Climate Code Red Part 1

Climate Code Red.

David Spratt.

& Philip Sutton.

Forewords.

Ian Dunlop.

As the world's population rises toward nine billion by mid-century, the inevitable logic of exponential growth in consumption is now hitting the real limits of global ecosystems and resource availability. The immediate pressure points are human-induced climate change, water availability, and peaking global oil supply, which are converging rapidly in a manner not previously experienced. But those pressure points const.i.tute only the tip of the broader global-sustainability iceberg: further constraints and limits will become increasingly evident as the major developing countries move up the growth escalator.

This situation is not unexpected: it has been forecast for decades, going back before the 1972 publication of The Limits to Growth, a book that described how expanding human population and consumption patterns would run up against the limits of the natural world. In the meantime, we have created a political and capitalist system which has proved incapable of recognising that the most important factor for its own survival is the preservation of a global biosphere fit for human habitation. Our inst.i.tutions are totally short-term focused: politically, due to the electoral cycle, and corporately, due to perverse incentives. Thus, we are uniquely ill-equipped to handle these major problems, which are all long-term.

Our ideological preoccupation with a market economy that is based on maximising short-run profit is rapidly leading us towards an uninhabitable planet. As inconvenient as it may be, politically and corporately, conventional economic growth and rampant consumerism cannot continue. Markets are important, but they operate within rules; henceforth, the rules must change to ensure long-run sustainability.

Nationalism and short-term vested interests have so far prevented the development of a global governance framework capable of handling this Tragedy of the Commons, and the issue of global sustainability is now much bigger than any nation state. Global warming, in particular, is moving far faster than scientists had predicted, to the point that we are already in the danger zone.

The stark fact is that we face a global sustainability emergency, but it is impossible to design realistic solutions unless we first understand and accept the size of the problem. We know those solutions; what is lacking is the political will, first, to honestly articulate the problem and, second, to implement those solutions.

Unadorned by political spin, Climate Code Red is a sober, balanced a.n.a.lysis of this challenge that proposes a realistic framework to tackle the emergency. It should be essential reading for all political and corporate leaders and, particularly, for the community. The extent of change that we require will only occur if the political and corporate world sees that the community is demanding it.

If we are to have a reasonable chance of maintaining a habitable planet, placing our efforts on an emergency footing is long overdue. We only play this game once; a trial run is not an option.

Ian Dunlop is a former international oil, gas, and coal industry executive. He chaired the Australian Coal a.s.sociation from 198788 and the Australian Greenhouse Office Experts Group on Emissions Trading from 19982000, and he was CEO of the Australian Inst.i.tute of Company Directors from 19972001. He is chairman of the Australian National Wildlife Collection Foundation (CSIRO) and deputy convenor of the Australian a.s.sociation for the Study of Peak Oil.

Ken Caldeira.

For my PhD research, I studied what happened to ocean chemistry at the time the dinosaurs became extinct. The meteorite that destroyed the dinosaurs also acidified the oceans, leading to the disappearance of coral reefs and many other marine organisms. It is becoming clear that modern industrial civilisation is generating a new ma.s.s extinction (with its own ocean acidification) of a magnitude not seen since that destruction of the dinosaurs some 65 million years ago.

Over the past few centuries, vast natural ecosystems on land and in the water have been converted to human use and abuse. Our carbon dioxide emissions are heating the planet and acidifying the oceans. Our physical environment is changing at a rate that is faster than at any time in the past hundreds of millions of years, except for those rare cataclysmic events that have killed off most life on Earth. Spratt and Sutton point out that if 'business as usual' means losing Arctic ecosystems, losing coral reefs, altering the great weather patterns, and so on, then we simply cannot afford it - the cost is too great.

At the risk of oversimplification: we are forced to make a choice. Either we can decide to live in a 'wilderness world' in which we use our technology to minimise our environmental footprint, and we grow and develop in ways that are consistent with long-term flouris.h.i.+ng of the rich diversity of life in this planet; or we can continue heading towards a nightmare vision of an Earth where climate is s.h.i.+fting and species are getting tossed overboard every day, every hour. (Invasive generalists, including weeds and the wealthy, may do fairly well, but specialist species and poor people have a threatened future ahead of them.) We will either learn to live with the world, or wreck it - and in wrecking the world, we will lose.

There is inertia both in the climate system and in our industrial infrastructure. Inertia in the climate system means we can pa.s.s thresholds now that set us on an irreversible trajectory to future tragedy. Inertia in our industrial infrastructure means that, under most accepted scenarios, without early retirement of major segments of our industrial capacity, it will take many decades to replace the coal-, oil, and gas-burning devices that pervade our planet. 'Business as usual' is accelerating us into ever-greater environmental risk - and eventually, that risk will come home to roost. As Spratt and Sutton point out, 'business as usual' must end now, if we are to allow our children and ourselves a more natural world in which humans tread lightly and live well. Sensibly, Climate Code Red asks us to take stock of the climate and sustainability emergency that is unravelling around us and respond with a large-scale transition to a post-carbon economy. There is no time for slow transitions.

Ken Caldeira is director of the Caldeira Lab of the Department of Global Ecology at Stanford University's Carnegie Inst.i.tution of Was.h.i.+ngton, whose research focuses on improving the science base needed to allow human civilisation to develop while protecting our environmental endowment. He also conducted research for the Energy and Environmental Sciences Directorate of the Lawrence Livermore National Laboratory from 1993 to 2005.

INTRODUCTION.

A Lot More Trouble.

'This is an emergency, and for emergency situations we need emergency action ...'

- UN secretary-general Ban Ki-Moon, 10 November 2007.

'I can't end this email without acknowledging that we are in a lot more climate trouble than we thought.' This response from a US-based polar researcher during a discussion we were having about how quickly Greenland might melt is not an orthodox scientific statement, but its disturbing tone expresses a level of anxiety and honesty that we heard many times while writing this book.

Perhaps the frankness of such responses reflected the fact that we are not climate scientists, and that we were asking questions not as peers but as policy researchers. In conducting our enquiries, we conversed with and drew on the work of many climate scientists who gave generously of their time, patiently answering sometimes-wayward questions, and welcoming our enquiries. Although our previous work had included advocacy on environmental and community problems, we found the scope and depth of climate research, the nuances, and interpretative differences between scientists a challenge. Yet it is critical that non-scientists engage with the science if all of us are to plot a pathway to a safe climate.

Climate scientists generally work in a specialised field, and the release of their scientific results and projections incorporates a.s.sess.e.m.e.nts of risks, probabilities, and uncertainties that can lead them to feel reticent about commenting publicly on the broader aspects of global-warming impacts and policies. Those outside the research community, however, have a different vantage-point in viewing the disparate evidence, which may explain why some of the most compelling writing on global warming has come from writers such as George Monbiot, Fred Pearce, Mark Lynas, and Elizabeth Colbert.

Climate Code Red explores what 'a lot more climate trouble' means, why it differs from the public story, and how we should go about thinking of new solutions to this global emergency. It concludes that we must cast aside climate policies that are doomed to fail, and that we must act with foresight and courage, because our task is urgent.

The evidence we have gathered has convinced us that we have only one chance to solve the global warming problem. Just as in hospitals, where 'code red' denotes a patient who needs advanced life-support, the phrase signals an emergency: an alarm that rings now, for all life on this fragile planet.

Debate over climate change took a radical new turn in September 2007, when research data revealed that the floating sea-ice in the polar north was disintegrating at a frightening speed - in the words of Penn State University climatologist Richard Alley, 'one hundred years ahead of schedule'. Eight million square kilometres of Arctic sea-ice is breaking up, and this demands that we look anew at the impact of global warming, and at what we must do to return to a safe-climate world.

Industrial activity is propelling the world's climate to a hot state not experienced for a million years, at a time long before modern humans evolved. We face a perilous journey across unfamiliar terrain, close to a precipice that, should we cross it, will see changes beyond recognition to life on Earth.

This is not an exaggerated claim; it is the sober view of many of the world's leading climate scientists, including NASA scientist Jay Zwally. When he was a young man, Zwally hauled coal for work. At the end of 2007, he told a gathering of fellow climate experts: 'The Arctic is often cited as the canary in the coalmine for climate warming ... and now as a sign of climate warming, the canary has died. It is time to start getting out of the coal mines.'

Robert Corell, chairman of the Arctic Climate Change Impact a.s.sessment (ACCIA), is equally blunt: For the last 10,000 years we have been living in a remarkably stable climate that has allowed the whole of human development to take place ... Now we see the potential for sudden changes of between 2 and 6 degrees Celsius [by the end of this century] .* We just don't know what the world is like at those temperatures. We are climbing rapidly out of mankind's safe zone into new territory, and we have no idea if we can live in it.

In the recent past, the story of climate change has been one of sudden and disruptive fluctuation as the Earth seesawed between ice ages and warm periods. This history warns that we must expect the unexpected, because dramatic changes that tip regional climates from one state to another can set off chains of events that echo around the globe.

Most of us think of climate change as a gradual, linear process that involves a smooth relations.h.i.+p between increasing levels of greenhouse gases and rising temperatures - that like the kitchen oven, if we are slowly turning up the control, we will produce a predictable warming. But climate doesn't work like that.

In fact, we live in a climate world of chaotic, non-linear transitions, where a small increase in the level of greenhouse gases, or in the energy imbalance of the climate system, can make a huge difference. An element of the climate system can flip from one state to another quickly and unpredictably. This is now occurring at the North Pole, where a tipping point, or critical threshold, has been pa.s.sed, and an area of summer sea-ice once as large as Australia is disintegrating quickly.

Further south, if the changing climate were to produce four or five consecutive years of drought in the Amazon, it might become sufficiently dry for wildfires to destroy much of the rainforest and for burning carbon to pour into the skies. This change in the regional climate pattern would further reduce rainfall, and the drying and dead forest would release very large amounts of greenhouse gases. These impacts, like many others, would cause further threshold events.

If this kind of momentum builds sufficiently, and enough tipping points are crossed, we will pa.s.s a point of no return. We wish it were otherwise. Indeed, this is not a book we intended to write; but when our work led us to understand that we had already entered the era of dangerous climate change, it became a story we felt compelled to tell.

Originally, we wrote this book as a report to address three areas of climate policy that we wished to bring to the attention of the Garnaut Climate Change Review (the Garnaut Review): the implications of recent climate research, appropriate reduction targets, and the case for emergency action. The review was commissioned by the Australian federal Labor leader Kevin Rudd, and the state and territory Labor governments, six months prior to the November 2007 federal election that swept Labor to power.

Our first concern in presenting ideas to the review was to draw attention to the seriousness of recent climate data.

Our second concern was to show that a response to the climate crisis in 'politics as usual' mode would not be fast enough to solve the problem.

Our third concern was to encourage the review to choose targets that would achieve a safe result and not replicate mistakes made elsewhere in setting targets that would be ineffective. An example of this was the Stern Review, delivered to the UK government in late 2006 and received enthusiastically in most quarters. The economist Sir Nicholas Stern had graphically outlined the future impacts of rising global temperatures. An increase of 2 degrees above the pre-industrial level was not acceptable, he explained, because it would likely mean, amongst other things, the loss of 1540 per cent of species, a loss of fresh water of 2030 per cent in vulnerable regions, and the potential for the Greenland ice sheet to begin melting irreversibly, pus.h.i.+ng sea levels up several metres.

Stern's conclusion, however, was chilling: to limit the rise to 2 degrees was, in his opinion, too challenging, politically and economically. Instead, he suggested going for a 3-degree target. Yet a 3-degree rise would likely destroy most ecosystems and take global warming beyond the control of human action. It seemed incomprehensible that so few people spoke out forcefully against Stern's target and the death sentence that he was accepting for so many people and species. How could society be so mad as to go for a target that would kill much of the planet's life?

As we started to write our short submission, events in the Arctic intervened to demonstrate dramatically that dangerous climate change is not in the future, but is happening now. Over one northern summer, it became clear that the task was not to weigh up what would be a reasonable rise in temperature; rather, it was to ask: by how much do we need to lower the existing temperature to return our planet to the safe-climate zone? Global warming now demands an emergency response in which we put aside 'business and politics as usual', and devote our collective energy and capacity for innovation to stopping a slide to catastrophe.

Why do business leaders, politicians, community advocates, and sectors of the environment movement fail to grasp fully the momentous problem that we face? How can they not 'get it', when the evidence is now so abundant? We hope that this book will help to identify why real action has so often been blocked, and help to map out a pathway through the barriers.

Many people, including UN secretary-general Ban Ki-Moon, now call the situation that we face a 'climate emergency'; but it could just as easily be called a warming, water, food, or energy emergency. The issues of global warming, water shortages, peak oil, ecosystem destruction, resource depletion, global inequity, and the threat of pandemics intersect and intertwine. Together, these threats and risks const.i.tute a sustainability crisis, or emergency.

In exploring these ideas, our short submission became this unintentional and lengthier book. The story we tell is disturbing and compelling, in equal measure. It poses a choice: to act with great effort now, or to know that it will soon be too late to act effectively. It will be little comfort ten years from now to look back and think ruefully of what we might have done, and of what might have been achieved.

Climate Code Red has three interrelated parts.

The first section reviews the scientific evidence and a range of expert insights flowing from the increasing speed of the Arctic sea-ice melt. It also considers recent climate data and a.n.a.lysis about critical subjects such as carbon sinks, biodiversity loss, and climate sensitivity. Drawing on this review, the second section a.n.a.lyses current debates about climate targets, and proposes a set of reduction targets consistent with achieving a safe-climate future. The third section identifies the need for a rapid transition to a sustainable economy. It argues that the task needs to be constructed as a climate emergency - that we cannot continue at the meandering, slow pace dictated by 'business and politics as usual', which today stands in the way of necessary change.

* The increase to date has been 0.8 degrees.

PART ONE.

The Big Melt.

'We are all used to talking about these impacts coming in the lifetimes of our children and grandchildren. Now we know that it's us.'

- Professor Martin Parry, co-chairman of the Intergovernmental Panel on Climate Change (IPCC) impacts working group, 18 September 2007.

CHAPTER 1.

Losing the Arctic Sea-Ice.

In the northern summer of 2007, the area of sea-ice floating on the Arctic Ocean dropped dramatically, reaching the lowest extent that we have seen since records began. This event has profound consequences for climate policy, the role and methods of the Intergovernmental Panel on Climate Change (IPCC), and the a.s.sessment of predicted sea-level rises, and it begs the question of whether we have already pa.s.sed a critical tipping point beyond which human interference with the Earth's climate system becomes very dangerous.

In its February 2007 report on the physical basis of climate science, the IPCC said that Arctic sea-ice was responding sensitively to global warming: 'While changes in winter seaice cover are moderate, late summer sea-ice is projected to disappear almost completely towards the end of the twenty-first century.' The IPCC thought it would take a hundred years for the sea-ice to disintegrate; but, even before its report was published, its projections lagged behind the changing physical reality of the Arctic environment.

In a presentation to a Carnegie Inst.i.tution climate conference on 1 November 2005, Tore Furevik, professor of oceanography at the Geophysical Inst.i.tute in Bergen, had already demonstrated that actual Arctic sea-ice retreat in recent years has been greater than had been estimated in any of the 19 Arctic models of the IPCC.

In December 2006, data was presented to an American Geophysical Union (AGU) conference suggesting that the Arctic may be free of all summer sea-ice as early as 2030. According to Marika Holland of the US National Center for Atmospheric Research (NCAR) in Colorado, this would set up a 'positive feedback loop with dramatic implications for the entire Arctic region'. This view was then supported by studies published in March and May 2007 by Holland, along with Mark Serreze and Julienne Stroeve of the US National Snow and Ice Data Centre (NSIDC) at Colorado University.

Soon, events on the ground would outrun even this research. Despite the warnings, experts were shocked at the extent of Arctic ice-sheet loss during the 2007 northern summer. Serreze told the Guardian on 4 September: 'It's amazing. It's simply fallen off a cliff and we're still losing ice.'

A feature in the Was.h.i.+ngton Post on 22 October 2007 painted a bleak picture: This summer the ice pulled back even more, by an area nearly the size of Alaska. Where explorer Robert Peary just 102 years ago saw 'a great white disk stretching away apparently infinitely' from Ellesmere Island, there is often nothing now but open water. Glaciers race into the sea from the island of Greenland, beginning an inevitable rise in the oceans. Animals are on the move. Polar bears, kings of the Arctic, now search for ice on which to hunt and bear young. Seals, walrus and fish adapted to the cold are retreating north. New species - salmon, crabs, even crows - are coming from the south. The Inuit, who have lived on the frozen land for millennia, are seeing their houses sink into once-frozen mud, and their hunting trails on the ice are pocked with sinkholes.

On 16 September 2007, the Arctic sea-ice minimum fell to a record low of 4.13 million square kilometres, compared to the previous record low of 5.32 million square kilometres in 2005. This represented a precipitous decline in the ice extent of 22 per cent in two years, an area 'roughly the size of Texas and California combined, or nearly five United Kingdoms,' the NSIDC announced. This compares to the decreasing trend in ice area of 7 per cent per decade, between 1979 and 2005.

NSIDC research scientist Walt Meier told the Independent on 22 September that the 2007 ice extent was 'the biggest drop from a previous record that we've ever had and it's really quite astounding ... Certainly we've been on a downward trend for the last thirty years or so, but this is really accelerating the trend'.

But it wasn't just the area, or extent, of the sea-ice that was declining rapidly; an even more dramatic story lay hidden beneath. In the early 1960s, the ice was 3.5 metres thick; by the late 1980s, it was down to 2.5 metres; and now, in 2008, large areas are only 1 metre thick. This thinning is accelerating, with half of it having occurred in the past seven years. Taken together, the shrinking ice area and the declining ice thickness mean that the total ma.s.s of summer ice has dropped to less than 20 per cent of the volume that it was 30 years ago.

Before the big melt of September 2007, Serreze had speculated that we may have already reached the tipping point at which there is rapid sea-ice disintegration: 'The big question is whether we are already there or whether the tipping point is still ten or 20 years in the future ... my guts are telling me we may well be there now.' His 'educated guess' was a transition to an ice-free Arctic summer by 2030. His colleague at Colorado Ted Scambos agreed: '2030 is not unreasonable ... I would not rule out 2020, given non-linearity and feedbacks ... I just don't see a happy ending for this.'

These views were supported by Ron Lindsay of the University of Was.h.i.+ngton: 'Our hypothesis is that we've reached the tipping point. For sea-ice, the positive feedback is that increased summer melt means decreased winter growth and then even more melting the next summer, and so on.'

In 2006, former Australian of the Year, palaeontologist, and climate-change activist Tim Flannery suggested that 'at the trajectory set by the new rate of melt, however, there will be no Arctic icecap in the next five to fifteen years.' By the time September 2007 was over, even these predictions would need to be revised: it was becoming a battle for scientists to keep up with a dramatic climate event that was moving at unimagined speed.

Wieslaw Maslowski of the Naval Postgraduate College in California used US military submarine sonar mapping of the Arctic sea-ice during the many decades of the Cold War in his research, in which he modelled the processes of Arctic sea-ice loss. As early as 2004, he predicted a blue Arctic Ocean free of sea-ice by the summer of 2013, having recognised that the thinning ice was losing volume at a much faster rate than was indicated by satellite-derived surface-area data.

The polar icecap is now floating in water about 3.5 degrees warmer than its historical average. Maslowski found that the sea-ice is being thinned by the northward heat flux of warm summer Pacific and Atlantic waters, not just higher air temperatures. The US National Oceanic and Atmospheric Administration's (NOAA) Arctic report card for 2007 also found that a new wind-circulation pattern is blowing more warm air towards the North Pole than during the previous century; in 2007, winter and spring temperatures were 'all above average throughout the whole Arctic and all at the same time', unlike in previous years.

A team led by Donald Perovich of the Cold Regions Research and Engineering Laboratory in New Hamps.h.i.+re reported in 2007 on research which calculated that, since 1979, the Arctic Ocean has been absorbing sufficient additional heat to melt up to 9300 cubic kilometres of sea-ice, which is equivalent to 3 million square kilometres of ice, 3 metres thick. This is consistent with work by Maslowski and others suggesting that the majority of the ice loss is coming from warmer seas, and not directly from changes in the Arctic climate.

When the ice becomes sufficiently thin, it will be sensitive to a 'kick' from natural climate variations, such as stronger wind and wave-surge action, which will result in rapid loss of the remaining summer ice cover. It could happen any year now. Louis Fortier, scientific director of the Canadian research network ArcticNet, says worst-case scenarios about sea-ice loss are coming true, and that the Arctic Ocean could be ice-free in summertime as soon as 2010. Maslowski told the December 2007 conference of the AGU that 'our projection of 2013 for the removal of ice in summer is not accounting for the last two minima, in 2005 and 2007... So given that fact, you can argue that maybe our projection of 2013 is already too conservative.' NASA climate scientist Jay Zwally told the same conference that, after reviewing recent data, he had concluded that 'the Arctic Ocean could be nearly ice-free at the end of summer by 2012,' while Josefino Comiso of the NASA G.o.ddard s.p.a.ce Centre said: 'I think the tipping point for perennial sea-ice has already pa.s.sed ... It looks like [it] will continue to decline and there's no hope for it to recover [in the near period].' NASA satellite data shows the remaining Arctic sea-ice is unusually thin, making it more likely to melt in future summers.

While the extent of the sea-ice in winter is about the same as it has been over recent decades, winter ice is becoming increasingly fragile. As the summer extent shrinks, more of the reset winter ice is new, first-year ice. In 2007, only 13 per cent of first-year ice survived the melt season. Because the summer-ice minimum was a record low in 2007, almost two-thirds of the winter ice was first-year ice and, as such, is in a highly vulnerable state. As a result, the northern summer of 2008 is likely to see even more open water.

How many more years will it be before the Arctic is icefree in summer? The ice retreat is likely to be even bigger each summer, because the refreezing of the ocean surface is starting from a bigger deficit each year, and the amount of older ice is continuing to decrease. Looking at the trends, it is not difficult to see why it may happen in 2009 or 2010, depending on regional weather patterns.

Publicly and privately, many cryosphere climate scientists are shocked and alarmed at these developments. Some Australian climate scientists have expressed similar sentiments, privately acknowledging that the issues of dangerous climate change, caps, and mitigation strategies need urgent review, and that much of the orthodox thinking on these issues is now out of date. What const.i.tutes 'dangerous climate change' is being urgently reviewed.

'The reason so much [of the Arctic ice] went suddenly, is that it is. .h.i.tting a tipping point that we have been warning about for the past few years,' says the head of NASA's G.o.ddard Inst.i.tute for s.p.a.ce Studies, James Hansen. He has repeatedly warned that the 'albedo flip' trigger mechanism over large portions of ice sheets could lead to 'eventual non-linear ice sheet disintegration'.

Hansen coined the phrase 'albedo flip' to describe a rapid change, or flip, in the climate that occurs when large areas of ice sheets are lost as a consequence of human-induced warming. In relation to climate, albedo is a measure of the proportion of solar radiation that is reflected (rather than absorbed) when it hits the Earth's surface. White ice reflects most of the radiation (with an albedo of 0.80.9), whereas dark surfaces, such as bitumen or dark sea, can have an albedo of less than 0.1 (the Earth's average albedo is 0.3). So when light-reflecting ice sheets are lost and replaced by dark sea, rock surface, or green vegetation, the Earth suddenly absorbs a lot more solar radiation, and the region can heat rapidly. The heating causes more regional ice-sheet disintegration, in a cla.s.sic example of 'positive feedback'. This is now occurring in the Arctic. The eventual consequence is higher global temperatures, which we estimate will increase by around 0.3 degrees.

There are other factors that impact on the albedo effect. As ice is lost and regional temperatures increase, the atmosphere holds more water vapour and the cloud-cover increases, and this 'negative feedback' cancels out some of the warming effect from the loss of reflective sea-ice. General climate models do show that the cloud feedback can damp, or delay, the climate system's response, but they also show that surface albedo changes far outweigh the influence of cloud changes. There are no general climate model studies which specifically address the question of the global warming that is likely to occur as a consequence of the total loss of the Arctic sea-ice and its albedo effect, but a finding of a 0.01 degree warming for every 1 per cent of ice-sheet loss indicates that 0.3 degrees would be the eventual global warming that would result from total Arctic sea-ice loss. A higher figure may be more consistent with recent evidence, including typical temperature flips in glacialinterglacial cycles. On the other hand, there is a small chance that later this century an abrupt change in the North Atlantic thermohaline circulation (the 'Gulf Stream'), caused by global warming, could generate a strong cooling effect along the Norwegian coast, which would lead to the reestablishment of year-round Arctic sea-ice cover.

But there is much support for Hansen's albedo-flip predictions, including from Pl Prestrud of Oslo's Center for International Climate and Environmental Research, who says: 'We are reaching a tipping point, or are past it, for the ice. This is a strong indication that there is an amplifying mechanism here.'

The 2007 summer Arctic Ocean surface temperatures are estimated to have been much warmer than in previous years, by up to 5 degrees, largely as a result of solar heating of the upper ocean, which was the result of less cloud cover increasing the albedo feedback. 'That feedback is the key to why the models predict that the Arctic warming is going to be faster,' Zwally told the 2007 AGU meeting. 'It's getting even worse than the models predicted.'

There are also questions about the quant.i.ty of methane and carbon dioxide that will be released as a consequence of rapid regional warming, as areas of tundra permafrost in the polar north defrost. One initial estimate is that carbon dioxide released from permafrost may contribute an extra 0.7 of a degree over the next 100 years, based on predicted global warming of 2 degrees. But there is uncertainty about these figures, because they depend on how much extra positive feedback is included, for example, from water vapour; how much permafrost is thawed; and how much carbon is released. This figure is a conservative estimate, because it does not include the warming effect of methane release.

The Arctic summer of 2007 demands that we look in detail at its consequences. Sea-ice loss and Arctic warming are affecting the permafrost in Siberia, Alaska, and other regions; they are triggering caribou decline in Canada; and they are 'shrubifying' the tundra. 'What happens in the Arctic actually does not stay in the Arctic,' says oceanographer Richard Spinrad, who is deputy chief of the NOAA. In this case, one of the most significant knock-on impacts is going to be on the Greenland ice sheet.

CHAPTER 2.