Ice on Greenland is melting four times faster than it did just 16 years ago, a study reports.

The melting, which is a result of the Earth's warming atmosphere and oceans, is happening much faster than scientists had thought and will likely lead to faster sea-level rise.

"Increasingly, large amounts of ice mass are going to leave as meltwater, as rivers that flow into the sea," said study lead author Michael Bevis of Ohio State University.

A large part of this melting ice is in Greenland's southwestern area, which scientists didn't think was melting so fast. "Southwest Greenland could become a major contributor to sea level rise under continued climate warming," the study said.

The study was published Monday in the peer-reviewed journal Proceedings of the National Academy of Sciences. It is yet another scientific study that reports on the loss of ice in the world's coldest places, including Antarctica.

Rising seas are especially concerning for coastal U.S. cities, including New York City and Miami, along with vulnerable island nations around the world.

Sea level has risen nearly 8 inches worldwide since 1880, primarily because of global warming, but also because of sinking land in some areas. It's one of the most obvious results of our warming planet, which is heated up by burning fossil fuels such as oil, gas and coal.

Researchers were able t