Archaeologists are combing California's coast, searching for artifacts before they're lost to rising seas. A recent survey of Marin County turned up twenty sites scientists hadn't seen before.  
 
Mike Newland, an archaeologist at Sonoma State University, organized the volunteer effort. He found obsidian, shells, handstones and pestles that belonged to the Coast Miwok people.

He says erosion and an accelerated rise in sea level caused by climate change, threaten to erase our coastal past.

"It's not going to just affect one cultural group," Newland explains. "This is the history of all of us. Worldwide. Everybody's going to have to make some hard decisions. About what to look at, what to keep, what to dig, what to let go."

Newland says this is the first project in the country to examine how climate change threatens archaeological sites, and he plans to expand it to the entire California coast. He's already led a survey of Monterey's coastline, and a similar effort in San Diego will begin next year.