The Pacific Islands Forum in Tonga this year has drawn 1,500-plus delegates from 40 countries including Australia and New Zealand, Pacific island nations and territories — plus China and the U.S.

Monday, as the forum began, United Nations Secretary-General Antonio Guterres warned of rising ocean temperatures and rising sea levels that can decimate corals, an essential element of island ecosystems, and inundate low-rising islands, displacing entire island nations. A global study shows the Southwest Pacific has been worst-hit by sea level rise, Guterres said: “I am in Tonga to issue a global SOS — Save Our Seas — on rising sea levels.”