A science lesson for Maurice Newman and Senator Brandis

This is the first half of a speech Australia's chief scientist delivered to the Carbon Market Institute Conference in Melbourne this week. The second half, in which Prof Chubb lays down the scientific landscape that provides reasonable certainty about climate change, will be published tomorrow.

I note that the Attorney General in his recently reported comments about free speech remarked that alternative views have a right to be heard and that to suppress them would be ‘medieval’ – by which I infer he meant that we in contemporary times are better than that.

And I think the first part at least is right – we should not suppress views. But views should be given the weight they warrant – and that weight should be based at least in part on the knowledge and expertise of the individual offering the view.

I particularly agree that genuine scientific evidence should be aired and be subject to the scrutiny of peers, wherever it may lead. And if the evidence is shown to be soundly based it will add to our knowledge and understanding and be used to adjust our conclusions. If it is not, it has no place in the argument. As I said, it should be given the weight that it warrants.

On the other hand, there are those who only offer opinion, but they often do so with a level of certainty that disguises that it is more likely a leap of faith. An intuitive step outside the limitations of science-based argument – as I saw it described elegantly in a spoof corporate video I saw recently. Belief trumping evidence, you might say.

A couple of weeks ago, I was told about one of those shows we now see often on TV. You know the ones, where journalists talk to other journalists all of whom have complete confidence in their ability to offer certitude on any topic.

During the course of this particular program I gather they discussed climate change. One of them, I am told, commented that they didn’t need to kowtow to experts on the subject. Now I would be pretty sure that when their car breaks down none of them would take it to the fish monger to get it fixed – or even to get an opinion. So I suggest that what they really meant was that they didn’t need to have particular regard for the overwhelming bulk of opinion because it is expert. After all, it would tell them what they clearly didn’t want to know, so don’t listen and it isn’t there.

And we all know what follows: cherry pick and sow the seeds of doubt.

As a consequence, climate science experts have been labelled and disparaged. They have been represented as part of one giant conspiracy for ideological (i.e. destruction of the free enterprise system) or (personal) financial reasons.

There are accusations of fraud, that climate change is a ‘delusion’ or that the science is ‘a religion’. There are calls for some scientists to be jailed; accusations of venality – where scientists say and do whatever it takes to get another research grant or another airfare to a conference where the group thinkers huddle, or that they are Nazis.

And this is all because there is no body of scientific knowledge that can refute what we now understand to be happening to our planet. And because some of the scientists express exasperation even irritation at what they see as a distortion of the science and the misuse or worse of scientific evidence. And because they are telling us what some people just don’t want to hear.

Then there is ‘group think’, apparently a characteristic of the climate scientists.

It is an intellectually bankrupt argument bordering on the facile.

Have those who trot out the line ever stopped to think just how ’group think’ might be arranged? How a few thousand scientists from all sorts of disciplines using all sorts of techniques and technologies and from all over the world could be coerced into a shared view (dare I say consensus) that human activity is having an impact on our climate?

In other words, regardless of what their observations show, it is suggested that the scientists will spin them or manipulate them so that they can rise as one and declare that human activity is one of the reasons why the planet is warming. Really?

Unlikely, so let’s sow the seeds of doubt.

As big tobacco discussed in 1969 – “Objective No. 1: To set aside in the minds of millions the false conviction that cigarette smoking causes lung cancer and other diseases; a conviction based on fanatical assumptions, fallacious rumors, unsupported claims and the unscientific statements and conjectures of publicity-seeking opportunists. Even more florid than now maybe, but the direction is familiar.

The Attorney General might have been right in labelling suppression of alternative views as medieval. But if the passage of time is supposed to lead to enlightenment, let me just say that the notion of ‘shooting the messenger’ goes back further than medieval times, all the way back to ancient Greece in fact. Bring on enlightenment.

I know that by the very nature of science not every single detail is ever totally settled or completely certain. Nor has every pertinent question yet been answered. But the evidence is mounting, it has been scrutinised as never before – and it leads inexorably towards a level of probability that the prudent would heed.

Ian Chubb is the Chief Scientist of Australia.