This has been a year of climate-related records, so it comes as no surprise that the Arctic sea ice has shrunk to its lowest extent since satellites measurements began in 1979. The National Snow And Ice Data Center (NSIDC) announced the record melt yesterday, although scientists could see this one coming for weeks.
NSIDC scientist Walt Meier was quoted in the New York Times.
Parts of the Arctic have become like a giant Slushee this time of year.
This text is from the NSIDC press release.
Arctic sea ice cover melted to its lowest extent in the satellite record yesterday, breaking the previous record low observed in 2007. Sea ice extent fell to 4.10 million square kilometers (1.58 million square miles) on August 26, 2012. This was 70,000 square kilometers (27,000 square miles) below the September 18, 2007 daily extent of 4.17 million square kilometers (1.61 million square miles)...
NSIDC scientist Walt Meier said, "By itself it's just a number, and occasionally records are going to get set. But in the context of what's happened in the last several years and throughout the satellite record, it's an indication that the Arctic sea ice cover is fundamentally changing."
According to NSIDC Director Mark Serreze, "The previous record, set in 2007, occurred because of near perfect summer weather for melting ice. Apart from one big storm in early August, weather patterns this year were unremarkable. The ice is so thin and weak now, it doesn't matter how the winds blow."
"The Arctic used to be dominated by multiyear ice, or ice that stayed around for several years," Meier said. "Now it's becoming more of a seasonal ice cover and large areas are now prone to melting out in summer."
With two to three weeks left in the melt season, NSIDC scientists anticipate that the minimum ice extent could fall even lower.
In 2007, Arctic sea ice extent reached an all-time low in the satellite record that began in 1979. Arctic sea ice follows an annual cycle of melting through the warm summer months and refreezing in the winter. While Arctic sea ice extent varies from year to year because of changeable weather conditions, ice extent has shown a dramatic overall decline over the past thirty years. The pronounced decline in summer Arctic sea ice over the last decade is considered a strong signal of long-term climate warming.
The melt season isn't over yet, so we're on course to shatter the 2007 all-time low in the Arctic. And though it got very little attention, we also set a new melt record in Greenland this summer, as reported in the Science Daily's Greenland Melting Breaks Record Four Weeks Before Season's End.
Melting over the Greenland ice sheet shattered the seasonal record on August 8 — a full four weeks before the close of the melting season, reports Marco Tedesco, assistant professor of Earth and atmospheric sciences at The City College of New York...
The melting season in Greenland usually lasts from June — when the first puddles of meltwater appear — to early-September, when temperatures cool. This year, cumulative melting in the first week in August had already exceeded the record of 2010, taken over a full season, according to Professor Tedesco's ongoing analysis.
"With more yet to come in August, this year's overall melting will fall way above the old records. That's a goliath year — the greatest melt since satellite recording began in 1979," said Professor Tedesco.
This year, Greenland experienced extreme melting in nearly every region — the west, northwest and northeast of the continent — but especially at high elevations. In most years, the ice and snow at high elevations in southern Greenland melt for a few days at most. This year it has already gone on for two months.
"We have to be careful because we are only talking about a couple of years and the history of Greenland happened over millennia," cautioned Professor Tedesco. "But as far as we know now, the warming that we see in the Artic is responsible for triggering processes that enhance melting and for the feedback mechanisms that keep it going. Looking over the past few years, the exception has become part of the norm."
The Arctic sea ice gets most of the attention, but record-breaking melting of the Greenland ice sheet is a far more important event because it actually raises sea-level. If the entire ice sheet were to melt away, sea-level would rise about 7 meters (about 23 feet), which would most definitely change the definition of beach-front property. Realtors would be thrown into chaos. Wide-spread panic would almost certainly ensue in the real estate business.
Still, realtors needn't worry about the Greenland ice sheet melting down to nothing for a few centuries yet (maybe). However we are sure to see gradual (and accelerated) ice melt in Greenland as the decades roll by. Scientists don't fully understand the dynamics of these big ice sheets. That's not to say that anything could happen in a relatively short time frame (a few decades), but it seems that our ignorance more often than not obscures unforeseen climate disasters. Or, we could get lucky.