The National Snow and Ice Data Center (NSIDC) reports the Arctic sea ice melt season got off to a slow start this year, but ice extent is now plummeting.

Arctic sea ice extent declined slowly through the first three weeks of April, compared to recent years. The slow decline through March and the first few weeks of April meant that by mid-April, ice extent was at near-average levels. However, much of the extensive ice cover is thin ice that will melt quickly once temperatures rise in the Arctic. Over the past week, extent has started to fall sharply.

NSIDC says the relatively high ice extent will have little influence on how much ice melts this summer, explaining that much of the ice cover is recently formed thin ice that will melt out quickly and that sea ice extent in spring does not tell us much about ice extent the following summer. More important to the summer melt is the thickness of the ice cover, and summer weather.

A new study published in Geophysical Research Letters concludes the only physically plausible link with the Arctic sea-ice retreat observed in recent years is the anthropogenic increase in greenhouse gas concentrations:

The most likely explanation for the linear trend during the satellite era from 1979 onwards is the almost linear increase in CO2 concentration during that period.

The Arctic sea ice melt season is off to an extremely slow start, with extent and area numbers approaching the long-term averages.

Will the trend lines soon start falling of a cliff? Well, the Polar Science Center at the University of Washington reports that ice volume is still at or near record lows for this time of the year. Ice volume for March 2012 was 20,800 km³, the same as last year but 35% lower than the maximum in 1979, 24% below the mean, and 1.7 standard deviations from the trend.

Most of the older, thicker ice has disappeared from the Arctic.

This March, first-year ice made up 75% of the Arctic sea ice cover. Thicker multi-year ice used to make up around a quarter of the Arctic sea ice cover. Now it constitutes only 2%. This thin, young ice is susceptible to melting. The areas in purple on the map above can be expected to disappear quickly once the melting season gets underway in earnest.

Melting sea ice is apparently initiating a previously unknown feedback effect. In a study published in Nature Geoscience, researchers report that significant amounts of methane are released from the ocean into the atmosphere through cracks in the melting sea ice.  Previously, large methane plumes have been observed emanating from the seabed in the relatively shallow sea off the northern coast of Siberia, but the latest findings come far away from land in the deep, open ocean where the surface has in the past been capped by ice. The researchers conclude:

We suggest that the surface waters of the Arctic Ocean represent a potentially important source of methane, which could prove sensitive to changes in sea ice cover. The association with sea ice makes this methane source likely to be sensitive to changing Arctic ice cover and dynamics, providing an unrecognised feedback process in the global atmosphere-climate system.

The researchers estimate open ocean emissions are comparable to emissions seen on the Siberian shelf.

Methane is about 70 times more potent as a greenhouse gas than carbon dioxide when it comes to trapping heat. Because methane is broken down rather quickly in the atmosphere, it is about 20 times more powerful averaged over a 100-year period.

Arctic temperatures set a new record high in 2011, beating the record set just the previous year in 2010.

Surface temperature anomaly for the region extending from 64oN to 90oN, from 1880 through 2011, in degrees Centigrade above or below the temperature during the 1951-1980 base period.  

The annual mean surface temperature (land and air) for the region north of 64oN (the Arctic Circle is at 66° 33′N) in 2011 was 2.28° C above the 1951-1980 base period, beating 2010′s record of 2.11° C.  Temperatures in the region have been rising rapidly since the late 1970s and have not dropped below the long-term mean since 1992 — nearly 20 years.

Even with the cooling effects of a strong La Niña influence and low solar activity for the past several years, 2011 was one of the 10 warmest years on record – and the warming is especially concentrated in the Arctic.

Annual global surface temperature anomalies, 2011.  The largest and most extensive
warming (indicated in shades of red) was concentrated in the Arctic.
Source: NASA Goddard Institute for Space Studies.

NASA’s James Hansen expects record-breaking global average temperatures in the next two to three years because solar activity is on the upswing and the next El Niño will increase tropical Pacific temperatures. The warmest years on record so far were 2005 and 2010, in a virtual tie.

The carbon dioxide level in the atmosphere was about 285 parts per million in 1880, when the GISS global temperature record begins. By 1960, the average concentration had risen to about 315 parts per million. Today it exceeds 390 parts per million and continues to rise at an accelerating pace.

Rising temperatures are being accompanied by a decline in Arctic ice volume.

Ice volume for December 2011 was 12,230 km³ , 47% lower than the maximum in 1979, 37% below the mean and 1.6 standard deviations from trend. PIOMAS  ice volume for September 2011 was 380 km³ lower than the previous record of 2010, but this difference is within the estimated uncertainty of PIOMAS. The same appears to be true for December 2011 as well – ice volume is lower but within the range of uncertainty – as the University of Washington’s Polar Science Center reports 2011 volume is lower than the previous record of 2010.

The U.N. World Meteorological Organization reports greenhouse gas concentrations in the atmosphere reached a new high in 2010 – and the rate of increase has accelerated.

The publication WMO Greenhouse Gas Bulletin: The State of Greenhouse Gases in the Atmosphere Based on Global Observations through 2010 reports there was a 29% increase in radiative forcing from greenhouse gases between 1990 and 2010.

Globally averaged levels of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) have reached new highs, with CO2 at 389.0 ppm, CH4 at 1808 ppb, and N2O at 323.2 ppb. These values are greater than those in pre-industrial times (before 1750) by 39%, 158% and 20%, respectively.

CO2 is the single most important man-made greenhouse gas in the atmosphere, contributing about 64% of the total increase in climate forcing by greenhouse gases. CO2 emissions result from the burning of fossil fuels, deforestation, and changes in land-use.

CH4 – contributes about 18% to the overall global increase in radiative forcing. Methane emissions result from human activities such as cattle raising, rice planting, fossil fuel exploitation and landfills. About 40% of methane emissions come from natural sources such as wetlands. After a period of temporary relative stabilization from 1999 to 2006, atmospheric methane has again been rising, likely because of the thawing of the methane-rich northern permafrost and increased emissions from tropical wetlands.

N2O contributes about 6% to the overall global increase in radiative forcing. N2O emissions result from the use of nitrogen-containing fertilizers, including manure, which has profoundly affected the global nitrogen cycle. Over a 100 year period, its impact on climate is 298 times greater than equal emissions of carbon dioxide.

Halocarbons together account for about 12% of the increase in radiative forcing. Some halocarbons such as chlorofluorocarbons (CFCs), previously used as refrigerants, as propellants in spray cans and as solvents, are decreasing slowly as a result of international action to preserve the Earth’s protective ozone layer. However, concentrations of other gases such as HCFCs and HFCs, which have been substituted for CFCs because they are less damaging to the ozone layer, are increasing rapidly. HCFCs and HFCs are very potent greenhouse gases and last much longer in the atmosphere than carbon dioxide.

While greenhouse gases continue to rise at an increasing rate, the leaders of Earth’s “greatest” nations continue to fiddle. After the Copenhagen climate talks in 2009 ended in a debacle, governments pledged to try to sign a new treaty in 2012, when the current provisions of the Kyoto protocol expire. Fiona Harvey at the U.K. Guardian reports that before critical climate talks even begin next week, most of the world’s leading economies are privately admitting that no new global climate agreement will be reached before 2016 at the earliest – and that even if it were negotiated by then, they would stipulate it could not come into force until 2020.

2020 is too late if catastrophic climate change is to be averted. Fatih Birol, chief economist at the International Energy Agency (IEA) and one of the world’s foremost authorities on climate economics, warns:

If we do not have an international agreement whose effect is put in place by 2017, then the door to holding temperatures below 2 ° C will be closed forever.

While global leaders fiddle, Earth is already beginning to burn (and drown). In an advance draft of the Summary for Policymakers of the upcoming report Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX, the IPCC observes there has been an increase in temperature extremes, extreme precipitation events, and economic losses from extreme weather- and climate-related disasters.

While noting the effects of climate change are already being felt, the IPCC is pulling its punches. Joseph Romm at Climate Progress fumes:

The thing to remember about IPCC reports is that pretty much everyone involved has to sign off on every word, so it is inevitably a least common denominator document. The actual scientific literature from 2011 is far more useful than this report.

Romm in his post discusses and provides links to many recent studies showing the systemic influence of global warming on climate events. Climate change is already here – and will keep getting worse.

Massive die-offs of oyster larvae in the Pacific Northwest show ocean acidification from an excess of CO2 emissions has already begun.

In Netarts Bay, from 2006 to 2008, oyster larvae began dying dramatically. Elizabeth Grossman, in an article in Yale Environment 360, quotes Netarts Bay hatchery owner Mark Wiegard:

Historically we’ve had larvae mortalities [usually related to bacteria] . . . My wife sent a few samples in and Hales [Burke Hales, a biogeochemist and ocean ecologist at Oregon State University] said someone had screwed up the samples because the [dissolved CO2 gas] level was so ridiculously high.

Taylor Shellfish Hatchery in Washington, the country’s largest producer of farmed shellfish and one of the largest oyster producers, has also reported dramatic losses.  Hood Canal has some of the Pacific Northwest’s highest levels of ocean acidification. Taylor’s hatchery there experienced the loss of about three-quarters of its oyster larvae, losses which are now being mitigated by buffering the high acidity.

Wild oyster beds in the Pacific Northwest are suffering, too.  Wild oysters in Willapa Bay,  Puget Sound, and off the east coast of Vancouver Island have seen reproductive failure because acidic waters have prevented oyster larvae from forming shells. Acidic water sometimes kills oyster larvae outright, so that they fail to survive past the egg stage. At other times the eggs hatch; but the larvae, stressed as they try to forms their first shells, fail after a week or two.

The water now washing ashore in Oregon and Washington actually absorbed its CO2 30 to 50 years ago. Oceans absorb about 50% of the CO2 released by burning fossil fuels. Since then, emissions have been rising even more dramatically.

Ocean acidity has increased approximately 30% since the Industrial Revolution and is on track to be 150% more acidic by the end of the century than it has been for 20 million years. Ocean acidification depletes seawater of the compounds that organisms need to build shells and skeletons, impairing the ability of corals, crabs, sea stars, sea urchins, plankton and other marine creatures to build the shells they need to survive. Ocean acidification could destroy all of the globe’s coral reefs by 2050 and threatens the entire marine ecosystem.

2011 has seen new record lows established for Arctic average sea ice extent and area; sea ice volume; and for global sea ice area.

Neven at Arctic Sea Ice Blog reports that the 12 month rolling average for Arctic sea ice extent set a new record in October 2011 at 10.66 million km². The previous record of 10.67 million km² had been set in October 2007.

The record for Arctic sea ice area has also been broken. The October 2007 was again the previous record, standing at 8.39 million km². Annual average Sea Ice Area dropped to 8.34 million km² for the 12-month period ending in October 2011.

Sea ice volumes have been decreasing far more quickly. The previous record value from PIOMAS was 15,075 km³, set in the 12-month period ending in January 2008, a record that held for just 29 months. The 12-month period ending in September 2011 set a new record, averaging 13,140 km³.

Global sea ice area (Arctic and Antarctic combined, as calculated at Cryosphere Today) has also reached its lowest maximum on record, as seen in this graph posted here.

It’s hard to see the new record in the graph above, but Neven posts this chart showing the numbers.

Earth’s cryosphere continues to wither under the assault from global warming.

A new study published in Nature Geoscience by Ian Joughin and Richard B. Alley titled Stability of the West Antarctic ice sheet in a warming world reports recent observations by satellite show substantial mass loss from the West Antarctic ice sheet (WAIS).

Losses range from 100 to 200 gigatonnes per year, the equivalent to 0.28 to 0.56 mm per year sea-level rise – and the rate is increasing.

This excerpt is from the abstract:

Ice sheets are expected to shrink in size as the world warms, which in turn will raise sea level. The West Antarctic ice sheet is of particular concern, because it was probably much smaller at times during the past million years when temperatures were comparable to levels that might be reached or exceeded within the next few centuries. Much of the grounded ice in West Antarctica lies on a bed that deepens inland and extends well below sea level. Oceanic and atmospheric warming threaten to reduce or eliminate the floating ice shelves that buttress the ice sheet at present. Loss of the ice shelves would accelerate the flow of non-floating ice near the coast. Because of the slope of the sea bed, the consequent thinning could ultimately float much of the ice sheet’s interior. In this scenario, global sea level would rise by more than three metres, at an unknown rate.

The study’s authors suggest loss of the large ice shelves by atmospheric or oceanic forcing would probably lead to collapse of the bulk of the marine ice sheet. Temperature predications for 2100 approach the thresholds of ice-shelf viability in many simulations.

With CO2 emissions increasing by a record amount in 2010, temperatures by the end of the century are likely to be at the top end of or even exceed IPCC predictions. Meeting the 2° target the IPCC warns is necessary to avert dangerous climate change depends on limiting atmospheric CO2 to no more than 450 ppm. We are a little below 400 parts per million now – and heading higher. Recent research has found that the WAIS collapsed and rebuilt multiple times matching the cycle of Northern Hemisphere’s pattern of glaciation and glacier retreat – collapsing much more frequently when atmospheric CO2 hit 400ppm.

Sea level rise is now going up about 3.5 centimeters per decade. A collapse of the marine ice sheet in West Antarctica would raise sea levels by more than three meters over the course of several centuries or less – in the past, sea levels have risen at a speed of up to one meter per 20 years.

It’s bad enough that the Greenland ice sheet is melting: Greenland setting a new melt record in 2010, and Greenland melting in 2011 well above average with near-record mass loss. Now we may be witnessing the start of the destabilization of the WAIS.

Bad news: a new study finds that the prospects for avoiding dangerous global warming are bleak, indeed.

In the study, titled Emission pathways consistent with a 2°C global temperature limit, the team of scientists reanalyzed a large set of previously published emission scenarios based on integrated assessment models. They found that in the set of scenarios with a ‘likely’ (greater than 66%) chance of staying below 2°C, emissions peak between 2010 and 2020 and fall to a median level of 44 Gt of CO₂ equivalent in 2020 (compared with estimated median emissions across the scenario set of 48 Gt of CO₂ equivalent in 2010).

Current climate models show if the increase in average global temperatures is to be kept below 2°C (3.6°F), emissions must not only peak by 2020, emissions must fall by almost 10% by 2020  – and then continue to fall rapidly to well under half of current emissions by 2050.

Climate scientist Neil Edwards commented on the study’s findings:

The alarming thing is very few scenarios give the kind of future we want.

The International Energy Agency (IEA) recently announced global CO₂ emissions decreased for the first time since 1990, due to the 2008-2009 economic crisis – but warned, don’t expect a trend. A large rebound is anticipated in 2010. (Note: a report published by the European Commission’s Joint Research Centre and PBL Netherlands Environmental Assessment Agency found that global carbon dioxide (CO₂) emissions increased by more than 5% in 2010, reaching an all-time high.)

The IEA’s findings are contained in a free document that contains highlights from CO₂ Emissions from Fuel Combustion 2011, an IEA statistics publication which will be released in November 2011. The full document, which contains all the latest information on the level and growth of CO₂ emissions, is being released to inform the upcoming UN climate negotiations in Durban. Key findings include:

1. Two-thirds of global emissions for 2009 originated from just ten countries, with the shares of China and the United States far surpassing those of all others (combined, these two countries alone produced 41% of the world’s CO₂emissions).
2. Between 1990 and 2009, CO₂ emissions from the combustion of coal grew from 40% to 43% and natural gas from 18 to 20%, while CO₂ emissions from oil fell from 42% to 37%.
3. Two sectors – electricity and heat generation and transport – produced nearly two-thirds of global CO₂ emissions in 2009, up from 58% in 1990.

In their study, the climate scientists found only three of the 193 scenarios examined would be very likely to keep the warming below the danger level – and all of those require heavy use of energy systems that actually remove greenhouse gases from the atmosphere. That would require, for example, both creating biofuels and storing the carbon dioxide from their combustion in the ground. Edwards put it this way:

What we need is at the cutting edge. We need to be as innovative as we can be in every way.

In the statement quoted above, Edwards is assuming that the objective is to preserve the energy-intensive economic growth paradigm. But the paradigm is the problem. Every day it is becoming increasingly clear that cutting edge technology and innovation are not the answer.

One example: many Oregonians across the political spectrum, including Governor John Kitzhaber, have promoted forest biomass as a energy source, thinking woody debris from thinning, brush clearing and removing dead trees could help the state meet its renewable energy goals while at the same time restoring forest health and providing jobs in rural communities. But not so fast, say OSU researchers: managing forests for biofuel production will increase carbon dioxide emissions from the forests by at least 14%. The OSU press release quotes co-author Beverly Law:

Until now there have been a lot of misconceptions about impacts of forest thinning, fire prevention and biofuels production as it relates to carbon emissions from forests. If our ultimate goal is to reduce greenhouse gas emissions, producing bioenergy from forests will be counterproductive. Some of these forest management practices may also have negative impacts on soils, biodiversity and habitat. These issues have not been thought out very fully.

Looking to technology and innovation to enable humans to continue to pursue the economic growth that is consuming the very ecosystems that sustain us is just the denial of an addict. What is necessary is acceptance: growth is destructive and must be reversed. We must welcome and embrace the collapse of our current economic system, and learn to live within an economic system that conserves rather than consumes the larger systems of which it is a part.

A new assessment of the impacts of climate change in the Arctic finds that the changes in the sea ice on the Arctic Ocean and in the mass of the Greenland Ice Sheet and Arctic ice caps and glaciers over the past ten years have been dramatic and  and represent an obvious departure from the long-term patterns. The study is titled Snow, Water, Ice and Permafrost in the Arctic.

The assessment finds that the past six years (2005–2010) have been the warmest period ever recorded in the Arctic. The higher surface air temperature are driving changes in the cryosphere. Two components of the Arctic cryosphere – snow and sea ice – are interacting with the climate system to accelerate warming in a feedback loop. Loss of ice and snow in the Arctic enhances climate warming by increasing absorption of the sun’s energy at the surface of the planet. Temperatures in the permafrost have risen by up to 2 °C and the southern limit of permafrost has moved northward in Russia and Canada- a trend which could result in dramatically increased emissions of carbon dioxide and methane. Melting ice could change large-scale ocean currents. Melting glaciers and ice sheets worldwide have become the biggest contributor to global sea level rise. Arctic glaciers, ice caps, and the Greenland Ice Sheet are contributing much more to global sea level rise than previously measured. High uncertainty surrounds estimates of future global sea level, with latest models predicting a rise of 0.9 to 1.6 m above the 1990 level by 2100. But, the assessment cautions, the combined outcome of these effects is not yet known. Interactions (‘feedbacks’) between elements of the cryosphere and climate system are particularly uncertain.

The assessment was done by the Arctic Monitoring and Assessment Programme (AMAP), an international organization headquartered in Norway. Member nations include the eight Arctic rim countries: Canada, Denmark/Greenland, Finland, Iceland, Norway, Russia, Sweden, and the United States. Other nations and organizations participate as well.

The National Snow and Ice Data Center (NSIDC) reports Arctic sea ice extent declined through April more slowly than usual, as cool conditions helped retain ice in Baffin Bay, between Canada and Greenland. Still, April 2011 continued the overall downward trend of the past thirty years, ranking fifth lowest in the satellite record. The two lowest years for April were 2007 and 2006.

University of Washington’s Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) model of sea ice volume shows continued very low ice mass in the Arctic compared to previous decades.

Joseph Romm at Climate Progress reports on a study showing the Greenland ice sheet has been losing mass over the last decade.

Greenland ice mass anomaly – deviation from the average ice mass over the 2002 to 2010 period.

Say goodbye to much of the Arctic tundra. Climate change will result in the tundra being replaced by trees, shrubs, and other plants. That’s one of the conclusions of a new study to be published in the scientific journal Climate Dynamics.

Imagine the vast, empty tundra in Alaska and Canada giving way to trees, shrubs and plants typical of more southerly climates. Imagine similar changes in large parts of Eastern Europe, northern Asia and Scandinavia, as needle-leaf and broadleaf forests push northward into areas once unable to support them. Imagine part of Greenland’s ice cover, once thought permanent, receding and leaving new tundra in its wake.

These three figures show the arrangement of arctic climate types using (a) observational data from 1950-99 and a combination of 16 climate-change models factoring in moderate greenhouse gas increases over the next 89 years (b) and (c). The climate types and vegetations in the arctic are abbreviated as Fi (ice cap/permanent ice cover); Ft (tundra); Ec (boreal continental/shrubs); Eo (boreal oceanic/needle leaf forests); Dc (temperate continental/needle leaf and deciduous tall broadleaf forests); and Do (temp

Changes to Arctic vegetation will follow shifts in the region’s climates. Tundra coverage is expected to shrink by 33 – 44% by the end of the century, while temperate climate types that support coniferous forests and needle-leaf trees would expand northward into the breach.

Lead author Song Feng says the vegetative changes could induce a positive feedback loop:

The expansion of forest may amplify global warming, because the newly forested areas can reduce the surface reflectivity, thereby further warming the Arctic. The shrinkage of tundra and expansion of forest may also impact the habitat for wildlife and local residents.

Tundra in Alaska and northern Canada would be reduced and replaced by boreal forests and shrubs by 2059. Within another 40 years, the tundra would be restricted to the northern coast and islands of the Arctic Ocean. The melting of snow and ice in Greenland following the warming will reduce the permanent ice cover. The ice would then be replaced by tundra. Also, increasing drought conditions could reduce the overall vegetation growth in the Arctic regions.