Thursday, August 23, 2012

Arctic sea ice shrinks to record low, estimates show

The area of ice in the Arctic Ocean has thawed to a record low, surpassing the previous 2007 minimum in a sign of climate change transforming the region, according to some scientific estimates.

  1. Only on NBCNews.com

    1. Faith in Army's direction hits all-time low, survey shows
    2. Mormon in America: Church members on impact of Romney campaign
    3. Growing number of Latinos have no religious affiliation
    4. California school district sued over abstinence-only sex ed
    5. Hidden health hazards in food delivery trucks
    6. Nine states that are likely to decide the election
    7. Cues from Big Tobacco: Tanning industry retaliates

"We reached the minimum ice area today (Thursday). It has never been measured less than right now," Ola Johannessen, founding director of the Nansen Environmental and Remote Sensing Center in Norway, told Reuters.

"It is just below the 2007 minimum."

The U.S. National Snow and Ice Data Center (NSIDC), widely viewed as the main authority on sea ice, has projected that the 2007 minimum extent is set to be breached next week . The summer thaw usually continues well into September.

Other scientists monitoring the ice interpret satellite data in slightly differing ways.

An ice chart compiled by the Danish Meteorological Institute (DMI) showed the ice extent had also just shrunk a fraction past the 2007 minimum. The DMI said it would defer to the NSIDC to judge when a record had been set.

Ice has been shrinking steadily in recent decades in the Arctic, threatening the livelihoods of indigenous peoples and wildlife. It is also helping to open an area rich in oil and gas and bringing the promise of new, shorter shipping routes.

"This is due to climate change," Nicolai Kliem, head of the ice service at DMI, said of the long-term decline in summer ice. Scientists project that summer sea ice could vanish completely in coming decades.

Runaway thaw
The retreat of the ice may be self-reinforcing. Ice reflects sunlight back into space and as it shrinks it exposes dark water that absorbs more heat, accelerating thawing.

Johannessen stressed his measurement was of the "area" of ice, now less than 4.0 million square kilometers (1.5 million square miles), omitting the open water between ice floes.

The NSIDC prefers a bigger "extent", including such gaps, on the grounds that pools of meltwater that form on sea ice are hard to distinguish from open ocean.

Kliem said the ice was becoming more prone to melt because there was less of the hard, resilient ice that endures more than one year. The ice usually reaches a minimum in September before forming again as winter approaches and reaching a maximum in March.

"We had quite a big ice cover in March 2012, above average. But because there is little long-term ice it melts more quickly in summer," he said.

In a sign of widening interest in the polar region as a short-cut shipping route between the Pacific and the Atlantic, Beijing sent an icebreaker across the Arctic this summer to Iceland - the first Chinese vessel to cross the Arctic Ocean.

(c) Copyright Thomson Reuters 2012. Click For Restrictions - http://about.reuters.com/fulllegal.asp

Source: http://www.msnbc.msn.com/id/48766244/ns/us_news-environment/

carrot top george huguely whitney houston casket photo match play championship the national enquirer marie colvin cm punk

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.