The Pielke graph below,
on hurricane landfalls,
has been used here.
A climate alarmist
has turned it into
bad news by the use
of data mining.
The gray bars
are the strong
hurricanes,
Category 3+.
If you data mine,
you could state
that Category 3+
landfalling
hurricanes
have been in
a rising trend
since the 1970's,
when sorted
by decade:
Category 3+
Landfalling
Hurricanes
Sorted by
Decade:
1970s = 38
1980s = 41
1990s = 55
2000s = 58
2010s = 60
The conclusion
would be a rising
trend for Cat 3+
in the past
50 years.
I had previously
stated there was
no obvious hurricane
trend ( Category 1 - 5 ).
That's still true.
(1)
Some of the Cat 3+
increase could be
attributed to better
measurement,
sensing and
detecting.
Wind speeds
can slow
very quickly
just before
as a hurricane
makes landfall.
Wind speeds
drop drastically
as a hurricane
crosses a coast,
where there are
more observers.
(2)
Data sorted by decade
could be deceptive too.
Any arbitrary division
of years can produce
meaningless patterns.
Throw dice fifty times,
divide the results
into groups of ten,
and we are likely
to see meaningless
"patterns".
(3)
The best
explanation
is that the 1970s
starting point
for the first chart,
happened to be
a quieter period
for overall tropical
cyclones / hurricanes.
In fact,
major hurricanes
were just as frequent
in the 1950s and 1960s
as they are now.
There's a
cyclical pattern,
and no obvious trend
since the 1950s.
Data prior
to the 1950s
are questionable.
The cyclical
pattern
is linked
into the
Atlantic
Multidecadal
Oscillation.
NOAA describe its effect:
We have been
in the AMO
warm phase
since the
mid 1990s,
just as
we were
in the 1950s.
In between,
the AMO was
in its cold phase,
Starting
in the 1970s,
and just
looking at
Category 3+
landfalling
hurricanes,
is data mining,
that leads
to a different
conclusion
than looking
at ALL
good data
since 1950,
looking at
ALL
landfalling
hurricanes.
In the
North Atlantic,
and the Western
North Pacific,
good data
are available
since 1950.
Hurricane
landfalls
in those
two basins
accounted
for about 68%
of all global
landfalls from
1970 to 2019.
The chart below
shows a 10-year
moving average
of tropical cyclone
global landfalls
from 1950 to 2019.
The numbers
since 1970
are identical to
the top graph.
Numbers from
1950 to 1969,
are based on
actual landfalls
for the N Atlantic
and NW Pacific,
added to the average
for the rest of the world
between 1970 and 2019.
The dotted line
is major hurricanes.
To be more specific,
( and more confusing )
( and more confusing )
1970 to 2019
is based on
observations, and
uses data identical
to the first chart.
The black line shows
all tropical cyclone
landfalls of at least
hurricane strength
and the
dashed black line
shows all landfalls
of tropical cyclones
of major
hurricane strength.
For 1950 to 1969
there are
actual data on landfalls
in the North Atlantic
and Northwest Pacific,
added to the average
number of landfalls
from the rest
of the world ,
based on
observations from
1970 to 2019
(there is no trend
over the period).
The grey line and
dashed line represent
an estimate of total
hurricane-strength
and major
hurricane-strength
tropical cyclone landfalls
from 1950 to 1969.
The dotted lines represent
plus and minus one standard
deviation from this average.