Fossils discovered in Greenland ice sheet, revealing increased risk of sea level rise

Greenland has melted before. As the climate warmsit is It will melt again —Scientists warn that sea levels could rise by 20 to 25 feet this time.

During one warm period in the past 1.1 million years, not only the edges but also the center of Greenland’s giant ice sheet melted, revealing a dry, barren “tundra” that was home to a wide variety of life. has been found in a new study. insects and plants. The findings were shared in a new paper published today in the Proceedings of the National Academy of Sciences.

When the ice sheets first melted, the levels of greenhouse gases in the atmosphere were lower than they are today. now Increase in carbon dioxide in the atmosphereScientists say Greenland’s ice sheet is melting more easily than previously thought.

“Greenland has existed with ice for 2.7 million years,” said University of Vermont scientist Paul Biermann, who co-led the study. “There is some evidence that this ice sheet is fragile.”

Researchers have been studying material at the bottom of the Greenland ice sheet, the largest in the northern hemisphere, since 2014. They examined sediment from the bottom of an ice core (called GISP2) taken from two miles below the surface of the center. Ice sheet about 30 years ago.

One ounce of sediment sample was packed with clues about Greenland’s past. Microscopic examination of the tiny black specks revealed insect eyes, arctic poppy seeds, parts of arctic willow, and small fragments of soil fungi and spike moss. Biermann called this a “frozen ecosystem beneath the ice.” ”

Researchers say the fossils provide “direct evidence” that 90% of the ice sheet was once gone.

“Finding these fossils in the center of the ice sheet is clear evidence that Greenland’s ice disappeared (in the past),” Biermann said. “And if you lose the center of the ice sheet, you’ve lost everything.”

The discovery supports the so-called “fragile Greenland” hypothesis, which suggests that nature, without human influence, has caused the ice sheet to melt at least once since its formation, Biermann said.

Greenland’s ice sheet measures 656,000 square miles and currently covers about 80% of the island’s territory. To put it into perspective, it’s about three times the size of Texas.

NASA, which has mapped Greenland’s ice loss, says the ice sheet has been “rapidly declining in recent years,” causing global sea levels to rise by about 0.03 inch a year. According to Biermann, the melting of Greenland’s ice mass is currently the biggest contributor to sea level rise.

“At the beginning of climate warming, it was mountain glaciers that were melting most of the ice and adding water to the oceans,” he says. “We’re in Greenland now.”

It may take thousands of years for all of Greenland to melt, Biermann says, but the consequences will be dire. Hundreds of millions of people could lose their homes and jobs. Places that we hold dear to our hearts will be lost.

“When people ask me, I like to say, ‘Why does that matter? I say, think of your favorite beach. And you’re 25 feet deep in water. “Imagine your favorite beach,” Biermann said.

more