Selasa, 21 Februari 2012

Protecting the Arctic

U.K. Environmental Audit Committee, hearing February 21, 2012
Peter Wadhams (left) and John Nissen (right)
The meeting started at 2.12pm and ended at 4.08pm.

The video below starts with a presentation by Professor Tim Lenton, University of Exeter, who is not a member of the Arctic Methane Emergency Group. The video further features Professor Peter Wadhams, University of Cambridge, and John Nissen, Chair, Arctic Methane Emergency Group.

Click on Read More if you don't see the video (it may take some time for the video to start), the transcript and written submission below.







AMEG Submission to U.K. Environment Audit Committee, for hearing on 21st February 2012


Oral presentation to 'Protecting the Arctic'


By John Nissen, AMEG Chair

1. Introduction

“Thank you, Chair, for extending this opportunity to present evidence on behalf of the Arctic Methane Emergency Working Group - a collaboration of scientists, engineers and communicators.

As you have just heard from my colleague Professor Wadhams – and is stated in our written submission – the imminent collapse of Arctic sea ice poses a new emergency situation, which threatens an irreversible transition towards abrupt and catastrophic climate change – a point of no return which must be avoided at all costs. We consider this a planetary emergency – a matter of national and international security of the highest order.

Professor Wadhams has clearly indicated the devastating consequences that will follow a collapse of sea ice, in terms of ocean circulation, weather patterns, flood and food supply. I am here to address the issue of methane, as this will escalate events if not addressed by similar means: cooling the Arctic.

2. Some facts about methane

Methane is the main constituent of natural gas. As a GHG, methane is 72 times more potent than C02 over the first 20 years, weight for weight.

The Arctic has the potential to release a staggering amount of methane – triple the weight of anthropogenic CO2 in the atmosphere. Because of its potency as a greenhouse gas, a release of just 1% of this methane – 35 billion tons - would triple the current rate of global warming.

3. What is happening?

The scenario we describe in our written submission and brochure is one of simple common sense: this vast quantity of methane is contained in and by the ice, as the ice thaws the methane is released.

About half of the Arctic methane is held in or by ice below the seabed. This methane appears to be in a critical condition. As the sea ice disappears, the whole Arctic Ocean is heating more rapidly, leading to release of methane in ever larger quantities. Because of its greenhouse effect, this methane can then cause global warming to escalate out of control. Then it's difficult to imagine how civilisation could survive beyond a few decades.

The plausibility of such devastating methane release has long been recognised, although the sheer speed of events now evident has taken everybody by surprise and disbelief.

The emerging evidence indicates the conditions are developing to bring this nightmare scenario into reality. As a result of the sea ice retreating, the Arctic is now warming at least 4 times faster than other parts of the world, and with seabed temperatures rising as much as 3C, methane is being released in increasingly large quantities.

4. ESAS methane instability

The East Siberian Arctic Shelf is the largest continental shelf area on the planet and contains most of the Arctic Ocean’s methane.

Ongoing expeditions have reported increasing instability in this shallow area of the Arctic, with plumes of methane a kilometre wide erupting from the ocean floor and reaching the surface. The instability of methane over the whole region is such that a sudden release of 50 billion tons is possible at any time. That would cause global warming to speed up by four or five times, overwhelming current international efforts to keep global warming within the so-called “safe” limit of 2 degrees.

The prospect of drilling being allowed here is terrifying. Note that unstable sub-sea methane was the cause of the Deepwater disaster.

We must heed these clear signals that vast undersea methane stores are becoming unstable in the Arctic.

5. Emergency action to avoid passing point of no return

We are close to a point of no return – no going back – a point where we have escalating temperatures in the Arctic and escalating release of methane, with global warming spiralling upward, out of control, while the prospects of our own survival spiral downwards.

What can be done? We have the expertise, we have technological know-how, and we have the inherent capability to confront a threat of this magnitude. All we need is the political leadership – the kind of leadership that Churchill showed in WW2. Instead of a human enemy we face ever increasing forces of nature turned against us.

We have have to take immediate and drastic action - as Professor Wadhams says: next September could see the Arctic virtually sea ice free - at which point the consequences will start to move out of our control.

Our window of opportunity has to be measured in months rather than years.

If we want to protect the Arctic we need to cool it – and quickly.

This matter must be raised immediately at the highest level in government.


Written submission AMEG

Note that this written submission will be presented orally by two people: Professor Peter Wadhams focusing on sea ice retreat and John Nissen dealing with methane and required actions.

'Protecting the Arctic'

This is a submission on behalf of the Arctic Methane Emergency Group (AMEG) [1], which includes among its founding members Peter Wadhams, Professor of Ocean Physics, Cambridge; Stephen Salter, Emeritus Professor of Engineering Design, Edinburgh; and Brian Orr, PhD, former Principal Science Officer at the UK DoE (as was).

Most geoscientists like to separate policy from science - so they will state what is happening to the Earth System but not suggest the kind of interventions that could prevent the situation from gradually deteriorating. Especially the subject of the deliberate intervention known as geoengineering has been taboo until very recently, and it is still treated with great suspicion. However this perception of gradual deterioration, where the timescale is over decades or longer, has totally changed with the discovery of both the extraordinarily rapid decline of sea ice and the possibility of sudden discharge of gigatons of the potent greenhouse gas, methane, from sediments at the bottom of the Arctic Ocean. (Methane is the main constituent of natural gas.)

AMEG was formed from a group of scientists, engineers and communicators, to alert the world to the dangers that have to be faced, and the need for immediate and drastic action to reduce the risk of passing a point of no return with the sea ice – a point after which the Arctic Ocean would become free of sea ice for much or all of the year without any possibility of restorative intervention. Following such a decline of sea ice, the Arctic would continue warming but at a much greater rate than hitherto, causing an escalation of methane emissions from both marine and terrestrial sources and risking runaway (abrupt) global warming.

Passing such a point of no return would be catastrophic for the whole of humanity, as, inexorably, global temperatures would spiral upwards and food production downwards.

Therefore we consider our present situation is extremely dangerous and warrants the designation of "planetary emergency".

We see only one way to avoid passing this point of no return, which is to intervene by cooling the Arctic, principally by using geoengineering techniques starting immediately.

We now consider the imminence of sea ice collapse and the consequences in more detail.

Sea Ice Retreat

No doubt the Committee would support the precautionary principle that, if there is a reasonable likelihood of a catastrophic event occurring, governments should try to take what precautions they can in order to anticipate or mitigate it. There were very complacent consensus statements about the Arctic sea ice from the IPCC in the AR4 report of April 2007, saying the sea ice was very likely to last beyond the end of the century. Furthermore the policy of emissions reduction, to keep within a target global warming of 2 degrees C, has been based on there not being a tipping point of the Arctic sea ice and there not being a significant rise in methane level such as to rival CO2’s climate forcing.

Since the IPCC reported it has become widely accepted that Arctic amplification of global warming is largely due to the albedo “positive feedback” effect of sea ice retreat: the melting of sea ice exposes the water to warming in the sunshine, which leads to further melting in a vicious cycle (no doubt mentioned in Tim Lenton’s submission). Quantification of this affect has only very recently been attempted, in a paper to the 2011 AGU by Hudson [2]. The startling conclusion is that the rate of warming of the Arctic could double or even triple, once the Arctic Ocean is ice-free in September. And it could double again, once the ocean is ice-free for half the year. But the timescale makes this all the more worrying.

The annual average extent of the Arctic sea ice cover has been diminishing since the 1950s. At first this was at a slow rate, some 3% per decade, but since the early 2000s has accelerated at 10% per decade. The retreat is especially rapid during the summer months. It is accompanied by a thinning, which has been shown by measurements from submarines to be a very rapid one, with a reduction of 43% in mean ice thickness between the 1970s and early 2000s. So far the record year for summer ice retreat is 2007, although it was almost matched by 2011. But the inexorable thinning that accompanies the retreat has caused the summer volume of the ice cover to the lowest ever last year, less than 30% of its value 20 years ago [3a]. The trend in volume is such that if one extrapolates the observed rate forward in time, by following an exponential trend line, one obtains a September near-disappearance of the ice by 2015. However, following an equally valid logarithmic trend, one finds that summer 2012 and 2013 are the most likely years for such a collapse [3b]. Thus one has to conclude that, on current best evidence, there is a distinct possibility of a collapse in extent leaving relatively little ice this summer, and a collapse is likely by 2015.

Subsequently the ice-free period begins to stretch over a greater number of months, with 5 months ice-free within about three years according to the extrapolation of trends for different months [3c]. Already the summer retreat is allowing the temperature of the ocean to rise significantly in summer all over the shelf seas, up to 4-5C, and this is liable to continue at an increased rate. The warming is already causing undersea permafrost to thaw and release trapped methane in large plumes, increasing the atmospheric methane load and threatening to accelerate global warming [4]. All these changes are based on observations, not models, so one is forced to consider urgently what response is appropriate. This new emergency situation, which threatens abrupt and catastrophic climate change, cannot be ignored.

Saving the sea ice

The discovery of rapid decline of sea ice and its apparent effect to escalate emissions of methane from ESAS has taken the scientific community completely by surprise. Hitherto attention has been focussed on sea ice extent, but recent evidence shows a collapse in extent could occur this year or in the next few years. Following a collapse in extent, the climate forcing from the “albedo effect” could more than double. And if the Arctic Ocean were to become ice free for six months or more, the climate forcing could double again. And when there is no more ice to melt, the heat flux all goes into heating the water. The possibility of sea ice collapse this summer is why we urge the government to consider what can be done immediately and consider the planning, development and deployment of geoengineering techniques [5] for deployment as soon as possible.

Note that the loss of sea ice would destroy an entire ecosystem and habitat, with severe implications on biodiversity, while also destroying the way of life for indigenous peoples. Thus geoengineering can be seen to have remarkable benefits when used in this context.

Also note that as the Arctic heats, there is increasing instability of jet stream and weather systems, leading to extremes of weather, already being observed.

Successful geoengineering to cool the Arctic should help to stabilise the Greenland ice sheet, slow the glaciers and reduce the risk of metre or more sea level rise, of particular concern to countries with low-lying populated regions.

Methane feedback

While the sea ice has been retreating, there have been growing signs of critical instability of undersea methane in the Arctic Ocean, especially in the East Siberian Arctic Shelf (ESAS) area where vast plumes of methane have been seen bubbling to the surface [4]. Research in this area has been limited, but it appears that emissions have risen dramatically over the past few years, and it is thought that this could be as a result of the water above the seabed reaching a temperature threshold. The exact mechanism for this accelerated methane release is not understood (and there is some controversy over appropriate modelling), however governments must act according to best evidence in a precautionary manner, and take a continued escalation of methane emissions under sea ice retreat as a matter for extreme concern.

Shakhova and Semiletov estimate that 50 gigatonnes of methane are available for immediate release from ESAS [5], and, if this amount were released into the atmosphere, the methane level would rise by eleven or twelve times, causing global warming to rapidly escalate, in turn causing more methane emissions in a feedback loop.

Such an escalation of methane emissions would cause abrupt and catastrophic climate change within a few decades. Even much slower emissions (e.g. 1% of potential methane over 20 years) could put the climate system out of any control for climate change mitigation with catastrophic consequences sooner or later.

We bring your attention to the facts that there is no likelihood of even a reduction in global emissions of CO2 in the foreseeable future; both emissions and concentration of CO2 are increasing at record rates; and the atmospheric methane level has been rising since 2007 after a decade of little change [7]. The most recent evidence suggests that this latest rise could be at least partially due to methane emissions from shallow seas in the Arctic, see below.

Other evidence

In just the past few years the loss of Arctic snow and ice and the associated albedo effect has nearly doubled; Arctic subsea methane hydrate is venting to the atmosphere [8]; permafrost carbon has been found to be double what was previously thought [9]; and large amounts of nitrous oxide are being released from thawing permafrost [10].

The catastrophic risk of global warming leading to very large emissions of methane from large Arctic carbon pools, especially from subsea methane hydrate, is documented in the 2007 IPCC assessment [11].

This situation is documented by the US Investigation of the Magnitudes and Probabilities of Abrupt Climate Transitions (IMPACTS) project [12]. Since this overview was published in 2008 the Arctic situation has deteriorated to the point that we need no more research to confirm the planetary emergency. In particular it had been assumed that Arctic methane hydrate was stable this century and that when hydrate did destabilize by ocean warming it would not vent to the atmosphere. Recent observed findings that methane is venting to the atmosphere disprove these assumptions. On land the Arctic permafrost carbon pool has been found to be double the estimates.

The Arctic is undergoing very rapid and accelerating changes. In combination, these changes imply a strong positive feedback to increased climate warming through increased greenhouse gas (GHG) emissions, decreased albedo, and hydrology and ocean circulation changes (Chapin et al., 2005 [13]; Lawrence and Slater, 2005 [14]).

These positive physical and biogeochemical feedbacks can, with high probability, cause a change in state over a period of less than a decade or two in terrestrial ecosystems climate forcing that is several times greater than is the change in radiative forcing from fossil fuel burning. There is then the likelihood of methane feedback, whereby the radiative forcing leads to an increase in methane emissions, in a positive feedback loop – leading to abrupt and catastrophic climate change (Chu [15]).

The associated changes in terrestrial ecosystems composition, spatial distribution, and GHG dynamics are irreversible over millennia, comparable to the temporal scale of glacial-interglacial cycles. A degree of boreal/arctic feedback to warming has already been documented, (see Chapin et al., 2005 [13]).

The greatest single threat of the worst abrupt warming is from Arctic methane hydrate. In combination with all the other Arctic positive feedback emissions that are operant this is a planetary emergency. The current abundance of carbon stored in hydrates is generally believed to be greater than the recoverable stocks of all the other fossil fuels combined (Buffet and Archer, 2004 [16]; Gornitz & Fung, 1994 [17]), and methane is 72 times more potent as a greenhouse gas than is carbon dioxide over 20-year time horizons (IPCC, 2007a [18]). There is evidence that methane hydrate releases have caused abrupt climate changes in the past, such as the Palaeocene-Eocene Thermal Maximum 55 million years ago when the planet abruptly warmed 5-8K (Dickens, 2003 [19]). There is also disputed evidence that hydrate dissociation greatly amplified and accelerated global warming episodes in the late Quaternary period (Kennett et al., 2000) [20]. The stability of the contemporary hydrate inventory to the unprecedented temperature rise from anthropogenic emissions is unknown. The Arctic contains hundreds of gigatons of methane hydrate with a time scale for release of decades, and the release is predicted to be abrupt at each location because the hydrates lie close to the edge of the gas hydrate stability zone defined by temperature and pressure. Plausible scenarios could lead to methane becoming more important than CO2 as a greenhouse gas on a time-scale of decades, with the associated warming leading to further hydrate dissociation, as well as terrestrial permafrost melting, which will release additional methane and be self-sustaining.

How to cool the Arctic quickly

The most cost-effective techniques involve reducing the sunlight falling on the Arctic, either by producing a fine haze of aerosol or fine-grain particles or by brightening clouds. As far as we know, neither technique has been tried on a large scale; but both techniques has natural analogues which suggest that they should be safe and effective, if their effects are modelled carefully so that their deployment avoid unwanted side-effects.

However, neither technique is sufficiently developed for immediate deployment. Thus we have to consider increasing existing cooling effects from aerosols and decreasing any factors that could have a significant short-term warming effect in the Arctic. Of particular interest is to curb inadvertent methane emissions and black carbon (commonly known as soot), especially at high latitudes [21]. Drilling for natural gas in the Arctic can produce a lot of methane leakage to the atmosphere and is not advisable until we have technology in place to cool the Arctic [22].

High risk developments in the Arctic

Although this is not a remit of AMEG, we would like to mention a hazard arising from drilling in the Arctic where there is methane hydrate, especially on the continental shelf edge. We have a concern that much of this hydrate has become unstable, as its stability zone has moved as a result of warming of the seabed [23]. Drilling can easily cause this hydrate to disassociate into methane gas and water explosively, which can be disastrous for any ship above, because it will sink in the reduced density of water filled with methane bubbles. But our main concern is that such a destabilisation of the hydrate can cause a slump with a tsunami-inducing force which could cause a chain reaction of destabilisation across the whole Arctic Ocean shelf margin. This margin contains many megatonnes of methane as hydrate, enough to start a methane feedback if a significant proportion were released in one go. Thus we urge that there is a halt on all drilling for methane hydrate in the Arctic until precautions have been developed and a proper risk assessment made.

Conclusions

We believe that the large positive feedback from loss of Arctic summer sea ice and snow albedo with Arctic subsea methane already venting is enough to advance the possibility of methane feedback taking hold from decades to years. The mandatory requirement to avoid a possible sea ice collapse this year, and point of no return, leads to an unprecedented engineering challenge.

The findings of our group were presented at AGU 2011, San Francisco, and we have discussed the latest evidence with leading experts in relevant fields. This evidence points ever more strongly to there being a planetary emergency, so we are striving to get this recognised and acted upon at the highest level in governments, and would welcome your support.

When there is so much at stake, it is the duty and moral obligation of governments to act on the precautionary principle to protect their own citizens [24]. By collaborating with others to protect the Arctic, a climate of cooperation can be engendered to protect the whole planet for the benefit of ourselves and future generations.

John Nissen, Chair of the Arctic Methane Emergency Group

Peter Wadhams, Professor of Ocean Physics at the University of Cambridge


References

[1] AMEG
http://arctic-methane-emergency-group.org

[2] Hudson (2011) - Albedo effect and Arctic warming
http://www.agu.org/pubs/crossref/2011/2011JD015804.shtml
http://www.npolar.no/npcms/export/sites/np/en/people/stephen.hudson/Hudson11_AlbedoFeedback.pdf

[3a] PIOMAS, September, exponential trend for sea ice volume
http://neven1.typepad.com/.a/6a0133f03a1e37970b0153920ddd12970b-pi

[3b] PIOMAS, September, trend lines compared
https://sites.google.com/site/arctischepinguin/home/piomas

[3c] PIOMAS, all months
http://neven1.typepad.com/.a/6a0133f03a1e37970b0153920dd89a970b-pi

[4] Vast methane 'plumes' seen in Arctic Ocean - The Independent
http://www.independent.co.uk/news/science/vast-methane-plumes-seen-in-arctic-ocean-as-seaice-retreats-6276278.html

[5] SRM geoengineering to cool Arctic
How to cool the Arctic - John Nissen, December 2011
http://arctic-news.blogspot.com/p/how-to-cool-arctic.html

[6] 50 Mt of methane from ESAS available for release at any time
http://www.cosis.net/abstracts/EGU2008/01526/EGU2008-A-01526.pdf

[7] Methane level over past century
http://www.esrl.noaa.gov/gmd/webdata/ccgg/iadv/graph/mlo/mlo_ch4_ts_obs_03437.png

[8] Sam Carana, Methane venting in the Arctic
http://arctic-news.blogspot.com.au/2012/02/methane-venting-in-arctic.html

[9] Sam Carana, Potential for methane releases
http://arctic-news.blogspot.com/p/potential-for-methane-release.html

[10] Elberling et al, 2010
High nitrous oxide production from thawing permafrost
http://www.nature.com/ngeo/journal/v3/n5/abs/ngeo803.html

[11] Risk of Catastrophic or Abrupt Change - IPCC AR4 WG 3 2.2.4
http://ipcc.ch/publications_and_data/ar4/wg3/en/ch2s2-2-4.html

[12] IMPACTS project
http://esd.lbl.gov/research/projects/abrupt_climate_change/impacts/tasks.html

[13] Chapin et al., 2005
Role of Land-Surface Changes in Arctic Summer Warming
http://www.sciencemag.org/content/310/5748/657.abstract

[14] Lawrence and Slater, 2005
A projection of severe near-surface permafrost degradation during the 21st century
http://www.agu.org/pubs/crossref/2005/2005GL025080.shtml

[15] Stephen Chu
Video on methane feedback
http://www.youtube.com/watch?v=oHqKxWvcBdg

[16] Buffet and Archer, 2004
Global inventory of methane clathrate: sensitivity to changes in the deep ocean
http://geosci.uchicago.edu/~archer/reprints/buffett.2004.clathrates.pdf

[17] Gornitz & Fung, 1994
Potential distribution of methane hydrates in the world's oceans
http://www.agu.org/pubs/crossref/1994/94GB00766.shtml
http://pubs.giss.nasa.gov/abs/go00200p.html

[18] IPCC - Global Warming Potential
Intergovernmental Panel on Climate Change (IPCC, 2007)
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-10-2.html#table-2-14

[19] Dickens on PETM, 2003
Excess barite accumulation during the Paleocene-Eocene thermal Maximum: Massive input of dissolved barium from seafloor gas hydrate reservoirs
http://specialpapers.gsapubs.org/content/369/11

[20] Kennett et al. on methane excursions, 2000
Carbon Isotopic Evidence for Methane Hydrate Instability During Quaternary Interstadials
http://www.sciencemag.org/content/288/5463/128.abstract

[21] An analysis of short term measures to slow global warming
http://www.nature.com/news/pollutants-key-to-climate-fix-1.9816

[22] High emissions from gas field
http://www.nature.com/news/air-sampling-reveals-high-emissions-from-gas-field-1.9982

[23] U.S. Department of Energy - Drilling Safety and Seafloor Stability
http://www.netl.doe.gov/technologies/oil-gas/FutureSupply/MethaneHydrates/about-hydrates/safety-stability.htm

[24] UNFCCC Convention 1992, Article 3, point 3
http://unfccc.int/essential_background/convention/background/items/1355.php

Environmental Audit Committee
http://www.parliament.uk/eacom
The Environmental Audit Committee considers the extent to which the policies and programmes of government departments and non-departmental public bodies contribute to environmental protection and sustainable development, and it audits their performance against any sustainable development and environmental protection targets. Unlike most select committees, the Committee’s remit cuts across government rather than focuses on the work of a particular department.

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