I do not believe we can effectively move Australia to a lower emission economy, which is what we need to do if we're going to make a contribution to a global reduction in greenhouse gases, without putting a price on carbon.

In economics, one of the most important concepts is 'opportunity cost' - the idea that once you spend your money on something, you can't spend it again on something else.

You will never find a better friend to the United States than Australia.

Many Liberals are rightly dismayed that on this vital issue of climate change we are not simply without a policy, without any prospect of having a credible policy but we are now without integrity. We have given our opponents the irrefutable, undeniable evidence that we cannot be trusted.

When politicians offer you something for nothing, or something that sounds too good to be true, it's always worth taking a careful second look.

The question of whether or to what extent human activities are causing global warming is not a matter of ideology, let alone of belief. The issue is simply one of risk management.

What we're seeing at the moment is people being radicalised or adopting Islamist, murderous Islamist ideology very, very quickly so that you have people that are not on the counterterrorism radar screen who then often, as a result of mental illness, will then attach themselves to this murderous ideology and then act very quickly.