Kamis, 28 Februari 2013
An Affordable Solution to Global Warming
REDD (reducing emissions from deforestation and forest degradation) is a very affordable way to reduce the amount of global warming pollution released into the atmosphere. In order to create an economic incentive for developing nations to reduce the clearing of their tropical forests, they would need to be paid more than they could make by using the newly cleared land for other activities like establishing cattle pastures or growing crops. Funding the preservation of tropical forests is considerably less expensive than the costs of reducing pollution from industries, vehicles and power plants. Using REDD policies, we can greatly reduce tropical deforestation, and thus reduce global warming, with modest funding.
Funding for a REDD system can come from a combination of three sources. The quickest source of funding would be voluntary funding from countries, individuals, or organizations. Voluntary funding presents the fastest way for developing nations to build up the capacity needed to protect tropical forests, so they can measure their reductions and follow the required certification processes. Industrialized countries must help developing countries acquire the technology and train their staff to ensure that certifiable reductions are made. Other countries have already begun giving voluntary funding to REDD programs. For example, Norway gives over $500 million yearly.
Another important source of REDD funding should be market-linked funding. There has been proposed legislation in the United States to set up a capped carbon market system in which companies will need to buy emissions “allowances” for the amount of global warming pollution they plan to emit. Every year the companies would be allowed to buy fewer allowances, thus cutting down on emissions over time. These allowances would be sold each year in an auction and the revenue from these sales can be used by the government for a variety of programs, including REDD. This arrangement would limit the global warming pollution coming from the United States and also provide funding to reduce pollution from tropical deforestation. Similar systems in other countries would also provide funding in this way.
The third source of money for REDD is direct carbon market funding. This funding would also come from the cap-and-trade carbon market, but in a different way. As fewer allowances are offered at auction, some companies will want to buy extra allowances if they have not yet found a way to reduce emissions. They could buy these extra allowances from programs that are making extra reductions, thus offsetting any extra pollution produced by the company. REDD programs could sell the reductions made by protecting tropical forests in this way. This funding will be more useful in later years because the tropical countries will have built up capacity and experience to ensure that they are providing high quality offsets: meeting strict certification criteria and showing they are representing real reductions in emissions.
It’s Cold and My Car is Buried in Snow. Is Global Warming Really Happening?
For years, climate contrarians have pointed to snowfall and cold weather to question the scientific reality of human-induced climate change.
Such misinformation obscures the interesting work scientists are doing to figure out just how climate change is affecting weather patterns year-round.
Understanding what scientists know about these effects can help us adapt. And, if we reduce the emissions that are driving climate change, we can dramatically reduce the pace of change and better prepare for the consequences in the future.
What is the relationship between weather and climate?
Weather is what’s happening outside the door right now; today a snowstorm or a thunderstorm is approaching. Climate, on the other hand, is the pattern of weather measured over decades.
NASA and NOAA plus research centers around the world track the global average temperature, and all conclude that Earth is warming. In fact, the past decade has been found to be the hottest since scientists started recording reliable data in the 1880s. These rising temperatures are caused primarily by an increase of heat-trapping emissions in the atmosphere created when we burn coal, oil, and gas to generate electricity, drive our cars, and fuel our businesses.
Hotter air around the globe causes more moisture to be held in the air than in prior seasons. When storms occur, this added moisture can fuel heavier precipitation in the form of more intense rain or snow.
At the same time, because less of a region’s precipitation is falling in light storms and more of it in heavy storms, the risks of drought and wildfire are also greater. Ironically, higher air temperatures tend to produce intense drought periods punctuated by heavy floods, often in the same region.
These kinds of disasters may become a normal pattern in our everyday weather as levels of heat-trapping gases in the atmosphere continue to rise.
The United States is already experiencing more intense rain and snowstorms. The amount of rain or snow falling in the heaviest one percent of storms has risen nearly 20 percent, averaged nationally—almost three times the rate of increase in total precipitation between 1958 and 2007.
Some regions of the country have seen as much as a 67 percent increase in the amount of rain or snow falling in the heaviest storms — and an updated version of this figure from thedraft National Climate Assessment suggests this increase may have risen to 74 percent between 1958 and 2011.
Overall, it’s warming, but we still have cold winter weather.
The seasons we experience are a result of the Earth’s tilted axis as it revolves around the Sun. During the North American winter, our hemisphere is tilted away from the Sun and its light hits us at a different angle, making temperatures lower.
While climate change won’t have any impact on Earth’s tilt, it is significantly shifting temperatures and causing spring weather to arrive earlier than it used to. Overall, spring weather arrives 10 days earlier than it used to, on average. “Spring creep" is something scientists projected would happen as the globe continues to warm.
The Arctic connection.
Winters have generally been warming faster than other seasons in the United States and recent research indicates that climate change is disrupting the Arctic and ice around the North Pole.
The Arctic summer sea ice extent broke all records during the end of the 2012 sea ice melt season. Some researchers are pointing to a complex interplay between Arctic sea ice decline, ocean patterns, upper winds, and the shifting shape of the jet stream that could lead to extreme weather in various portions of northern mid-latitudes — such that some places get tons of snow repeatedly and others are unseasonably warm.
In the Arctic, frigid air is typically trapped in a tight loop known as the polar vortex. This super-chilled air is not only cold, it also tends to have low barometric pressure compared to the air outside the vortex. The surrounding high-pressure zones push in on the vortex from all sides so the cold air is essentially "fenced in" above the Arctic, where it belongs.
As the Arctic region warms faster than most other places, however, the Arctic sea ice melts more rapidly and for longer periods each year, and is unable to replenish itself in the briefer, warmer winter season. This can destabilize the polar vortex and raises the barometric pressure within it.
For two winter seasons (2009/2010 and 2010/2011), the polar vortex was notably unstable. In addition, another measurement of barometric pressure—the North Atlantic Oscillation (NAO)—was in negative mode, weakening part of the barometric pressure "fence" around the polar vortex. This instability allows the cold Artic air to break free and flow southward, where it collides with warmer, moisture-laden air. This collision can produce severe winter weather in some regions and leave milder conditions in other parts of the northern hemisphere.
The winter of 2009/2010 recorded the second lowest negative phase of the NAO since the 1970s, which helps to explain the record snowfalls across the northeastern United States. The 2010/2011 winter also trended toward a strong negative phase.
During the 2011/2012 winter, there was a shift in the position of the jet stream, which separates cold arctic air from warmer air. Typically New England, the Great Lakes, and parts of the Great Plains sit north of the jet stream and remain cold in the winter season. However, the 2011/2012 winter jet stream position meant these regions were south of it for most of the winter, which helped produce the fourth warmest U.S. winter on record.
It’s not clear how much impact this trend will have in the future, especially as the Arctic ice continues to lose mass.
It’s not too late.
The choices we make today can help determine what our climate will be like in the future.Putting a limit on heat-trapping emissions, encouraging the use of healthier, cleaner energy technologies, and increasing our energy efficiency are all ways to help us to avert the worst potential consequences of global warming, no matter what the season.
Minggu, 24 Februari 2013
1.5C rise in temperature enough to start permafrost melt, scientists warn
Team of scientists use radiometric dating techniques on Russian cave formations to measure historic melting rates
Frost crystals at the entrance of Ledyanaya Lenskaya cave, Siberia. Photograph: Vladimir V Alexioglo
A global temperature rise of 1.5C would be enough to start the melting of permafrost in Siberia, scientists warned on Thursday.
Any widespread thaw in Siberia's permanently frozen ground could have severe consequences for climate change. Permafrost covers about 24% of the land surface of the northern hemisphere, and widespread melting could eventually trigger the release of hundreds of gigatonnes of carbon dioxide and methane, which would have a massive warming effect.
However, any such melting would be likely to take many decades, so the initial release of greenhouse gas would probably be on a much smaller scale.
The researchers, led by experts from Oxford University, studied stalactites and stalagmites in Siberian caves that have formed over hundreds of thousands of years. The stalactites and stalagmites formed during periods of gradual melting, when meltwater dripped into the caves, but stopped growing when temperatures fell again and the permafrost refroze. Scientists can measure the growth and halting of stalactite and stalagmites by cutting through the structures at various points corresponding to given time periods in the Earth's history.
They found the stalactites in one far northern cave on the boundary of continuous permafrost grew during a period 400,000 years ago when temperatures were 1.5C higher than in pre-industrial times. That indicates that permafrost was melting at that time, and therefore that it could thaw again if temperatures rise to similar levels.
"I would expect to see continuous permafrost start to thaw along the boundaries at this threshold of 1.5C [in future]," said Anton Vaks, of the Earth sciences department at Oxford, who led the research. Temperatures in the region were 0.5-1C higher than in modern times for a period about 120,000 years ago, and at that time stalactites in caves further south, near Lake Baikal, showed signs of growth, and therefore melting.
But for the same period, the stalactites in the far northern cave – called the Ledyanaya Lenskaya cave, near the town of Lensk at latitude 60N – did not grow, showing that the permafrost remained intact at those temperatures. "This indicates that 1.5C appears to be something of a tipping point," said Vaks.
At present, global average temperatures are about 0.6C-0.7C above pre-industrial levels. This means, according to Vaks, that climate modellers should include the possibility of permafrost beginning to melt in their models.
The team of scientists, from Mongolia, Russia and Switzerland as well as the UK, used radiometric dating techniques on the cave formations. They report on their work in the journal Science Express, published on Thursday.
Vaks said the findings could have severe implications for the region, as melting permafrost could affect natural gas exploration and pipelines, as well as other infrastructure. It could also have more wide-reaching effects. "Although it wasn't the main focus of our research, our work also suggest that in a world 1.5C warmer – warm enough to melt the coldest permafrost – adjoining regions would see significant changes. Mongolia's Gobi Desert [could] become much wetter than it is today and this extremely arid area could come to resemble the present-day Asian steppes."
He said more research was needed to establish the likely speed and scale of melting as temperatures rise.
Climate change hitting entire Arctic ecosystem, says report
Arctic Monitoring and Assessment Programme study tells of profound changes to sea ice and permafrost, among others
Levels of summer sea ice in the Arctic have drastically reduced since 2005
Extensive climate change is now affecting every form of life in the Arctic, according to a major new assessment by international polar scientists.
In the past four years, air temperatures have increased, sea ice has declined sharply, surface waters in the Arctic ocean have warmed and permafrost is in some areas rapidly thawing.
In addition, says the report released today at a Norwegian government seminar, plants and trees are growing more vigorously, snow cover is decreasing 1-2% a year and glaciers are shrinking.
Scientists from Norway, Canada, Russia and the US contributed to theArctic monitoring and assessment programme (Amap) study, which says new factors such as "black carbon" – soot – ozone and methane may now be contributing to global and arctic warming as much as carbon dioxide.
"Black carbon and ozone in particular have a strong seasonal pattern that makes their impacts particularly important in the Arctic," it says.
The report's main findings are:
Land
Permafrost is warming fast and at its margins thawing. Plants are growing more vigorously and densely. In northern Alaska, temperatures have been rising since the 1970s. In Russia, the tree line has advanced up hills and mountains at 10 metres a year. Nearly all glaciers are decreasing in mass, resulting in rising sea levels as the water drains to the ocean.
Summer sea ice
The most striking change in the Arctic in recent years has been thereduction in summer sea ice in 2007. This was 23% less than the previous record low of 5.6m sq kilometres in 2005, and 39% below the 1979-2000 average. New satellite data suggests the ice is much thinner than it used to be. For the first time in existing records, both the north-west and north-east passages were ice-free in summer 2008. However, the 2008 winter ice extent was near the year long-term average.
Greenland
The Greenland ice sheet has continued to melt in the past four years with summer temperatures consistently above the long-term average since the mid 1990s. In 2007, the area experiencing melt was 60% greater than in 1998. Melting lasted 20 days longer than usual at sea level and 53 days longer at 2-3,000m heights.
Warmer waters
In 2007, some ice-free areas were as much as 5C warmer than the long-term average. Arctic waters appear to have warmed as a result of the influx of warmer waters from the Pacific and Atlantic. The loss of reflective, white sea ice also means that more solar radiation is absorbed by the dark water, heating surface layers further.
Black carbon
Black carbon, or soot, is emitted from inefficient burning such as in diesel engines or from the burning of crops. It is warming the Arctic by creating a haze which absorbs sunlight, and it is also deposited on snow, darkening the surface and causing more sunlight to be absorbed.
Arctic permafrost leaking methane at record levels, figures show
Experts say methane emissions from the Arctic have risen by almost one-third in just five years, and that sharply rising temperatures are to blame
Permafrost in Siberia. Methane emissions from the Arctic permafrost increased by 31% from 2003-07, figures show. Photograph: Francis Latreille/Corbis
Scientists have recorded a massive spike in the amount of a powerful greenhouse gas seeping from Arctic permafrost, in a discovery that highlights the risks of a dangerous climate tipping point.
Experts say methane emissions from the Arctic have risen by almost one-third in just five years, and that sharply rising temperatures are to blame.
The discovery follows a string of reports from the region in recent years that previously frozen boggy soils are melting and releasing methane in greater quantities. Such Arctic soils currently lock away billions of tonnes of methane, a far more potent greenhouse gas than carbon dioxide, leading some scientists to describe melting permafrost as a ticking time bomb that could overwhelm efforts to tackle climate change.
They fear the warming caused by increased methane emissions will itself release yet more methane and lock the region into a destructive cycle that forces temperatures to rise faster than predicted.
Paul Palmer, a scientist at Edinburgh University who worked on the new study, said: "High latitude wetlands are currently only a small source of methane but for these emissions to increase by a third in just five years is very significant. It shows that even a relatively small amount of warming can cause a large increase in the amount of methane emissions."
Global warming is occuring twice as fast in the Arctic than anywhere else on Earth. Some regions have already warmed by 2.5C, and temperatures there are projected to increase by more than 10C by 2100 if carbon emissions continue to rise at current rates.
Palmer said: "This study does not show the Arctic has passed a tipping point, but it should open people's eyes. It shows there is a positive feedback and that higher temperatures bring higher emissions and faster warming."
The change in the Arctic is enough to explain a recent increase in global methane levels in the atmosphere, he said. Global levels have risen steadily since 2007, after a decade or so holding steady.
The new study, published in the journal Science, shows that methane emissions from the Arctic increased by 31% from 2003-07. The increase represents about 1m extra tonnes of methane each year. Palmer cautioned that the five-year increase was too short to call a definitive trend.
The findings are part of a wider study of methane emissions from global wetlands, such as paddy fields, marshes and bogs. To identify where methane was released, the researchers combined methane levels in the atmosphere with surface temperature changes. They did not measure methane emissions directly, but used satellite measurements of variations in groundwater depth, which alter the way bacteria break down organic matter to release or consume methane.
They found that just over half of all methane emissions came from the tropics, with some 20m tonnes released from the Amazon river basin each year, and 26m tonnes from the Congo basin. Rice paddy fields across China and south and south-east Asia produced just under one-third of global methane, some 33m tonnes. Just 2% of global methane comes from Arctic latitudes, the study found, though the region showed the largest increases. The 31% rise in methane emissions there from 2003-07 was enough to help lift the global average increase to 7%.
Palmer said: "Our study reinforces the idea that satellites can pinpoint changes in the amount of greenhouse gases emitted from a particular place on earth. This opens the door to quantifying greenhouse gas emissions made from a variety of natural and man-made sources."
Palmer said it was a "disgrace" that so few satellites were launched to monitor levels of greenhouse gases such as carbon dioxide and methane. He said it was unclear whether the team would be able to continue the methane monitoring in future. The pair of satellites used to analyse water, known as Grace, are already over their expected mission life time, while a European version launched last year, called Goce, is scheduled to fly for less than two years.
The new study follows repeated warnings that even modest levels of global warming could trigger huge increases in methane release from permafrost. Phillipe Ciais, a researcher with the Laboratory for Climate Sciences and the Environment in Gif-sur-Yvette, France, told a scientific meeting in Copenhagen last March that billions of tonnes could be released by just a 2C average global rise.
More on methane
While carbon dioxide gets most of the attention in the global warming debate, methane is pound-for-pound a more potent greenhouse gas, capable of trapping some 20 times more heat than CO2. Although methane is present in much lower quantities in the atmosphere, its potency makes it responsible for about one-fifth of man-made warming.
The gas is found in natural gas deposits and is generated naturally by bacteria that break down organic matter, such as in the guts of farm animal. About two-thirds of global methane comes from man-made sources, and levels have more than doubled since the industrial revolution.
Unlike carbon dioxide, methane lasts only a decade or so in the atmosphere, which has led some experts to call for greater attention to curbs on its production. Reductions in methane emissions could bring faster results in the fight against climate change, they say.
Arctic Death Spiral Bombshell: CryoSat-2 Confirms Sea Ice Volume Has Collapsed
The sharp drop in Arctic sea ice area has been matched by a harder-to-see, but equally sharp, drop in sea ice thickness. The combined result has been a collapse in total sea ice volume — toone fifth of its level in 1980.
Arctic sea ice volume in 1000s of cubic kilometers (via Robinson)
Back in September, Climate Progress reported that the European Space Agency’s CryoSat-2 probe appeared to support the key conclusion of the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the University of Washington’s Polar Science Center: Arctic sea ice volume has been collapsing much faster than sea ice area (or extent) because the ice has been getting thinner and thinner.
Now the Natural Environment Research Council (NERC), the UK’s primary agency for funding and managing environmental sciences research, has made it official. In a Wednesday press release, they report:
Arctic sea ice volume has declined by 36 per cent in the autumn and 9 per cent in the winter between 2003 and 2012, a UK-led team of scientists has discovered….The findings confirm the continuing decline in Arctic sea-ice volume simulated by the Pan-Arctic Ice-Ocean Modelling & Assimilation System (PIOMAS), which estimates the volume of Arctic sea ice and had been checked using earlier submarine, mooring, and satellite observations until 2008.
This should be the story of the day, week, month, year, and decade. As NERC notes, sea ice volume is “a much more accurate indicator of the changes taking place in the Arctic.”
Many experts now say that if recent volume trends continue we will see a “near ice-free Arctic in summer” within a decade. And that may well usher in a permanent change toward extreme, prolonged weather events “Such As Drought, Flooding, Cold Spells And Heat Waves.”
It will also accelerate global warming in the region, which in turn will likely accelerate both the disintegration of the Greenland ice sheet and the release of the vast amounts of carbon currently locked in the permafrost.
The findings were published online in Geophysical Research Letters (subs. req’d). In a U. of Washington news release, polar scientist and coauthor Axel Schweiger said:
“Other people had argued that 75 to 80 percent ice volume loss was too aggressive. What this new paper shows is that our ice loss estimates may have been too conservative, and that the recent decline is possibly more rapid.”
Creative tech guru and programming analyst Andy Lee Robinson has made a video of the PIOMAS data
Here is the rest of the NERC press release:
… Researchers used new data from the European Space Agency’s CryoSat-2 satellite spanning 2010 to 2012, and data from NASA’s ICESat satellite from 2003 to 2008 to estimate the volume of sea ice in the Arctic.They found that from 2003 to 2008, autumn volumes of ice averaged 11,900 km3. But from 2010 to 2012, the average volume had dropped to 7,600 km3 - a decline of 4,300 km3. The average ice volume in the winter from 2003 to 2008 was 16,300 km3, dropping to 14,800 km3 between 2010 and 2012 – a difference of 1,500 km3.“The data reveals that thick sea ice has disappeared from a region to the north of Greenland, the Canadian Archipelago, and to the northeast of Svalbard,” says Dr Katharine Giles, a NERC-funded research fellow at the Centre for Polar Observation & Modelling (CPOM) at UCL (University College London), who co-authored the report, published online in Geophysical Research Letters….Other satellites have already shown drops in the area covered by Arctic sea ice as the climate has warmed. Indeed, sea-ice extent reached a record minimum in September 2012. But CryoSat-2, launched in April 2010, differs in that it lets scientists estimate the volume of sea ice — a much more accurate indicator of the changes taking place in the Arctic.“While two years of CryoSat-2 data aren’t indicative of a long-term change, the lower ice thickness and volume in February and March 2012, compared with same period in 2011, may have contributed to the record minimum ice extent during the 2012 autumn,” says Professor Christian Haas of York University, Canada Research Chair for Arctic Sea Ice Geophysics, co-author of the study and coordinator of the international CryoSat sea ice validation activities.CryoSat-2 measures ice volume using a high-resolution synthetic aperture radar altimeter, which fires pulses of microwave energy down towards the ice. The energy bounces off both the top of sections of ice and the water in the cracks in between. The difference in height between these two surfaces let scientists calculate the volume of the ice cover.The findings are the result of a huge international collaboration between teams from UCL, the European Space Agency, the Jet Propulsion Laboratory, the University of Washington, York University, Alfred Wegener Institute for Polar & Marine Research, Woods Hole Oceanographic Institution, Morgan State University and the University of Maryland.The team confirmed CryoSat-2 estimates of ice volume using measurements from three independent sources – aircraft, moorings, and NASA’s Operation IceBridge.
If you were wondering whether “death spiral” was the right visual metaphor for the collapse of Arctic ice, Robinson has a graphic for you:
It is almost certainly too late to save the Arctic’s summer sea ice from near-total destruction. Let’s hope the same isn’t true for the biosphere. The time to act is now if we don’t want to betray our children and future generations.
Related Posts:
Why The Arctic Sea Ice Death Spiral Matters
Arctic sea ice extent takes a nosedive this year. What does it mean for us? (Source: Japan Aerospace Exploration Agency)
In the past week the Arctic sea ice cover reached an all-time low, several weeks before previous records, several weeks before the end of the melting season. The long-term decline of Arctic sea ice has been incredibly fast, and at this point a sudden reversal of events doesn’t seem likely. The question no longer seems to be “will we see an ice-free Arctic?” but “how soon will we see it?”. By running the Arctic Sea Ice blog for the past three years I’ve learned much about the importance of Arctic sea ice. With the help of Kevin McKinney I’ve written the piece below, which is a summary of all the potential consequences of disappearing Arctic sea ice.
Arctic sea ice became a recurrent feature on planet Earth around 47 million years ago. Since the start of the current ice age, about 2.5 million years ago, the Arctic Ocean has been completely covered with sea ice. Only during interglacials, like the one we are in now, does some of the sea ice melt during summer, when the top of the planet is oriented a bit more towards the Sun and receives large amounts of sunlight for several summer months. Even then, when winter starts, the ice-free portion of the Arctic Ocean freezes over again with a new layer of sea ice.
Since the dawn of human civilization, 5000 to 8000 years ago, this annual ebb and flow of melting and freezing Arctic sea ice has been more or less consistent. There were periods when more ice melted during summer, and periods when less melted. However, aradical shift has occurred in recent times. Ever since satellites allowed a detailed view of the Arctic and its ice, a pronounced decrease in summer sea ice cover has been observed (with this year setting a new record low). When the IPCC released its Fourth Assessment Report in 2007, it was generally thoughtthat the Arctic could become ice-free somewhere near the end of this century. But changes in the Arctic have progressed at such speed that most experts now think 2030 might see an ice-free Arctic for the first time. Some say it could even happen this decade.
What makes this event significant, is the role Arctic sea ice plays as a reflector of solar energy. Ice is white and therefore reflects a large part of incoming sunlight back out to space. But where there is no ice, dark ocean water absorbs most of the sunlight and thus heats up. The less ice there is, the more the water heats up, melting more ice. This feedback has all kinds of consequences for the Arctic region. Disappearing ice can be good for species such as tiny algae that profit from the warmer waters and extended growing season, but no sea ice could spell catastrophe for larger animals that hunt or give birth to offspring on the ice. Rapidly changing conditions also have repercussions for human populations whose income and culture depend on sea ice. Their communities literally melt and wash away as the sea ice no longer acts as a buffer to weaken wave action.
But what happens in the Arctic, doesn’t stay in the Arctic. The rapid disappearance of sea ice cover can have consequences that are felt all over the Northern Hemisphere, due to the effects it has on atmospheric patterns. As the ice pack becomes smaller ever earlier into the melting season, more and more sunlight gets soaked up by dark ocean waters, effectively warming up the ocean. The heat and moisture that are then released to the atmosphere in fall and winter could be leading to disturbances of the jet stream, the high-altitude wind that separates warm air to its south from cold air to the north. A destabilized jet stream becomes more ‘wavy’, allowing frigid air to plunge farther south, a possible factor in theextreme winters that were experienced all around the Northern Hemisphere in recent years. Another side-effect is that as the jet stream waves become larger, they slow down or even stall at times, leading to a significant increase in so-called blocking events. These cause extreme weather simply because they lead to unusually prolonged conditions of one type or another. The recent prolonged heatwave, drought and wildfires in the USA are one example of what can happen; another is the cool, dull and extremely wet first half of summer 2012 in the UK and other parts of Eurasia.
The accumulation of heat in Arctic waters also influences other frozen parts of the Arctic, such as glaciers and ice caps onGreenland and in the Canadian Archipelago. As there is less and less sea ice to act as a buffer, more energy can go into melting glaciers from below and warming the air above them. This has a marked effect on Greenland’s marine-terminating glaciers and the Greenland Ice Sheet. Not only are glaciers flowing faster towards sea, but there is also a rapid increase in the summer surface melt Greenland experiences, leading to accelerating mass loss from the Greenland Ice Sheet. As the Arctic warms, an increased contribution to sea level rise is inevitable.
Another way Arctic warming could have worldwide consequences is through its influence on permafrost. Permanently frozen soils worldwide contain 1400-1700 Gigatons of carbon, about four times more than all the carbon emitted by human activity in modern times. A 2008 study found that a period of abrupt sea-ice loss could lead to rapid soil thaw, as far as 900 miles inland. Apart from widespread damage to infrastructure (roads, houses) in northern territories, resulting annual carbon emissions could eventually amount to 15-35 percent of today’s yearly emissions from human activities, making the reduction of greenhouse gases in the atmosphere a much more difficult task.
An even more worrying potential source of greenhouse gases is the methane in the seabed of the Arctic Ocean, notably off the coast of Siberia. These so-called clathratescontain an estimated 1400 Gigatons of methane, a more potent though shorter-lived greenhouse gas than carbon dioxide. Methane clathrate, a form of water ice that contains a large amount of methane within its crystal structure, remains stable under a combination of high pressure and low temperature. At a depth of 50 meters or less the East Siberian Arctic Shelf contains the shallowest methane clathrate deposits, and is thus most vulnerable to rising water temperatures. Current methane concentrations in the Arctic already average about 1.90 parts per million, the highest in 400,000 years.
Apart from these unrecoverable sources of fossil fuel the Arctic is also endowed with large amounts of recoverable oil and natural gas. As the sea ice retreats, the Arctic’s fossil treasures are eyed greedily by large corporations and nations bordering the Arctic Ocean. Not only might this lead togeopolitical tensions in a world where energy is rapidly becoming more expensive, it is also highly ironic that the most likely cause of the disappearance of Arctic sea ice – the extraction and burning of fossil fuels – could lead to more extraction of said fuels. Another feedback loop.
News articles referring to the Arctic and its sea ice usually have pictures of polar bears accompanying the text. But although many animals in the Arctic will be impacted negatively by the vanishing of Arctic sea ice, much more is at stake. After thousands of years in which the sea ice played a vital role in the relatively stable conditions under which modern civilization, agriculture and a 7 billion strong world population could develop, it increasingly looks as if warming caused by the emission of greenhouse gases is bringing an end to these stable conditions. Whether there still is time to save the Arctic sea ice, is difficult to tell, but consequences will not disappear when the ice is gone. It seems these can only be mitigated by keeping fossil fuels in the ground and out of the air. Whichever way you look at it, business-as-usual is not an option.
For more information on Arctic sea ice, check out the Arctic Sea Ice blog.
– Neven Acropolis with Kevin McKinney
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