Researchers took rock and soil core samples from Virginia, New Zealand and Eniwetok Atoll in the Pacific and looked at material from the Pliocene epoch (2.7 million to 3.2 million years ago). Using this data, the researchers predict that future generations could face a rise in sea levels, between 12 to 22 meters (40 to 70 feet) — although this may take hundreds to thousands of years.