Hawaii must brace itself for global warming's effects

THE ISSUE An international panel has predicted a rise in sea level of nearly two feet during this century.

A moderate but bleak assessment of global warming bodes ill for Hawaii in the decades and centuries ahead. At some point, a state policy is needed to cope with the sea as it continues to encroach on the islands' coastlines.

The International Panel on Climate Change of the United Nations concluded a session during the past week in Paris with the modest projection that the sea level will rise by 7 to 23 inches by 2100 and the coasts will continue retreating for at least 1,000 years. Seas rose about 6 to 9 inches during the past century.

That assessment is far lower than the rise of 20 to 55 inches by 2100 projected in a study published in the journal Science last month. Other climate experts predict the sea level will rise at levels that can be measured by feet more than inches.

"A foot to foot-and-a-half rise vertically has a tremendous impact horizontally," said coastal geologist Dolan Eversole. He showed the Star-Bulletin's Diana Leone a slide of Waikiki with that amount of sea-level rise leaving only a sliver of land remaining above water between Ala Wai Canal and the beaches.

"You could imagine about the same effects on Haleiwa and Waialua," said Eversole, a University of Hawaii Sea Grant geologist on loan to the state Department of Land and Natural Resources.

The department's goal is "to balance coastal development with beach conservation," said Sam Lemmo, administrator of its Office of Conservation and Coastal Lands. "Because there's no balance, that's why our beaches are disappearing."

A major factor, of course, is global warming. The panel in Paris, which has made four assessments since 1990, concluded for the first time that global warming is "unequivocal" and that human activity -- carbon dioxide and other heat-trapping greenhouse gases -- has been the main cause for the temperature rise since 1950.

The panel predicted that the global climate will increase by 3.5 to 8 degrees if carbon dioxide concentrations in the atmosphere reach twice their pre-industrial levels. Many energy and environment experts believe the rise will double that after mid-century in the absence of a prompt and sustained shift away from the burning of coal and oil, the main sources of carbon dioxide, and a shift to nonpolluting energy options.

The Bush administration, which has been skeptical about the human cause of global warming, cannot regard the report lightly. Created by the United Nations, the panel of hundreds of scientists and reviewers is by its nature cautious because its reports must be unanimous, approved by 154 governments, including the United States.

The time for skepticism has passed. And for our island state, it isn't too soon to start planning for the consequences of rising seas.