iF yoU TRy to get to the bottom of the versus 19 per decade for the prior two periods). And 1951 to 2000
global-warming contro- had, by far, the highest amount of carbon introduced into the
versy by reading books and articles on the subject, you quickly atmosphere by humans!
run into a true quandary. Interestingly, the latest IPCC report does not predict more hur-
Alarmists are quite convinced of their cause and the solutions: ricanes—only that hurricanes might be more intense (an assertion,
Act now, or dire results will follow in a century or so and be even by the way, that some prominent hurricane experts deny). As is
worse in the next millennium. Skeptics are just as convinced that shown in Figure 1, the last half of the 20th century had 8 percent
the case has not yet been made to justify reducing gross domes- fewer intense storms than the average of the prior 100 years.
tic product worldwide by the 1 percent to 3 percent that the In- Another theory now debunked is the so-called hockey stick
tergovernmental Panel on Climate Change (IPCC), a scientific proposed by Michael Mann, one of the fathers of the man-made
body created by the World Meteorological Organization and by global warming thesis. He was quite influential in the 2001 IPCC
the United Nations Environment Program, indicates in its 2007 pronouncement that global warming was mostly caused by hu-
report is necessary to combat global warming. They argue that the man activity. His graph of global temperatures measured over
resulting cost (reaching as high as $1 trillion or more a year) could 1,000 years, taken from tree-ring growths, showed a rather con-
be better spent solving other, more pressing problems. stant global temperature until the past 100 years. The rise of a
Alarmists state that the scientific community is overwhelm- little over half a degree Celsius since then, if fitted to a curve that
ingly in consensus that recent global warming is man-made, looks like a hockey stick, might imply a global temperature in-
yet skeptics quote scientists on the other side who suggest that crease in the next 100 years of perhaps 2 to 4 degrees Celsius.
on global Warming
tOBKAtINA / dREAMStIME
the earth is going through its usual climate-changing cadence,
as it has for the past million years (and that the past 10 years
have seen a slight global cooling).
Surprisingly, the controversy on climate change also seems
to line up along political lines. Liberals tend to be proponents
of the theory that the warming is induced by human activity,
while conservatives tend to be more skeptical.
After reading a number of books and articles on the subject,
I would like to offer my perspective. I should also disclose that
in my prior actuarial career, I was very involved in the measurement of hurricane risk. I helped to get my firm’s hurricane
simulation model accepted by the Florida Commission on Hurricane Loss Projection Methodology, an entity that was formed
to vet various commercial ventures that quantify hurricane risk
using meteorology, engineering, and statistics. This background
is instrumental in my emerging skepticism on the dire threat of
man-made global warming.
Some alarmists argue that higher hurricane frequency
in the past few decades is clear evidence of man-made
global warming. Yet it simply is not true. It makes for
catchy headlines to cite Hurricane Katrina’s devastation as a motivator to constrict our economy by limiting oil consumption, but there is simply no evidence
of increasing hurricane frequency.
The U.S. began systematic cataloguing of hurricanes around 1850. If you look at the record of
landfalls by 50-year segments (see Figure 1), the
last half of the 20th century had 25 percent fewer hurricanes than each of the two prior 50-year
periods (an average of 14 hurricanes per decade
The IPCC adopted Mann’s thesis because it fit with its preconceived biases about the industrial world’s use of carbon-based energy and supported calls for a severe ratcheting back
of petroleum use—a main feature of the Kyoto treaty. Kyoto was
signed by President Clinton but never submitted to the Senate
for ratification. The likely reason is that the U.S. Senate passed a
resolution (by a 95-to-0 margin) opposing Kyoto because it exempted the two large countries of China and India and because
it would result in serious harm to the U.S. economy.
Mann’s theory is now known to be fatally flawed and is no
longer even cited by the IPCC. Yet it still found its way into
former Vice President Al Gore’s slide show and Oscar-winning
documentary. In addition to “smoothing” errors to get temperatures for the prior 900 years to look relatively uniform, Mann’s
tree-ring growth data could measure only alleged temperature
changes in the warm growing months and indicated nothing
about winter temperatures. Furthermore, the data were totally
contrary to overwhelming evidence that the world did not have
uniform climate conditions over the past millennium. What
about the Medieval Warm Period (when there was farming in
Greenland), and what about the Little Ice Age (when the Thames
River in London used to regularly freeze over)?
A real question is, how much peer review did the IPCC give
to Mann’s work? Does correlation mean causation? Did the panel’s zeal to try to show anthropogenic sources of global warming
overcome its responsibility to present science fairly?
Battle of the Books
The main evidence that the IPCC cites in its 2007 report on
global warming rests with half a dozen climate-change models
that foretell a likely average temperature increase of 2 to 4 degrees Celsius over the next 100 years. The models all blame the