Climate-change scientists predict sea to rise 1 foot by 2050

Scientists are predicting the ocean could rise by as much as a foot in the Hawaiian Islands by 2050 and that droughts may become more frequent on leeward sides of the islands.

By 2050, warmer temperatures will also contribute to the annual bleaching of coral reefs and a reduction in mosquito-free habitat for endangered Hawaii birds.

The predictions are contained in a report resulting from the collaboration of more than 100 scientists, which was prepared in advance of a public forum from 9 a.m. to noon today at the Hawai‘i Imin International Conference Center in Hono­lulu.

The report, "Climate Change and Pacific Islands: Indicators and Impacts," partially supported by the National Oceanic and Atmospheric Administration and the U.S. Fish and Wildlife Service, assesses climate change in Hawaii and other Pacific islands.

Contributing scientist John Marra said sea levels will rise globally as much as 2 feet by the end of the century.

By comparison, sea levels rose by about half a foot in the last century, said Marra, NOAA climate services director for the Pacific islands.

The impact of rising ocean levels will particularly be felt on the northern shores and in places susceptible to flooding and erosion.

"Over time, extreme events are going to be more frequent, lasting longer," he said. "That will have a cumulative impact."

The scientists’ predictions are based in part on looking at past records along with developing climate models for ocean warming and the melting of polar ice, among others.

In Hawaii the impacts will be felt in business and recreational areas.

For example, Marra said, places such as the low-lying commercial Mapunapuna area on Oahu will flood more regularly, and ponding will be more regular at Kapiolani Park, because rainwater won’t have as much depth to percolate before reaching the groundwater level.

He said the impact on tourism will be the loss of beach, and that while beach replenishment in Waikiki might work for now, it may not be the answer in the future.

"If it gets high enough, it might not work," he said.

Scientists predict annual rainfall will decrease across the state overall.

Victoria Keener, an East-West Center research fellow and lead editor for the Pacific Islands Regional Climate Assessment, said trends show a decrease in frequency of high-intensity rain and an increase in the frequency of droughts and dry days.

"The leeward side of most of the Hawaiian Islands is projected to have an increase in drought risk," she said.

She said some tops of mountains such as on Kauai and windward Maui are predicted to have decreasing occurrence of droughts.

Keener said the state has a potential advantage in establishing policies to deal with climate change and decreasing rainfall because it has a state water commission with the responsibility to sustainably manage Hawaii’s water resources.

"I think Hawaii has a good chance to be a leader in the field of proactive climate change adaptation," she said.

Keener said businesses can also avoid potential damage by being proactive.

For instance, the vice president of PVT Land Co., which operates a landfill, heard about a predicted increase in above-average rainfall on Oahu from weather forecasters and decided to take steps to make improvements that would affect the diversion and capacity to hold storm water on the company’s property, she said.

The improvements were put to the test when the Nana­kuli area, where the company is located, received 10 inches of rain from a single storm in 2011.

Other landfills were forced to close down.

"Due to their good use of a climate forecast, PVT Land Co. was open for business the next day," Keener said.