if the Aus opens up to on-demand mass immigration from polynesia , philipines and indonesia many of their problems will be resolved.
(1) any island territory affected by global warming can evacuate enmasse and settle in aus
(2) indonesians and filipinos will be happy to work either as guests or settlers in a nearby land and be patriotic citizens - for them the aus income is way higher up the scale. manpower for a strong armed forces will no longer be an issue and having a friendly neighbour up north is a big help.
(3) they can finally settle the continent properly and exploit its resources instead of pining for some lost figment of 101% gorahood and engrish heritage, resulting in serbs being given preference over nearby indonesians
(4) the influx of asiatic culture will suppress and squeeze out racism in due course via electoral politics
(5) plans for a new caliphate hatched by the faithful will be shelved as pop starts increasing steeply again
(6) preferential trade benefits from the countries which benefit.
am sure there will be holdouts for a 'white australia' - these can migrate off to NZ, UK or some desolate island like christmas or pitcairn island to setup their new camp.
all it takes is pragmatism. and I strongly suspect these proposals will not find favour