Up to 100 feet of shoreline will disappear around the state if sea level rises just 1 foot.
That's according to University of Hawaii scientists, who discovered that sea-level rise is the most important reason for coastal erosion in the islands and recently studied why beach erosion is more pronounced on Maui than on Oahu.
"The Big Island is pushing down on the Pacific Plate and there's kind of a moat that goes around there," said Brad Romine, coastal management specialist with the University of Hawaii Sea Grant. "Maui is closer to that and so it's sinking a little faster, and as you move away to Oahu, it's not sinking at such a fast rate."
Romine and UH School of Ocean and Earth Science and Technology Professor Charles "Chip" Fletcher said that at 6 inches a century, sea-level rise in Hawaii is not as fast as the global average of 1 foot. They said it's because winds in the Pacific help to push a lot of water to the west of us.
Fletcher said, "It's been predicted that sea-level rise will be on the order of 1 foot by mid century and 3 feet by the end of the century."
With this new research, the researchers said we know this rise will play a significant part in eroding Hawaii's shores in the decades ahead.
"So it'll help with management decisions for managing beach erosion problems around the state," Romine said. "We can start to focus our effort a little bit more on where sea-level rise might impact some of our beaches."
"In the end, when it comes to beach erosion and sea-level rise, there's no magic wand," said Fletcher. "The number of tools that you have at your disposal for managing the problem is very limited and typically they're very expensive."
Fletcher and Romine said researchers work hand in hand with the state's Department of Land and Natural Resources to develop management tools in coastal retreat, adaptation and re-nourishment.
Unfortunately, they said, they have no erosion data for Kauai or the Big Island.