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Posts Tagged permafrost

The Climate Show #29: if the sun don’t come, you get a tan from standing in the English rain Gareth Renowden Oct 11

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This week The Climate Show brings you an all news special. We have wet summers for Europe, permafrost warming delivering a methane kick, La Niña driving floods that make sea level fall, a glacier calving in Antarctica, mammoths and sabre tooth tigers — all delivered with Glenn and Gareth’s inimitable panache (!).

Watch The Climate Show on our Youtube channel, subscribe to the podcast via iTunes, listen to us via Stitcher on your smartphone or listen direct/download from the link below the fold.

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Story references

Wet British summers: Guardian, Nature.

Permafrost & methane: Skeptical Science.

US swing voter survey: China Daily(!)

La Niña driving sea level fall: Geophysical Research Letters.

SE Australia drying: eScience News

Thwaites Glacier calving: From a Glaciers Perspective.

Mammoths

Thanks to our media partners: Idealog Sustain, Sciblogs, and Scoop .

Theme music: A Drop In The Ocean by The Bads.

Title reference: Gareth’s favourite Beatles track…

Why Arctic sea ice shouldn’t leave anyone cold Gareth Renowden Aug 26

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In this guest post Neven Acropolis, the man behind the excellent Arctic Sea Ice blog, looks at the reasons why we need to pay attention to the rapid loss of sea ice in the Arctic Ocean.

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 civilisation, 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, a radical shift has occurred in recent times.

1 kinnard2011

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 thought that 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.

2 albedofeedbackWhat 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.

3 jetstreamBut 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 destabilised jet stream becomes more ‘wavy’, allowing frigid air to plunge farther south, a possible factor in the extreme 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 on Greenland 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.

4 greenlandsurfacemeltjuly2012

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.

5 permafrostdistribution

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 clathrates contain 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 average methane concentrations in the Arctic already average about 1.90 parts per million, the highest in 400,000 years.

6 methaneconcentration

7 russiaplantsflagApart 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 to geopolitical 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 civilisation, 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 Neven’s Arctic Sea Ice blog.

Image credits:
Arctic sea ice extent reconstruction – Kinnard et al. 2011

Sea ice albedo feedback – NASA

Polar jet stream – NC State University

Greenland ice sheet surface melt – NASA

Permafrost distribution in the Arctic – GRID-Arendal

Atmospheric methane concentration – NOAA ESRL

Russia plants flag at North Pole – Reuters

The Benefits of Soil Carbon Bryan Walker Feb 15

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The UN Environment Programme’s just released Year Book 2012 includes a report The Benefits of Soil Carbon which looks at the vital role played by soil carbon in regulating climate, water supplies and biodiversity, and maintaining the ecosystem services that we depend on. The report is 15 pages long and well presented for general reading. I thought it well worth drawing attention to. I’ll point to a few of the report’s highlights here, in particular those that relate to climate change.

First, it offers a reminder of how important a carbon storehouse the soil is.  The top metre of the world’s soils stores more than three times the amount of carbon held in the atmosphere (approximately 2200 billion tonnes of carbon, two-thirds of it in the form of organic matter). This sequestration gives soils an essential role in climate regulation. However, soils are vulnerable to carbon losses through degradation. They also release greenhouse gases to the atmosphere as a result of accelerated decomposition due to land use change or unsustainable land management practices.

This is not a theoretical problem. With frequent reference to scientific papers the report says that since the 19th century, around 60 per cent of the carbon in the world’s soils and vegetation has been lost owing to land use. In the past 25 years, one-quarter of the global land area has suffered a decline in productivity and in the ability to provide ecosystem services because of soil carbon losses. Soil erosion associated with conventional agricultural practices can occur at rates up to 100 times greater than the rate at which natural soil formation takes place. Peatland drainage worldwide is causing carbon-rich peat to disappear at a rate 20 times greater than the rate at which the peat accumulated.

Climate change itself is expected to have significant impacts on soil dynamics. Among them the report points to the concern of experts that if permafrost thaws, enormous amounts of carbon might be released into the air, greatly intensifying global warming. Although the magnitude of this effect remains highly uncertain, recent estimates of frozen soil carbon are huge. According to some scientists, some 18.8 million km2 of northern soils hold about 1700 billion tonnes of organic carbon.

In discussing the intensification of land use the report notes among other factors that modern industrialized crop production relying on monocultures of highly efficient cash crops generally results in a negative carbon budget, especially when crop residues are not returned to the soil.

The report touches on a number of practices which have a deleterious effect on the carbon content of soils, but its main thrust is towards strategies to maintain and increase carbon stocks in soils. It covers three major land use systems, grasslands, croplands and forests. The press release outlines some of the key findings:

The Year Book encourages the development of universally agreed and reproducible field and laboratory methods for measuring, reporting and verifying changes of soil carbon over time.

Carbon stocks can be enhanced by ensuring that carbon inputs to the soil are greater than carbon losses. For example:

  • Forests have considerable potential for reducing greenhouse gas emission to the atmosphere by storing large stocks of carbon both above and below ground.
  • Improvements of grasslands offer a global greenhouse gas mitigation potential of 810 Mt of CO2 up to 2030, almost all of which would be sequestered in the soil.
  • In croplands, integration of several crops in a field at the same time can increase organic material, soil biodiversity and soil health, as well as increase food production, particularly for subsistence farmers.
  • Paludiculture is an innovative alternative to conventional peatland agriculture. It involves biomass cultivation on wet and rewetted peatlands, which can contribute to climate change mitigation by reducing emissions through rewetting of drained peatland soils, and by replacing fossil resources with renewable biomass alternatives.

Across the globe, there are examples of how multiple benefits can be delivered through effective management of soil carbon:

In Kenya, the World Bank’s BioCarbon Fund is providing the Kenya Agricultural Carbon Project with US $350,000 to pay smallholder farmers to improve their agricultural practices, to increase both food security and soil carbon sequestration.

From Dakar to Djibouti, the Great Green Wall initiative is a massive afforestation project to create a 15 km wide strip of trees and other vegetation along a 7000 km transect to improve carbon sequestration, stabilize soils and conserve soil moisture amongst others.

In China, similar approaches are being monitored to assess whether land degradation in arid areas can be reversed.

In Brazil, changes in crop production practices have been found to have significant effects on soil carbon stocks. Conversion to no-till techniques in soybean, maize and related crop rotation systems resulted in a sequestration rate of 0.41 tonnes soil organic carbon per hectare per year.

In Argentina, significant increases in soil carbon stocks have also been achieved, where farmers changed to no-till systems, along with enhanced benefits in water retention, infiltration and erosion prevention.

There’s no startlingly new information in the report, but it’s a useful document which hopefully will play a part in informing those who work on government and global policy matters. While there’s more than the mitigation of climate change at stake in the maintenance of the world’s soils, it is obviously an issue of enormous importance for its potential to either moderate the level of atmospheric carbon or increase it. The most alarming possibility of thawing permafrost is perhaps bracketed in a special category of its own as a consequence of global warming. But there’s more than sufficient at stake in the ways we regularly manage our soils to warrant the close attention the report calls for.

The Climate Show #8: Kevin Trenberth and our shaky future Gareth Renowden Mar 03

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The Climate Show returns with a packed show, featuring one of the world’s best known climate scientists, NZ-born, Colorado-based Dr Kevin Trenberth — star of the Climategate “where’s the missing heat” emails. He’s been in New Zealand to visit family (experiencing the Christchurch quake in the process) and to attend a conference, and his comments on the state of our understanding of climate change should not be missed. John Cook of Skeptical Science returns with his new short urls and an explanation of why declines have never been hidden, and Gareth and Glenn muse on Arnie “Governator” Schwarzenegger riding to the rescue of climate science, cryospheric forcing and carbon cycle feedbacks from melting permafrost, and a new paper that suggests that current policies are pointing us towards extremely dangerous climate change. All that and hyperbranched aminosilica too…

Watch The Climate Show on our Youtube channel, subscribe to the podcast via iTunes, or listen direct/download here:

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Follow The Climate Show at The Climate Show web site, on Facebook and Twitter.

Show notes below the fold.

News & commentary:

Christchurch earthquake, Feb 22 2011. At the time of writing the death toll was expected to rise to over 240. At least 100 of those who died were tourists or foreign students. If you would like to donate to support the recovery effort, please consider the Red Cross appeal.

Schwarzenegger: It’s Time to Terminate Skepticism on Climate Change

Good northern hemisphere cryosphere graphic from NASA, and bad news from the permafrost.

Models guiding climate policy are ‘dangerously optimistic’: Computer models predicting future climate change are underestimating emissions and overestimating technology, warns climate scientist Kevin Anderson. Guardian story here, and full paper [Anderson and Bows. Beyond 'dangerous' climate change: emission scenarios for a new world. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences (2011) vol. 369 (1934) pp. 20-44 -- PDF], and Bryan Walker’s discussion at Hot Topic.

Increased flood risk linked to global warming

Feature interview:: Kevin Trenberth, head of the Climate Analysis Section at the National Center for Atmospheric Research in Boulder Colorado. Born in NZ, worked at MetService, now based in Colorado, one of the highest profile climate scientists in the world, and a regular subject of attacks by denialists. The AMS paper referenced is available from KT’s web site linked above.

Debunking the skeptic with John Cook from Skeptical Science.
Skeptical Science Short URLs: http://sks.to/url

http://www.skepticalscience.com/Link-to-skeptic-rebuttals-with-short-URLs.html

Clearing up misconceptions about ’Hide the Decline’

1. It’s not about ’global temperatures’ but a small number of high latitude tree rings:
http://sks.to/diverge

2. ’Hide the decline’ has nothing to do with ’Mike’s trick’ which is the simple technique of plotting instrumental temperature and reconstructions on the same graph.

3. It’s not hidden at all but openly discussed in the peer-reviewed literature since 1995:
http://sks.to/decline

Solutions

Green Machine: Sucking carbon dioxide out of the air.

Thanks to our media partners: Celsias.co.nz, Scoop and KiwiFM.

Theme music: A Drop In The Ocean by The Bads.

Wake Up, Freak Out — then Get a Grip Gareth Renowden Dec 18

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Excellent animation by Leo Murray explaining climate system feedbacks and the potential for us to pass “tipping points” that could make our efforts to reduce emissions completely redundant. More information (including script and references) at wakeupfreakout.org. Hat-tip to Peter “Crock of the Week” Sinclair for finding it

Methane rise continues Bryan Walker Feb 23

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More cautionary news on rising methane levels is reported in yesterday’s Independent. Two leading experts on CH4 in the atmosphere, Euan Nisbet and Ed Dlugokencky, were due to reveal at a conference that, after a decade of near-zero growth, “globally averaged atmospheric methane increased by [approximately] 7ppb (parts per billion) per year during 2007 and 2008.” They consider it likely that 2009 will have shown the same rising trend, since the figures for the first half of the year showed a 7 ppb rise on the 2008 level. 

They are properly cautious about the rises and comment that they may just be a couple of years of high growth which may drop back to what it was.  But they stress the importance of understanding the causes of the rises, because of the potential for increased CH4 emissions from strong positive climate feedbacks in the Arctic where there are unstable stores of carbon in permafrost. Permafrost melt carries the potential for methane release.

If there is a feedback mechanism at work it’s bad news as the Independent makes clear in terms that its readers can understand:

’Many climate scientists think that frozen Arctic tundra… is a ticking time bomb in terms of global warming, because it holds vast amounts of methane, an immensely potent greenhouse gas. Over thousands of years the methane has accumulated under the ground at northern latitudes all around the world, and has effectively been taken out of circulation by the permafrost acting as an impermeable lid. But as the permafrost begins to melt in rising temperatures, the lid may open — with potentially catastrophic results’.

This is not alarmism on the part of the Independent. The scientists involved in reporting the rises are careful and restrained in their statements.  We may hope that the increases turn out not to be significant in terms of feedbacks under way.  But it is a sober reminder of how quickly things may change if natural feedbacks kick in and amplify the warming already caused by our human activity.  See Gareth’s earlier post on methane hydrates in the Arctic.

Incidentally, it was good to see a newspaper competently and thoroughly reporting climate change science news.  It can happen, and when it does it’s a different world from the ignorant and careless journalism that has been so apparent recently in relation to the UEA emails and the IPCC report.  Rationality and proportion marked an excellent piece of science reporting.

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