A new study in the
peer-reviewed journal
Geophysical Research
Letters:
Titled:
“The Amplified Arctic
Warming in the Recent
Decades May Have Been
Overestimated by
CMIP5 Models”.
Measured warming
since 1968 in the Arctic
has been faster than
the rest of the world,
but much slower than
climate models predicted.
The problem is that
models over-predict
the loss of Arctic sea ice:
“Further analysis indicates
that the overestimation
mainly comes from the
exaggerated heating
contribution from the
Arctic sea ice melting.”
Which means,
they add,
“future secular
Arctic warming
may have been
over‐projected.”
In plain English:
Yet another wrong
temperature prediction.
Why do all
the mistakes
seem to go
in one direction ?
The authors
calculate the
Arctic warmed
at a rate of about
+0.14 degrees C.
per decade
starting in
the 1890s,
Then cooled
mid-century.
Then warming
started again,
at about
+0.21 degrees C.
per decade
after 2010,
( +0.07 degrees C.
per decade faster
than the prior
warming trend. )
The climate models
showed essentially
no warming,
as of the 1890s,
underestimated
the warming rate
until about 1940,
then predicted
too much warming
-- the trend rises
to +0.3 degrees
per decade by 2010 !
Climate models
underestimate
the warming rate
early in the century,
and overestimate it
after 1970.
We are currently
in a period
when the Arctic
is not warming
as fast as
the models claim.
The study authors
say projections of
Arctic heating,
over the coming
few decades,
are likely
exaggerated.
It's important
for models
to predict
climate change
well if we are
to rely on them
for public policies.
But climate
models
overstate
Arctic ice melt,
and make
unreliable
global average
temperature
projections.