Protecting the Arctic
Written evidence submitted by the Arctic Methane Emergency Group
This is a submission on behalf of the Arctic Methane Emergency Group (AMEG) , 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. Quantification of this affect has only very recently been attempted, in a paper to the 2011 AGU by Hudson . 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 . 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  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.
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 . 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 , 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 . 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.
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 ; permafrost carbon has been found to be double what was previously thought ; and large amounts of nitrous oxide are being released from thawing permafrost .
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 .
This situation is documented by the US Investigation of the Magnitudes and Probabilities of Abrupt Climate Transitions (IMPACTS) project  (quoted in italics below). 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 ; Lawrence and Slater, 2005 ).
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 ).
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 ).
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 ; Gornitz & Fung, 1994 ), and methane is 72 times more potent as a greenhouse gas than is carbon dioxide over 20-year time horizons (IPCC, 2007a ). 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 ). There is also disputed evidence that hydrate dissociation greatly amplified and accelerated global warming episodes in the late Quaternary period (Kennett et al., 2000) . 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  . D rilling 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  .
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  . 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. B ut 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.
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 . 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
 Hudson (2011) - Albedo effect and Arctic warming
[3a] PIOMAS, September, exponential trend for sea ice volume
[3b] PIOMAS, September, trend lines compared
[3c] PIOMAS, all months
 Vast methane 'plumes' seen in Arctic Ocean - The Independent
 SRM geoengineering to cool Arctic
How to cool the Arctic - John Nissen, December 2011
 50 Mt of methane from ESAS available for release at any time
 Methane level over past century
 Sam Carana, Methane venting in the Arctic
 Sam Carana, Potential for methane releases
 Elberling et al, 2010
High nitrous oxide production from thawing permafrost
 Risk of Catastrophic or Abrupt Change - IPCC AR4 WG 3 2.2.4
 IMPACTS project
 Chapin et al., 2005
Role of Land-Surface Changes in Arctic Summer Warming
 Lawrence and Slater, 2005
A projection of severe near-surface permafrost degradation during the 21st century
 Stephen Chu
Video on methane feedback
 Buffet and Archer, 2004
Global inventory of methane clathrate: sensitivity to changes in the deep ocean
 Gornitz & Fung, 1994
Potential distribution of methane hydrates in the world's oceans
 IPCC - Global Warming Potential
Intergovernmental Panel on Climate Change (IPCC, 2007)
 Dickens on PETM, 2003
Excess barite accumulation during the Paleocene-Eocene thermal Maximum: Massive input of dissolved barium from seafloor gas hydrate reservoirs
 Kennett et al. on methane excursions, 2000
Carbon Isotopic Evidence for Methane Hydrate Instability During Quaternary Interstadials
 March issue of Scientific American, p11, refers to an analysis of short term measures
to slow global warming in January issue of Nature.
 High emissions from gas field
 U.S. Department of Energy - Drilling Safety and Seafloor Stability
 UNFCCC Convention 1992, Article 3, point 3
14 February 2012