Climate Change Models

How good are the latest climate models?

“Modellers have an inbuilt bias towards forced climate change because the causes and effect are clear”.¹

So... how good are the latest climate models? The mathematics is sophisticated and certainly intimidating to everyone else. And there is an impressive degree of consensus on their predictions. Take this test of one of the key components of ‘Greenhouse theory’ - the degree to which warming of the oceans leads to water vapour in the atmosphere ‘trapping’ the Sun’s heat. This is a key component of the theory that a little bit of CO2 can create very significant changes in the way the Climate System operates.

Below are 12 graphs included in a paper called ‘On the determination of climate feedbacks from ERBE data’ ²

Basically, all but the first graph show that as the temperature of the surface of the seas increases slightly, the amount of heat trapped by Water vapour increases, so less is radiated back into space, accelerating the ‘greenhouse effect’. We should be worried!

Yet, there's that odd graph out - one of the 12 totally contradicts the other 11 models. Could it be, as the sceptical physicist, Lubo Motl, quips, that this one is a tainted model - with its parameters ‘tweaked’ to fit prejudices - created by Climate Change ‘deniers’ funded by Oil industry money? But no -

It is just one example of how the Climate Change models aren't just useless, they are worse than useless. But don’t take my word for that, here’s what one of the loudest supports of ‘Climate change theory’, an English mathematician called Gavin Schmidt, employed by NASA as an expert on climate, says about his models:

“...due to inherent limitations in knowledge of past boundary conditions, the appropriate initial state of the ocean and limited simulation lengths possible with state-of-the-art models, the experiments being performed are often abstractions, rather than reconstructions of a particular time-period’.

(from a paper by all the top Climate Change fanatics, Gavin Schmidt, Drw Shindell, Ron Miller, Michael Mann and David Rind called General circulation modelling of Holocene [ the current climate] climate variability’ in Quaternary Science Review 23 2004) .

Abstractions! This is fine stuff. But there’s more:

“[Past] conditions are presumed to have been relatively stable... [In many models] there is an implicit assumption that longer term processes that are not explicitly considered (ice sheets, carbon cycle, sea surface temperatures... , the ocean heat transports... are constant. This can be problematic, particularly for the oceans and land surface (including the vegetation), both of which influence and are influenced by the atmospheric state. However the advantage of solid statistics (due to averaging out of short-term ‘weather’ noise) is frequently paramount.”

The need for ‘solid statistics’ takes precedence over the complications of reality?

When mathematicians do attempt to include some of those tricky ‘variables’, “defining initial conditions is extremely tricky and laborious.”

One problem with past temperature records from say ice cores, is that typically these are all obtained from one location, which may or may not be typical. A network of records,- the larger the better- is needed - but as soon as you move from one place to another, uncertainties enter into the comparisons - “problems in chronology, differences in time resolution, confounding on-climatic influences, biases in spatial sampling”, for example, as Schmidt and others have admitted. “There is such a degree of weather ‘noise’ or intrinsic variability that no particular climate simulation, however sophisticated will follow the same semi-random path that the actual climate took.

Yet another annoying thing is that “the oceans retain a ‘memory’ of the past few hundred years which can play a role in the subsequent climate evolution.... any one experiment will have a great deal of chaotic behaviour...”

In fact, “accurate estimates of changes in forcing [forces other than the one being measured by the model that also affect climate ] through time are extremely sparse and come with high uncertainties.”

What sort of factors are these messing up the models? “They are changes in the amount of sunlight reaching the Earth, changes it eh amount of water vapour in the atmosphere, changes in cloud cover - just about everything that determines climate really!

“The most important greenhouse gas is water vapour.” Which denier said that? Well, several. But so did all the leading Climate Change fanatics, Gavin Schmidt, Drw Shindell, Ron Miller, Michael Mann and David Rind in a called General Circulation modelling of Holocene [ that is, the current climate] climate variability’ in Quaternary Science Review 23 (2004).

So it’s not controversial. It is water vapour that controls the Earth’s ‘greenhouse effect’, not CO2.

Historical measures of changes in the amount of sunlight reaching the Earth can be made through looking at the amount of certain mineral isotopes found, fore example in ice cores. This sounds rather impressive, and so it has been repeatedly used. However, as the climate change proponents themselves say, these records have “generally been calibrated to the estimates of solar forcing at the Maunder Minimum [1650-1710, and the time of the Little Ice Age in the Northern Hemisphere], themselves highly uncertain and so do not provide an independent estimate of the forcing”. In short , isolating the effects of changes in the amount of sunlight reaching the Earth is “difficult” particularly because of “the number of other factors that change at the same time”.

As for the effects of ocean currents, the proponents of Climate modelling offer only rather grudgingly that “ocean dynamic might well lead to hemispheric differences”.

Then there are “a large number of additional radiative forcings” that are also not possible to accurately model including:

“dust, tropospheric and stratospheric ozone, natural sulphates, organic aerosols, stratospheric water vapour and minor greenhouse gases (such as SO2)”.

Alas, there are no ways known on how to include these. And so, the simple fact is, in the climate modellers own words,: “At present, no climate models have included the full range of effects.”

Why not give up the attempts to model climate change then? But “Given the uncertainties in the magnitude of solar forcing, the climate sensitivity and the ability of the proxy date to capture long-term variability, the match is surprisingly good”!

This is cherry-picking and opportunism. Even the modellers themeselves shave to conclude that the results of their climate simulations are “likely to remain speculative for some time to come” and that people should be “extremely wary of extrapolating results to longer periods”.