Bob Fitzgerald lives on the edge of a flat field that's just a few feet above sea level. It's the same spot on Maryland's Eastern Shore where his ancestors settled before the U.S. became a country.
"The land grant came into the family in 1666," he says.
When he was a child his parents grew tomatoes, cucumbers and string beans. Now nearing 80, Fitzgerald plants corn and soybeans to supply local chicken farms.
This area is some of the oldest farmland in America. But the land here is sinking, and as the climate warms, sea levels are rising. Fitzgerald says a tidal creek that runs alongside his fields is flooding more. Just the other day the water in one section of his land was higher than he'd ever seen it.
"It looked like a lake," he says. "You could not see a piece of grass sticking up, the tide was that high."
Fitzgerald shows me a small dirt berm he built to keep water out. But the floods spill over it probably once a month now. So far, he says, the saltwater has killed 15 acres of his soybean crop. In its place are bare patches of soil and a wall of tall, feathery phragmites, an invasive plant common in wetlands.
"I mean, I have actually thought about having dirt hauled in just to build this up another 6 inches or something, just to hold it off," he says. But he's not sure it's worth it.
A few miles away, Kevin Anderson says encroaching saltwater is costing him money.
"There's 20 acres of farmland that I mortgaged and paid for 20 years ago that's not producing any income now," he says.
Anderson is a fifth generation farmer, but says it's hard to plan these days. And he has a young daughter who's thinking about farming. He says everyone wants to know: What land is worth fighting to keep, and what land should they just let go?
"You know if you're going to draw a line in the sand, let's make an educated guess where we're going to draw the line," he says. "Give me an idea of what this farm will look like in 25 years.
That's exactly what Kate Tully hopes to do. She's an agroecologist with the University of Maryland, and she's tracking how this impact of climate change is hurting farmers here. We meet on a patch of land that's so degraded that the owner turned it over for Tully's research.
"That's where the corn was just two years ago," she says, gesturing to a largely bare field with clumps of brown and green. The soil is sandy with dried salt, and there are bluish-gray patches of microbial crust.
Tully says that as the Atlantic Ocean heats up, it's expanding. That means higher tides and more flooding. But that may not be all that's happening.
She bends over a pipe in the ground and pulls up two black tubes. One registers salinity; it's three times what corn can handle. The other measures groundwater level. It's just a couple feet down, visible inside the pipe.
Tully thinks the sea is pushing underneath the land and into the groundwater. She worries this briny mix is then rising with sea levels, killing from below. It's a threat that stretches all the way down the Eastern Seaboard to the Florida Everglades.
Tully wants to help farmers here hold on as long as they can, so she's testing out crops that are more salt tolerant. "We have barley and wheat, and we tried to plant switchgrass as well," she says.
Switchgrass might help restore the land. Tully thinks another solution could be to set land aside for conservation and pay farmers to do that.
"Everyone says when it comes down to it, Mother Nature is going to win this war," she says.
Farmers need a plan for coping with changes now, she says, and for adapting long term, because the bottom line is clear. As the Earth continues to warm, some land that's been farmed for centuries will be lost to rising seas.