Washington, D.C. [US]February 12 (ANI): An investigation of the Antarctic ice sheet in a 2 degree warmer world shows how important it is to comply with the Paris Agreement.
Researchers have long speculated that melting the western Antarctic ice sheet (WAIS) during the last interglacial period (LIG) between 1.29,000 and 1.16,000 years ago could have contributed significantly to global sea level rise. However, no direct physical evidence for such melting has been identified.
Chris Turney and colleagues report a high-resolution record of environmental and ice sheet changes from the Patriot Hills Blue Ice Area on the periphery of the WAIS. Deuterium isotope measurements showed an interruption in ice recording that began just before the LIG about 130,000 years ago.
This interruption indicates a significant loss of ice mass during the LIG, which coincides with a well-documented peak sea temperature, suggesting that warming the ocean led to a loss of the ice sheet.
DNA analysis of old microbes preserved in the ice revealed a high proportion of methane-using bacteria immediately before the ice sheet was lost, which is compatible with increased methane values due to the methane release from marine sediments.
Modeling the ice sheet based on the ocean and atmospheric temperatures consistent with those during the LIG predicted an Antarctic contribution to global mean sea levels of approximately 2 to 6 meters in the first 1000 years. The results indicate that the WAIS is very sensitive to future warming, according to the authors.