Australia's Deputy Prime Minister Julia Gillard said on Monday it is Australia's national interest to prevent further climate change as Australia is a dry and hot place.

She said at the time when the Copenhagen Summit is ongoing that all are striving to see the world to reach an agreement that will make a difference over time and the world is watching for good reason.

Gillard claimed herself to be an optimist personally when it comes to value the potential outcome of the summit, but at the same time saying the world's never been here before.

"As the Prime Minister said, as Senator Wong (Climate Change Minister) has said, the world's never been here before. It's not like we can look back at past experience and say we know how this goes."

Actions on climate change will make a difference to the children of this nation, to their children, to our long-term future, Gillard said, "And we know how devastating inaction is. We know that the science is in about what it will mean for our nation and what it will mean for the world."

She also said on Monday the main item in Copenhagen is whether the world can strike an agreement to take us forward, to deal with the challenge of climate change and to cool down the warming globe.