SCIENCE AT THE SHINE DOME canberra 7 - 9 may 2008

Symposium: Dangerous Climate Change: Is it inevitable?

Friday, 9 May 2008

Welcome

Professor Kurt Lambeck, PresAA, FRS

Good morning. I'm pleased to see you all bright and sparky this morning after last night's wonderful dinner. Welcome, everybody, to this Science at the Shine Dome and to the Academy's Annual Symposium, 'Dangerous climate change: Is it inevitable?'

Climate change and climate variability remain one of the most debated science issues – and I think this meeting is an illustration of that – although I guess some would say that a lot of discussion in the press, in particular, where it has its greatest impact, is not always terribly scientific. But, because it is obviously a very important issue, it has to be kept at the forefront of discussion.

Responding to the implications of the best science available is one solution; doing nothing because the science is not perfect is, of course, another. But if the human race had consistently taken the latter path, I suspect we would still be living in the caves.

In the last few weeks there has been some renewed attention given to expressions of doubt about the theory and evidence underpinning climate change and climate variability, and in a sense I am tempted to use the words that Robyn Williams used in a similar context, that some may find it presumptuous of someone who is not a scientist, who has undertaken no original research, to challenge prevailing orthodoxy.

I am perfectly happy to accept that even a political scientist may have something to contribute to the debate, and I feel free to contribute to any debate about political theory (if I were foolish enough to do so) because I think it is part of the process of identifying where the misunderstandings are in the minds of those who ultimately have to make the policy decisions. How to get the larger community to sift through the information to make informed decisions, I believe, is the real challenge: how to get people to be able to separate fact from emotion. I am tempted to use what I am sure must be a Biblical quote about asses and water, that you can take asses to water but you can't make them drink.

To take an example: if, in some of the debate that we have heard, those people had listened to my Press Club address a couple of years ago, they would not be making the statements that they have made about sea level rise. But I can't blame them for not having listened to that, because it is all buried in a huge amount of information that is out there. So it would be unfair to say that. It does point, however, to the real challenge we have, of how to get the signal to rise above the noise level.

The Academy is acutely aware of this challenge, and it has tried to address this over the years in a number of ways. We do that through the workshops, we do it through our Nova web site and we do it through the public addresses by the Academy's members. This workshop is part of that process of putting the evidence on the table in a way that makes it accessible to the larger community. It is part of the process of identifying where greater effort is required to explain the underlying science. It is part of the process to identify what science needs to be done to really understand climate change, to understand the assumptions upon which it rests and to understand the uncertainties associated with the inferences drawn and the gaps in our understanding of the interactions between many of the components that make up the Earth's system.

The recent death of Edward Lorenz, the man who found that perfect weather forecasts were impossible because even small changes in inputs parameters led to dramatic changes in the model results, is perhaps worth highlighting here. In his paper Predictability: Does the flap of a butterfly's wings in brazil set off a tornado in Texas? he expressed succinctly – as one of our new Fellows Nalini Joshi said on Wednesday – the very core of the problem that we are faced with, because it is the breakdown of order into chaos that leads to the uncertainties of predictions in our climate system, and it is what makes it impossible to get deterministic solutions for climate.

It is what makes it important to understand the multiplicity of interactions and feedbacks in the climate system, and it is what makes it so difficult to see whether any long-term trends are masked by the quasi-cyclic behaviour of many natural forcing systems. Can the natural variation superimposed upon the accepted higher levels of CO₂ in the atmosphere trigger instabilities that spin the Earth into a dangerous climate change? Do we wait for this to happen, or do we identify what can be done now to reduce the likelihood of it happening?

That is what we are going to hear about today. And without any further ado, I am going to hand over to Graeme Pearman, because I am anxious to hear what the speakers are going to do about this.

Thank you very much, Graeme.