A new study by NASA has said Antarctica has gained more ice over the years than it is losing, contradicting earlier reports that ice sheet in the region has been depleted due to global warming and climatic change.
The study challenges a 2013 report by the United Nations' Intergovernmental Panel on Climate Change (IPCC) that ice mass in the Antarctic region has been decreasing for over two decades due to climate change.
Researchers from NASA's Goddard Space Flight Center in Greenbelt, Maryland, have analysed satellite data to find that the Antarctic ice sheet gained 112 billion tons of ice a year from 1992 to 2001.
"We're essentially in agreement with other studies that show an increase in ice discharge in the Antarctic Peninsula and the Thwaites and Pine Island region of West Antarctica," said Jay Zwally, a glaciologist with NASA and lead author of the study, which was published in the Journal of Glaciology.
"Our main disagreement is for East Antarctica and the interior of West Antarctica — there, we see an ice gain that exceeds the losses in the other areas," he added, saying his team "measured small height changes over large areas, as well as large changes observed over smaller areas."
But does the study mean slowdown in climatic change? Not really, because it also found net ice gain slowed to 82 billion tons per year between 2003 and 2008 (compared to 112 billion tons a year from 1992 to 2001), which is a matter of concern.
"If the losses of the Antarctic Peninsula and parts of West Antarctica continue to increase at the same rate they've been increasing for the last two decades, the losses will catch up with the long-term gain in East Antarctica in 20-30 years. I don't think there will be enough snowfall increase to offset these losses," said Zwally.
What is even more interesting is IPCC's study found consistent rise in sea level — 2.8 mm per year — between 1993 and 2010 due to climate change and global warming. The study also attributed 0.27 mm rise in sea level per year to melting of the Antarctic ice sheet.
But how can that happen if one is to go by the NASA study's claim that East Antarctica and the interior of West Antarctica gained ice by an average of 0.7 inches per year, enough to outweigh the losses from melting glaciers in other parts of the continent?
"The good news is Antarctica is not currently contributing to sea level rise, but taking 0.23 millimeters per year away," said Zwally. "But this is also bad news. If the 0.27 millimeters per year of sea level rise attributed to Antarctica in the IPCC report is not really coming from Antarctica, there must be some other contribution to sea level rise that is not accounted for."
