Monday, November 26, 2012

Breaking the Chain

by John Nissen, Chair of the Arctic Methane Emergency Group (AMEG)

The problem

As the sea ice retreats, exposed water absorbs more sunshine, heating the water and causing further melt of the sea ice in a vicious cycle.  This appears to be the dominant positive feedback loop in the Arctic, although snow retreat may contribute nearly as much to the warming of the Arctic generally.

This cycle is shown in the purple square in the diagram below, marked "Vicious cycle [1]".

The basic strategy for preventing an exponentially worsening situation is to cool the Arctic sufficiently to halt Arctic warming and prevent a record sea ice minimum in 2013 [click to enlarge image].
The most immediate negative impact of this cycle and the warming of the Arctic atmosphere is a disruption of polar jet stream from its normal behaviour, such that there are more frequent and more severe weather extremes experienced in the Northern Hemisphere.  This impact has grown so conspicuously over the past few years that we can honestly say that we are now experiencing abrupt climate change.  The result of this climate change is widespread crop failure and an ever deepening food crisis.

However there are longer term impacts and threats, in particular:
(i) Greenland Ice Sheet destabilisation,
(ii) accelerated methane discharge,
(iii) loss of biodiversity and habitat, and
(iv) making it more difficult to keep to global warming targets.

As the snow and sea ice retreat from their levels in the 70s, more solar energy is absorbed.  Taking the 70s as the baseline (zero forcing), this year's retreat produced as much as 0.4 petawatts of climate forcing averaged over the year.  Much of this heat energy is retained in the Arctic, causing ice to melt and sea and land temperatures to rise.  As temperatures rise, there will be slightly more thermal radiation into space, dissipating some of this energy.  However most of this heat energy will slowly dissipate across the planet - and 0.4 petawatts is equivalent to half the forcing producing by anthropogenic CO2 emissions (1.6 watts per square metre).  Peter Wadhams has estimated that the sea ice retreat by itself is equivalent to the forcing from 20 years of CO2 emissions, thus making it much more difficult for the global temperature to be kept below the so-called safe limit of 2 degrees warming.

However these long term effects are somewhat academic, if the immediate impact is to raise food prices far above a safe level.

It is much easier to think about and quantify the longer term impacts of Arctic warming than the more immediate impacts.  This is a trap for the unwary.  Therefore AMEG is trying to bring the world's attention to the immediate impacts, as they turn out to be colossal even this year, and are likely to be worse in 2013 and even worse than that in 2014.

It is clear that abrupt climate change has started, but not in the way we had been told to expect.  Yes, there would be more climate extremes as the planet heated, but we were expecting a linear or near linear behaviour of the climate system, with gradual temperature change over the century.  Instead we have striking non-linearity, with exponential growth in frequency and severity of climate extremes.  This non-linearity is almost certain to have arisen from the exponential decline in sea ice, as shown in the PIOMAS sea ice volume trend.  The trend is for September ice to fall to zero by 2015.  Thus we can expect one month without sea ice in 2015, with the possibility for this event in 2014 or even in 2013.

Apart from volcanic eruptions and earthquakes with their step changes of state, the behaviour of the sea ice is possibly the most non-linear part of the Earth System because the melting is a threshold process.  Until recently it was not well understood how the retreat of sea ice could cause a commensurate increase in weather extremes.  But now it has become clear.

The retreat of sea ice is causing a non-linear rise in Arctic temperature, so that it is now rising at about 1 degree per decade, which is about 6x faster than global warming, reckoned to be rising at between 0.16 and 0.17 degree per decade.  The temperature gradient between the tropics and the Arctic has reduced significantly over the past decade.

It now appears that the polar jet stream behaviour is critically dependent on this gradient.  As the gradient diminishes, the jet stream meanders more, with a bigger amplitude of the Rossby waves, with peaks further north and troughs further south.  This effect alone produces weather extremes - hot weather further north than normal and cold weather further south than normal.  But as well as meandering more, the jet stream is also tending to get stuck in so-called 'blocking patterns', where, instead of moving gradually eastwards, the jet stream wave peak or wave trough stays in much the same place for months.

As a climate scientist, one might have expected a reduced gradient between tropics and pole to have some effect on weather systems, because there is less energy to drive them.  The normal pattern comprises 3 bands of weather systems around the planet for each hemisphere, with each band having 'cells' of circulating air.  The air rises at the tropics, falls at the next boundary, rises at the next, and falls at the pole.  There has to be an odd number of bands, so that there is air rising at the equator and falling at the poles.  The jet streams are at the boundary between the bands.

Such a pattern is visible on Jupiter but with many more bands.  The number of bands is dependent on the temperature difference between equator and poles.  When the temperature gradient reduces, one would expect the number of bands to reduce.  For the Earth System it would have to reduce from 3 bands to 1 band! Thus as the gradient reduces the weather systems spread in a chaotic manner, meandering more wildly.  This is exactly what has been observed.

The sticking of the jet stream must be associated with non-uniformities of surface topology and heat distribution.  Thus highs and/or lows are getting stuck over some feature or other, while the jet stream meanders around them.

Thus there is a reasonable explanation for how we are getting weather extremes, simply as a result of a reduced temperature gradient between Arctic and tropics.   Another argument that has been given, most notably by Professor Hansen, is that the extreme weather events are simply a result of global warming - i.e. a general rise in temperature over the whole surface of the planet.  Global warming can indeed explain a gradual increase in the average intensity of storms (whose energy is derived from sea surface warming) and in the peaks of temperature for heat waves.  But global warming does not explain the observed meandering of the jet stream and associated weather extremes, both hot/dry and cold/wet.  On the other hand the warming of the Arctic can explain the increased meandering of the jet stream and the non-linear increase of extreme events.

Since this hypothesis seems reasonable, it is fitting that the precautionary principle should be applied when it comes to trends.  The forecasting of extreme events must take into account the trend towards more extreme events as the Arctic warms.  And the Arctic is going to be warming about twice as fast in 2015 as it is this year, because of sea ice retreat.

Furthermore the change from a basic 3 bands to 1 band is likely to be a threshold process, i.e. highly non-linear.

This all adds up to a picture of abrupt climate change, which is happening now.

We must be prepared to deal with the direct impact on food prices, in order to try and avoid so much social rest that it leads to international conflict.

But we must also attack the underlying cause of the climate extremes, and for this we have no option but to cool the Arctic with the necessary cooling power firstly to halt Arctic warming and the sea ice retreat "as soon as possible", and secondly to gradually bring the temperature and sea ice back to the state they were in decades ago - the state required to return the planet's climate and temperature to the old norm, under which civilisation flourished for thousands of years.

In view of the rapid deterioration in the food situation, "as soon as possible" has to be for next year - with the aim of preventing a worse retreat of sea ice in the summer.  The financial cost of a year's deterioration runs into hundreds of $billions, but we also have a cost in human misery measured in perhaps a billion people moving into starvation or near starvation.  On top of that, we have the possibility that if we don't act quickly, it may be too late - i.e. we will have passed the point of no return.

Thus our geoengineering to cool the Arctic is worthy of a war effort to obtain large scale deployment in a matter of months.

Sunday, September 23, 2012

AMEG Policy Brief


ARCTIC METHANE EMERGENCY GROUP
                                  
POLICY BRIEF
(Issued Sept.17, 2012)


The Arctic Methane Emergency Group (AMEG) is an independent climate policy group ( website www.ameg.me ) giving advice to governments concerning the unfolding crisis in the Arctic arising from the precipitous decline in Arctic sea ice. AMEG comprises scientists, engineers, environmentalists, economists and communicators, who have cumulative expertise to judge the situation and recommend appropriate responses. They are particularly concerned with Arctic warming, associated ice losses and possibilities for consequent releases of methane on a large scale which has the potential to send global warming spiralling out of control. The group has become increasingly concerned about the effect of rapid Arctic warming on jet stream behaviour, which is producing increasingly frequent and severe climate extremes in the Northern Hemisphere. These extreme weather events are already causing decreases in global food production and rising grain prices with more declines expected. These trends can be expected to lead at some point to widespread famine.


AMEG is determined to bring the difficult truth to governments, having noted the difficult position of climate scientists who are often harassed if they bring this terrible news to the public. We will also provide frank assessments about all possible measures to deal with the rapidly growing problems.

Growing crisis in the Arctic requires rapid intervention

This year’s record minimum Arctic sea ice extent (some 22% below the 2007 and 2011 minimum extents) strongly suggests that a final collapse in the sea ice is underway and closely following an exponential downward trend in sea ice volume [1]. AMEG has repeatedly warned that this would happen and raised the issue in their submission to the UK Environment Audit Committee (EAC) hearing on "Protecting the Arctic," on Hansard record [2]. The complete collapse of sea ice (where practically none is left (<10%) for at least one day of the year) is now likely by 2016. The extreme danger lies in the repercussions of this sea ice loss, especially those resulting from seabed methane emissions and from altered jet stream behaviour – the latter already being experienced with extremes of drought and floods in many regions of the northern hemisphere. It should be noted that we cannot be certain that we would not start to experience significant problems with agricultural productivity even before we reach this point.

AMEG is confident that the crisis can still be averted successfully provided that immediate action is taken to cool the Arctic. This will inevitably involve a degree of intervention known as geoengineering as we have no other options to achieve the necessary rate and intensity of cooling required to stabilise the sea ice and buy time. AMEG therefore calls for urgent further research into technologies to help cool the Arctic and for tests and preparations to start without delay in order to be ready for rapid deployment of some of the more effective (and safe) techniques that are currently available for regional cooling of the Arctic. We must avert further collapse of sea ice and subsequent climate catastrophe. AMEG warns there is a real risk of further (and theoretically even nearly total) ice collapse by summer 2013.

AMEG stresses that to effectively reduce the threat of catastrophic climate change governments around the world must commit to a comprehensive plan of action and that geoengineering methods to cool the Arctic are now required on at least a temporary basis. AMEG repeats that it is also imperative for governments to act to immediately start reducing emissions dramatically.

Repeated warnings about sea ice collapse by AMEG sea-ice expert Professor Peter Wadhams of Cambridge University have not been reflected in most discussions of the topic because most models have projected a much less rapid retreat as has been apparent through the World Climate Research Programme Coupled Model Intercomparison Project. The Phase 3 models (CMIP3) used for the IPCC AR4 drastically under-projected losses of ice and even the current Phase 5 (CMIP5) ones (which will be fundamental to the upcoming IPCC AR5) have not been able to replicate what is unfolding right now. It is therefore extremely unwise to rely upon such model predictions in light of empirical observations demonstrating that the rate of change is far worse than such models predict.

However, the collapse was predictable simply from observed trends of sea ice volume: the Arctic has been warming and sea ice has retreated, leaving more open water in summer and further thinning of the ice year on year. In summer, the minimum extent and thickness (and hence volume) of the sea ice is getting ever smaller. Exponential volume trends indicate zero ice by September 2016 or earlier, by which time the extent must necessarily also have collapsed. It would most likely be too late by this time to attempt intervention to cool the system due to the significantly greater amounts of heat absorbed by open water than by reflective ice.

With arctic methane emissions the focus of the climate community had mostly been on land-based permafrost emissions as it was assumed that sea-based emissions could not be activated much until far greater amounts of warming had time to penetrate the deeper ocean. However AMEG has been advised by Natalia Shakhova and Igor Semiletov – Russian scientists who are the principal researchers around the East Siberian Arctic Shelf – that escalating emissions from the seabed there pose a threat of abrupt global climate change as the protective and insulating cover of the sea ice disappears [3]. There is so much methane stored under the seabed in this region that less than a one percent release of the potent greenhouse gas in that region alone, e.g. as a result of a large earthquake or rapid seabed heating (as caused by warmer river run off from warming land) could cause a substantial spike in the rate of global warming, considerably altering the path of global climate for the worse.

There are ominous signs of an escalation of seabed emissions with enormous plumes of methane bubbles rising from the shallow bed of the Laptev Sea reaching the surface. There have been recordings of extremely high rates of ebullition via sonar, recordings of extremely elevated atmospheric levels ( >300% background levels) from a ship traversing the Siberian coast and increasingly high atmospheric in situ readings at the Barrow monitoring station. Both satellite and dedicated aircraft measurements have indicated growing atmospheric methane levels over much of the Arctic Ocean.

AMEG has recently warned of increased climate extremes and a global food crisis that could deepen as the Arctic warms. This year’s severe drought in the US is not an isolated event; much of the world has been afflicted by extreme weather in one form or another, with floods and droughts impacting agriculture. Such extremes have been on the increase. Recent research by scientists such as Dr. Jennifer Francis of Rutgers University [4], shows convincing evidence that this increase is partly due to dramatic warming of the Arctic and changing polar jet stream behaviour. Food prices have already been persistently high for several years despite adverse economic circumstances, and adverse weather conditions is an identified factor behind this.

Droughts and floods have been gradually increasing in intensity for a number of years as predicted by the IPCC AR4 report (2007) on climate change. However the Arctic is warming faster than the rest of the planet, weakening and at times slowing the jet stream, increasing the frequency and duration of warm/dry spells and cool/wet spells, and this is making matters worse (and faster) than predicted. This year we have seen widespread crop failures and a rise in food prices, with a Global Hunger Alert by the World Bank [5]. Unless emergency measures are immediately taken to cool the Arctic and restore the sea ice one can expect an ever-worsening food crisis in years to come, with the prospect of famine on a vast scale and associated conflict and social breakdown.

There are other serious longer term repercussions of sea ice disappearance and Arctic warming such as accelerated disintegration of the Greenland Ice Sheet, which would cause very serious sea level rise. AMEG has chosen to focus on methane escalation and disruption of agriculture as they can be seen to be occurring already with potentially apocalyptic results if Arctic warming continues unabated.

AMEG’s conclusion is that there is now a planetary emergency. Only by grasping the nettle and intervening with great determination, as in a war effort, is there a chance of remedying the situation before it is too late. International collaboration to fight this common "enemy" of Arctic meltdown must bring all nations together, in the cause of our very survival.

References:
[1] PIOMAS sea ice volume
Note that reading for August 2012 is spot on the exponential trend line.

[2] Hansard on Environment Audit Committee evidence

[3] ESAS threat
Shakhova, N. and I. Semiletov (2012). Methane release from the East-Siberian Arctic Shelf and its connection with permafrost and hydrate destabilization: First results and potential future development. Geophys. Res., Vol. 14, EGU2012-3877-1.

[4] Dr Francis et al. on link of Arctic Amplification to extreme weather events

[5] Global hunger alert

Saturday, September 1, 2012

The biggest story of all time

[scroll down for AMEG news release]

What is happening in the Arctic is what Peter Wadhams, myself and others in AMEG have been dreading – that our deductions from the physics of the Arctic sea ice situation have come true. We also understand some of the dreadful repercussions from a sea ice collapse, which nobody has wanted to believe. But it is also like a cloud lifted, because now we can tell the world that we’ve been right all along. The sea ice extent was bound to start collapsing within the next year or two, because the thickness was decreasing steadily. Now it’s happened. Now people will have to face up to the repercussions. Now people can realise that our only choice, if we want to avoid decent into a hellish nightmare, is to geo-engineer like mad – use all the measures and techniques at our disposal that we can deploy immediately or at least before next summer’s melt, in the hope of trying to prevent further collapse.

We have left action awfully late. The first sea ice collapse in 2007 should have prepared us for further collapse in the following years. The physics is elementary. It was not put in the climate models, which have continued to forecast that the sea ice would last for decades. The Hadley Centre models were predicting end century demise. This is what is cemented into IPCC AR4 on which all climate negotiations are based. These models have now proved rubbish. Yet it was the chief scientist at the Met Office, Prof Julia Slingo, ultimately responsible for the Hadley models, who rubbished the PIOMAS data on sea ice volume, saying that her models would prove Wadhams and AMEG wrong. This is on public record, because she gave this as evidence to the Environment Audit Committee hearing on “Protecting the Arctic”.

But far more serious than the denial of physics and the laws of nature was the denial of the precautionary principle – if our concerns about sea ice loss and repercussions (particularly a methane excursion) had even a small probability of proving correct, it would have been sensible to prepare for the worst by developing the geoengineering techniques that could provide enough cooling power to avoid a sea ice collapse. The cost would have been minimal in relation to the cost of trying to deal with repercussions – which some of us fear could be the end of civilisation. But nothing happened, so no geoengineering has been prepared.

AMEG has had a predicament – a dilemma. If we say how bad the situation really is, people will brand us as doom-mongers and not want to listen. If we don’t, then nobody will learn the truth.

But now it’s different. Our predictions on the sea ice have proved correct. We have the credibility. Our timescales are appropriate. (Only the other day a student wrote an article for the Ecologist saying that, after consulting experts at UEA, he was convinced that AMEG had got its timescales wrong.)

The most visible repercussions of sea ice decline and rapid Arctic warming (it’s warming five or six times the global average by my reckoning, and that ratio will leap up as the sea ice disappears) are the escalating emissions of methane, now seen to be bubbling in vast plumes from the East Siberian Arctic Shelf seabed, and the global weirding, seen to be affecting farmers all over the world as the Arctic warms, polar jet stream meanders more, sticking in places to cause weather extremes, long periods of both hot dry weather and cool wet weather. These two repercussions have been AMEG’s focus of late, see press release.

Never in the history of the human race has there been so much danger to confront. We have the brains – we should have the intelligence – to deal with it. Psychologically we have real problems, continuing to believe that we are immortal and “it can’t happen to us”. It is.

Best wishes,

John
Chair, AMEG
www.ameg.me


     
ARCTIC SEA ICE CRASHES: GLOBAL FOOD AND METHANE FEEDBACK EMERGENCY - AMEG WARNS ACTION NOW IMPERATIVE

AMEG press release, 1st September 2012

The record low Arctic sea ice extent, reached in the past few days, shows that a collapse
in the sea ice is underway, and the minimum to be reached in a few weeks, could be
as much as a million square kilometres below the September 2007 and 2011 minima
(which were almost the same). AMEG has repeatedly warned that this could happen,
raising the issue in their submission to the UK Environment Audit Committee (EAC)
hearing on “Protecting the Arctic”, on Hansard record. The complete collapse of sea ice,
till practically none is left for at least one day of the year, is now likely by 2015. The
extreme danger lies in the repercussions of the sea ice loss, especially those resulting
from seabed methane emissions and from altered jet stream behaviour – the latter already
being experienced with extremes of drought and floods in different parts of the northern
hemisphere. However AMEG is confident that a crisis can be averted if immediate
action is taken to cool the Arctic, but this will inevitably involve a degree of intervention
known as geoengineering because of the large cooling power required. Preparations
need to start straightaway for deployment of the best candidate techniques, with a view to
rapid deployment, hopefully in time to head off a worse collapse of sea ice next summer.

The repeated warnings about the sea ice by AMEG sea ice experts (including Professor
Peter Wadhams of Cambridge University) have been ignored or scorned as doom-
mongering by climate scientists, who claim that the sea ice will last for decades. So the
current collapse may come as a nasty surprise to many people. However the collapse
could have been expected from observed trends, particularly of sea ice volume. The
Arctic has been warming, sea ice has retreated leaving open water in summer, and the
relentless Arctic summer sun has warmed the water to produce further thinning of the
ice. Each year, come the minimum ice extent at the end of summer, the thickness and
volume of the ice has been less. The trend reaches zero volume before September 2015,
by which time the extent must obviously have collapsed.

The AMEG warning on methane emissions has also been ignored or scorned by climate
scientists, who claim that the emissions will be too slow to have an appreciable global
warming effect this century. However AMEG has been advised by Russian scientists,
Natalia Shakhova and Igor Semiletov, that escalating emissions from the East Siberian
Arctic Shelf seabed pose a threat of abrupt climate change, as the protective and
insulating cover of the sea ice disappears. There is so much methane stored under the
seabed that only one percent release of this potent greenhouse gas, e.g. as a result of a
large earthquake or rapid seabed heating, could cause intolerable global warming.

AMEG has recently warned of increased climate extremes and a global food crisis that
will deepen as the Arctic warms. This year’s severe drought in the US is not an isolated
event; much of the world has been afflicted by extreme weather in one form or another,
with floods and droughts impacting agriculture. Such extremes have been on the increase.
Recent research by scientists, such as Dr Jennifer Francis of Rutgers University, shows
convincing evidence that this increase is related to dramatic warming of the Arctic and
changing polar jet stream behaviour.

Droughts and floods have been gradually increasing in intensity for a great many years,
as the IPCC AR4 report (2007) predicted would occur with global warming. However
the Arctic is warming faster than the rest of the planet. This has weakened the jet stream,
increasing the frequency and duration of warm/dry spells and cool/wet spells, and thereby
making matters much worse. This year we have seen widespread crop failures and a rise
in food prices*. Unless emergency measures are immediately taken to cool the Arctic and
restore the sea ice, one can expect an ever worsening food crisis in years to come, with
the prospect of famine on a biblical scale.

There are other serious repercussions of sea ice disappearance and Arctic warming, such
as a disintegration of the Greenland Ice Sheet to cause massive sea level rise. But AMEG
has chosen to focus on methane escalation and the food crisis because they can be seen to
be already under way, with apocalyptic results if Arctic warming continues unabated.

AMEG’s conclusion is that we have a planetary emergency as a result of the downward
spiral of sea ice. Only by grasping the nettle and applying geoengineering with great
determination, as in a war effort, do we have a chance of remedying the situation before it
is too late. International collaboration to fight this common “enemy” of Arctic meltdown
must bring all nations together, simply in the cause of survival.

* Severe Droughts Drive Food Prices Higher, Threatening the Poor - World Bank

Monday, August 13, 2012

Getting the picture

Have a look at the picture below. It shows a graph based on data calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) developed at the Applied Physics Laboratory/Polar Science Center at the University of Washington.
image from arctische pinguin - click to enlarge
The PIOMAS data for the annual minimum values are the black dots. The trend (in red) is added by Wipneus and points at 2015 as the year when ice volume will reach zero. Note that the red line points at the start of the year 2015. The minimum in September 2014 will be already be close to zero, with perhaps a few hundred cubic km remaining just north of Greenland and Canada.
image from arctische pinguin - click to enlarge
Above image, again based on PIOMAS data, shows trends added by Wipneus for each month of the year. The black line shows that the average for the month September looks set to reach zero a few months into the year 2015, while the average for October (purple line) will reach zero before the start of the year 2016. Similarly, the average for August (red line) looks set to reach zero before the start of the year 2016.

In conclusion, it looks like there will be no sea ice from August 2015 through to October 2015, while a further three months look set to reach zero in 2017, 2018 and 2019 (respectively July, November and June). Before the start of the year 2020, in other words, there will be zero sea ice for the six months from June through to November.

Actually, events may unfold even more rapidly. As the ice gets thinner, it becomes more prone to break up if there are storms. At the same time, the frequency and intensity of storms looks set to increase as temperatures rise and as there will be more open water in the Arctic Ocean. 


Above photo features Peter Wadhams, professor of Ocean Physics, and Head of the Polar Ocean Physics Group in the Department of Applied Mathematics and Theoretical Physics, University of Cambridge. Professor Wadhams has been measuring the sea ice in the Arctic for the 40 years, getting underneath the ice with the assistance of submarines, collecting ice thickness data and monitoring the thinning of the ice. This enabled 1970s data and 1980s data to be compared, which showed that the ice had thinned by about 15%. Satellite measurements only started in 1979.

Thinning of the ice is only one of the problems. "The next stage will be a collapse," Professor Wadhams warns, "where the winter growth is more than offset by the summer melt. If we look at the volume of ice that is present in the summer, the trend is so rapidly downwards that this collapse might happen within three or four years."

Apart from melting, strong winds can also influence sea ice extent, as happened in 2007 when much ice was driven across the Arctic Ocean by southerly winds. The fact that this occurred can only lead us to conclude that this could happen again. Natural variability offers no reason to rule out such a collapse, since natural variability works both ways, it could bring about such a collapse either earlier or later than models indicate.

In fact, the thinner the sea ice gets, the more likely an early collapse is to occur. It is accepted science that global warming will increase the intensity of extreme weather events, so more heavy winds and more intense storms can be expected to increasingly break up the remaining ice, both mechanically and by enhancing ocean heat transfer to the under-ice surface.

Recent events in the Arctic underline this warning. A huge cyclone battered the sea ice early August 2012. The image below, from The Cryosphere Today, shows a retreat in sea ice area to 3.09958 million km2 on the 222nd day of 2012, down from 3.91533 million km2 on the 212th day of 2012, i.e. 815,750 km2 less in ten days. Or, more than one-fifth less in just ten days.

Image from  The Cryosphere Today - click to enlarge

Saturday, August 11, 2012

Storm exacerbates Arctic predicament

Image created by Sam Carana from sea ice maps generated by Polar View at the University of Bremen 
"What a difference a day makes", Sam Carana said when posting above image well before the Arctic was even bearing the full brunt of the storm. The NASA image below was captured on August 6, 2012, and shows that the center of the storm at that date was located in the middle of the Arctic Ocean.

Image by By NASA Goddard Photo and Video
John Nissen, Chair of the Arctic Methane Emergency Group (AMEG), comments:

"The storm is huge, and breaking up and destroying the sea ice that has become thin, as we feared would happen as the thickness has been declining steadily from year to year. Thus, as the end game for the ice, we are seeing more positive feedback and no sign of any negative feedback to rescue the situation.

There are at least three positive feedbacks working together to reinforce one another - and now a fourth on salinity:
  1. The albedo flip effect as sea ice is replaced by open water absorbing more sunlight, warming and melting more sea ice.
  2. As the sea ice gets very thin, it is liable to break up easily and get blown into open water where it will melt more easily.
  3. The open warmer water is allowing increased strength of storms, which break up the ice to make for more open water.
  4. The storms are churning up the sea to a depth of 500 metres, producing salinity at the surface that will mean slower ice formation in winter and more open water next year.
These feedbacks are dangerous for methane. AMEG has been warning that, as the sea ice retreats, storms will warm the sea bed, leading to further release of methane. In ESAS, we only need mixing to a depth of 50 metres - so a storm capable of mixing to 500 metres will really stir things up.

These feedbacks are also dangerous for food security, already damaged through climate extremes induced by Arctic warming, hence our piece in the Huffington Post.

The only way to head off catastrophe is to cool the Arctic, which must involve geoengineering as quickly as possible. We must try to remain positive and determined about this, despite the gloomy news."


Above image shows a retreat in sea ice area to 3.15521 million km2 on the 221st day of 2012, down from 3.91533 million km2 on the 212th day of 2012, from The Cryosphere Today.

The image below, from Polar View at the University of Bremen, shows sea ice concentration at August 10, 2012, with huge chunks of ice visibly detached from the main ice.

(Click here for full-size image)

Wednesday, July 18, 2012

Food security threatened by sea ice loss

The mission of the Arctic Methane Emergency Group (AMEG) is:
  (i)   to alert the world to the rapid retreat of sea ice;
  (ii)  to warn of the consequences; and
  (iii) to ensure measures are taken to cool the Arctic and deal with the consequences.

So far we have concentrated on the methane threat which has resulted from loss of sea ice and Arctic warming; this threat will be aggravated by further loss of sea ice and faster warming. However a second consequence concerns weather disruption, which is proving to have serious implications for food security. 

If you share AMEG’s concerns on this issue, we have produced an example letter for you to send to a government representative, urging action.

There is a growing realisation in the scientific community that our current weird weather, being stuck first on heat and drought and then on cold and wet, is due to the sticking or 'blocking pattern' of the jet stream - this in turn due to the Arctic sea ice disappearing and Arctic warming. It was front-page news in The Times earlier this week [1]. Also there's an article about it in the New Scientist [2]  (page 36):
"In summers with less sea ice in the Arctic... the jet stream slows down, it takes a more mazy path, with meanders that move around more slowly... stays in one place for weeks... weather is likely to become more extreme".
This deterioration of the climate is likely to become more marked as the sea ice disappears, which is happening faster than acknowledged by many scientists, including those at the Met Office. On 21st February, AMEG presented evidence to the Environment Audit Committee (EAC) for their hearing on “Protecting the Arctic”. In a subsequent hearing, this evidence was disputed by Professor Julia Slingo, chief scientist at the Met Office, which includes the Hadley Centre. Then in early July, EAC published AMEG's rebuttal, in particular slating Professor Slingo for denial of the speed of sea ice retreat [3]. AMEG rubbishes all the Hadley Centre models on which so much government policy is based because they do not take into account the observations of what is happening to sea ice thickness and volume. The ridiculous optimism of climate change predictions from these models has engendered a false sense of security about the sea ice and methane, as if nothing need be done. However AMEG shows that geoengineering is vital to cool the Arctic, and the government needs to act, as a matter of national and global security.

Quoting from the appendix of [3]:
"One of the questions raised at our hearing on 21st February concerned what life would be like in 20 years’ time, i.e. by 2032. We have considered this in respect of different scenarios, depending on methane emissions. We estimate that the Arctic is warming at about 1 degree per decade, around five times faster than the rest of the planet, and this is mainly because of sea ice retreat and more open water to absorb solar energy. In 10 years, i.e. by 2022, PIOMAS volume data suggests that the Arctic Ocean will be essentially free of ice for 6 months of the year, and the Arctic will then be warming at about 4 degrees per decade. The Arctic temperature will be 5 or 6 degrees hotter than today. The disruptive effect on Northern Hemisphere weather systems will be traumatic, leading to severe food shortages for all and starvation for millions if not billions of people."
Please support us! On the web site you will find a template for a suitable letter to send to a government representative, such as an MP.

References:

[1] The Times, front page, July 11th: “Endless rain flows from melting ice” (registration required)

[2] How global warming is driving our weather wild (registration required)
http://www.newscientist.com/article/mg21528721.800-how-global-warming-is-driving-our-weather-wild.html

[3] Supplementary written evidence from John Nissen, AMEG
http://www.publications.parliament.uk/pa/cm201213/cmselect/cmenvaud/writev/171/arc31.htm

Thursday, July 5, 2012

Supplementary evidence to the EAC from John Nissen on behalf of AMEG


Supplementary evidence to the Environmental Audit Committee (EAC) from John Nissen on behalf of AMEG


The Growing Crisis in the Arctic

I am writing on behalf of AMEG, the Arctic Methane Emergency Group, in regard to conflicting evidence you have received during your inquiry “Protecting the Arctic”.

The inquiry is both a highly commendable reaction to, and a highly authoritative confirmation of, the fact that for the last few decades the Arctic environment is being changed at a rate unprecedented in human history. The world’s scientific establishment is unequivocal that these changes to the Arctic environment, particularly the retreating sea ice, were initiated as a consequence of global greenhouse gas emissions arising from human activities. But, as the sea ice retreats, the open water absorbs more sunshine, warming the water and melting more ice in a vicious cycle known as “positive feedback”. Thus global warming from greenhouse gases is amplified in a process known as “Arctic amplification”. There is good evidence to suggest that the Arctic is currently warming several times faster than the average over the whole planet, see Appendix.

In the course of the EAC’s ongoing inquiry it has focused on the issue of the retreating sea ice because it is this feature of the changing environment that has attracted the interests of the oil, shipping and fishing industries and is also the critical disruptive element in the Arctic environment. AMEG representatives, Professor Peter Wadhams and I, have pointed out extreme dangers associated with the retreat, warranting the designation of a planetary emergency – a crisis of unprecedented magnitude to threaten all mankind – a matter of national and international security.

The EAC invited many organisations to give their evidence on how the near future of the Arctic would play out. AMEG provided compelling evidence that not only was the rate of reduction of sea ice extent and depth much higher than is currently being predicted by models (such as used by the Hadley Centre) but that the consequential release of entrapped methane, an extremely powerful greenhouse gas, was also accelerating, risking catastrophic exacerbation of global warming in coming decades. However the chain reaction of Arctic warming and further methane release could be stifled if the Arctic were cooled quickly by measures including geoengineering.

In her evidence, Professor Julia Slingo of the Meteorological Office flatly contradicted the AMEG evidence, particularly the evidence of rapid sea ice retreat given by Professor Wadhams. Especially, Professor Slingo said she did not find the PIOMAS volume data credible, and she was expecting to see “better data” fitting the Hadley Centre models soon. We wish to point out that it is quite extraordinary that Professor Wadhams, an acknowledged expert on sea ice who has spent many years studying sea ice thickness, should have his evidence thus repudiated. However, the committee might bear in mind that the reputation of the Hadley Centre, part of the Met Office, is largely based on their modelling expertise; and their models are still predicting the sea ice demise many decades in the future. Thus Professor Slingo was in effect attempting to defend the Hadley Centre reputation.

What the committee may not know is that there was a whole assemblage of models used by the IPCC in 2007 for their AR4 report. Most of these models predicted the sea ice survival beyond the end of the century. None of the models showed the positive feedback from sea ice retreat that we refer to above. An excuse could be made that this feedback is difficult to quantify and to model, so was omitted on procedural grounds. However the resultant predictions bore no relation to reality. Even in the 1990s, the observations of sea ice extent were deviating from the most pessimistic of the models. Then in September 2007 the sea ice extent plummeted to a record low, about 40% below the level at start of satellite measurement. Nevertheless, IPCC, supported by models from the Hadley Centre, continued on the assumption that global warming predictions could be made for the whole century without taking into account possible sea ice disappearance and massive methane release. Even with the “wake-up call” of sea ice retreat in 2007, the Hadley Centre would not admit that their models were fundamentally flawed and they continue to ignore the evidence of sea ice volume, which is showing an exponential downward trend.

Note that in their written evidence to EAC, the Met Office says: “In September 2007, sea ice extent reached an all-time low, raising the question of whether the sea ice is likely to melt more quickly than has been projected. There is, however, no evidence to support claims that this represents an exponential acceleration in the decline.” They also assure the EAC to trust models giving 2040 as the earliest date for the Arctic to become ice-free during summer. However the PIOMAS volume data clearly shows acceleration in decline, a close fit to the exponential trend curve, and a likely date for an ice-free September around 2015. (Note that as the volume approaches zero, so must the extent, implying a collapse in extent before 2015.)

And they are even now ignoring the evidence of the growing methane emissions from the East Siberian Arctic Shelf (ESAS) where “vast plumes of methane bubbles, many over a kilometre across” have been reported arising from the seabed by the Russian scientists, Shakhova and Semiletov. In her oral evidence, Professor Slingo shows apparent ignorance of the Arctic methane situation, which may have misled the committee. She ignores the vast area of ESAS (over 2 million square kilometres) and claims that only a small fraction of methane from hydrates reaches the surface. That may be true for methane from the shelf margins at several hundred meters depth; but the shelf itself is mostly less than 40 metres deep, so the methane has little time to be oxidised and most of it reaches the surface. Furthermore she suggests only a small rise in temperature at the seabed, but in ESAS temperature rises of up to 6 degrees have been recorded. Far from the stratification of the water, which Professor Slingo suggests, there has been a growing turbulence as the sea ice cover is removed, resulting in this seabed warming.

This denial of the true situation might mislead the committee into thinking that there is no significant amount of methane entering the atmosphere, let alone a growth. But methane detection stations show recent spikes in methane levels which can only be easily explained by seabed origin. Furthermore satellite measurements have shown a growing anomaly of excess methane over the Arctic Ocean, again suggesting a seabed origin. All this evidence was available to the Met Office but they chose to ignore it.

Thus the Met Office (and Hadley Centre within it) is party to a complete denial of what is actually happening in the Arctic with accelerated warming, precipitous decline in sea ice and ominous rise in methane emissions.

Margaret Thatcher, in her opening of the Hadley Centre, 25th May 1990 said: “Today, with the publication of the Report of the Inter-Governmental Panel on Climate Change, we have an authoritative early warning system… [This] Report confirms that greenhouse gases are increasing substantially as a result of Man's activities; that this will warm the Earth's surface, with serious consequences for us all, and that these consequences are capable of prediction. We want to predict them more accurately and that is why we are opening this Centre today.”

We wish to hold the Met Office and its chief scientist to account for putting out scientifically unfounded and incorrect information to delude the government and public that no possible Arctic planetary emergency exists.

The importance of the sea ice for the planet is not in dispute; it provides a reflective mirror to reflect solar energy back into space, thus cooling the planet. James Lovelock has made his own estimate that loss of sea ice would be equivalent to the warming of all the CO2 that has accumulated in the atmosphere as a result of mankind’s emissions over the past century. In any event, recent research has confirmed that retreat of sea ice to date is a major cause of Arctic amplification. Therefore, if the Arctic Ocean were to become free of sea ice for several months of the year, as possible by 2020 according to the PIOMAS data, there would necessarily be a spurt in Arctic warming. This would be serious in terms of mounting disruption of the Northern Hemisphere climate system (see below). But it would also lead to an inevitable increase in the rate of methane release, risking the onset of an unstoppable methane feedback, whereby the methane causes further Arctic warming and in turn further methane emission in a positive feedback loop. A warning of the danger to all humanity from such methane feedback has been made by top scientists, such as US Energy Secretary and Nobel Laureate, Steven Chu, and NASA climate scientist, Jim Hansen. The likelihood of runaway methane feedback as the sea ice disappears cannot be easily estimated from current evidence, but, even if small, it has to be considered seriously because of the extraordinary devastation were it to get going.

The current disruption of the Northern Hemisphere climate system, with an ever increasing incidence of severe heat waves on the one hand and severe flooding on the other, is likely due to the warming of the Arctic in relation to the tropics, thus reducing the temperature differential that has a stabilising effect on the jet stream and weather system patterns. There is evidence that the jet stream is now getting “stuck” such as to cause the unusual and unpredictable weather which is of considerable concern to farmers. Allowing the Arctic to continue warming is thus a very real danger to food security – which is a strong argument for cooling the Arctic, regardless of other considerations.

The evidence given by Professor Tim Lenton suggesting that the global warming produced by Arctic methane would only amount to 0.1 degree or less, by the end of the century, can be dismissed if you accept that the sea ice cover will be removed as quickly as the PIOMAS data suggests. Even climatologist Professor David Archer of the University of Chicago, who recently claimed that AMEG concerns on methane were “much ado about nothing”, admits that a release of only one fifth of the 50 Gt of methane, which researchers Shakhova and Semiletov say could be released “at any time”, would take global warming over the 2°C limit established by IPCC as “dangerous anthropogenic interference” with the climate system.

But Professors Slingo and Lenton are not alone in their misleading analysis of the situation. We are appalled that there appears to be no recognition within any part of the scientific establishment, whether Government Departments, Research Councils, Institutes or Universities, of the imminence of extremely dangerous developments that would flow from allowing the present incipient runaway situation to develop in the Arctic. This amounts to a collective denial of danger – a collective burial of heads in the sand.

Similarly there appears to be little or no willingness to consider possible actions that could be taken immediately and within the next few years, as necessary in view of the rapidity with which the position in the Arctic is deteriorating.

So, what is to be done? Clearly a major effort has to be made immediately to cool the Arctic otherwise the whole of humanity is put at risk. Even if you, as a committee, concluded that the danger is overstated by AMEG, we would argue that the effort is worthwhile as an insurance policy. Suppose that this effort is made and proves to have been unnecessary, what has been lost? The technology for cooling the Arctic will have been developed for use at a later date or for a different circumstance.

Contrast the anti-precautionary approach espoused by Professor Slingo, Professor Lenton and the people from the modelling community who submitted evidence against geoengineering just before our hearing. They would prefer to see nothing done immediately to cool the Arctic on the grounds that there is uncertainty in the situation, and it is not yet proven whether (i) the Arctic sea ice is disappearing as rapidly as AMEG warns, and (ii) the methane threat is as great as AMEG warns. This is extraordinary for people who one would expect to espouse a precautionary principle in government, as surely they would in any other situation where there is a risk to millions of lives. Unless these people can prove that there is no risk arising from collapse of sea ice and escalation of methane emissions, which clearly they cannot, the committee has a responsibility to advise government that measures to cool the Arctic need to be taken on a precautionary principle.

Governments are expected to protect their own citizens on this principle, even if the danger is not proven. We would like to quote Article 3, paragraph 3, from the UNFCCC Convention, article 3, paragraph 3:
"3. The Parties should take precautionary measures to anticipate, prevent or minimize the causes of climate change and mitigate its adverse effects. Where there are threats of serious or irreversible damage, lack of full scientific certainty should not be used as a reason for postponing such measures, taking into account that policies and measures to deal with climate change should be cost-effective so as to ensure global benefits at the lowest possible cost. To achieve this, such policies and measures should take into account different socio-economic contexts, be comprehensive, cover all relevant sources, sinks and reservoirs of greenhouse gases and adaptation, and comprise all economic sectors. Efforts to address climate change may be carried out cooperatively by interested Parties." (Our underlining)
Note that AMEG considers that the cooling of the Arctic should be seen as one of many efforts to bring the atmosphere and oceans back towards their pre-industrial state, especially since such efforts reduce both immediate and longer-term risks arising from Arctic warming, sea ice retreat and methane release. AMEG is fully supportive of these efforts.

Why do these intelligent people from the modelling community seem to view all geoengineering as intrinsically dangerous? That may be the view in the media and among many environmentalists, but these scientists should be capable of a more rational assessment of each technique on its merits, on the limited scale as required for cooling the Arctic.

The candidate techniques AMEG proposes are all based on natural phenomena that can be observed. They can be switched off if and when any dangerous side-effects become apparent. There is nothing intrinsically dangerous about geoengineering – mankind has been doing it for millennia by altering the environment, albeit inadvertently.

Let’s look on the positive side. Cooling the Arctic and saving the sea ice has the obvious benefit of saving an entire ecosystem. Furthermore common sense suggests that geoengineering will tend to make things better because it is reversing the trends resulting from regional warming. One of the main effects of Arctic warming has been to cause disruption of regional weather patterns in the Northern Hemisphere, with more weather extremes and less long-term predictability of the weather. This has can only have had an adverse effect for farmers who rely on annual cycles like the monsoons. Thus cooling the Arctic should improve this situation. Yet Professor Slingo, in her oral evidence, states that, like the climate forcing from CO2 emissions, geoengineering will have "huge ramifications" implying that it is likely have serious side effects. Of course the very modelling that can be used to anticipate such side effects can also be used to avoid them, by adjusting the parameters of the techniques to be used (see note below). Thus modelling has an important part to play in the successful deployment of geoengineering.
Note: Each geoengineering technique has adjustable parameters, to allow the technique to be tailored to a particular situation. In the case of stratospheric aerosols, the height, latitude and time-of-year for the release of aerosol (or aerosol precursor) can be adjusted for maximum positive effect and minimum negative effect, using models to estimate these effects in advance. In the case of techniques to brighten or remove tropospheric clouds, more localised effects can be obtained; and parameters can be adjusted for different locations of deployment giving a great deal of flexibility as well as control.
Now we have no option other than to employ our best technology and expertise to get out of the crisis situation we have got ourselves into.

We respectfully suggest that modellers should turn their attention to modelling the effects of different geoengineering techniques, showing how unwanted side-effects can be minimised and working out how best to use various techniques in combination. This would be a useful contribution to the enormous challenge now faced to cool the Arctic. They must stop lulling the climate change community, and hence governments, into a false sense of security with their obsolete models which don't take account of reality.

In the light of the above we are writing to plead that you immediately alert the Prime Minister and his cabinet to the above conclusions: how the deteriorating situation in the Arctic has extremely threatening implications for all mankind if measures are not immediately adopted to cool the Arctic in order to reverse the current trends of retreating sea ice, escalating methane release and disruption of Northern Hemisphere climate. We realise that, under normal circumstance, we should wait for your report; but this is no ordinary situation. The sooner measures to cool the Arctic can be taken, the better. This is a daunting challenge, perhaps the biggest ever faced by humanity, but it can be met if there is a determined and concerted effort over the coming weeks and months by top scientists, engineers and yes modellers, tasked specifically to deal with the problems in the Arctic.

Only a directive from the highest levels of government is capable of initiating the programme of action required. The UN and all world governments must be alerted to the perilous situation now exposed.

Traditionally governments have tended to react to events rather than forestall them. But in this case we risk sliding irreversibly into ultimate climate catastrophe. We are close to a point of no return. Not to act as quickly as possible to halt the slide would be an abject failure of the most primary responsibilities of government. And, because such a catastrophe would threaten the life of every person on the planet, not to act would also be suicidal.

We implore the committee to give its full and serious attention to the challenge that this inquiry has thrown up, a challenge that whilst embracing the Arctic environment in its essence goes far beyond that in its enormously far-reaching implications for the rest of the planet. The committee has a unique opportunity to change the course of history.

John Nissen, Chair of AMEG
29th June, 2012

Appendix – “Life in 2032”

One of the questions raised at our hearing on 21st February concerned what life would be like in 20 years’ time, i.e. by 2032. We have considered this in respect of different scenarios, depending on methane emissions. We estimate that the Arctic is warming at about 1 degree per decade, around five times faster than the rest of the planet, and this is mainly because of sea ice retreat and more open water to absorb solar energy. In 10 years, i.e. by 2022, PIOMAS volume data suggests that the Arctic Ocean will be essentially free of ice for 6 months of the year, and the Arctic will then be warming at about 4 degrees per decade. The Arctic temperature will be 5 or 6 degrees hotter than today. The disruptive effect on Northern Hemisphere weather systems will be traumatic, leading to severe food shortages for all and starvation for millions if not billions of people.

If in addition there were an early release of the 50 Gt of methane that Shakhova and Semiletov say could be released from the East Siberian Arctic Shelf “at any time” (due to seabed warming and the instability of methane-holding structures), then we could expect over 3 degrees of global warming by 2032, liable to start runaway methane feedback. Not only would we be facing world-wide starvation but probably global conflict as well.

On the other hand if geoengineering and other measures were successful in cooling the Arctic sufficiently to bring back the sea ice to its pre-2007 volume and extent, then growth of methane emissions into the atmosphere would almost certainly be curtailed and the dreaded methane feedback avoided. The weather systems in the Northern Hemisphere weather systems would be stabilised, allowing the world farming community to plan for providing a growing world population with food. The spread of insect-born disease would be slowed. Conflicts arising from degraded environments would be reduced. And we would have more time to solve the underlying problems to ultimately remove the requirement to use geoengineering technology.

Tolerability of life in 2032 will thus depend on whether governments act quickly in response to today’s rapidly deteriorating situation by taking measures to cool the Arctic.


The parliamentary document: 
http://www.publications.parliament.uk/pa/cm201213/cmselect/cmenvaud/writev/171/arc31.htm
Submissions to date to the Environmental Audit Committee's inquiry 'Protecting the Arctic': 
http://www.publications.parliament.uk/pa/cm201213/cmselect/cmenvaud/writev/171/contents.htm

Monday, May 14, 2012

Message from the Arctic Methane Emergency Group

From the Arctic Methane Emergency Group, AMEG
http://www.ameg.me/

1. A planetary catastrophe to be averted

We are starting our first post on this blog by presenting what we consider the overwhelming scientific evidence of a planetary emergency arising from a combination of: (i) the warming of the Arctic, (ii) the rapid melting away of Arctic sea ice, (iii) the releasing into the atmosphere of ever larger quantities of the potent greenhouse gas, methane, from thawing structures, and (iv) positive feedback between these three processes.
Figure 1. The huge temperature rise in the Arctic (latitudes 60 North to North Pole), compared to temperatures at lower latitudes (surface air temperatures as nine-year running means relative to the 1880–1890 mean). 


Figure 2. Yearly Minimum Arctic Icve Volume Data from the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS), at the Polar Science Center, with trend (in red) added by Wipneus.  


Figure 3. The striking rise of methane in the Arctic (click on image to enlarge)


Figure 4. Global emissions cause warming, especially in the Arctic, where warming is further accelerated by feedbacks, in particular sea ice loss and methane releases, threatening to lead to runaway global warming. 

We argue that the response to this emergency should be concerted international action, taking measures to cool the Arctic which would include geoengineering of a kind known as “solar radiation management” (SRM) [1]. These measures should be taken as quickly as conceivably possible in order to reduce the risk of passing a point of no return – a point beyond which the whole climate system would tip, inevitably, irreversibly and inexorably, into such a hot state as to threaten the survival of civilisation.

This is the situation in a nutshell:
  • the Arctic is warming rapidly – much faster than global warming;
  • the sea ice volume is plummeting; 
  • a collapse in sea ice extent is likely by 2015;
  • a collapse in sea ice means loss of habitat and biodiversity, risking the breakdown of an important marine food chain;
  • a collapse in sea ice also means faster warming of the Arctic, creating more climate disruption and weather extremes in the Northern Hemisphere.
This is bad enough. Add to this the menace of Arctic methane. Consider that: 
  • methane’s potency as a greenhouse gas is about 105x that of CO2 over 20 years, weight for weight [2];
  • there’s a vast quantity of methane frozen into Arctic seabed [3];
  • loss of sea ice cover allows storms to mix the warmed surface water with colder water beneath, causing shallow seabed to warm, thawing out methane-holding structures;
  • because of warming and instabilities in the seabed, large quantities of methane could be released quite rapidly – enough to drastically exacerbate global warming [4]; 
  • methane bubbles have now been observed in huge plumes, over 1km across, in shallow sea [5], suggesting an escalation of methane emissions could be happening already, even without further warming of the Arctic;
  • Arctic methane may be contributing to rising global levels of methane in the atmosphere [6].
The worst fear is that methane could build up in the atmosphere sufficiently to start a runaway cycle of greenhouse warming and more methane release, leading to abrupt and catastrophic climate change.

The only way to prevent a chain of events which could lead to such a runaway cycle is to cool the Arctic, save the sea ice and dampen methane emissions. To minimise risk, we need to use all possible means.