Greenland ice sheet on course to lose ice at fastest rate in 12,000 years, study finds ~ The washngton post
By 2100, the ice sheet will shrink to the size it was during the last time the world was hotter than today.
The Greenland ice sheet is on track to lose mass at about four times the fastest rate observed over the past 12,000 years. At its current trajectory, such melting would dump huge quantities of freshwater into the sea, raising global sea levels and disrupting ocean currents, scientists concluded in new research Wednesday.
The new findings, published in the journal Nature, warn that the only way to avoid a drastically accelerated meltdown of the massive ice sheet in coming decades is for the global community to curtail emissions of greenhouse gases in the near-term.
Greenland is already the largest contributor to sea level rise, though Antarctica has the potential to increase sea levels even more. As sea levels creep upward, coastal storms including hurricanes and nor’easters become more destructive. Recent trends in more frequent “sunny day flooding” at high tide in places such as Annapolis, Md.; Norfolk; Charleston, S.C.; and Miami is also linked to sea level rise.
Researchers found that the current rate of mass loss from the Greenland ice sheet is already comparable to that seen at the end of the last ice age, during a geological period known as the early Holocene. At that time, the global average surface temperature was about 5.4 degrees Fahrenheit above the preindustrial average, a temperature the world is on track to exceed by the end of this century, depending on rate of global emissions.
“It is no secret that the Greenland Ice Sheet is in rough shape and is losing ice at an increasing rate,” Jason Briner, a geology professor at the University at Buffalo and lead author of the new study, said in a news release. “I think this is the first time that the current health of the Greenland Ice Sheet has been robustly placed into a long-term context.”
Briner and colleagues were able to put together an unbroken history of the Greenland ice sheet’s mass change, relying on computer modeling and field research in southwestern Greenland.