Rising sea levels are a “worldwide catastrophe” which uniquely threatens Pacific Islands, UN Secretary-General Antonio Guterres has warned. The UN chief raised the alarm at a meeting of the Pacific Islands Forum – the most important political gathering in the region – in Nukuʻalofa, the capital of Tonga on Tuesday. He also released two UN reports which detail disastrous changes to the ocean caused by climate change. “The ocean is overflowing,” Guterres said. “This is a crazy situation: Rising seas are a crisis entirely of humanity’s making. A crisis that will soon swell to an almost unimaginab…