Greenland ice sheet is melting at rapid rate

The melting of Greenland’s ice sheet has accelerated to unprecedented rates in the face of rising temperatures, analysis of ice cores has found.

Surface melting across the mile-thick ice sheet increased in the 19th Century as human activity started to warm the climate, but ramped up in the 20th and early 21st centuries and shows no signs of abating, scientists said.

Ice loss from Greenland, including run-off from melted snow and ice on the top of the ice sheet, is contributing to sea level rises.

If Greenland ice continues to melt at unprecedented rates as a result of warmer summers, it could accelerate the already fast pace of sea level rise, the researchers warned.

Analysis of ice core samples from sites 6,000ft (1,829m) above sea level has enabled the researchers to assess melting dating back 350 years.

The scientists combined the results from ice cores with satellite data and climate models to reconstruct meltwater run-off at lower elevations on the edge of the ice sheet that contributes to sea level rise.

They found that increases in melting closely follow the start of industrial-era warming in the Arctic in the mid-1800s but the magnitude of the melt has exceeded natural variability in the past few decades.

Study co-author Sarah Das, from Woods Hole Oceanographic Institution in the US, said: “From a historical perspective, today’s melt rates are off the charts and this study provides the evidence to prove this.”

Total ice sheet melt-water run-off had increased 50% compared with the start of the industrial era and had seen a 30% increase since the 20th Century alone, she said.

Summer melting in 2012 was at levels that represented “exceptional highs” for the past 350 years.

Greenland’s melting ice.