A recent NASA study(1) predicts the Arctic Ocean will lose all perennial ice by the end of this century. Such an occurrence will have devastating impact on the Arctic region and start in motion a process that will change the climate dramatically.
"If the perennial ice cover, which consists mainly of thick multi-year ice floes, disappears, the entire Arctic Ocean climate and ecology would become very different," said Josefino Comiso, a researcher at NASA's Goddard Space Flight Center, Greenbelt, Md., who authored the study.
Already, much of the perennial ice is gone. The following animation shows Arctic sea ice extent from January 1, 1990, and January 1, 1999, respectively. Click the two-directional arrow below and drag it along the timeline to see the polar ice caps recede.
As the ice melts, the Arctic waters will begin to warm. With less ice to reflect the sun's rays back into space, the ocean will absorb more of the sun's heat. Eventually, the melting will be become irreversible.
--S.L.
*Special thanks to Bill O'Connor for creating this Flash movie.
1. http://eob.gsfc.nasa.gov/Newsroom/NasaNews/2002/2002112710960.html