Arctic icecap safe from runaway melting: study (potential reprieve for polar bears... WHEW!!)

PARIS (AFP) – There is no "tipping point" beyond which climate change will inevitably push the Arctic ice cap into terminal melt off, according to a study released Wednesday.

The northern polar cap has shrunk between 15 and 20 percent over the last 30 years, unleashing concern that on current trends -- with regional temperature increases twice or triple the global average -- it could disappear entirely during the summer months by century's end.

One of the factors in this calculation is a so-called positive feedback, in which a reduced area of floating ice helps to stoke global warming.

As ice cover recedes decade by decade, more of the Sun's radiative force is absorbed by dark-blue sea rather than bounced back into space by reflective ice and snow.

But a new study published in the British science journal Nature shows that there is nothing inevitable about this process, and that it can be halted or even reversed.

"There is no 'tipping point' that would result in unstoppable loss of summer sea ice when greenhouse gas-driven warming rose above a certain threshold," said Steven Amstrup, a professor at the University of Washington and lead author of the study.

Up to now, many scientists worried that there was an as yet unidentified temperature threshold which, once passed, would doom the ice cap.

But the study, based on computer models, indicates that if annual emissions of greenhouse gases are substantially reduced over the next two decades, an initial phase of rapid ice loss would be followed by a period of stability and, eventually, partial recovery.

If so, that could mean a reprieve for polar bears, which use floating ice shelves as a staging areas for stalking ringed and bearded seals, their preferred food.

and then this from the La Times

Arctic ice melt may promote cross-breeding
Mating between different species could lead to the extinction of many Arctic animals, because hybrid offspring are often less hardy, scientists say.

http://www.latimes.com/news/science/la-sci-arctic-animals-20101216,0,439283.story

As the world heats up and polar ice melts, different types of bears, whales and seals could meet and mate — but these unions may be far from happy, researchers said Wednesday.

In fact, interspecies sex brought on by the melting Arctic ice could lead to the extinction of many endangered Arctic animals, the scientists said in an article published in the journal Nature.

At least 22 species are at risk of hybridizing in 34 different combinations, according to a team led by Brendan Kelly, an Alaska-based evolutionary biologist with the National Oceanic and Atmospheric Administration. The pairings include polar bears and grizzlies, narwhals and beluga whales, and various assortments of seals. Some of those species are listed as endangered or threatened.

Because hybrid offspring — or their offspring, in turn — are often infertile, maladapted or sickly, much of the genetic biodiversity of the Arctic could be lost, the scientists warned.

26 Nov 10 - “One of the disconnects the Church of Al Gore/IPCC has yet to address regarding so-called Global Warming is why is it the Arctic ice extent is receding while the Antarctic ice extent is growing at historic rates,” says this great article on strata-sphere.com.

[img]http://www.iceagenow.com/Arctic_Ocean_floor.jpg[/img]

“Given the fact CO2 levels are ubiquitous across the Earth, if this was really a global climate driver we should see higher temperatures (and less ice) across the globe, adjusted for latitude and the amount of land vs. sea surface area.”

“Well it seems we may have an answer to why the Arctic water temperatures were rising and the ice was melting – massive undersea volcanoes. (This article, Volcanic eruptions reshape Arctic ocean floor, says it well.)
“Recent massive volcanoes have risen from the ocean floor deep under the Arctic ice cap, spewing plumes of fragmented magma into the sea, scientists who filmed the aftermath reported Wednesday.

“The eruptions — as big as the one that buried Pompei — took place in 1999 along the Gakkel Ridge, an underwater mountain chain snaking 1,800 kilometres (1,100 miles) from the northern tip of Greenland to Siberia.

“Scientists suspected even at the time that a simultaneous series of earthquakes were linked to these volcanic spasms.
“But when a team led of scientists led by Robert Sohn of the Woods Hole Oceanographic Institution in Massachusetts finally got a first-ever glimpse of the ocean floor 4,000 meters (13,000 feet) beneath the Arctic pack ice, they were astonished.

“What they saw was unmistakable evidence of explosive eruptions rather than the gradual secretion of lava bubbling up from Earth’s mantle onto the ocean floor.
Previous research had concluded that this kind of so-called pyroclastic eruption could not happen at such depths due to the crushing pressure of the water.

1. “On land, explosive volcanic eruptions are nothing exceptional, although they present a major threat,” said Vera Schlindwein, a geologist with Germany’s Alfred Wegener Institute for Sea and Polar Research, which took part in the study.

But the new findings, published in Nature, showed that “large-scale pyroclastic activity is possible along even the deepest portions of the global mid-ocean ridge volcanic system.”

The mid-ocean ridge runs 84,000 kilometres (52,000 miles) beneath all the world’s major seas except the Southern Ocean, and marks the boundary between many of the tectonic plates that make up the surface of the Earth.

When continental plates collide into each other, they can thrust up mountain ranges such as the Himalayas.

But along most of the mid-ocean ridge — including the Gakkal Ridge — the plates are pulling apart, allowing molten magna and gases trapped beneath the crust to escape.
Sohn and his colleagues gathered their data in July last year aboard the ice breaker Oden, using state-of-the-art instruments including a mutlibeam echo sounder, two autonomous underwater vehicles and a sub-ice camera designed for the mission.

Both sonar and visual images showed an ocean valley filled with flat-topped volcanos up to two kilometres (1.2 miles) wide and several hundred metres high.”

“The natural basin that is the Arctic Ocean is possibly the reason why Arctic water temperatures were rising because the warming caused by these massive underwater explosions couldn’t really circulate out of the basin.

“Is it simply coincidence that the regions of the Arctic Ocean experiencing thin ice ... is the same region that is right over these massive undersea volcanoes just discovered?
See entire great article, including graphs:
http://strata-sphere.com/blog/index.php/archives/5589

[the above found at IceAgeNow.com – http://www.iceagenow.com/Eruptions_as_big_as_Pompeii_under_Arctic_ice.htm ]

They are trying to spin the Arctic sea ice extent numbers now too.

Example from a recent nationwide article:
..In 2010, the extent of sea ice cover in the Arctic at its lowest point in September was 31 percent less than the 1979-2000 average. It was the third lowest year after 2007 and 2008.

Curious there is no mention of 2009! Heres some facts to debunk this BS:

FACT: Satellites started monitoring the icecaps in 1979! So “history” only goes back to 1979

FACT: 2009 Sea ice was at the same level in 1979! http://www.dailytech.com/Article.aspx?newsid=13834

FACT: History of Northwest Passage - Navigated in 1905 and multiple times in 1940s (Note: 80% of man-made CO2 came after 1940)

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