Look at that nice warm sand on the beach. Isn’t it inviting?

Well, enjoy it while it lasts. By 2100, California’s coastline probably won’t have much sand left to build a castle or plant an umbrella because of climate change.

Sea-level rise is already threatening billions of dollars’ worth of homes, businesses, roads and infrastructure statewide, the county said. Local governments are caught in an awkward position; they need to level with people about the realities of sea-level rise without resorting to a doomsday approach and an urgent warning to head for higher ground.

“While we know these changes are happening, we can only estimate how soon we will see more dramatic impacts,” said Jack Liebster, community development planning manager. “By beginning to prepare now, we can find ways to live with higher water levels as well as create suitable defenses.”

On June 3, the county of Marin’s Community Development Agency will host an informational event about sea-level rise on Stinson Beach as part of a statewide campaign called Shrinking Shores. Shrinking Shores events will be hosted from as far south as Santa Monica to Humboldt Bay in the north, in anticipation of World Oceans Day, a global celebration and collaboration for a better future on June 8.

At Stinson Beach, beach-goers will see a dramatic illustration about predicted ocean levels through the end of the century. Temporary signposts and flags will be stuck into the sand to depict scenarios of future sea-level rise. Shrinking Shores organizers will staff a booth near the “Year 2100” level of the beach. Experts will be available to discuss the science behind the predicted rises, and the county’s sustainability team will provide information about ways to reduce greenhouse gas emissions.

Communities will be better prepared to meet the challenges by assessing what is vulnerable to rising tides, creating opportunities for residents to learn from the experts, and by involving everyone in collaborative planning for the expected environmental changes.

CDA planners also created Collaboration: Sea-level Marin Adaptation Response Team to get more people educated and involved in the process of planning for a coordinated response.

The Shrinking Shores tent will be located on Stinson Beach near the main parking lot and restrooms from 10 a.m. to 1 p.m. The county also will be hosting two public workshops about sea-level rise at 6:30 p.m. June 6 at Dance Palace, 503 B Street, Point Reyes Station, and 6 p.m. June 14 at Stinson Beach Community Center, 32 Belvedere Ave.