"Roger Chapman" wrote in message
...
On 29/11/2011 10:50, dennis@home wrote:

Those who claim that they are inaccurate have prejudices rather than
more accurate models to support their assertions.

You can know how inaccurate the models are without having to have a more
accurate model.
Those that think you need a more accurate model to prove the other one
is bad don't understand the basics.

You only know how inaccurate the predictions are after the event. As it is
the models are predicting continuously rising temperatures and all that is
really at stake is the rate of rise.

Any model that doesn't show the rise is automatically deemed to be wrong.
You can't get any funding for a model that is wrong.
Even if a model does show the required rise it doesn't mean its actually a
good model as it may just have fudge factors in it.
It doesn't help that the actual mechanisms and fudge factors and even the
data used in the models are kept secret to avoid public scrutiny.
It does make people wonder what is being hidden and why.

By contrast those who are predicting that global temperatures are now
falling have no model and nothing to hang their hat on bar the 1998 figure
which sticks out like a sore thumb.

There have been models that showed different results, they were deemed to be
wrong.

The Met Office still has 1998 as the warmest year yet but the two American
centres (it is not clear exactly how independently) producing their own
temperature record both conclude that 2010 and 2005 are first equal and
1998 only third.

Well its never going to be clear as the data has been screwed with in
unknown ways and the raw data has gone missing.
Or at least that was the latest excuse for the data being unavailable for
public scrutiny.


To give an example of a very common but frequently very inaccurate model
just look at weather forecasting.

Weather forecasting is frequently very accurate. It is very rare for there
to be a major cock-up.

They are almost always wrong if you look more than a few days ahead.
They are only correct about 50% of the time for the next day.


What's more we know why its inaccurate and we don't need a more accurate
model to prove it, without prejudice.

But you do not have another model to make a more accurate prediction.

There are lots of other models, they all produce different results for much
of the time.
You only have to look at the different organisations producing forecasts to
see that.


Funny enough many of the reasons weather forecasts are inaccurate also
apply to climate models, like not knowing the initial conditions very
well.

At least some of the apparent inaccuracy we see now is as a direct result
of the furore over that hurricane when the Met Office got the track of the
storm wrong. Caution now rules and bad weather will now almost always be
less extreme than forecast and turn up latter than forecasted.

They didn't get it wrong.
They just used the wrong data.