Nuku’alofa (Tonga), Aug 27 (IANS): United Nations Secretary-General Antonio Guterres issued a "global SOS" in Tonga on Tuesday, urging governments to step up climate action to "save our seas", as two new reports revealed how rising sea levels are threatening the vulnerable Pacific region and beyond.

Guterres called on world leaders to drastically slash global emissions, quickly phase out fossil fuels and massively boost climate adaptation investments to protect people from current and future risks, Xinhua news agency reported.

He said global average sea levels are rising at rates unprecedented in the past 3,000 years.

A study by the World Meteorological Organization (WMO) -- 'State of the Climate in the South West Pacific' -- alongside a report by the UN Climate Action Team -- 'Surging Seas in a Warming World' -- showed that changes to the ocean are accelerating, with devastating impacts, the UN chief added.

The reports, released on the sidelines of the 53rd Pacific Islands Forum (PIF) Leaders meeting on Tuesday, confirm that relative sea levels in the Southwestern Pacific "have risen even more than the global average, in some locations, by more than double the global increase in the past 30 years, Guterres said.

He explained that "Pacific islands are uniquely exposed" as average elevation is just one to two meters above sea level, around 90 percent of people live within five kilometers of the coast, and half of all infrastructure is within 500 meters of the sea.

The Secretary-General reiterated his long-standing appeal for G20 nations, "the biggest emitters", to take a leading role in these efforts.

"And the world must massively increase finance and support for vulnerable countries. We need a surge in funds to deal with surging seas," Guterres stressed.