Let's distinguish between a model and an algorithm as they are often conflated.

Before the Bohr-Rutherford model of the atom (electrons in fixed orbits about the nucleus) there was a known algorithm for calculating the spectrum of the hydrogen atom which involved integer values. Nobody knew why it worked. When the model was proposed with accompanying mathematics built on first principles, the integers turned out to be the electron orbit number in the model. Although mathematics perfectly described the simple case of the hydrogen atom it could not extend to more complex atoms other than serve as a basis for approximation. To this day day there is no perfect algorithm that describes their spectra, only approximations. Nevertheless, the model survives (albeit that orbit numbers got replaced with other ideas).

A model serves as a concrete way of seeing something mathematical. In climate science there is no simple case analogous to the hydrogen atom, only complexity. We are stuck with approximation. We are deducing algorithms that may successfully describe the past and therefore provide faith in future projections. It's a work in progress.

Prof Akasufo's projections use the algorithms (there isn't just one) designed for long term projections for short term foresight and hindsight. This leaves his work open to dispute. Also, his exiting-the-Little-Ice-age theory which he uses as the default point of comparison for projections arrived at is also in dispute.

"I have no disrespct for Arrhenius but I do for people who continue to quote this paper as if it were still somehow relevant."

We shouldn't split hairs over what was discovered in 1896. CO2 is a greenhouse gas and the higher its concentration the higher the its effect. Is it responsible for the very high night-time temperature on Venus. Is this in seriously in dispute in any reputable scientific forum/publication?

With no disrespect meant to him in return, perhaps John should be plying his scientific arguments in the right place, rather than this layman's blog-spot, as he has obviously has ground-breaking news to share with the scientific community.

john..are the 'other greenhouse gasses'
in the modeling..?

lets not forget that home compost produces..*methane
[tax them greenies with worm farms]

how about nitrogen..80 times as bad as c02
you know nitrogen..that makes that nice green salad

farmers use lots of it...in making soy juice
and worse is that 60%..of all nitrogen applied onto crops
by the protected farmers industry

nitrogen..turns into nitrous oxide..
[120 times worse than a c02]

then we come to that solar cell cleaner
hundreds of times worse than c02

and the list goes on
but so too the collective ignorances

i note the normal carbon tax
cheer squad is mute with guilt

abbot if he really didnt want the tax
would raise these questions in parlement

that he dont
reveals he is just a mr no..[too]
he wants the tax..but wants to be..seen as opposing it more

so when he goes the double disolution
workers will once again resent,,the new tax

and the new laws his election will raise..

[but those running the 2 party
scam..will say well done allround]

and still the party blindness
from the party lotalists refuse to face the ugly truth

this is about the next the cut for workers
that cuts their wage

recall gst..10% cut in wage
recall compulsory super to bailout
the investers[running the 2 pary scam]

10%..cut in workers wage

ditto the carbon tax
dont be foooled that only 1000..[oops sorry only 500 will pay]

and that 9/10 will get extra..the darn tax is indexed

meaning its going to grow..at inflation rate..FOREVER
based on spin and lies

look at the big number
the carbon tax is going to cost 70 BILLION..to get rid of
erxpected to raise over a trillion

who is paying that LOSS of income

the mug workers
ie larratters/liberals greenies alike

next tax the other GREENhouse gasses
more tradeable commodies..[thin air]

silence is guilt?

Oh dear, John Reid.

>>Pericles says: "But what I do know is that the preponderance of evidence, taken as a whole, points to a probable catastrophe if we continue pumping greenhouse gases into the atmosphere."<<

I sincerely trust you are more careful in your references "as a researcher with CSIRO with a PhD in Upper Atmosphere Physics."

For the record, stevenlmeyer is the one knowledgeable about the preponderance of evidence. The same person who asked me this:

>>As I said in my previous post, we should have the answer by around 2030. How old are you Pericles? Think you'll still be around and compos mentis in 2030? Maybe we can resume this discussion then. :-)<<

Less than twenty years into the future? I certainly hope to be around then, stevenlmeyer, sound in mind and limb. And if you'd like my predictions, here they are. One, that we will still be arguing about climate change. Two, that we will be doing so in a world whose climate has barely shifted from its present state. And three, that we will have made significant progress towards widespread access to renewable energy sources.

If you'd like a fourth, bonus prediction, it would be that there will be some who will claim that two is as a result of three. But won't be able to "prove" it, hence the ongoing argument.

Pericles

Sorry mate - incorrect attribution. I am not used to this blog which has the author's name at the bottom of each post rather than near the top.

Luciferase says:
"We are deducing algorithms that may successfully describe the past and therefore provide faith in future projections."

That "may" successfully describe the past? May?

My point is that that they DO NOT successfully describe the past and therefore should NOT be used to provide future projections. To base public policy on such models would be criminally stupid but that is precisely what is about to happen. Please look at the maps from the Ensembles Project half way down the page at

http://www.scienceheresy.com/2011_03/hindcasting/index.html

I will say it again - the models do not work!

This is hardly surprising. Meteorological models can predict no more than 3 weeks ahead. Oceanographic models can predict no more than 6 months ahead (e.g. El Nino). We are expected to believe that if we couple these models together they are suddenly able to predict decades or even centuries ahead. Give me a break.

I appreciate your arguments from spectrography; yes the algorithms existed before the models. The big difference is that those algorithms worked to a very high degree of precision. Climate models do not work at all, that's the problem.

Look to the source of your arguments John

http://climate.nasa.gov/causes/

I prefer actual established scientific organisations rather than those devoted to a single aim.

We cannot continue to pollute, degrade our ecosystems and use all our fossil fuels without consequences.

You have not discussed any of the above - preferring to focus on a single issue - which has been proven as untrue. Climate modelling continues to bear out predictions. I wish you were correct. But we don't live on a magic pudding - what we are doing has repercussions.

http://www.globalchange.gov/publications/reports/scientific-assessments/us-impacts/key-findings

http://climate.nasa.gov/effects/

All we do know for sure is that the climate is definitely changing. You can debate the cause if you wish, but making changes to clean sustainable technologies is just simply good sense. If the changes are not as severe as predicted - well then we got off - lucky us and we will have gained a sustainable future.

But to do nothing - which I believe from your posts, is what you are arguing, is absurd.

John Reid wrote, Friday, 30 September 2011 12:16:42 PM:

>... Science is primarily about evidence, and the rigorous testing of hypotheses against observations. ... Anthropogenic Global Warming (AGW) ... remains only an hypothesis; not a proven fact ...

Scientists do not deal in "proven fact", only hypotheses which might be later disproved by new evidence.

As a professional I have to weigh up the available evidence and act in the interests of my clients, and ultimately, in the public interest. I can't wait for certainty.

The evidence presented for human caused global warming is now sufficiently credible to act on. The cost of not acting would be unacceptably high.

So in the course I wrote on "ICT Sustainability", I treat global warming as a certainty and then go on to detail how computers and telecommunications can be used to reduce carbon emissions: http://www.tomw.net.au/ict_sustainability/