Tim Flannery

What role can Australia play in setting the agenda on climate change? We could lead the world if we chose to. The question really is what role do we want to play? Will Kevin Rudd deliver? I worry he's too cautious in his approach to climate change. Leadership in the absence of complete knowledge, and in the face of some intense opposition, is hard. It takes a real hero to do that.

How crucial are the upcoming US elections in terms of the climate change debate?Who is your pick of the candidates? Surprisingly, from a climate perspective, its difficult to say who the best candidate is. Both Obama and McCain have good policies, which is perhaps why climate has been a non-issue in the campaign.

What will be the effect of a desalinisation plant on Sydney's water crisis? Water prices will be far higher than necessary, and greater greenhouse gas emissions. We should have built a small plant as an insurance policy, and hoped never to have had to run it.

How do you respond to those who say it's too late to stop the juggernaut of climate change? It's not too late. If we start at [UN Climate Change Conference in] Copenhagen next year with a biting treaty, we could beat this problem.

What's the most prevalent misunderstanding people have on climate change? That it is their children's problem. I greatly fear that we'll be seeing very serious global changes in a decade or so. You've been accused of misanthropy in the past: having spent much of your life looking at the effect of humans upon the natural world.

Do you find it hard to be sympathetic about people at times? No. People are Gaia's intelligence; her most wondrous production. We need to rise to our own potential greatness, and I get disappointed when instead we squabble in the mud.

What should every Sydney household be doing as a matter of course as responsible guardians for the environment? Getting to know their country, and world. I mean really getting to know and understand it and how it works. How many Sydneysiders know how many plant species are found only in their precious sandstone environment? How many have seen a hanging dick? (If you don't know what that is, google Origma solitaria).

What are some practical green tips the modern Sydneysider can learn from how the Eora once took care of Sydney's lands? To the Eora, some of whom were known as Kadigal - the people of Kadi, Sydney Harbour - the water is sacred. Where does the lawn fertiliser you put on the grass go when it rains? The contents of your toilet bowl?

What were the biggest mistakes of Sydney's first settlers? Believing that we've boundless plains to share. For a start, they weren't just our plains and they weren't boundless.

What Sydney sites represent the perfect equilibrium between mankind and nature? North Head. It's the last home of the bandicoot and penguin in the Harbour area.

Who are the great environmental heroes working in Sydney today? Jeff Angel, and 10,000 unsung heroes who weed the bush, walk in it and admire its blooms.

What books - fiction and non-fiction - would you recommend to Sydneysiders wishing to understand their city and its environmental history? Watkin Tench's diary, A Narrative of the Expedition to Botany Bay, and my The Birth of Sydney.

You've borrowed Doc Brown's DeLorean from Back to the Future for the weekend. Where do you go? The past or the future? Back to the 25th January 1788. I'd love to know what Sydney was like the day before.

Tim Flannery's Quarterly Essay, Now or Never: A Sustainable Future for Australia will be published on Mon 22 Sep, $15.95. Prof Flannery will discuss Now or Neveras part of the Sydney Ideas Lecture Series on Mon 29 Sep, The Seymour Centre.