Photo: AFP / Theo Rouby
NASA is predicting Pacific Island states will see at least 15 centimetres of sea-level rise in the next 30 years.
This comes from analysis by NASA's sea level change science team.
It also said this amount of rise will occur regardless of whether greenhouse gas emissions change in the coming years.
NASA said its sea level change team undertook the analysis of this region at the request of several Pacific Island nations, including Tuvalu and Kiribati, and in close coordination with the US Department of State.
It also created maps showing which areas of different Pacific Island nations will be vulnerable to high-tide flooding - otherwise known as nuisance flooding or sunny day flooding - by the 2050s.
It comes as the Alliance of Small Island States this week issued a declaration saying they will not lose their rights under international law, regardless of sea-level rise].
Nadya Vinogradova Shiffer, who directs ocean physics programs for NASA's Earth Science Division, said NASA's new flood tool shows what the potential increase in flooding frequency and severity look like in the next decades for the coastal communities of the Pacific Island nations.
"Sea level will continue to rise for centuries, causing more frequent flooding," she said.
NASA said the analysis by the sea level change team also found that the number of high-tide flooding days in an average year will increase by an order of magnitude for nearly all Pacific Island nations by the 2050s.
It predicted areas of Tuvalu that currently see less than five high-tide flood days a year could average 25 flood days annually by the 2050s. Regions of Kiribati are set to experience an average of 65 flood days by that time.
Team members, led by researchers at the University of Hawaii and in collaboration with scientists at the University of Colorado and Virginia Tech, started with flood maps of Kiribati, Tuvalu, Fiji, Nauru, and Niue, with plans to build high-resolution maps for other Pacific states soon.
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NASA said the maps can assist Pacific Island nations in deciding where to focus mitigation efforts.
Tuvalu youth leader Grace Malie said science and data can help the community of Tuvalu in relaying accurate sea level rise projections.
She is involved with the Rising Nations Initiative, a United Nations-supported program led by Pacific Island nations to help preserve their statehood and protect the rights and heritage of populations affected by climate change.
"This will also help with early warning systems, which is something that our country is focusing on at the moment."
Malie said she is living with the reality of climate change.
"Everyone (in Tuvalu) lives by the coast or along the coastline, so everyone gets heavily affected by this."
NASA said a combination of global and local conditions, such as the topography of a coastline and how glacial meltwater is distributed in the ocean, affects the amount of rise a particular region will experience.
Ben Hamlington, the agency's sea level change science team lead, said while "we're always focused on the differences in sea level rise from one region to another...in the Pacific the numbers are surprisingly consistent".
Researchers would like to combine satellite data on ocean levels with ground-based measurements of sea levels at specific points, as well as with better land elevation information.
"But there's a real lack of on-the-ground data in these countries," Hamlington said.
NASA said the combination of space-based and ground-based measurements can yield more precise sea level rise projections and improved understanding of the impacts to countries in the Pacific.