ONE TOWN SQUARE: at the intersection of peak oil, climate change, and land use

Scientists at the University of Bremen are saying Arctic sea ice extent reached a new record low this year.

Alerting message from the Arctic: The extent the Arctic sea ice has reached on Sep. 8 with 4.240 million km2 a new historic minimum (Figure 1). Physicists of the University of Bremen now confirm the apprehension existing since July 2011 that the ice melt in the Arctic could further proceed and even exceed the previous historic minimum of 2007. It seems to be clear that this is a further consequence of the man-made global warming with global consequences. Directly, the livehood of small animals, algae, fishes and mammals like polar bears and seals is more and more reduced.

The University of Bremen’s ice map shows the Northwest and Northeast passages are simultaneously ice free
This happened for the first time in 2008 – it did not happen in 2007, the year that saw the record minimum ice extent.

The daily sea ice maps of the University of Bremen are based on observations of the Japanese microwave sensor AMSR-E, in orbit on board the NASA spacecraft Aqua since 2002. The institute receives the data from two servers in the US and Japan and produces the maps based on the ASI (ARTIST Sea Ice) algorithm using the 89 GHz channels of AMSR-E. Other retrieval algorithms like NASA Team or Bootstrap may find slightly different sea ice extent values.

To wit: the National Snow and Ice Data Center has just called the yearly minimum Arctic sea ice extent, finding it the second lowest in the satellite record.

Arctic sea ice appears to have reached its lowest extent for the year. The minimum ice extent was the second lowest in the satellite record, after 2007, and continues the decadal trend of rapidly decreasing summer sea ice.

Please note that this is a preliminary announcement. Changing winds could still push ice flows together, reducing ice extent further. NSIDC scientists will release a full analysis of the melt season in early October, once monthly data are available for September.

* * *

The last five years (2007 to 2011) have been the five lowest extents in the continuous satellite record, which extends back to 1979. While the record low year of 2007 was marked by a combination of weather conditions that favored ice loss (including clearer skies, favorable wind patterns, and warm temperatures), this year has shown more typical weather patterns but continued warmth over the Arctic. This supports the idea that the Arctic sea ice cover is continuing to thin. Models and remote sensing data also indicate this is the case. A large area of low concentration ice in the East Siberian Sea, visible in NASA Moderate Resolution Imaging Spectroradiometer (MODIS) imagery, suggests that the ice cover this year is particularly thin and dispersed this year.

The Japan Aerospace Exploration Agency (JAXA) also pegs 2011 as the second lowest year for Arctic sea ice extent.

If September 9 holds up as the date of minimum ice extent, that’s the earliest date of minimum extent in years – and earlier than the average date (September 10) over the period of satellite records, which began in 1979.

While the absolute sea ice extent values might vary slightly from one method to the other – and even the day of the absolute minimum might vary slightly – all methods find consistently that all minima since 2007 have been lower than all minima before, i.e. the last four minima (2007-2011) are the four lowest on record.

And there’s little doubt that 2011 saw new record for Arctic sea ice volume . . .

. . . and area.

Global warming and climate change have already come to the Arctic. The full consequences of this new reality have yet to be seen.

The National Snow and Ice Data Center (NSIDC) reports average Arctic sea ice extent for July 2011 was the lowest level for the month since satellite records began in 1979.

Daily Arctic sea ice extent as of August 2, 2011, along with daily ice extents for previous low-ice-extent years. Light blue indicates 2011, dashed green shows 2007, dark blue shows 2010, purple shows 2008, and dark gray shows the 1979 to 2000 average. The gray area around the average line shows the two standard deviation range of the data.

Ice loss slowed substantially over the latter half of the month as the weather changed. A high-pressure cell centered over the northern Beaufort Sea broke down and a series of low-pressure systems moved over the central Arctic Ocean, bringing cooler conditions and likely pushing the ice apart into a thinner but more extensive ice cover.

In the first week of August, with a month or more to go in the melt season, Arctic sea ice area has already dropped below not just the year-to-date values, but the annual low points of any satellite-era year before 2007.

Shipping routes in the Arctic have less ice than usual for this time of year, and more of the Arctic’s oldest ice has disappeared.

Sea ice concentration (left) and ice age (right) over the Arctic Ocean. In the Beaufort Sea off the coast of Alaska, ice has melted back to the edge of a tongue of older, thicker ice. In the "Ice Age" image, red shows ice 5 years old and older, green shows 4-year-old ice, light blue shows 3-year old ice, dark blue shows second-year ice, and purple shows first-year ice.

Over the past few weeks, the sea ice edge has retreated from the shores of Siberia and Eurasia, opening up much of the Northern Sea Route – the shipping lane that runs along the Eurasian Arctic coast from Murmansk on the Barents Sea, along Siberia, and through the Bering Strait. Some ice remains, particularly in the East Siberian Sea, but the reduced ice cover in the region has already made the route feasible this year. Taking advantage of the early retreat of sea ice in the Kara and Barents seas, the tanker Perseverance set sail on June 29, 2011 from Murmansk, Russia, aided by two icebreakers; and completed the passage on July 14. The company plans to send six to seven more ships through the Northern Sea Route this summer.

On the other side of the Arctic, the Northwest Passage is still choked with ice. However, ice loss in the Northwest Passage is well ahead of average, nearly matching last year when sea ice in the Parry Channel (the northern part of the Northwest Passage) reached the lowest levels in records dating back to 1968.

In an unusual mid-month update, the National Snow and Ice Data Center (NSIDC) reports Arctic sea ice is now disappearing faster than in 2007, the year that saw a record low for sea ice extent at the end of the melt season in September:

Arctic sea ice extent declined at a rapid pace through the first half of July, and is now tracking below the year 2007, which saw the record minimum September extent. The rapid decline in the past few weeks is related to persistent above-average temperatures and an early start to melt. Snow cover over Northern Eurasia was especially low in May and June, continuing the pattern seen in April.

To date in July, air temperatures over the North Pole (at the 925 millibar level, or roughly 1,000 meters or 3,000 feet above the surface) were 6 to 8 degrees Celsius (11 to 14 degrees Fahrenheit) higher than normal.

NSIDC explains why the early ice melt is significant:

When sea ice starts to melt in spring, small ponds known as melt ponds form on its surface. The small pools create a darker surface (a lower albedo) that fosters further melt. How early sea ice melt starts is one indicator of how much the ice will melt in a given year. New research by Don Perovich and colleagues shows that an early start to sea ice melt increases the total amount of sunlight absorbed through the melt season.

Arctic sea ice volume continues to plunge to record lows, too . . .

. . . as older, multi-year ice is replaced by  younger, thinner ice more susceptible to melting in the summer.

The Arctic’s death spiral continues.

A new report just released by the International Program on the State of the Oceans finds the condition of the oceans is declining far more rapidly than even pessimists had expected. It’s bad enough that many marine species — including those that make coral reefs — could be extinct within a generation. Humans may have set Earth on track for a sixth mass extinction event.

The key findings of the International Earth system expert workshop on ocean stresses and impacts Summary Report should be enough to shake any cognizant being out of their lethargy:

• Human actions have resulted in warming and acidification of the oceans and are now causing increased hypoxia – symptoms that indicate disturbances of the carbon cycle associated with each of the previous five mass extinctions on Earth.
• The speeds of many negative changes to the ocean are near to or are tracking the worst-case scenarios from IPCC and other predictions. Consequences matching those predicted under the “worst case scenario” include decrease in Arctic Sea Ice, melting of the Greenland and Antarctic ice sheets, sea level rise, and release of trapped methane from the seabed.
• The magnitude of the cumulative impacts on the ocean is greater than previously understood, as interactions between different impacts can be negatively synergistic.
• Timelines for action are shrinking. Delays will mean increased environmental damage with greater socioeconomic impacts.
• Resilience of the ocean to climate change impacts is severely compromised by the other stressors from human activities, including fisheries, pollution and habitat destruction.
• Ecosystem collapse is occurring as a result of both current and emerging stressors including chemical pollutants, agriculture run-­off, sediment loads and over-­extraction of many components of food webs.
• The extinction threat to marine species is rapidly increasing due to overexploitation, habitat loss, and, increasingly, climate change.

But don’t count on any response from our political or economic elites, other than wanton disregard. They have proved to not be cognizant beings.

A press release quotes Dr. Alex Rogers, Scientific Director of the International Programme on the State of the Ocean (IPSO), which convened the workshop:

The findings are shocking. As we considered the cumulative effect of what humankind does to the ocean the implications became far worse than we had individually realized. This is a very serious situation demanding unequivocal action at every level. We are looking at consequences for humankind that will impact in our lifetime, and worse, our children’s, and generations beyond that.

Co-author Dan Laffoley issued a call for action:

The world’s leading experts on oceans are surprised by the rate and magnitude of changes we are seeing. The challenges for the future of the ocean are vast, but unlike previous generations we know what now needs to happen. The time to protect the blue heart of our planet is now, today and urgent.

The chances of any significant action being taken are precisely zero. The sad reality is the ocean and its ecosystems are doomed to succumb to a constantly bombardment of multiple attacks.

Dan Allen at Energy Bulletin scathingly observes that humans have proved to be less than rational:

[A]ny sane society . . . when faced with such an overwhelming abundance of scientific evidence, would be gnashing its collective teeth and running for the powerdown-exits en masse at this point. No sane society would ignore the screaming warnings of every single Earth system. No sane society would knowingly doom their children and grandchildren to misery and starvation. No sane society would stand by and do NOTHING — NOT ONE DAMN THING!! — while their very life-support systems eroded away before their eyes.

But we are surely not sane.

Political solutions have failed us, are failing us, and will certainly continue to fail us. The only option we have – to slam on the brakes and to stop burning coal, tout de suite – won’t be undertaken voluntarily; to think otherwise is delusional. Climate catastrophe is where we are. As Allen says, that’s the bed we’ve made:

So, sadly, at this late hour, we just flat-out NEED the dark angel of economic collapse to swoop down onto the stage, ‘Deus ex Machina’ style, and save the day.

God help us.

Pray for the collapse of the global industrial economy. And do what you can to begin fashioning a replacement.

The National Snow and Ice Data Center (NSIDC) reports Arctic sea ice extent for May 2011 was the third lowest in the satellite data record since 1979, continuing its long-term decline.

The chart below shows the lowest year for May was 2004, followed by 2006. The long-term rate of decline for May now stands at -2.4% per decade.

During the month of May, sea ice declined at a near average rate, while air temperatures in the Arctic remained generally above average.

Although ice extent is low for this time of year, ice extent at the end of summer largely depends on Arctic weather over the next few months. Years with dramatic ice loss, such as 2007, have been associated with comparatively warm, calm, and clear conditions in summer that have encouraged ice melt. Summers with slow melt rates are opposite and tend to be stormier than average. The number of storms influences how warm, windy and cloudy the Arctic summer is.

The chart below compares this year to 2007, which saw dramatic, record-breaking ice loss in the Arctic.

NSIDC explains why

The last four summers have been dominated by an atmospheric pattern known as the Arctic dipole anomaly, which has been associated with low sea ice extent at the end of summer. This pattern features unusually high pressure over the Beaufort Sea and unusually low pressure over the Kara and Laptev Seas, which promote warm southerly winds along the Siberian coast, helping to melt ice and push it away from the coasts and out of the Arctic Basin through Fram Strait.

While the atmospheric pattern for May 2011 bears some resemblance to the Arctic dipole anomaly pattern, the centers of the pressure anomalies are in different locations this year, and it is not yet clear whether the pattern will persist through the summer and contribute to low ice extent.

Arctic sea ice volume continues to drop, too. In this chart published at the Polar Science Center, shaded areas represent one and two standard deviations of the anomaly from the trend.

Sea ice volume is an important climate indicator, as it depends on both ice thickness and extent and is therefore more directly tied to climate forcing than extent alone.

The National Snow and Ice Data Center (NSIDC) reports sea ice reached its maximum extent on March 7 this year. Sea ice extent on this date tied for the lowest winter maximum extent in the satellite record. Arctic sea ice extent for the month of March 2011 was the second lowest in the satellite record.

The amount of older, thicker ice has increased slightly over last year. Older ice that has survived several summer melt seasons tends to be thicker, while newer ice is thinner and more vulnerable to melt in summer. The trend of spring ice cover becoming increasingly dominated by younger and generally thinner ice (because of strong summer melting reducing the amount of ice surviving into winter) remains striking.

There is still almost none of the oldest ice, older than four years old, that used to dominate much of the Arctic Ocean.

The National Snow and Ice Data Center (NSIDC) reports Arctic sea ice appeared to reach its maximum extent for the year on March 7, marking the beginning of the melt season. This year’s maximum tied with 2006 for the lowest in the satellite record.

Since the start of the satellite record in 1979, the maximum Arctic sea ice extent has occurred as early as February 18 and as late as March 31, with an average date of March 6. Sea ice extent in February and March tends to be quite variable, because ice near the edge is thin and often quite dispersed. The thin ice is highly sensitive to weather, moving or melting quickly in response to changing winds and temperatures, and it often oscillates near the maximum extent for several days or weeks.

The graph above shows daily Arctic sea ice extent as of March 22, 2011, along with daily ice extents for 2006, which had the previous lowest maximum extent, and 2007, the year with the lowest minimum extent in September.

This winter, the Arctic has seen the lowest December, January, and February (tied with 2005) sea ice extent in the satellite record.

Even more importantly, Arctic ice volume is also continuing its long-term decline.

Shaded areas show one and two standard deviations from the trend.

Monthly average Arctic ice volume for September 2010 was 78% below the 1979 maximum and 70% below its mean for the 1979-2009 period.

Arctic ice continues in its downward death spiral.

The National Snow and Ice Data Center reports Arctic sea ice extent for February 2011 tied with February 2005 as the lowest recorded in the satellite record.

Sea ice extent was particularly low in the Labrador Sea and Gulf of St. Lawrence.

The February trend is now at -3.0 percent per decade.

A new study published in the journal Science concludes ocean currents entering the Arctic Ocean are the warmest in more than 2,000 years – well outside the natural bounds. The warm waters will likely lead to ice-free seas around the North Pole in summers.

[E]arly–21st-century temperatures of Atlantic Water entering the Arctic Ocean are unprecedented over the past 2000 years and are presumably linked to the Arctic amplification of global warming.

The scientists say that waters at the Fram Strait – at the northern end of the Gulf Stream, between Greenland and the Norwegian archipelago of Svalbard – averaged 6 degrees Celsius (42.8°F) in recent summers.

The study showed that water from the Fram Strait has warmed roughly 3.5 degrees Fahrenheit in the past century. The Fram Strait water temperatures today are about 2.5 degrees F warmer than during the Medieval Warm Period, which heated the North Atlantic from roughly 900 CE to 1300 CE and affected the climate in Northern Europe, Greenland, and northern North America. Air temperatures in Greenland have risen roughly 7 degrees F in the past several decades.

Joseph Romm at Climate Progress has posted a key graph from the study:

Due to positive feedbacks between the ice, the Arctic Ocean and the atmosphere, the rate of Arctic sea ice decline has been accelerating – as seen is this graph from the University of Washington’s Polar Science Center:

As Arctic temperatures rise, summer ice cover declines, more solar heat is absorbed by the ocean, and additional ice melts. Warmer water delays freezing in the fall, leading to thinner ice cover in winter and spring, making the sea ice more vulnerable to melting during the next summer.

Lead author Robert Spielhagen of the Academy of Sciences, Humanities and Literature in Mainz, Germany says the decline of Arctic sea ice is due in part to the warmer waters reaching the Arctic:

We must assume that the accelerated decrease of the Arctic sea ice cover and the warming of the ocean and atmosphere of the Arctic measured in recent decades are in part related to an increased heat transfer from the Atlantic.

Arctic sea ice is in a death spiral.

Dr. Jeff Masters at Wonderblog reports record warm ocean temperatures across much of Earth’s tropical oceans during the summer of 2010 created the second worst year globally for coral-killing bleaching episodes.

The summer 2010 bleaching episodes were worst in Southeast Asia, where El Niño warming of the tropical ocean waters during the first half of the year was significant. In Indonesia’s Aceh province, 80% of the bleached corals died, and Malaysia closed several popular dive sites after nearly all the coral were damaged by bleaching. In the Caribbean’s Virgin Islands, coral bleaching was not as severe as experienced in 2005. But in other portions of the Caribbean, such as Venezuela and Panama, coral bleaching was worse than that experienced in 2005.

Masters says the outlook for Earth’s coral reefs is grim:

The large amount of carbon dioxide humans have put into the air in recent decades has done more than just raise Earth’s global temperature–it has also increased the acidity of the oceans, since carbon dioxide dissolves in sea water to form carbonic acid. Corals have trouble growing in acidic sea water, and the combined effects of increasing ocean temperatures, increasing acidity, pollution, and overfishing have reduced coral reefs globally by 19 percent since 1950. Another 35 percent could disappear in the next 40 years, even without the impact of climate change, according to a report released in October 2010 by the World Meteorological Organization and the Convention on Biological Diversity. Coral loss has been the most severe in Earth’s hottest ocean, the Indian Ocean. Up to 90% of coral cover has been lost in the Maldives, Sri Lanka, Kenya and Tanzania and in the Seychelles. Global warming has heated up most of the tropical ocean surface waters by about 0.5°C (0.9°F) over the past 50 years, and the remarkable bleaching episodes of 1998 and 2010 both occurred when strong (natural) El Niño episodes heated up Pacific tropical waters to record levels. If the Earth continues to heat up this century as expected, coral bleaching episodes will grow more frequent and intense, particularly during strong El Niño episodes. The twin stresses of ocean acidification and increasing ocean temperatures will probably mean that by 2050, it will be difficult for any coral reefs to recover when subject to additional stresses posed by pollution or major storms, according to a talk presented by Stanford climate scientist Ken Caldeira at last month’s American Geophysical Union (AGU) meeting.

Corals cover just 0.2% of the world’s oceans, but contain about 25% of all marine species. What’s more, coral reefs are the linchpin of the Ocean’s ecosystems: if coral reefs fail, other ocean ecosystems will topple as well. And the greatest of them all, Australia’s Great Barrier Reef, is at risk. With the southern hemisphere now in mid-summer, Ocean temperatures along the reef are currently up to 1°C above average, due, in part, to the current moderate to strong La Niña event. NOAA’s Coral Reef Watch has issued its highest level of coral bleaching alert for the northern 2/3 of the Great Barrier Reef.

Forecast stress on coral due to warm ocean temperatures for Australia, Jan - Apr 2011. The northern 2/3 of the Great Barrier Reef are under the highest alert level for coral bleaching. Waters are cooler along the southern portion of the reef, due, in part, to the storms that have brought record flooding to portions of Queensland, Australia. Image credit: NOAA Coral Reef Watch.

Tags: Arctic ice