New research by an international drilling team finds that Greenland ice survived global temperature increases without excessive damage. The findings may have implications for the understanding of modern temperature changes.
The North Greenland Eemian Ice Drilling Project has released new research stating that a significant rise in global temperature 130,000 years ago did not have as major an impact on Greenland ice as was previously postulated.
The drilling team was faced with an immense task. In Greenland, layers of snowfall accumulate and compress over thousands of years. When these permanent blocks of sheet ice are sampled, they reveal data about variations in climate over the years.
Before this research endeavor, scientists were unable to retrieve records of climate conditions prior to 110,000 years ago. In order to examine conditions in the Eemian periodoccurring 130,000 to 115,000 years ago, scientists had to design a new approach for penetrating folded sheets of ice. Scientists used a sonar detector to identify variations in the crystal makeup of the ice. The variations assisted drillers in approaching the ice with a better understanding of the structure of the ice folds.
The international drilling team bored 1.5 miles into the surface of Greenland over a 2 year period. The ice cores were analyzed to reveal cloud temperature at the time of snowfall, atmospheric conditions, precipitation rates, and air composition. Among other research goals, the team hoped that their research on ancient temperature increases would lead to conclusions about the potential effects of climate change in the near future.
During theEemian period, the temperature was roughly 15 degrees Fahrenheit warmer than it is today. The research team found that, contrary to predictions, the Greenland ice sheets were only a few hundred meters lower during the Eemian period than they are in the latest modern analyses. This research indicates that the melting of Greenland ice contributed to less than half of the sea level rise that occurred during the warming period.
Although the Greenland ice melted at a rapid rate of 6 centimeters annually, the ice sheets survived even the most intense temperatures of the warming period, losing a maximum of only 25 percent of their total mass over 6,000 years.
Extreme predictions of potential climate change put the global temperature increase at 9 degrees by the end of the century. The melting of Greenland ice is frequently cited as an urgent matter in light of continued temperature increases. Scientistspostulate that, based on the new research, even such a large increase in temperature would not cause complete devastation of the Greenland ice sheets.
While the research indicates less damage to ice than previously estimated, scientists explain that if the melting of Greenland ice accounts for only half of the ancient rise in sea level, the majority of the other half resulted from large-scale melting of Antarctic ice. The ice drilling researchers maintain the position that, despite lower rates of Greenland ice melting, their findings are cautionary evidence of the worldwide consequences of climate change.