The politics of climate change are veering in starkly different directions in the neighboring states of North Carolina and Virginia. Foolhardy denial about the severity of rising seas is underway in North Carolina, where the Republican Legislature, prodded by tourism-dependent coastal counties and alarmed homeowners, ordered a state commission of experts to soften its estimate that coastal waters could rise 39 inches by the end of the century. The commission was told to revise its outlook, take into account dissenting views of climate change and produce a forecast of no more than 30 years — in hopes of keeping the estimated sea-level rise to no more than eight inches.

By contrast in Virginia, a bipartisan group of political leaders is forthrightly talking about the problem. Last week, they met to consider ways to adapt the low-lying Hampton Roads region in southeastern Virginia to science-based predictions that the seas will rise at least a foot in 30 years and five feet or more by the end of the century.

“The challenge is not theoretical,” said Representative Scott Rigell, an Eastern Shore Republican. Gov. Terry McAuliffe, a Democrat, announced the creation of a new state commission on the ocean threat.

At the heart of the Hampton Roads area is Norfolk, home to the world’s largest naval base and a city that the White House warned in May is among the nation’s most vulnerable to rising sea levels. “This is a matter of national security,” Alice Hill, a senior adviser to the National Security Council, said at the Virginia meeting.