·
Now IPCC Hurricane Data
is Questioned
Open science: Got Excel? Debunk
this
More trouble looms for the IPCC. The
body may need to revise statements made in its Fourth Assessment Report on
hurricanes and global warming. A statistical analysis of the raw data shows
that the claims that global hurricane activity has increased cannot be
supported.
Les Hatton once fixed weather models at
the Met Office. Having studied Maths at
Hatton has released what he describes
as an 'A-level' statistical analysis, which tests six IPCC statements against
raw data from the National Oceanic and Atmospheric (NOAA) Administration. He's
published all the raw data and invites criticism, but warns he is neither
"a warmist nor a denialist", but a scientist.
Hatton performed a z-test statistical
analysis of the period 1999-2009 against 1946-2009 to test the six conclusions.
He also ran the data ending with what the IPCC had available in 2007. He found
that
"When you average the number of
storms and their strength, it almost exactly balances." This isn't
indicative of an increase in atmospheric energy manifesting itself in storms.
Even the
The IPCC does indeed conclude that
"there is no clear trend in the annual numbers of tropical cyclones."
If only the IPCC had stopped there. Yet it goes on to make more claims, and
draw conclusions that the data doesn't support.
Claims and data
Thre IPCC's WG1 paper states:
"There are also suggestions of increased intense tropical cyclone activity
in some other regions where concerns over data quality are greater." Hatton points out the data quality is similar in each area.
The IPCC continues: "It is more
likely than not (> 50%) that there has been some human contribution to the increases
in hurricane intensity." But, as Hatton points out, that conclusion comes
from computer climate models, not from the observational data, which show no
increase.
"The IPCC goes on to make
statements that would never pass peer review," Hatton told us. A more
scientifically useful conclusion would have been to ask why there was a
disparity. "This differential behaviour to me is very interesting. If it's
due to increased warming in one place, and decreased warming in the other -
then that's interesting to me."
Hatton has thirty years of experience
of getting scientific papers published, but describes this one, available on
his personal website, as "unpublishable".
"It's an open invitation to tell
me I'm wrong," he says. He was prompted to look more closely by the
Climategate emails, and by his years of experience with computer modelling. All
code and data on which policy conclusions are made should be open and freely
downloadable, he says - preferably with open tools.
You can download both the paper and the
code and tools from here.®
Bootnote
The IPCC's AR4 chapter lead was Kevin
Trenberth, who features prominently in the Climategate emails. In 2005, the
"I personally cannot in good faith
continue to contribute to a process that I view as both being motivated by
pre-conceived agendas and being scientifically unsound. As the IPCC leadership
has seen no wrong in Dr. Trenberth’s actions and have retained him as a Lead
Author for the AR4, I have decided to no longer participate in the IPCC
AR4."
Critics point out that an increase in
low-intensity storms being recorded is due to better instrumentation. Most are
at sea, and thanks to radar and satellites, more are now observed.