>The paper is essentially Curry whining that climate science is too difficult, instead of getting to work and figuring out the physics and math, like the rest of us try to do.

Where is she whining ? I mean she is critizising certain features of GCM's, like in particular that

>There is growing evidence that climate models are running too hot and that climate
sensitivity to carbon dioxide is at the lower end of the range provided by the IPCC.
Nevertheless, these lower values of climate sensitivity are not accounted for in IPCC
climate model projections of temperature at the end of the 21st century or in esti-
mates of the impact on temperatures of reducing carbon dioxide emissions.

As far as I understood, this critique is based on observations (p.7):

>Lewis and Curry (2014) used an observation-based energy balance approach to
estimate ECS. Their calculations used the same values (including uncertainties) for
changes in greenhouse gases and other drivers of climate change as given in the Fifth
Assessment. However, their range of values for ECS were approximately half those de-
termined from the CMIP5 climate models.

It is clear that predicting climate is shit difficult and at this infancy stage very likely
quite error-prone. As she rightly pointed out alone on the math side there are
major difficulties, like:

>The solution of Navier–Stokes equations is one of the most vexing problems in all
of mathematics: the Clay Mathematics Institute has declared this to be one of the top seven problems in all of mathematics and is offering a $1 million prize for its solution.

so on page (vii) she writes:

>By extension, GCMs are not fit for the purpose of justifying political policies to fundamentally alter world social, economic and energy systems.

The question here seems what do you make out of this sentence? What are the consequences?

from the last page:

>The Global Warming Policy Foundation is an all-party and non-party think
tank and a registered educational charity which, while openminded on
the contested science of global warming, is deeply concerned about the
costs and other implications of many of the policies currently being advo-
cated

Yes, following the climate models in particular GCMs seem to be quite faulty. But they can be faulty into two directions, i.e. things can be less worse or way worse. If the thermometers in your living room gets suddenly hot (at least at some places) do you keep sitting and pretend nothing has happened?
Or do you keep trying to check as best as possible and eventually precautiously switch down the thermostat even if you don't really know wether the heating is the source of the problem?

I think that there had been deficiences especially with respect to the point "check as best as possible." That is as already Judith Curry pointed out, if all models (in the example the "hypothesis why it is so hot in the living room") appear rather bad in explaining the phenomena then nobody really knows what the best model is:

>Is it possible to select a ‘best’ model? Well, several models generally show a poorer
performance overall when compared with observations. However, the best model
depends on how you define ‘best’, and no single model is the best at everything.

and so the choice for approaches to find solutions was partially less based on
purely scientific choices, but also on who is able to secure which funds with which effort.

The fact that people like Tim van Beek is now busy producing cars for the "economic elite" instead of e.g. working on fluid dynamics is saying something.