Off the northern tip of the Pacific nation of Tuvalu, an anti-aircraft gun emplacement juts above the surf. Built by American troops during World War II to fight the Japanese, the concrete installation was originally on land but is now offshore, a tiny island created by the rising seas and changing shorelines. Today, as new regional rivalries disrupt the Pacific, local leaders are pointing out the obvious: the seas now pose a greater threat than guns.

During a visit to Australia this week, Tuvalu’s prime minister, Enele Sopoaga, warned Scott Morrison that a failure to address climate change risked undermining the so-called “Pacific pivot”, Canberra’s efforts to bolster ties in the area to prevent powers such as China gaining influence. Australia has recently boosted its Pacific aid budget, promised deeper military cooperation and announced plans for a naval base in Papua New Guinea. However, as Mr Sopoaga told ABC News, “We cannot be regional partners under this step-up initiative, genuine and durable partners, unless the government of Australia takes a more progressive response to climate change.”

Leaders such as Mr Sopoaga want Canberra to scrap plans for Adani’s new coalmine in Queensland. He said that his nation, whose atolls and reefs are on average two metres above sea level, could be “totally destroy[ed]” without urgent action on climate change. Fiji has already begun relocating communities affected by coastal erosion and flooding. But in minuscule countries such as Tuvalu, where sea levels are rising four millimetres a year and land masses are constantly changing, threatened communities have nowhere to go. New Zealand has proposed introducing a special visa for climate change refugees, but Pacific nations have largely rejected the idea because they would prefer to keep living in their homes. “Tuvaluans want to continue to be Tuvaluans,” Golriz Ghahraman, a New Zealand MP, said in August.

Tuvalu’s appeal to Australia came as delegates from almost 200 countries gathered in Poland to discuss the climate change commitments agreed to in Paris three years ago. Australia will be represented by the environment minister, Melissa Price, who is attending despite Morrison telling 2GB last month: “I’m not going to spend money on global climate conferences and all that nonsense.” He also suggested he would end Australia’s contribution to the global Green Climate Fund, which helps developing countries respond to climate change. (Per capita, Australia is the fourteenth-largest donor, but has the second-highest emissions of the forty-three donor nations.) Morrison has insisted that Australia will easily meet its Paris emissions targets without further action, even though government data has repeatedly indicated that it will not. The latest figures, released last Friday, showed that emissions increased last year and were at their highest levels since 2011.

When Kevin Rudd, as prime minister, pressed for global action on climate change, the Coalition claimed that Australia should not try to lead the way. Now, Australia is a laggard. In September, the Pacific Islands Forum, an organisation of Pacific nations that includes Australia, released a statement declaring climate change to be “the single greatest threat” to Pacific people. But Australia allegedly tried to water down the wording, to the consternation of Pacific leaders.

Australia’s approach to climate change is crucial to its future, but it also has international ramifications. In Poland, Australia is reportedly planning to join other Pacific nations in producing a joint statement calling for action on climate change. For Australia, which is concerned about the growing influence in the region of countries such as China and Russia, this act would be an important display of solidarity with its neighbours. For Pacific leaders, Australia’s support is likely to be just as important as whether China or some other nation buys its wharves, or funds its undersea cables, or builds its next set of gun emplacements.