Exceptionally Rapid Ancient Sea Level Rise Illuminates Rate of Coming Changes
Some new research published in Nature looks backwards to prehistoric sea level rise and influences how current and future seas will respond to climate change.
An international team of researchers looked at a period of exceptionally rapid sea level rise14,560 years ago (stories of the flood...?), where at the start sea levels were 120 meters lower than today (civilizations and cities lost to the seas...?) and proceeded to rise 14 meters over a 350 year period (Melt-Water Pulse 1A), coinciding with a particularly warm period called the Bølling oscillation. At that time sea level was rising 40cm a year, roughly 13 times as quickly as is happening now.
By looking at core samples of coral reef in Polynesia, the researchers found that rather than most of the sea level rise coming from melting ice in the northern hemisphere, melting of the Antarctic ice cap was responsible for half of the rising seas.
As far as the impact on current and future warming on sea level rise, the researchers say that their study "demonstrates the complex reaction of the ice caps to a major climatic disturbance, particularly for the potential instability of the Antarctic ice cap."
Furthermore, because climate models prior to 2007 "did not provide realistic simulations of the dynamic response of the polar ice caps to global warming used by the present study," we're more likely look at sea level rise double that predicted in 2007, or 600-180cm by 2100.