Former prime minister Kevin Rudd says he is looking forward to contributing to action on climate change as part of his appointment to a United Nations panel.

UN secretary-general Ban Ki-moon announced earlier today that Mr Rudd was appointed to a panel to work on global sustainability and reducing poverty.

Mr Rudd spoke briefly about his new role on the campaign trail in Brisbane today.

"This is a way in which I can make a modest contribution to the future of acting globally and nationally on climate change," he said.

Mr Ban says he has asked the panel to "think big".

"The time for narrow agendas and narrow thinking is over," Mr Ban said.

In addition to Mr Rudd, the panel includes other politicians from around the world including the former prime ministers of Norway, South Korea, Japan and Mozambique.

The panel has been tasked with producing a report by the end of next year.

In a statement issued this morning, Mr Rudd said the first meeting of the panel would be held in about a month and he would not be paid for the role.

"It is anticipated the panel will only meet once in 2010 and hold two meetings in 2011," the statement said.

"This appointment is entirely consistent with Mr Rudd's work as a Member of Parliament should he be re-elected at the coming election."

Greens Leader Bob Brown has wished Mr Rudd well in the role.

"Kevin Rudd has got an international statesman renown which will add to that UN panel and it's really a matter for him to determine there," he said.

"I'm sure he'll be waiting until after the election to see just how he complements his time in the parliament with the international stage."

Prime Minister Julia Gillard has guaranteed Mr Rudd will be given a senior frontbench position if Labor wins government, but the Opposition has questioned whether Mr Rudd can do both jobs.

Opposition Leader Tony Abbott says Ms Gillard must explain what role Mr Rudd would play in any future Labor cabinet.

"This is an official appointment to a serious UN panel that is going to involve significant time out of Australia," he said.

But Mr Rudd has said the position is only part-time and would only involve travel overseas for a few meetings a year.

Mr Rudd is officially on the campaign trail for Labor after last week declaring he could not sit "idly by" to watch Mr Abbott "slide into office" by default.