Arctic Ice Cap: Too Young, Too Thin

When it comes to Arctic sea ice, it is indeed possible be too young and too thin.

As the boreal winter was winding down a couple weeks ago, satellite data suggested the geographic extent of the Earth's northern ice cap was continuing to contract.

With some time to crunch the season's data, researchers at the National Snow and Ice Data Center are confirming that Arctic sea ice is at its fifth smallest extent since satellite tracking began in 1979. (All six record lows have happened since 2004.) "Sea ice extent averaged over the month of March 2009 was 15.16 million square kilometers (5.85 million square miles)," reports the NSIDC. "This was 730,000 square kilometers (282,000 square miles) above the record low of 2006, but 590,000 square kilometers (228,000 square miles) below the 1979 to 2000 average."

Coming nearly simultanously with the breakup of the ice bridge securing the Wilkins Ice Sheet to Antarctica, you'd think all this news would throw some cold water on the latest emanations from the misinformers...or at least give the schedulers and editors of the major news outlets a little more discernment when booking them for punditry on the science or economics of global warming. Perhaps some climate scientists could substitute.

Equally dismaying, the level of older ice at the Arctic is at a record low. This is the ice that persists over several summers, and thickens up each winter. It's also the shiny cap that reflects sunlight back into space during the 24 hours a day, 7 days a week, 6 months a year of sunlight that hits the pole -- a major brake on summer heat in the northern hemisphere.

Prior to 2000, this long-lived ice comprised about 30 percent on average of the northern ice cap. Now it's down to 9.8 percent. The less of this ice capping the planet, the more open ocean to absorb the sun's heat, warming the water...creating more heat, which melts more ice, so there's yet less ice to reflect heat back into space...

Have we already passed a tipping point where the northern ice cap won't be able to recover? Some researchers out of the University of Washington believe that based on the current trends, it could waste away to just a quarter of its current size, around 1 million square kilometers (roughly 620,000 square miles) by 2037.