Huge tides and waves linked to climate change are already forcing people from their homes, says Cardinal John Ribat of Port Moresby.
"For us, Amoris Laetitia will always be there," Cardinal Ribat told CNA.
"You can have time to talk about this," he said, but stressed his country is facing one major problem that can't wait for a solution: climate change.
"It is really the biggest issue for us. We cannot keep quiet about it. We have to come out with it," he said, noting that the "king tides, king waves" and rough winds "belting" the island nation are already forcing many people from their homes.
These are the things "we cannot stop. They continue to come, and they are more powerful than us," the Cardinal said, explaining that while temporary sea walls have been set up, "they won't hold".
"Our situation, it's timely, you either talk about it or you see these people finished ... There's not timing for it. The time is either now or never."
Cardinal Ribat said his red hat was timely above all because it allows him to have more heft when voicing the country's concerns, particularly on the issue of climate change.
"It's happening at this time and we don't know where it is coming from and why it is happening ... we have islands disappearing, being washed because of the high-rise sea level and people there, they have to move," he said, noting that many of the smaller islands "are not able to sustain themselves" for much longer.