Junk climate science
claims man made CO2
controls the climate,
the future climate
is easy to predict,
and future climate
change is an
existential threat.
That's complete nonsense.
Mild global warming since
the 1690s has been 100%
good news, and there is
no logical reason to claim
future global warming
will be just the opposite --
100% bad news.
Most of the warming
since 1940 has been
in colder, drier regions,
mainly during their
six coldest months,
and mainly at night.
Warmer winter nights
in Alaska are good news,
not an existential threat !
Real climate science
is mainly questions
that need answers.
And some prior
conclusions
that turn out
to be wrong.
Real science
is never "settled".
Sometimes climate
patterns thought
to be understood,
change for no
obvious reason.
Two important indicators
for predicting the effects
of climate change, on
eastern North Pacific
marine ecosystems,
seem to have changed
in the past two decades.
In the last century,
oceanographers and
fishery biologists "knew"
the relationships between
ocean climate cycles
and regional fish stocks,
from California to Alaska.
There were regular
ocean climate cycles
called the Pacific Decadal
Oscillation index (PDO)
( north of 38 degrees N. )
and the North Pacific
Gyre Oscillation (NPGO)
( south of 38 degrees N. )
For decades there was
a correlation between
Pacific Decadal Oscillation
and salmon abundance
trends.
“We were able use
these indices to describe
changes in collective
environmental features,
including sea surface
temperature, sea surface
height, sea level pressure,
salinity, chlorophyll-a,
and ocean nutrients.
They also helped us
understand and predict
changes in the productivity
of species like plankton
and fish that are sensitive to
long-term weather patterns,
without having to understand
specific relationships
between individual species
and their environment,”
said Mike Litzow,
NOAA fisheries
oceanographer,
“We could count on
these indices as reliable tools
to summarize this broad suite
of climate-biology-relationships.”
But that changed,
beginning around
1988-89.
There was a shift in
North Pacific climate.
The Aleutian Low,
a semi-permanent
low pressure system
that's a main driver
of the PDO pattern,
became less active.
The Aleutian Low
had a major influence
on ocean variables
such as temperature,
wind mixing of the
water column, and
ocean currents
related to the PDO.
The relationship between
these two major climate
indicators and fish stocks
weakened after the
late 1980s.
“In other words,
the PDO and the NPGO
were less effective tools
for helping us understand
and predict biological
productivity in the ocean,”
added NOAA Fisheries
Mary Hunsicker,
a coauthor
on the study.
A “warm” phase
of the climate
( a positive PDO )
had favored
high production
for Alaska fish stocks,
and low production for
Washington, Oregon
and California stocks.
The “cool” phase
of the climate
previously had
the opposite effect
on Alaska and
west coast stocks.
The NPGO was important
for predicting survival
for West Coast salmon.
When the PDO
was in
a "warm" phase,
as in 1925-1945,
and from
1977 through
the late 1980s,
Alaska salmon
production
was high.
When the PDO
was in
a "cool" phase,
as in 1947-1976,
Alaska salmon
production
was low.
“In the
20th Century
we could
reliably predict
trends in
salmon abundance
because there was
a clear link between
inter-decadal changes
in North Pacific climate
and salmon stocks,”
said Hunsicker.
“This was
a simpler approach
than understanding
the complex ecosystem
relationships affecting
salmon production."
For many years,
the PDO and NPGO
served as useful
indices for predicting
fish productivity
and distribution
patterns.
Scientists,
resource managers,
and fishermen
used them to guide
sustainable resource
management and
business planning.
But ocean temperatures
are changing, and so are
wind patterns that drive
ocean currents and
ocean mixing.
Correlations between
the PDO and NPGO indices
and regional climate, and
other variables, that have
previously been strong,
are now weaker, or have
disappeared completely.
Science is never settled !