In the bizarre world
of junk climate science,
computer games that
over predict global
warming by 2x to 3x.
are called "climate
models".
Earth's response
to increasing
greenhouse gas
concentrations,
is unknown,
but assumed to be
mild warming,
based on
lab experiments
with carbon dioxide
in artificially dried air.
In reality, we've had
intermittent global
warming since the
1690s, of at least
+2 degrees C.
Rising CO2 levels
could not be
the explanation
for most of that
global warming.
That experience
makes it hard to
believe that CO2
levels suddenly
became the
only variable
that affects the
global average
temperature,
after 1975,
as many people
claim today.
A commonly used
measure of the
effect of CO2 is
the equilibrium
climate sensitivity
( ECS )
ECS is the long term
global surface
temperature response
to an abrupt doubling
of atmospheric carbon
dioxide (CO2).
Estimates of ECS have
historically centered
on a warming of +3˚C.
for each doubling
of the CO2 level,
with the most recent
United Nations
Intergovernmental
Panel on Climate Change
(IPCC) report deeming
an ECS between
+1.5 C. and +4.5˚C.
to be most likely.
That is a huge range, and
the range has not changed
since being published in the
1079 Charney Report.
Those of us who do not
believe in a coming climate
crisis, mock the alarmists,
with their never changing
ECS prediction,
and its huge +/- 50%
margin of error.
We like to focus on actual
measurements of global
warming, that are 1/3 to 1/2
of what was predicted
by people who believe
in the +3.0 C. "formula".
It has been a very
stubborn challenge
to get the scientific
community to revise
their estimated
ECS, with the goal
of making better
global average
temperature
predictions.
The good news
is ECS estimates
are now getting
revised.
The bad news is that
many models are
revising ECS higher,
when they have
already been too high,
predicting too much
global warming
since the 1970s.
Given that models,
on average, grossly
over predicted
the global warming
in past decades,
it's very unlikely
revising models
to predict MORE
global warming,
will make their
predictions
more accurate
in the future.
In fact, the ECS revisions
upwards imply accurate
predictions are NOT the
primary goal of climate
models.
Climate models
are very popular.
They are very complex
methods of presenting
personal opinions about
climate change, that might
not be taken seriously
if just written on a piece
of paper.
The computer games,
called climate models,
are merely props
in a fictional
"climate change
theater play" that
leftists believe in,
just like Catholics
believe in god.
Very few people
know the "models"
make wrong
predictions,
because the
leftist-biased
mass media
does not think
that's important
for you to know.
In a recent study,
Zelinka and coauthors
compared ECS values
derived from CO2
quadrupling experiments
conducted with 27 CMIP6
models that were available
at the end of
November 2019
with values from
all 28 models
from the previous
(CMIP5)
generation.
The latest models
have wide-ranging
ECS sensitivities,
spanning values
of +1.8 to +5.6˚C.
-- they predict
more warming
than their
predecessors
by about +0.5˚C.
Ten of the models
now have
CO2 sensitivities
exceeding +4.5˚C,
beyond the top of
the past IPCC's
"most likely” range.
The primary reason
for more global warming
claimed by new models
was shown to be clouds.
Specifically, both the
water content and the
areal coverage of
low-level clouds
decrease more strongly
with greenhouse warming
in the new models.
That causes enhanced
absorption of sunlight
– an amplifying feedback
that ultimately results
in more global warming.
This alleged stronger
amplifying cloud feedback
is particularly dramatic
over the Southern Ocean.
Differences between old
(CMIP5) and new (CMIP6)
models is in how cloud
properties respond to
their environment – not
in how their environments
change – which leads to
a more positive cloud
feedback in CMIP6.