1998: 'Our models show conclusively that rising CO2 levels immediately cause an increase in global temperature.'

2009: 'Our models were never meant to suggest that rising CO2 levels immediately cause an increase in global temperature. There could easily be a delay of ten years...'

2019?: '...or twenty years...'

2029?: '...or thirty years...'

Can someone in authority please tell me: how long do we have to have rising CO2 and flat temperature levels before AGW is disproved? I may not be around to see it, but I hope my grandkids will.

June 2008 and the banks in America still have AAA rating. Can you trust the earth worshippers any more than the economist? Already the alarmist have proved wrong time and time again. Get the weather forecast correct for one week and then work on something a little more complicated.

“In other words a climate model is a numerical model or simplified mathematical representation of the Earth’s climate system, or parts thereof. It includes data from real world observations and creates parameters or variables for the unresolved or unknown processes.”

The words “parameters or variables for the unresolved or unknown processes “

Is techno-babble for “speculative guesswork”

Just as terms like “then further approximated through mathematical discretization.”

Means “subjective judgment”

And “restrict the resolution”

Equates to "fuzzy and inacertainable possibility"

In short “personal guess work”,

containing the same sort of logic which suggest someone will win the lottery based on submitting a ticket containing their childrens’ birth dates.

Like the article states:

“This disjunct between scientific and the media presentation, when contained within the paradigm of advocacy, represents a threat to the integrity and falsifibility of science.”

None of the climatological balderdash and bunkum should ever be the foundation for making the serious social and economic policy decisions which will effect our future and our children’s future.

You either have a good reason for doing something or you have the sort of third rate psuedo-twaddle which "grant-hungry" climatologists try to pass off as “science”.

Many centuries ago wars were fought only after inspecting of the entrails of a slaughtered goat.

Climatology presents us with sanitized goats entrails and we are expected to pursue an economic war strategy based upon that gut feeling…

Personally, I would as soon speculate what the moon is made of and if it should collide with the earth, the dairy industry will collapse from the ensuing cheese glut.

I see that we are still awaiting a cogent, well-argued refutation from the AGW alarmists ...

This article should be required reading for all concerned about the issue.

I agree with this article.

But I would go further though, you could take out the word ‘climate’ and most of it would still hold up. In fact it is generally a good criticism on how models are made and how models can be in error in all fields of study. Does that make modelling invalid generally?

No.

The future is inherently uncertain, but modelling is pretty much the only tool that can be used for risk assessment and mitigation. Future projections generally are not terrific, no scientist disputes this, but they are useful in showing us how much we know about whatever system we are modelling.

What is also not being talked about is that policy decisions are not made after the fact. Real data is gathered after the fact, by definition. Policy is made on future predictions of trends and models, this goes for nearly every field of policy making, from town planning and demographic projections and industrial growth to science-based projections such as the effects on agriculture of disease incursion or pest outbreak or pesticide resistance. But for politicians and policy-makers it is usually necessary to attach economic consequences otherwise they find decisions exceptionally difficult to make. Who would want to spend millions of dollars maintaining a quarantine program if it was probable that it wouldn’t save any money for our agricultural industries at all? This is where they become unscientific; they are economic risk models.

What I would like to know from the author is this: should scientists generally stay out of communicating research to the media, just in case their field of research gets politicised?

I think the media have done a great job in misrepresenting what science is and what it does and completely bollixing up the public perception of science on a much more general level than just climate change. Anyone read those “research-has-shown” articles lately? Just for the record, if an ice-cream company pays a PR-firm to show that men prefer food to sex, and then gets “an expert” to comment on it, I think that they do a disservice to everyone.

If this article is saying that models are not the same as the "real world" then I along with all other modellers - of each Ian Reed is one - would agree.

Models do not "prove" anything but they do not stop Ian Reed saying in his article at http://www.agu.org/pubs/crossref/2003/2003WR002042.shtml that "Oak woodland is also predicted to have a significant impact by reducing recharge plus runoff by almost one half as compared with grassland." He hasn't proved that this is the case but there is strong likelihood that this will occur.

The climate change models say things like "If carbon dioxide levels increase by x% then it is likely that temperatures will rise by y degrees and will continue to rise".

If you have enough modellers coming to similar conclusions then it does not "prove" anything but any prudent person will take notice and say. If it is likely that temperatures will rise by y degrees will that make a difference? The prudent person may come to the conclusion that it is highly likely that it will make a difference detrimental to his or her wellbeing.

The prudent person might then say - is there a way to make it less likely that the temperature will rise and come to the conclusion that if we reduce the amount of carbon dioxide and other greenhouse gases in the atmosphere then it is likely that will help stop the temperature rise. The prudent person would then ask the question - By reducing the level of ghg concentrations will they be better off materially? if they come to the conclusion that they would be better off then would be foolish not to try to reduce ghg concentrations.

If the person realises that they can't do it on their own but have to enlist the support of the rest of humankind then they should advocate a policy of reducing greenhouse gases.

I consider myself to be a prudent person and will continue to advocate for a reduction in ghg emissions even without positive proof of its effect.