It's really corny to say, but if you are happily married and have good kids, that is about 98 per cent of what you should be seeking to achieve.

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.

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 you've got to do is recognize that you don't control everything for a start, you've got to play the cards you're dealt, the hand of cards you're dealt, as best you can, and that's what I always seek to do.

Americans understand that they have no stronger ally, no better friend, than Australia.

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.

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.