They are from Papua New Guinea's Carteret Islands near Bougainville, where people are being displaced by rising sea levels.
The Catholic Leader reports that many of the islands' coconut trees have fallen because their roots were eroded by the rising seas.
Visit organisers include the Sisters of Mercy and Caritas.
Mercy Sister Wendy Flannery said the people of the Carteret Islands contribute virtually nothing to global greenhouse pollution.
The Carteret Islanders Speaking Tour will move from Brisbane to Sydney, Newcastle, Canberra and Melbourne.
It is designed to raise public and political awareness in Australia. Organisers hope this will put pressure on the Australian government to act quickly in the setting of targets for emissions reductions.
Climate change forces island people to move
LINKS (not necessarily endorsed by Church Resources)
Carteret Islands (Wikipedia)
Climate change, water of "utmost importance": Benedict insists (CathNews, 6/9/07)
Climate change sceptics melt under spotlight, Columban priest reports (CathNews, 1/5/07)