Near Midway, Georgia, a public park sits where construction crews once dug a deep pit to build I-95. Decades of tidal flooding have turned that pit into a shallow mudflat, and on the opposite bank, the marsh grass that used to hold the shoreline together has been chewed away by the tide. "We've lost about 6, 8 feet right here," said Phil Odom, chairman of Liberty County's Consolidated Planning Commission, describing the collapse of the bank.

Georgia holds more than a third of all the connected salt marsh left on the Southeastern coast, hundreds of thousands of acres that buffer the coastline against storms. But as sea levels rise 1 to 2 meters over the next 75 years, those marshes will need room to move inland, not just protection where they already stand. When a migrating marsh hits a paved road or a building instead of open land, it has nowhere left to go, and the rising tide floods the marsh and whatever was built in its way.

A coalition of conservationists, scientists, and coastal officials, led in Georgia by the Georgia Conservancy, has mapped more than 56,000 acres of land where marshes are likely to migrate that remain open to development today. Coastal director Courtney Reich says the plan isn't a mandate or a land grab. It's meant to help landowners and local governments ask a simple question before they build: "Do we want to build up to the edge of the water or do we want to leave room?"

Leaving that room protects more than marsh grass. It protects the homes, roads, and infrastructure that the marsh would otherwise absorb the flooding for. Sign the petition to demand Georgia's coastal counties and state agencies formally adopt this migration map in their planning decisions, before more shoreline disappears the way it has near Midway.