third.
The economic damages from Katrina are estimated at
more than $100 bn by the federal organisation NOAA.
One of Lomborg´s main references is Kundzewicz et al. (2005)
(note 535). This reference says: "Out of more than a
thousand long time series made available to the authors, a data set
consisting of 195 long series of daily mean flow records was selected.
" Out of these 195, 140 were from Europe and North America. The
criteria for choice of stations included "catchment size, with priority
given to smaller catchments which are more likely to have less strong
anthropogenic influence . . ". None of the time series went
further than 2001; that is, the extremely large floods in east-central
Europe in 2002 do not enter the analysis.
The exclusion of catchments with much anthropogenic influence is
in a way sensible, but also has consequences. Those rivers which up
during history have relatively often produced disastrous floodings are
more likely than other rivers to have been affected now by the building
of dikes. Also, large rivers are more likely to gather precipitation
from a large area and hence to produce large floodings. The exclusion
of such river systems, and the fact that all time series stop no later
than 2001, all may contribute to leave out precisely those situations
where large floodings occur.
After the publication of that paper, some other papers have been
published with opposite results. Schmocker-Fackel & Naef (2010)
report increasing floods in parts of Switzerland (Journal of hydrology
381: 1-8). (Petrow & Mertz (2009) : Journal of hydrology 371:
129-141 analysed data from 145 river discharge gauges from all over
Germany for the period 1952 - 2002 and found a general rising trend in
extreme events for the western, southern and central parts of Germany.
These authors also publish a survey of previous studies. Many of these
indicate no general trend, or decreasing trend in one region
simultaneous with increasing trend in another region. A few indicate
marked increases in flood events, for instance in Australia: Franks
(2002): Hydrology and Earth System Sciences 6 (1), 11–16.
Page 109 top: "This is well correlated with the historic evidence that
shows much greater flood risks in the colder cliamtes of the
Little Ice Age."
Flaw: At least for the Czech Republic,
this is not true. The floodings in August 2002 were the largest ever
since the start of recordings in 1500 (Brazdil et al. (2006), cited by
Page 109 top: "This pattern was the main cause of flooding on the lower
Rhine . . ."
Flaw: The pattern described by Lomborg
does not hold true for the period 1951-2002 (Petrow & Mertz, cited
above). They found that the mainpart of stations in the Rhine catchment
area showed significantly increasing trends in flood events. For
Germany in general, they state that the trend analyses for the winter
maxima gave similar results
as the analyses for the annual maxima. Significant upward trends in
winter maxima were identified at 23% of all sites. No significant
downward trends were detected.
Page 109 : "For the river Vltava in the Czech Republic, floods have
decreased over the past century. "
Comment: This is technically correct, when
`the past century´ means the 20th century. However, it is also
misleading, because the largest flood ever recorded there was in 2002.
HAIL, LIGHTNING ETC.
Page 115: "Essentially, we see that serious tornadoes have declined substantially over the
Flaw: According to the paper
Verbout et al., cited by Lomborg, the trend for the period
1954-2003 has been as follows for the different categories of
F0 and larger (all reported tornadoes): More than a doubling
F1 and larger: No change
F2 and larger: More than 50 % decrease
F3 and larger: More than 50 % decrease
F4 and larger: Slight decrease, probably not significant
Lomborg refers to those categories that show a significant decrease
(F2+ and F3+), but not to those that show no significant trend (F1+ and
F4+). The authors of the paper write: ". . the F4 and greater record
has also remained relatively consistent throughout the time period, yet
the F2 and greater and F3 and greater records have a declining trend
over this period, with a possible disontinuity in the late 1970s. . .
suggesting overrating problems with the F2 rated series." Notice that
the F-scale was invented in 1971, and it was probably not used for
post-hoc classification of tornadoes until some years later. The
discontinuity in the late 1970s, especially for the F2 series,
suggests that former tornadoes were relatively often classified
as F2 or F3, whereas similar recent tornadoes might only be classified
as F1 or F2, respectively. In conclusion, there is probably no true
trend at all, implying that Al Gore is not right (no real increase) and
Lomborg is not right (no real decline). This might not have been
counted as a flaw in Lomborg´s book, had he not stressed the
point with italics and not called this "an important additional piece
Page 116, figure 34.
The data source is no longer at the web address given by Lomborg, but
is found here.
Flaw: The decline in fatalities in the
most recent years is exaggerated. Actually, the average yearly number
of fatalities due to hurricanes (before Katrina) and floods is
approximately the same now as in the 1940s. As the US population has
doubled (from 140 millions to 280 millions), the number of fatalies per
million is now half of what it were (hurricanes without Katrina) or
slightly above half (floods). The curves in the figure show a continued
decline after 2000. This must be an artifact due to the smoothing
procedure; with 11-year smoothing, the curves should have stopped in