Antarctica Holds 70% of Earth’s Fresh Water Despite Getting Under 80 Millimeters of Annual Snow
Updated
Updated · spacedaily.com · Jul 13
Antarctica Holds 70% of Earth’s Fresh Water Despite Getting Under 80 Millimeters of Annual Snow
1 articles · Updated · spacedaily.com · Jul 13
Summary
Under 80 millimeters of annual precipitation at the South Pole still qualifies Antarctica as a desert, because much of the continent receives far less than the 250-millimeter threshold.
More than 2 kilometers of average ice thickness lets that sparse snowfall accumulate for hundreds of thousands of years, locking up about 26.5 million cubic kilometers of water—roughly 70% of Earth’s fresh water.
Temperatures below minus 60 Celsius and a plateau above 3,000 meters keep the interior extremely dry, while places such as the McMurdo Dry Valleys have gone an estimated 2 million years without rain or snow.
That preserved ice also stores ancient air, volcanic dust and pollution records, making Antarctic cores a key archive for reconstructing past climate and atmospheric carbon dioxide.
The same system is vulnerable to warming: Antarctica may gain snowfall inland even as coastal ice loss accelerates, with Thwaites Glacier alone holding more than 0.5 meter of potential sea-level rise.
Antarctic sea ice has vanished, defying all models. Has the continent flipped from a climate buffer to an amplifier?
With a key Antarctic ice shelf collapsing this year, are we prepared for the 65cm sea-level rise to follow?
Can radical engineering stop the 'Doomsday Glacier,' or is it already too late for the world's coastlines?
Antarctica’s Ice Sheets: The Planet’s Largest Freshwater Store and Its Role in Sea Level Rise
Overview
Antarctica is both the world’s largest reservoir of fresh water, locked in its vast ice sheets, and the driest continent, with some regions not seeing significant precipitation for millions of years. This polar desert status is due to extremely cold temperatures and unique atmospheric conditions that limit moisture. Climate models show that the global water cycle is intensifying, leading to modest increases in Antarctic precipitation, mainly delivered by atmospheric rivers that transport large amounts of moisture. These changes are important for understanding how Antarctica’s ice and water dynamics affect global sea level rise and climate stability.