Arctic sea ice decline – experience and science.

The decline in sea ice witnessed over recent years has been of  concern to many people.  There are varying explanations for the phenomenon, however the outcome is a change of lifestyle for those living in the Arctic circle.

Whether as a result of cyclical conditions or the direct effects of human activity, people are facing major changes in places like Alaska.

An interesting article in the Fairbanks Newsminer.com looks at the effects of the climate change being experienced in Alaska. It highlights the immediacy of the situation for the people of Alaska and an insight into changes that others are yet to confront. It argues that while in other parts of the country, climate change is largely a future threat, in Alaska it is an immediate reality.

It points out that “while the Earth as a whole has warmed about 1.3 degrees Fahrenheit over the last century, Alaska has warmed more than 3 degrees in the last 50 years. Alaskans are already grappling with shifting animal species, altered weather patterns, and villages made uninhabitable in part because of shrinking sea ice.”

The warming is having effects on daily life. Here is and excerpt from another article in Newsminer.com

“It had been a weird summer — it was so warm people joked about getting tan — and now it was a weird fall. There wasn’t enough ice on the rivers to go ice fishing, and geese were still hanging around town. A whaling captain’s nephew had shot his first walrus a few weeks before — the Inupiat Eskimos hunt them along with seals and bowhead whales — but when he cut it open there was nothing in its stomach. (Sometimes there are clams you can eat.)

Other people were saying they’d seen walrus that looked thin. And there were reports that lots of walrus were hauling out farther down the shore.”

The National Snow and Ice Data Center predicts that this year’s melt will not reach the record levels of 2007, however, it finds “the Arctic sea ice is in a condition we have not seen since satellites began taking measurements.”

“thin first-year ice dominated the Arctic early in the melt season. Thin ice is much more vulnerable to melting completely during the summer; it seems likely that we will see a faster-than-normal rate of decline through the rest of the summer.”

and then this evaluation:

“So, will we break last year’s record low minimum extent? Will the North Pole become ice-free? Probably not this year. However, the ice is in a vulnerable state and there are six weeks of melting left, so a lot can still happen.

And perhaps the most important point as we continue to watch this season’s evolving ice cover is that, whether or not Arctic sea ice sets a new record low, this year continues the pattern of well-below-average ice extent seen in recent years.”

The problem with the continuing decline in sea ice is that the feed-back effect means that reflective sea ice that keeps the Arctic cooler is replaced with dark water that absorbs heat and so continues to further melt existing sea ice.  This then exacerbates the problem even further.

The articles in the Newsminer.com and other interesting articles on the changing climate of Alaska can viewed at the link here.

Also tonight the ABC will be looking at the problem of the declining sea ice on its Four Corners program on ABC1 at 8.30pm( repeated about 11.35 pm Tuesday August 5; also on ABC2 at 8 am Tuesday.)

“Four Corners journeys to the Arctic Circle to explore how the melt is challenging human understanding of global warming. The Four Corners team* joins scientists on board a Canadian icebreaker, Louis S St Laurent, as they scout for icebergs, bears and evidence of a changing seascape. Across the scientific community there is a quest for answers: How fast is the melt happening? Is it stoppable? What may be lost? What riches will be unlocked? How much global warming is caused by people and how much by nature?”

IMAGE: The National Snow and Ice Data Center has this as its latest assessment of the sea ice in the Arctic:

“Sea ice extent continues to decline, but we have not yet seen last July’s period of accelerated decline. Part of the explanation is that temperatures were cooler in the last two weeks of July, especially north of Alaska.

Because we are past the summer solstice, the amount of potential solar energy reaching the surface is waning. The rate of decline should soon start to slow, reducing the likelihood of breaking last year’s record sea ice minimum.”

Arctic sea ice graph

Credit: National Snow and Ice data Center.

PHOTO:

Visible-band satellite imagery confirms the low-concentration ice cover. This view places NASA MODIS Aqua data in a perspective generated in Google Earth, simulating a view from far above Earth.

—Credit: From National Snow and Ice Data Center courtesy NASA

NASA view sea ice above Earth

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~ by abstraktbiblos on Monday, 4 August, 2008.

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