NASA study: Net gains for Antarctic ice sheets

According to a latest study conducted by NASA, the net ice sheet gains significantly outweigh the losses on the Antarctic continent.

A recent study by NASA is challenging existing studies including the Intergovernmental Panel of Climate Change’s (IPCC) 2013 report on effect of climate change on Antarctica. In fact, so much more ice has been added into the continent over the past 10,000 years that it makes the gains of Antarctic ice sheet greater than losses. That net gain slowed to 82 billion tons of ice per year between 2003 and 2008.

“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 study lead Jay Zwally of NASA’s Goddard Space Flight Center. A few smaller areas experienced drastic height changes but there were minimal changes noticed overall.

“The good news is that Antarctica is not now contributing to sea level rise, but is taking 0.23 millimeters per year away”.

At the same time, Zwally says the gains in the Antarctic ice sheet mass will be offset by the losses in the Antarctic Peninsula and parts of West Antarctica if they continue to increase in their rate of melting. Future studies will attempt to gain more accurate readings of the dynamics of the ice in Antarctica, but for now researchers have to put the pieces together for themselves.

And as Slate columnist and meteorologist Eric Holthaus recently put it, Antarctica is notoriously hard for us to comprehend: “The quantities of ice, and therefore, the potential impact on the global climate system is beyond human comprehension – but often, so are the timescales”. In locations where the amount of new snowfall accumulating on an ice sheet is not equal to the ice flow downward and outward to the ocean, the surface height changes and the ice-sheet mass grows or shrinks. Global warming, or climate change, had previously been blamed for a loss in ice volume, and thus it was assumed the melting ice was causing the sea levels to rise.

This new study examined meteorological records that showed accumulations that dropped in the last 20 years where the team also investigated historical meteorological data deriving from ice cores and determined that snowfall from 10,000 years back has been apparently compacted and transformed into ice from previous millenia.

The agency is developing new tools – due to launch in 2018 – that will help more accurately measure long-term ice changes in Antarctica.

The upcoming ICESat 2 mission will be able to track snowpack changes in Antarctica down to the thickness of a pencil. But this is also bad news. This is in direct conflict with the IPCC’s calculation that Antarctica contributed 0.27 millimeters of sea level rise each year.