In the Honest
Global Warming
Chart Blog format:
"14.2.2
Predictability
in a Chaotic System"
"The climate system
is particularly challenging
since it is known that
components in the system
are inherently chaotic;
there are feedbacks
that could potentially
switch sign, and there are
central processes
that affect the system
in a complicated,
non-linear manner.
These complex, chaotic,
non-linear dynamics
are an inherent aspect
of the climate system.
As the IPCC WGI Second
Assessment Report (IPCC, 1996)
(hereafter SAR) has previously
noted, “future unexpected,
large and rapid climate system
changes (as have occurred
in the past) are, by their nature,
difficult to predict.
This implies that future climate
changes may also involve
‘surprises’.
In particular, these arise from
the non-linear, chaotic nature
of the climate system
... Progress can be made
by investigating non-linear
processes and sub-components
of the climatic system.”
These thoughts are expanded
upon in this report:
“Reducing uncertainty
in climate projections
also requires a better
understanding of these
non-linear processes
which give rise to thresholds
that are present
in the climate system.
Observations,
palaeoclimatic data,
and models suggest
that such thresholds
exist and that transitions
have occurred in the past
... Comprehensive climate
models in conjunction
with sustained observational
systems, both in situ and remote,
are the only tool to decide
whether the evolving
climate system is approaching
such thresholds.
Our knowledge
about the processes,
and feedback mechanisms
determining them, must be
significantly improved
in order to extract
early signs of such changes
from model simulations
and observations.”
(See Chapter 7, Section 7.7).
"14.2.2.1
Initialisation and flux adjustments"
" ... Models, by definition, are
reduced descriptions of reality
and hence incomplete and with error.
Missing pieces and small errors
can pose difficulties when models
of sub-systems such as the ocean
and the atmosphere are coupled.
As noted in Chapter 8,
Section 8.4.2,
at the time of the SAR
most coupled models
had difficulty in reproducing
a stable climate with
current atmospheric
concentrations of
greenhouse gases,
and therefore non-physical
“flux adjustment terms”
were added. "
Ye editor sez:
This sounds like
the climate models
are all fluxed up !