The Marshall Islands senior climate change advisor says most of the shoreline on the atoll of Ailinglaplap is eroding away.
Steve Why says the infrastructure at risk of eroding includes three airstrips, roads, causeways and schools.
Ailinglaplap is home to 1,700 people who live scattered on different islands in the atoll, which are about 30 to 90 centimetres above sea level.
Mr Why and a team from the Office of Environmental Planning and Policy Coordination have conducted a detailed climate change vulnerability survey of many of the 52 islands in the atoll.
They found coastal erosion is an increasingly serious problem.
He says lagoon side roads are eroding heavily, with adjacent beaches moving inland under higher sea levels.
Strong northeast trade winds over the past six months have elevated sea levels up to 15 centimetres.