It’s just one of many beaches that will be prey to rising sea level and erosion, two of the worrisome byproducts of climate change, an existential threat to this island state and coastal communities across the globe.

And not all the fixes applied this week at Sunset Beach will be appropriate at all points around Oahu; topography changes, ocean currents move along shorelines with varying effects.

But at a minimum, the start of a phased plan to restore what erosion stripped from the famed coastline is a welcome demonstration by the city. It exemplifies Honolulu’s promise to address climate change effects as they happen, and anticipate them in its planning process.

Crews began work this week to restore a sand dune that had eroded, undercutting and damaging the bike path along Kamehameha Highway. The broken bike path asphalt is being removed, sand will be moved to build up the dune. The public is invited to plant the dune with native coastal plants, helping to hold it in place.

In addition, special matting will be placed to create a pathway across the dune to the beach. Encouraging beachgoers to stick to the path is a necessary part of the plan.

All of this is aligned with a directive issued last month by Mayor Kirk Caldwell, a mandate that city departments and agencies take action to meet the impacts of climate change and sea-level rise.

In short, managers have the imperative to propose revisions to shoreline development rules and construction standards, taking other steps as needed to protect Oahu from the changes expected.

In the July 16 directive, Caldwell uses as the basis the findings of the city’s Climate Change Commission, which painted a dire picture of outcomes residents should expect from the extreme natural processes.

With no action, a projected sea-level rise of 3.2 feet by mid-century would damage or permanently flood 9,400 acres of land, over half of which is designated for urban use.

It would wipe out $12.9 billion in structural and land values, including 3,880 structures and 17.7miles of major roadway. An estimated 13,300 residents would be affected.

Obviously, action is required to head off losses of this magnitude. And all city departments and agencies are called on to incorporate new elements in the work they do. These would include looking for ways to reduce greenhouse gases in the atmosphere, which have been faulted for causing temperatures to rise.

The commission’s guidance, a seven-page document, lays out the belief that in the later decades of this century, sea-level rise will nearly double to 6 feet.

Those findings are endorsed by the state Department of Land and Natural Resources. Its leadership implored county governments to plan for such an outcome, anticipating wave over-wash, groundwater inundation, erosion and drainage backflow.

In addition to the commission, the city now has an Office of Climate Change, Sustainability and Resiliency, and making sure all targets are met is its function.

There is now officially no excuse to see the issue of climate change recede, along with the beach sand, in consideration for Oahu’s future. There is a whole new bureaucracy that is supposed to act as a prompt to keep the issue on the front burner — and its primary responsibility is to become agents of change. Residents of Oahu and the rest of the state also should examine their own actions for ways of reducing their “carbon footprint” and of conserving the natural coastal beauty.

At Sunset Beach, surfers and organizations are enlisted in educating the public about protecting the fragile dunes. Concern for coastlines is global, but Oahu’s North Shore seems a fitting place for Hawaii’s contribution toward their protection to begin in earnest.