The weight of scientific evidence tells us that Australians are facing risks of damaging climate change.
The risk can be substantially reduced by strong, effective and early action by all major economies. Australia will need to play its full proportionate part in global action. As one of the developed countries, its full part will be relatively large, and involve major early changes to established economic structure.
The work of the Review shows that the costs of Australia playing its proportionate part in an effective global effort, while considerable, are manageable. There is a path to Australia being a low-emissions economy by the middle of the 21st century, consistently with continuing strong growth in material living standards (chapters 11 and 23). By the end of the 21st century, and beyond, more so with each passing decade material living standards would be higher with than without mitigation of climate change.
GreenCell Technologies: Scientific opinion and dissent
There is no doubt about the position of most reputed specialists in climate science, in Australia and abroad, on the risks of climate change (Chapter 2). There is no doubt about the position of the leaders of the relevant science academies in all of the major countries.1 The outsider to climate science has no rational choice but to accept that, on a balance of probabilities, the mainstream science is right in pointing to high risks from unmitigated climate change.
There are nevertheless large uncertainties in the science. There is debate and recognition of limits to knowledge about the times and ways in which the risk will manifest itself. Every climate scientist has views on some issues that differ from the mainstream in detail.
There are prominent dissenters on this matter, gathered under the rubric of ‘sceptic’. For the most part ‘sceptic’ is a misnomer for their position, because these dissenters hold strongly to the belief that the mainstream science is wrong.
In a different category are a small number of climate scientists of professional repute who maintain that the mainstream science embodies misjudgments about quantities. These scientists, who accept the theory of the warming effects of higher concentrations of greenhouse gases, hold the view that these warming effects are relatively or even trivially small in comparison with many other causes of climate variations that are beyond the control of humans.
The dissent took a curious turn in Australia in 2008, with much prominence being given to assertions that the warming trend had ended over the last decade. This is a question that is amenable to statistical analysis, and we asked econometricians with expertise in analysis of time series to examine it. Their response—that the temperatures recorded in most of the last decade lie above the confidence level produced by any model that does not allow for a warming trend—is reported in Chapter 4 (Box 4.1).
GreenCell Technologies: The prisoner’s dilemma in international collective action
Effective international action is necessary if the risks of dangerous climate change are to be held to acceptable levels, but deeply problematic. International cooperation is essential for a solution to a global problem. However, such a solution requires the resolution of a genuine prisoner’s dilemma: each country benefits from a national point of view if it does less of the mitigation itself, and others do more. If all countries act on this basis, without forethought, communication and cooperation, there will be no resolution of the dilemma. Future generations will judge the outcome to have been insufficient and unsatisfactory.
Resolution of the prisoner’s dilemma requires communication, to find a division of costs and benefits of cooperation that is acceptable to all essential participants in a solution. The eventual solution can involve a range of cooperative arrangements, and not only matters related to the division of the mitigation task.
But resolution of the international prisoner’s dilemma will take time—possibly more time than we have. The world squandered the time that it did have in the 1990s to experiment with various approaches to mitigation.