The National Snow and Ice Data Center (NSIDC) reports that Arctic sea ice extent continues to track way below normal, despite cool temperatures over most of the Arctic Ocean in January.

Reuters quotes NSIDC director Mark Serreze:

It’s not that the ice keeps melting, it’s just not growing very fast.
We’ve grown back ice in the winter, but that ice tends to be thin and that’s the problem. You set yourself up for a world of hurt in summer. The ice that is there is also thinner than it was before and thinner ice simply takes less energy to melt out the next summer.

With thinner, more fragile ice and less cover,

You’ve got a double whammy going on.

If Arctic ice fails to build up sufficiently during the dark, cold winter months, it is likely to melt faster and earlier when spring comes.

A Canadian research project has found that climate change is happening much faster than the most pessimistic models expected.  Models predicted only a few years ago that the Arctic would be ice-free in summer by the year 2100, but the increasing pace of climate change now suggests it could happen between 2013 and 2030. Losing sea ice has impacts on everything else that goes on in the Earth’s systems.

A new study by the Pew Environment Group estimates the financial cost  to the world economy  of a warming and melting Arctic will be at least $2.4 trillion over the next 40 years. The study looks at the “social cost of carbon,” including the cost of climate change on agriculture, energy production, water availability, sea level rise, and flooding.

By the end of January, ice extent had dropped below the extent observed in January 2007. This winter continues the recent trend of slower Arctic ice growth.

The summer Arctic sea ice melt season now lasts nearly a month longer than it did in the 1980s. A later start of freeze-up and an earlier start to the melt season both contribute to the change. A recent paper by Thorsten Markus at NASA Goddard Space Flight Center suggests that the later freeze-up is the dominant factor lengthening the melt season. The analysis shows that, on average, autumn freeze-up starts nearly four days later each decade. Extensive open water at the end of the summer melt season, combined with warmer autumns, delay the autumn freeze-up. The larger expanses of open water absorb more solar energy, and before ice can form again, that heat must be released back to the atmosphere. This trend is most pronounced in the Beaufort, Chukchi and Laptev seas.

I would argue that, from a practical perspective, we almost have a seasonally ice-free Arctic now, because multiyear sea ice is the barrier to the use and development of the Arctic.

That’s what David Barber, Canada’s Research Chair in Arctic System Science at the University of Manitoba, reported on returning from an expedition that tried and pretty much failed to find a giant multiyear ice pack that was supposed to be in the Beaufort Sea. Instead he found only hundreds of miles of  “rotten ice” – 20-inch thin layers of fresh ice over small chunks of older ice.

An article in RedOrbit quotes Barber:

From a practical perspective, if you want to ship across the pole, you’re concerned about multiyear sea ice. You’re not concerned about this rotten stuff we were doing 13 knots through. It’s easy to navigate through.

The 2009 ice cover was the third-lowest on record, after 2007 and 2008. Joseph Romm has posted this graphic at Climate Progress:

According to Barber, the ice is currently being melted both by rays from the sun as well as from below by the warmer water. Scientists have also been seeing more cyclones, which become stronger as they pick up heat from the warmer water. The cyclones produce waves that break up ice sheets and also dump large amounts of snow, which provides a form of insulation and keeps the ice sheets from thickening.

Many scientists now expect the North Pole to be void of ice during summers by 2030 at the latest.

A new study published in the journal Nature reports that glaciers along the coastline of both the Antarctic and Greenland ice sheets are rapidly thinning.

Lead author Dr Hamish Pritchard from British Antarctic Survey (BAS) said:

We were surprised to see such a strong pattern of thinning glaciers across such large areas of coastline — it’s widespread and in some cases thinning extends hundreds of kilometres inland. We think that warm ocean currents reaching the coast and melting the glacier front is the most likely cause of faster glacier flow. This kind of ice loss is so poorly understood that it remains the most unpredictable part of future sea level rise.

The authors conclude that this ‘dynamic thinning’ of glaciers now reaches all latitudes in Greenland, has intensified on key Antarctic coastlines, is penetrating far into the ice sheets’ interior and is spreading as ice shelves thin by ocean-driven melt. Ice shelf collapse has triggered particularly strong thinning that has endured for decades.

The National Snow and Ice Data Center (NSIDC) reports that the Arctic ice melt season has come to a close:

Arctic sea ice appears to have reached its minimum extent for the year, the third-lowest extent since the start of satellite measurements in 1979. While this year’s minimum extent is above the record and near-record minimums of the last two years, it further reinforces the strong negative trend in summertime ice extent observed over the past thirty years.

The report continues:

This year, the minimum extent did not fall as low as the minimums of the last two years, because temperatures through the summer were relatively cooler. The Chukchi and Beaufort seas were especially cool compared to 2007. Winds also tended to disperse the ice pack over a larger region.

While the ice extent this year is higher than the last two years, scientists do not consider this to be a recovery. Despite conditions less favorable to ice loss, the 2009 minimum extent is still 24% below the 1979-2000 average, and 20% below the thirty-year 1979-2008 average minimum. In addition, the Arctic is still dominated by younger, thinner ice, which is more vulnerable to seasonal melt. The long-term decline in summer extent is expected to continue in future years.

Two German merchant ships have traversed the Northeast Passage after global warming and melting ice opened a route from South Korea along Russia’s Arctic coast to Siberia.

But this is not a cause for celebration. It’s a clarion call for immediate action to avert the worst impacts of global warming, before it’s too late.

The merchant ships MV Beluga Fraternity and MV Beluga Foresight arrived this week in Yamburg, Siberia, after traveling from Ulsan, South Korea,  to Siberia by way of the Northeast Passage. The trip was completed in late July without incident.

For the last few years, including this year, navigator Roald Amundsen’s famous Northwest Passage has been navigable. Then in 2007, the more crucial deep water channel called McClure Strait opened up. Now the shipping company Beluga Shipping GmbH is planning more trips through the Northeast Passage “over the coming months.”

Traditionally, shippers traveling from Asia to Europe have to go through the Gulf of Aden and through the Suez Canal into the Mediterranean Sea and, depending on their destination, into the Atlantic Ocean.

The Northeast Passage can cut a lot of nautical miles off the journey. For example, via the Suez Canal a trip from Korea to the Netherlands is about 11,000 nautical miles (12,658 miles). Using the Northeast Passage saves approximately 3,000 nautical miles (3,452 miles), 10 days, and a lot of fuel.

Although Russia has long used its northern coast for shipping fuel, supplies and other goods to its remote Arctic settlements, this was the first time a commercial shipping company has successfully transited the Northeast Passage. Explorers throughout history have tried, and failed; some have died in the attempt.

National Snow and Ice Data Center (NSIDC) scientists report they expect to see the minimum ice extent for the year within the next couple of weeks. This year won’t see a record low – but that’s small comfort.

While this year’s minimum ice extent will probably not reach the record low of 2007, it remains well below normal: average ice extent for August 2009 was the third-lowest in the satellite record. Ice extent has now fallen below the 2005 minimum, previously the third-lowest extent in the satellite record.

With the melt season drawing to a close, this year is now the third-lowest ice extent in the satellite record.

Arctic sea routes have not opened this year as they did last year. The  shallow and narrow southern route of the Northwest Passage – which is not a single passage, but rather a number of possible routes through the channels of the Canadian Arctic Archipelago – appeared to open briefly this August. This route was also open in 2007 and 2008. The deeper northern route, of great interest for potential commercial transport, was open in 2007 but is still blocked by ice this year. On the other side of the Arctic, the Northern Sea Route is open except for a narrow band of ice between the islands of Severnaya Zemlya and the Siberian mainland.

The National Snow and Ice Data Center (NSIDC) reports that 2009 is unlikely to see a new record low in Arctic sea ice extent:

During the first half of August, Arctic ice extent declined more slowly than during the same period in 2007 and 2008. The slower decline is primarily due to a recent atmospheric circulation pattern, which transported ice toward the Siberian coast and discouraged export of ice out of the Arctic Ocean. It is now unlikely that 2009 will see a record low extent, but the minimum summer ice extent will still be much lower than the 1979 to 2000 average.

Arctic sea ice extent is now greater than on the same day in 2008:

The Northern Sea Route appears likely to open soon, but ice still clogs many of the channels in the Northwest Passage.

The National Snow and Ice Data Center reports that Arctic ice in 2009 is melting at 2007’s record rate – although the ice extent is only the third lowest on record:

Arctic sea ice extent for the month of July was the third lowest for that month in the satellite record, after 2007 and 2006. The average rate of melt in July 2009 was nearly identical to that of July 2007. A strong high-pressure system, similar to the atmospheric pattern that dominated the summer of 2007, brought warm winds and clear skies to the western Arctic, promoting ice melt.

In 2007, unusually sunny skies throughout the summer melt season were one of the factors that helped lead to the record low ice extent. The clear skies allowed more of the sun’s energy to reach the surface, melting the ice and warming the ocean. This year, there were even fewer clouds over the Beaufort Sea than in 2007, leading to strong melt in that region. However, over the Chukchi and East Siberian Seas, the Arctic sky has been cloudier than 2007.

The National Snow and Ice Data Center (NSIDC) reports that Arctic sea ice extent in 2009 is declining more quickly than in 2008, but not as fast as in 2007.

As in recent years, melt onset was earlier than the 1979 to 2000 average. International sea ice researchers expect another low September minimum ice extent, but they do not yet know if it will fall below the 2007 record.

NSIDC in April said the melt season began with a substantial amount of thin first-year ice, which is vulnerable to summer melt. Satellite images from NASA show that thinning has been pretty dramatic.

RealClimate has an interesting piece reflecting on the unexpectedly low Arctic sea ice minimum in 2007 and the near-repeat in 2008. They observe:

What was unexpected was not the long term decline of summer ice (this has long been a robust prediction), but the size of 2007 and 2008 decreases which were much larger than any model had hinted at.

And then they proceed to ask several questions:

• were the data reliable?
• are the models missing some key physics?
• is the comparison being done appropriately?
• to what extent is the summer sea ice minimum even predictable?
• what is the role of pre-conditioning from the previous year vs. the stochastic nature of the weather patterns in any particular summer?

They discuss current prediction attempts by various scientists, noting that prediction methodology varies greatly as do the results. The mean prediction for this year is 4.7 M km² – equal to last year’s minimum, but not a new record. It would still be well below the sea ice trend expected by the IPCC AR4 models. 

We’ll see in September.