Professor Ian Chubb, Australia's Chief Scientist and a director of the CSIRO, is urging scientists to contribute to the climate change debate.

I became a scientist because I wanted to understand how things work. For me, the only reliable way to gain this understanding is the scientific method. Without it, we are left with prophecy, divination, fortune-telling and group-think.

Science is primarily about evidence, and the rigorous testing of hypotheses against observations.

According to the Anthropogenic Global Warming (AGW) hypothesis, an observed increase in atmospheric carbon dioxide concentration was the primary cause of the apparent global temperature increase of about 0.8 degrees Celsius during the 20th century. Yet there is little observational evidence supporting it, nor would a small temperature variation over one hundred years be an unusual or "extreme" event.

The truth is AGW remains only an hypothesis; not a proven fact about the Earth's climate. Support for it comes, we are told, from climate modelling. But can a grab-bag of hypotheses expressed in numerical form be described as genuine empirical evidence? And do the models stand up well when rigorously tested against observation?

As a researcher with CSIRO with a PhD in Upper Atmosphere Physics, I was involved in developing numerical fluid dynamical models similar to those used by climate modellers today.

The CSIRO website statement - "Climate models, which are based on the laws of physics and thoroughly tested, provide credible quantitative estimates of future climate change" - is misleading. The "laws of physics" actually play only a minor part in climate model design. Furthermore, the models have no real predictive power. Their "projections" rarely match observations. If they have been "thoroughly tested", the public should be told of the outcomes - especially the frequency of failure. As it is the modelers only show graphs which support their hypothesis.

A more comprehensive version of this letter is available at
http://www.scienceheresy.com/2011_09/rallying_to_the_chief_scientist.htm

So in other words, unless you can be 100% certain that you are correct and no matter how severe the consequences, it's better not to put a fence at the top of the cliff but just park an ambulance at the bottom.

Not exactly, rache.

>>So in other words, unless you can be 100% certain that you are correct and no matter how severe the consequences, it's better not to put a fence at the top of the cliff but just park an ambulance at the bottom<<

I think he is saying there's no point in bankrupting yourself putting up a fence at the edge of the cliff, if the drop is only four feet.

Because, as he points out, you are not actually able to look over the edge yourself to check. You are relying on a whole lot of people predicting the length of the drop with "a grab-bag of hypotheses expressed in numerical form".

By the time science makes up it's mind it will be too late to do anything about it. Nothing will ever change the fact ,we have to get off oil and gas. There just happens to be a co2 factor in it as well.

is there really a voice of reason...john?

i..recall...the ozone hole

recall the adverts..from the 90's
burning deserts..global warming

after thatchers..c02 thesis
[ie global cooling*..was proved fraud]

anyhow..lets look at your words

""The truth..is AGW remains..only an hypothesis;""

yes..as does their favoured cure

science isnt about..consencus
[not about..conclusion]
but endless study of fact..

not modeling..that gets tweaked
to re sync-up..the modle with the data

if..the modle/bling is right
it should match predictions
its as simple as poimting out..where it dont..!

and it dont]..trendlines begotten
from mixing data sets..is clear fraud

yes models are..""not
a proven fact..about the Earth's climate."'

""do the models stand up well
when rigorously tested against observation?""

no they dont

but mate..science concenus
lol..also proven fraud..has made those..with only faith/hope
not fact

fall for the grand scam..they took
the free gifts..got the subsidised buy-backs..they sold-out reason

they cant be reasond with
guilt..has made them deaf

""The CSIRO/website statement.."Climate models,which are based on the laws of physics..and thoroughly tested,..provide credible quantitative estimates of future climate change"

*is misleading.""

yes it is..but mate
if they got guilt..if they bought..into the lie

if they been..trying to be..oh so clever..
mate they are stuck..with a bad loss of face

they..dont want to hear
""The "laws of physics" actually play
only a minor part..in climate model design.""

they dont know
the affect of the sun or solar activity

""Furthermore,the models..*have no real predictive power."'

i seen that too

""Their "projections" rarely match observations.""

i noted that

""If..[..IF*..they have been.."thoroughly tested",
the public..*should be told..of the outcomes""

yes daily..they would say
we told you so
but then cant
cause the modle bling..is badly flawed

""..especially the frequency of failure.
As it is..the modelers only show graphs
which support..their hypothesis..""

yes mate
but what is a lone vouice
of reason..crying in the wilderness?

and yes
i know your not alone
but their minds..are numb

media is selling the scam
even the abc..has drunk the coolaid

WHAT CAN WE DO?
who is left..to listen?

We're going to run the experiment - that is to say humanity is going to continue pumping greenhouse gases into the atmosphere. By around 2030 we should know who is right, the climate scientists or the "sceptics."

If I'm still around and not gaga I'll be interested to see the outcome.

Here's the way I think about my own mortality. I'm watching a fantastic soap opera called human history and I just know the TV is going to be turned off before the final eopisode.