Malcolm Turnbull

Study after study has demonstrated that people are better off financially, healthier, happier if they are married, and indeed, I repeat, if they are formally married as opposed to simply living together.

We are already experiencing the symptoms of climate change, especially with a hotter and drier climate in southern Australia - the rush to construct desalination plants is an expensive testament to that.

It is our job above all in politics to tackle the big issues and to explain them, and have the honesty to say to people, 'There are no easy solutions here.'

But who knows, some years from now if there's a global emissions trading scheme agreement, as many have hoped for, then I'm sure Australia would be part of it.

The way to lose weight is to eat less, so I ate a lot less for a month and lost a lot of weight pretty quickly.

I am an ambitious person, but I am not ambitious in the sense that I want jobs only for the sake of them... I am here to do things I think are worthwhile. I am always careful that the political positions I take are consistent with good policy. I would not want to be prime minister of Australia at any price.

There is a tendency to try to dumb everything down and turn everything into a one-paragraph press release or even less, just a slogan.

I try to talk about policy issues intelligently, I try very hard to avoid thought bubbles. I make sure my speeches are well researched and footnoted. I make sure I am not talking through my hat.

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.

Are not the gays who seek the right to marry, to formalise their commitment to each other, holding up a mirror to heterosexuals who are marrying less frequently and divorcing more often?

So the proposition that the ideal parents for any child are its biological parents is a statement with which we can all agree in the generality, but which does not apply, for one reason or another, in many particular circumstances.

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.

Those who condemn gay marriage, yet are silent or indifferent to the breakdown of marriage and divorce, are, in my view, missing the real issue.

The only reason to be in politics is public service. There's no other reason. Frankly, if that's the best job you can get in terms of money, that's too bad, you know. Because frankly, it's not well paid, everyone knows that. So for most people it's a big sacrifice.

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.

I will go to the next election saying to Australians, vote for me, vote for the Liberal Party, and I will become your PM. So I'm offering myself as the alternative PM - that's one way people describe the Leader of the Opposition - but I'm not in politics for myself to realize a personal ambition.

On balance, after weighing the arguments, I believe that the time has come for Australia to create a new sovereign wealth fund.

Governments enjoying surpluses have a very strong temptation to splash money around, and while tax cuts are always appealing, cutting taxes at the top of a boom runs the real risk of creating a structural deficit when the boom subsides.

Look at countries like China, they are determined to dominate all clean technology areas, putting lots of money into wind, solar, electric vehicles and battery storage. America's political impotence, caused by their terrible partisanship, will see them left behind.

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.

To the former child migrants, who came to Australia from a home far away, led to believe this land would be a new beginning, when only to find it was not a beginning, but an end, an end of innocence - we apologise and we are sorry. To the mothers who lost the maternal right to love and care for their child - we apologise, and we are sorry.

I love radio - its immediacy and especially its intimacy... it is part of your life, whispering into your ear. You can't see it, but equally importantly it can't see you.

We need to recognise that the whole edifice of our fifth estate, of our journalism, has been built on a foundation of newspaper journalism and that that foundation is crumbling. The management of the media companies will deny that the end is nigh. I hope they are right.

Climate change is a global problem. The planet is warming because of the growing level of greenhouse gas emissions from human activity. If this trend continues, truly catastrophic consequences are likely to ensue from rising sea levels, to reduced water availability, to more heat waves and fires.

Anyone who thinks it's smart to cut immigration is sentencing Australia to poverty.