Climate Models
These General Circulation Models are 3D models which attempt to
solve a number of fluid dynamic equations over space and time.
There are a large number of them, more than 100 independent models with
ranges of assumptions and algorithms. Not much review of the
models or the code has been performed,
and the results are poor
especially over the last 20 years. See the
GCM results page. Also to
have an overview of this topic see the
slide presentation starting with
this slide.
It is the aim of these models to be able to accurately predict climate well into the future, at least as far away in time as the end of this century. The errors that are estimated by r Franks are quite relevant, but so are the comparison of results versus GCM models. See the video on the Model Error page.
These models suffer not just from the above systematic errors but fall short of predicting the past nearly as well as the models termed here as the alternative models.
The basic problems in the GCM models include the following:
Grid size and
physics included as well as the assumptions made.
The largest assumption is that CO2 dominates GHG which in turn dominates the heating of the atmosphere by OLR (outgoing long-wave radiation).
The natural causes detailed elsewhere are also assumed relatively constant such as solar irradiance.
There is also an issue with compute power available.
Judith Curry has more to say about the basic structure of these models at this Page. These assumptions are explored in more detail on the page Key Assumptions.
It is also apparent from the literature and private communication
with Patrick Michaels that the tuning of the models is also done, as the model outputs a hotter climate than makes sense in observation. There is independent study that shows that the models do tend to overstate warming.
There is also the point that needs to be made that the GCM models do also violate the laws of thermodynamics, and cannot model convection due to the large grid size, another indication that the models do not represent well the energy transfer and the chaos of the atmosphere.
Judith Curry speaks to the validity of the models below. Dyson also has some observations on this page, as does Prof Soon.
Guest
Post by Willis Eschenbach I came across a lovely photograph of a “fire
devil”, also called a “fire whirl”. I liked it because the photo
perfectly exemplified what is wrong with the current generation of
climate models. What is wrong with the models is that they don’t include
any of the vortex-based emergent atmospheric…
September 8, 2017 in
Climate News,
Emergence.
GCM Model Errors estimate of the large error
GCM Model Results The results of the IPCC
GCM do not model Convection Well
Patrick Michaels on GCM Models
