Article by on climate change by James Lovelock

[BigShot]

If you run a large enough ensemble, and do the stats right, yes. Climate is much more predictable than weather.

Yet at no point have the models, fine tuned to be reasonably accurate at short term weather forecasts been fine tuned to be accurate at predicting climate with any degree of accuracy, as there's been no chance to do so.

"Climate is much more predictable than weather."
How do you know that?
Noone has ever tested the predictions, for all you or anyone else knows they could be completely and utterly wrong. It could be that climate is actually less predictable than weather. You can't say with certainty as there is no empirocal science to back that claim up.

By all means, cut your carbon emissions, change your lifestyle, encourage others to do the same for a whole raft of definite reasons (reducing reliance on fossil fuels and the associated price fluctuations, lower cost loving, more efficient living, lower impact on ecosystems, no risk of devastaging oil spills to fuel your life - whatever) but when you move to AGW and using weather models which can't predict more than a few days ahead to predict climate decades ahead and just "trust" that it is accurate, without any evidence to believe that is is accurate, you're into a whole different territory.

 

[gregorach]

Like I said, there's a vast literature on model validation out there. The fact that you are not personally familiar with it does not mean it doesn't exist.

Really done now.

 

[BigShot]

Who said it doesn't exist?
I'd really appreciate it if you'd stop insinuating that I'm wilfully ignorant of this whole subject.

Someone could write a hundred volumes on model validation, but the fact remains that noone has empirically tested a single prediction.

 

[gregorach]

What do you think "validation" means?

 

[locum76]

bigshot - i agree with some of that but...

i personally believe the overwhelming body of evidence that constitutes climate change theory, just as i do for evolutionary theory. but lets you and i leave that aside.

I would say that it is important to start to plan for no fossil fuels now because we don't have plenty time and if we leave it too late the transition will be very hard. If we start now we may be able to ease into the transition. for that reason i think it is the correct thing for governments to push the alternative fuels agenda as much as possible, whether by guilt, taxes, love or big sticks. if the threat of global warming changes some minds then more power to the people who are pushing that agenda. Its probably changed a few minds already. if you wish to wait until it is too late - that is your choice.

i don't believe that you don't want to prepare yourself and your kin for these likely events though. you can't help everyone (overpopulation will see to that) but you can help those around you.

in light of all of that, doesn't digging your heels in just to avoid being told what to do, seem a bit silly?

rob

 

[BigShot]

I know what it means...
...but unless time machine technology is waaaaay further advanced than I thought it was - it hasn't been DONE.

You said just a few posts ago that we've not been able to test the predictions as if we did it'd be too late to do anything with the results (I paraphrase) - post #115.

Now you're trying to suggest that the validation has been done.
You can't have it both ways.

I'm saying (and on this point, this is all I'm saying) that at no time has that been done empirocally.
At no point has one of these models made a 50 or 100 year prediction that has been tested.

All of this is "theory" (and I say that in the lay use of the word) which is not established through the scientific method, unlike weather forecasting, which has, repeatedly.

 

[gregorach]

Ever heard of hindcasting?

 

[BigShot]

Locum - I think we may be on the same hymn sheet already.

We most certainly need to make the shift, and as it happens, I don't think it will be particularly easy either way.


If the only need is to get away from fossil fuels, why on earth do we need green taxes?
We already pay over half of our income into taxes (PAYE, NI, VAT, Cigarette, Fuel and Alcohol Duty, Departure Tax, Council Tax, etc etc etc) we do not need, do not want and can not afford yet more taxes under the banner of "green".

I don't believe the government has any business in telling us how to heat or light our houses, fuel our cars and so on.

If we want to hit people with any sticks at all, lets hit them with the "personal responsibility" and "consequences" stick.

Let's make everyone acutely aware that our current world can NOT continue. Let's make everyone accutely aware that for them, their kids, or at best their grandkids, oil and coal will no be on the menu and they must make a move to a different way.

Inventors will come up with the goods, we will move away from it.

But it's completely counter productive to deprive people of even more of their hard-earned money in order to further an agenda under false pretence.

Those who choose not to make the shift? Well, when the shift becomes one of necessity rather than choice they MIGHT have a rough time of it - but that's their own fault. Ain't personal responsibility a bitch?

I don't believe it will necessarily be rough though.

The change from domestic use of coal and wood to gas and electricity wasn't rough for the people who made it, it happened, for the most part, organically.

That is the only way the change from fossil to renewable should happen. That is the only way it needs to happen!

 

[BigShot]

Greg - yes, I have.
Get the model to model what has already happened.

Still doesn't make it empirically tested for the future.

Still doesn't mean that the model is correctly sensitive to the correct things. It's entirely concievable that one could make an incorrect model accurately hindcast the past.

One could devise a model which was far too sensitive to CO2 and yet accurately hindcasted past climate, yet it would be wildly innacurate in forecast.

 

[gregorach]

It's entirely concievable that one could make an incorrect model accurately hindcast the past.

No it's not. Get the model wrong with regard to CO2, and you can't reproduce the transient response to large volcanic eruptions.

Unless, of course, you believe that the basic principles involved in climate (i.e the laws of physics) suddenly changed in some fundamental way in the last 50 years or so...

Really, really done now.

 

[BigShot]

No, the laws of physics don't change (well, they might, but let's not get into that now eh?). At very least, they haven't.
However, that doesn't mean we've got it all tied down when it comes to weather (we haven't) or climate (we certainly haven't).

But even given that, it still doesn't hold that one can't hindcast accurately and be incapable of forecasting accurately.
There's more to it than CO2.

Transient responses to large volcanic eruptions, is that weather (short term) or climate (long term)?

It's entirely possible that those transient changes are weather anomolies caused by the eruption and that STILL leaves the door open for accurate weather and climate hindcasting and inaccurate climate forecasting.

 

[gregorach]

I'm really, really done now. If you want to find the answers to your questions, they are out there, if you're prepared to look. I'm sick of trying to explain anything to you.

You win. I give up. Happy?

 

[BigShot]

Not particularly, no.
I'm somewhat unhappy that you take such a negative view of this whole discussion...
I'm not going any further though as since you're now "really, really, really, really, really (is that enough? I can't remember how many there were) done now" I see no point.

I find it a shame you've reduced this to "sick of trying to explain anything to you" when it should be clear from my comments that I'm not some obstinate drunk in a pub who refuses to believe just because it doesn't sound right to him... but someone who has actually done some degree of reading on this and has yet to be convinced.

Just because I won't accept some of your arguments and some of your attempts at getting the last word (the only reason I can see that you keep coming back after being "really, really, realy [...] done now") does not mean I'm being wilfully ignorant or that I'm some idiot you need to get "sick of explaining" things to.

If you dislike this topic so strongly you shouldn't have got involved in the first place.

 

[gzornenplat]

No it's not. Get the model wrong with regard to CO2, and you can't reproduce the transient response to large volcanic eruptions.

It is perfectly possible to use the first half of a set of data to correctly predict the second
half and then incorrectly predict future events. I would have thought that you could come up
with an example yourself, but anyway, here's one:

1st half
warn day/cold day/warm day/cold day

2nd half
warn day/cold day/warm day/cold day

Theory: warm and cold days alternate

next 4 days: cold/cold/cold/cold

Theory stuffed.

The main problem with this method is that you already know what you are trying to predict
(i.e. the second half of the data) and therefore can tune your model to predict what you
know to be going to happen, even if you aren't actually using the later data in the model,
you already know what you consider to be 'correct'.

It's what you might describe as the 'Nostradamus Syndrome'. Once something has
happened, you can find the prediction. It's a darn sight more difficult to find a Nostradamus
prediction for something that hasn't happened and then see it proven true.

In the same way, if you have a firm conviction about AGW and/or you job depends on
keeping your masters happy, then there is no difficulty in finding a model and a set of
parameters which 'prove' your point of view. Either way.

 

[Rebel]

As for letting passion get the better of me, you should see me when I get started on creationists.

Whoopee, intellectual bushcrafter, I'm a creationist so get going.

 

[durulz]

Whoopee, intellectual bushcrafter, I'm a creationist so get going.

Odd how you associate anti-creationists with being 'intellectual'. What does that say about creationists?
No, I refuse to get dragged into this one. Reply all you want - I'm saying no more. Just couldn't help that little observation.