The West Coast will see an ocean several inches higher in coming decades, with most of California expected to get sea levels a half foot higher by 2030, says a report released Friday.

The study by the National Research Council gives planners their best look yet at how melting ice sheets and warming oceans associated with climate change will raise sea levels along the country’s Pacific coast. It is generally consistent with earlier global projections, but takes a closer look at California, Oregon and Washington.

Although the 6 inches expected for California by 2030 may seem minor, the report estimated that sea levels there will be an average of 3 feet higher by 2100. About 72 percent of the state’s coast is covered by sandy cliffs, and the rest includes beaches, sand dunes, bays and estuaries.

Seaside cliffs will be cut back about 30 yards over the next 100 years, and sand dunes will be driven back even more, said Robert A. Dalrymple, a professor of civil engineering at Johns Hopkins University and chairman of the group that wrote the report. After about 50 years, coastal wetlands will eventually be overwhelmed without new sources of sand or room to move inland.