9 Ağustos 2008Tim Flannery
Icebergs near Jakobshavn fjord, Ilulissat. Photograph: Bob Strong/ReutersIn this summer of 2008, it feels as if our future is crystallising before our eyes. Food shortages, the credit crisis, escalating oil prices, a melting Arctic ice cap and the failure of the Doha trade negotiations: one or all of these issues could be the harbingers of profound change for our global civilisation. And just 16 months from now, in December 2009 in Denmark, humanity will face what many argue is its toughest challenge ever: to agree the fundamentals of a climate treaty to succeed the Kyoto protocol.
It all seems to have happened so quickly. Just two years ago we received warning of an imminent disaster - a climatic shift that "could easily be described as hell: so hot, so deadly that only a handful of the teeming billions now alive will survive". The Cassandra was no deep green fundamentalist, but James Lovelock, the acclaimed scientist, pro-nuclear advocate and past adviser to Margaret Thatcher, who, 27 years earlier, had surprised the scientific community with his book Gaia: A New Look at Life on Earth (OUP). At a time when reductionist science (which breaks down the world into small units in order to understand it) prevailed, Lovelock took the opposite approach, describing Earth as a single, self-regulating entity, whose function can be disturbed by human activities. It became one of the most influential books of the 20th century.
In The Revenge of Gaia (Penguin), published in August 2006, the 86-year-old Lovelock concluded that "we have unknowingly declared war on Gaia", and that our only hope of rescue lies in a massive deployment of nuclear energy. The book found a wide readership, yet it failed to mobilise humanity to swift action. His nuclear solution instead divided environmentalists, and the bleakness of his vision was difficult to bear. And again his science went against conventional wisdom, for the most widely accepted assessment of future climate change at the time indicated that his bleak outcome was only a remote possibility.
Other, more conventional readings of our climatic future became available in 2006, the most influential of which was Al Gore's An Inconvenient Truth. His computer presentation, which became both a successful movie and a bestselling book, opens with dramatic footage of collapsing ice shelves, melting glaciers and hurricane damage, then goes on to catalogue deleterious changes in ecosystems as diverse as tundra and coral reefs. If Lovelock diagnosed Gaia as having a fever, then Gore laid out the symptoms detail by detail. His examples were drawn primarily from refereed scientific publications in the world's leading journals, backed up with personal anecdotes from many of the scientists involved. My own book The Weather Makers (Penguin) draws on the same body of data, as does the work of the Intergovernmental Panel on Climate Change, and countless other books and articles written at the time.
An Inconvenient Truth was fundamental to the great climatic awakening that occurred late in 2006. I have no doubt that in years to come whole books will be devoted to analysing this shift in global public sentiment, which occurred between mid-August and late September. It is exceedingly rare that a film or book makes such a profound impact, yet An Inconvenient Truth marked the moment when the fossil-fuel industry and its political pawns lost their decades-long grip on public opinion, and perhaps inevitably Gore - who had been Clinton's vice-president and had won the popular vote in the most divisive election in recent US history, only to be denied the presidency by the supreme court - was excoriated in the rightwing press. It was as if the bitter race for the presidency had spilled out into climate science. I was lecturing at universities in middle America in 2007 when Gore and the IPCC were jointly awarded the Nobel peace prize. The naked anger and cynicism - at everything from Gore to peace prizes and Norwegians in general - were frightening.
There are dangers in summarising complex science in a 90-minute presentation. Gore was excoriated for explaining that many glaciers are melting - faster indeed than any climatic model predicts - but failing to mention that a very few are growing. Furthermore, his explanation of the causes of climatic change in the geological past was of necessity simple, as was his narrative of contemporary climate change. Both result from a complex interaction of factors, as is well illustrated by the relationship between global warming and hurricane activity. After An Inconvenient Truth was published, researchers discovered that only around half of the increase in global hurricane activity could be directly attributed to an increase in Earth's average temperature. None of this, in my opinion, detracts from the veracity of Gore's exposition.
Few books about climate change have been written by the meteorologists and atmospheric physicists that dominate the field. One charming exception is Willi Dansgaard's memoir Frozen Annals (Niels Bohr Institute, 2005). Dansgaard's involvement with climate science goes back to 1947, when he was sent to northwestern Greenland by the Danish weather service. Much of his life has been spent on the Greenland ice cap, drilling, retrieving and analysing the ice cores that provide the key to our understanding of past changes in climate. His book is surprisingly funny and tender, and makes obvious how hard-won is our basic knowledge of climate science.
The first attempt at sampling the Greenland ice involved cutting pieces from bergs - an extremely hazardous practice that almost cost Dansgaard his life. While cutting into one, he writes, "with an almighty crash the ice split right between my feet and a 300 tonne block broke off. Fortunately, I fell on to the main part of the chunk, but now it started turning round so I ended up in the water . . . I began swimming around the chunk hoping to find a point of access to the ice. There was none . . . I was not afraid of being so close to drowning, but of deserting Inge and our two kids, and I was furious at having agreed to do the job without proper surveillance." Just "at that moment a true miracle occurred" - the arrival of a "rowboat sent out from Klaushavn".
A critical advance occurred in 1964, when an American-Danish collaboration began at Camp Century, perched high on the Greenland ice cap. The "camp" was a massive series of tunnels gouged in the ice, its facilities powered by a nuclear reactor. Spawned of the cold war, the facility had been envisaged as the first stage of a monstrous instrument of conflict, involving the sequestering of 600 nuclear missiles in 4,000km of tunnels. To support it, a city for 11,000 people was to be built inside the mighty ice cap - one of the most hostile and remote environments on Earth. The military planners, however, had failed to remember that ice flows, which means that tunnels and caverns drilled in it soon become hopelessly distorted.
Camp Century was destined to play a very different role, for it was here that the first deep drilling into the Greenland ice cap occurred. Dansgaard conveys beautifully what it was like to work in such a bizarre environment, along with the wonders revealed when analysing that core - the discovery of evidence for the little ice age, the medieval warm period, and the great ice age that covered northern Europe and North America. Then, at the very bottom - 1.4km down - the researchers found evidence of a distant time when Earth was slightly warmer than it is today. They had, they realised, pierced right through the 100,000 years of a full glacial cycle - an entire ice age - and had come out the other side into a world that existed 130,000 years ago. It was a triumph they hardly dared hope for.
Elucidating the cyclical nature of past changes in climate was the first great achievement of the ice-cap drilling project. One of the more striking cycles they discovered was a rapid warming that occurred every 1,500 years or so throughout the past 100,000 years. These oscillations between warm and cold conditions are now known as Dansgaard-Oeschger events.
A sophisticated understanding of the great climatic cycles has permitted a new approach to the climate problem that finds its closest parallel in the "wiggle matching" used by stock-market analysis. William Ruddiman is a climatic historian whose book Ploughs, Plagues and Petroleum, published by Princeton in 2005, uses this approach to identify evidence of human impact on the climate system, by identifying precisely where we are in the current cycle and comparing the trend with earlier ones. We are, he explains, 12,000 years into a cooling phase which, judging from previous cycles, should continue for tens of thousands of years more. Instead the world is warming. But what is most remarkable about Ruddiman's work is the evidence it provides for an initial disruption to the climate system that occurred long before the industrial revolution - around 8,000 years ago.
It was then, at the dawn of agriculture, that the "wiggle" of the current cycle first departed from earlier patterns - for instead of cooling, Earth's average temperature remained remarkably stable. Ruddiman thinks that this was caused by carbon and methane being released into the atmosphere from early agriculture and the destruction of forests. In his account, human activity and the great cycles struck a delicate balance that allowed the flowering of civilisations. He also sees evidence in the ice cores for the consequences of the Black Death (a drop of around two parts per million of CO2 as forests grew over abandoned fields, absorbing carbon from the atmosphere), as well as other historic events. Aspects of his work remain highly contentious, yet I believe that Ruddiman's realisation that the gaseous composition of Earth's atmosphere is an exquisitely sensitive barometer of changes to life itself represents a great breakthrough.
Now that the majority of politicians, industry leaders and the public are convinced there is a climate problem, the focus is on what to do. The most influential assessments of the problem's scale are doubtless those of the IPCC, whose projections of various outcomes form the basis of global negotiations and national action plans. One of the most influential of these projections concerns the extent to which Earth's surface will warm over the next century. The lower bound is 1.4°C; the upper bound is 5.8°C. This is an extraordinary range of possible impacts - 1.4°C poses some threat, but 5.8°C is widely recognised as sufficient to induce a Lovelockian Ragnarok. The chance of either outcome, according to the IPCC, is small - less than 10%, and so political dialogue has come to concentrate on the mid-range of the projections.
The moment of truth will arrive in December 2009, in Copenhagen, when the world's political leaders will come together to decide the basis of a new global treaty to replace the Kyoto protocol. It's no overstatement to say that the Copenhagen protocol, as it may well come to be known, will play a large role in deciding the fate of humanity. It will come into force in 2012, and if it fails to deliver we'll have to wait until 2020 for a replacement. That will be too late.
A number of recent publications assess the costs versus the benefits of action to combat climate change. Among the most influential, and the most hotly contested, is the Stern review on the economics of climate change, a dense 692-page argument, published last year, the most famous finding of which is that "the benefits of strong and early action far outweigh the economic costs of not acting". Nicholas Stern's argument was challenged almost immediately in Cool It by the Danish statistician Bjørn Lomborg, author of The Skeptical Environmentalist (Cambridge University Press).
Lomborg does not doubt that global warming is occurring, nor that it is caused by humans, but almost alone among commentators he finds reason to welcome it. In Europe, he explains, only 200,000 people die from excess heat each year, while 1.5 million die from cold. His message is simple: more warming, less death. Lomborg's style is marked by glib, misleading associations. Even if the sea rises, Lomborg says, we shouldn't worry - we'll just put up dykes. With dykes, he asserts, some nations might end up with more land than they have today. And so the arguments go on, from rising seas to extreme weather events to malaria and other tropical diseases, the collapse of the Gulf Stream, food shortages and water shortages. In one case after another, Lomborg asserts that it's cheaper and better to do nothing immediate to combat climate change, but to invest in adapting to its consequences. It is in great contrast to Stern's painstaking and detailed analysis, and it entirely fails to dent Stern's case.
In A Question of Balance: Weighing the Options on Global Warming Policies (Yale), the respected economist William Nordhaus asks how to deal most cost-effectively with the climate problem. He accepts the projections of the IPCC as a correct basis on which to undertake his analysis, and sets out to examine five policy options, ranging from "do nothing" through to "ambitious" proposals such as those advocated by Gore and Stern. He concludes that the ambitious proposals are disastrously expensive, and should be avoided. But do the IPCC projections reliably reflect future changes in climate?
In 2007, scientists began comparing real-world trends with the panel's projections. They found that for the key performance indicators - the rate of warming, the rise in sea level and CO2 accumulation - real-world changes were at the upper bound or beyond the worst-case scenario presented by the IPCC. Further evidence that climate change is moving faster than we thought can be found at the north pole. The sea ice that covers the Arctic Ocean has glistened brightly into space for at least 3m years, and by reflecting the sun's energy it acts as a refrigerator that cools the entire planet. But where the ice melts, the dark ocean is revealed, and that captures solar energy and turns it into heat.
In the summer of 2005, the rate of ice loss accelerated dramatically and has remained high ever since, the summer of 2007 seeing the greatest loss of Arctic ice ever. The scientific community is split on how the melting will turn out this year. A recent survey of Arctic specialists indicated that the majority consider a loss as great as that of 2007 to be unlikely, yet by June 2008 signs of a great melt were emerging and a senior adviser to the Norwegian government was warning that this may be the Arctic's first ice-free year. As I write, the rate of loss, while still well above average, has slowed somewhat. Yet even now it's impossible to predict. We can only project that if this summer's melt trajectory follows recent decades, by September this year the Arctic ice cap will have lost around half of its remaining ice, and be just 2.2m square kilometres.
Most of those interested in climate science nowadays access information online, and one of the most significant of such contributions was recently posted by James Hansen, director of Nasa's Goddard Institute, and his colleagues, who have provided a partial explanation for these changes. They revisited a key piece of science underpinning the IPCC's work - the findings about how much warming a given amount of atmospheric CO2 pollution would produce - and discovered that, when viewed over the longer term, Earth's climate system is about twice as sensitive to CO2 pollution as is illustrated in the panel's century-long projections. One conclusion they drew is that there is already enough greenhouse gas pollution in the atmosphere to cause 2°C of warming - bringing about conditions not seen on Earth for 2m to 3m years, and constituting, according to the authors, "a degree of warming that would surely yield 'dangerous' climate impacts".
Hansen and his colleagues pointed to a new understanding of how long it takes for the full warming consequences of a given amount of greenhouse gas to be felt. They concluded that we could expect to feel a third of any warming in the first few years. As Hansen and his colleagues put it: "Sea-level changes of several metres per century occur in the palaeoclimate record, in response to forcings slower and weaker than the present human-made forcing. This indicates that the ice may disintegrate and melt faster than previously assumed, and that the warming may be delayed less by the ice than assumed."
They also make a useful discrimination between climatic "tipping points" and "the point of no return". A tipping point is that at which the greenhouse gas concentration reaches a level sufficient to cause catastrophic climate change, while a point of no return is reached when that concentration of greenhouse gas has been in place sufficiently long to begin an irreversible process. Humanity is currently suspended between a tipping point and a point of no return, and the point of no return is likely to be reached within two decades.
In summarising their findings, the researchers state that "if humanity wishes to preserve a planet similar to that on which civilisation developed and to which life on Earth is adapted, palaeoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385ppm to at most 350ppm". This, they believe, can only be achieved by phasing out all conventional coal burning by 2030, and by aggressively reducing the amount of CO2 in the atmosphere by capturing it in growing tropical forests and in agricultural soils. That a rapid phase-out of coal is simply not enough is elegantly illustrated by the fact that the concentration of CO2 in the atmosphere would remain above 350ppm for 200 years were a coal phase-out achieved within the next decade or two, and nothing else done.
In his analysis, Nordhaus does identify one economically effective strategy worth pursuing. Called the "low-cost backstop", it revolves around identifying and developing some as yet unknown technology to combat the problem. Possible candidates include "low-cost solar power, geothermal energy, some non-intrusive climatic engineering or genetically engineered carbon-eating trees".
Writing in the New York Review of Books, Freeman Dyson has explored the unappealing option of such trees. The graph that first alerted humanity to the climate problem - drawn up by Charles David Keeling to show the CO2 increase from 1956 to the present - might, Dyson argues, hold the key to the solution. The graph has a generally rising line, with jags, like saw teeth, along it, which indicate a spike in CO2 each autumn in the northern hemisphere and a dip each spring. The difference between the minimum and maximum each year is around six parts per million, and it is due to the growth, then leaf fall, of the forests that grow across North America, Europe and Asia. It turns out, Dyson says, "that about 8% of the carbon dioxide in the atmosphere is absorbed by vegetation and returned to the atmosphere every year".
If only a way could be found, he muses, to permanently sequester that carbon, we would go a long way towards solving the climate crisis - hence the genetically modified trees. But the truth is that all trees are carbon eaters. They grow from the air by drawing CO2 into their leaves, and there solidifying it to build their wood, bark and leaf tissues. Trees are congealed CO2. What we need is a way of transforming the carbon they capture into an inert state. It turns out that humanity has had the capacity to do this for thousands of years, and is now on the brink of doing it on a very large scale.
The process of charcoal-making is called pyrolysis, and involves the heating of any biological matter in the absence of oxygen. The result is the generation of a synthetic gas, or a crude-oil like material, and charcoal. If the gas or oily matter is captured, it can be used to generate electricity or power transport. The charcoal is largely carbon (representing one-third to half of the carbon in the biomass) and it is inert. Indeed, the tenacity with which charcoal resists rotting, even when buried in the soil, is clear from C14-dating, which uses ancient charcoal from hearths or fires as much as 60,000 years old.
Modern pyrolysis involves machinery that captures flue gas or oil, and needs no external inputs to run the machine (some of the gas being used to heat the biomass). It's already being used on a small scale on farms, for urban garbage disposal (where 1,000-tonne units are deployed) and in forestry. On farms it has multiple benefits, for the charcoal can be ploughed back into the soil, where it balances acid soils, aids soil moisture retention, adds nutrients and acts as a habitat for soil fungi and bacteria. A farmer pyrolysing crop waste gains four benefits: 1) as usual, he gets to sell the commercial part of his crop; 2) he gets to generate electricity or transport fuel; 3) where carbon is traded, he can potentially sell the carbon he sequesters; and 4) by adding charcoal to his soil, he will increase the chances of getting a better crop the following year.
With so many benefits, why is pyrolysis not more widely used? Because pyrolysis machines are expensive, and farms are mostly still family businesses. If farmers are ever to be able to afford the machines, they'll need to be paid around $37 per tonne for the carbon they create. They'll also need to be living in areas with carbon trading schemes that allow charcoal as a recognised method of carbon sequestration.
While the developed world could go it alone with pyrolysis, unless China and India can be induced to take a lower carbon path than the west, there is absolutely no hope for us. While both maintain formidably tough international negotiating positions, there are signs of change, particularly in the energy sectors of both countries. China has a target for renewable energy of 10% by 2020, and is embarking on the largest nuclear power programme currently being developed, while India is pursuing wind and hydro power.
Were the leaders of either country seeking a guide to determining a negotiating position in Copenhagen, they could do no better than Oliver Tickell's just-published book Kyoto2 (Zed Books), which provides a big-picture approach to the prevention of climatic catastrophe. In essence, Tickell provides a blueprint for a global climate treaty. He documents the failings of the Kyoto protocol, then goes on to summarise the latest climate science, including the work of Hansen and his colleagues. The replacement to the Kyoto protocol, Tickell writes, must work effectively to achieve a level of atmospheric CO2 below 350ppm. At the heart of the proposal is a global trade in carbon with a series of reducing caps sufficiently rigorous to bring about such an outcome.
One of Tickell's most telling criticisms of Kyoto is its neglect of tropical forests as a means of sequestering carbon. The destruction of rainforests causes around 18% of the carbon going into the atmosphere annually, yet only a single project concerning tropical forests has been approved under Kyoto's clean development mechanisms. These allow for polluters to gain credits by investing in a variety of ways that reduce greenhouse gases. Dyson's analysis of the Keeling curve demonstrates just how powerful forests can be as sequesterers of carbon. It's widely acknowledged that Kyoto's successor must develop mechanisms that encourage the protection and regrowing of tropical forests.
Tickell's discussion of market mechanisms is densely technical, yet much of it reads as common sense. His emphasis on the urgent need for government regulation is also cogent and refreshing, for he recognises that carbon trading is necessary, but not sufficient to solve the problem. He calls clearly for governments to regulate so as to increase efficiency of energy use, to protect forests and to mandate approaches such as clean coal technologies, as well as discussing the need to limit population. Reading Kyoto2 gives one hope that there is a way forward. But will such recommendations ever be agreed to, and can they be carried out in time?
The books to read
George MonbiotGeorge Marshall, author of Carbon Detox (Gaia Books), understands the psychology of climate change and our inability to get to grips with it better than anyone else I have read. Mark Lynas's Six Degrees: Our Future on a Hotter Planet (Fourth Estate) is a lucid and deeply researched account of the predicted impacts of climate change, one degree at a time. In Kyoto2: How to Manage the Global Greenhouse (Zed Books) Oliver Tickell presents a global programme for cutting greenhouse gas emissions that is both radical and realistic.
Caroline LucasSeeing Green by Jonathon Porritt (currently out of print) changed my life. After reading it, I marched straight to the office of my local Green party to sign up. George Marshall's Carbon Detox is an upbeat and inspiring guide to lowering your carbon footprint. The Flood (Saqi Books), Maggie Gee's dystopian vision of a flooded future, with its well-drawn characters and lively prose, shows how the poor will always be the first to suffer the effects of climate change.
Mark LynasIn Kyoto2, Oliver Tickell makes a radical suggestion: that instead of trying to regulate emissions of carbon dioxide, we should instead go "upstream" and regulate the production of carbon-based fossil fuels. Think of a garden sprinkler: if you want to stop the lawn getting wet, you don't try to catch each drop as it falls - you turn off the tap.
The World Without Us (Virgin Books) by Alan Weisman contains a disarmingly simple but wonderfully clever idea: what would the planet look like if we all disappeared overnight? The perfect springboard for a much more engaging and fascinating discussion of humanity's environmental impact.
Fred PearceRachel Carson's Silent Spring (Penguin Modern Classics), published in 1962, was environmentalism's tipping point. Before Silent Spring, we worried about saving wildlife; afterwards we feared our own species would drown in a toxic tide of chemicals. In 1979 came Gaia: A New Look at Life on Earth (OUP) by James Lovelock. Not since Charles Darwin's Origin of Species has any book so shaken science's sense of how our world works. John Reader's Man on Earth (published in 1988 and currently out of print) is an overlooked masterpiece about the ecology of human cultures.
Leo HickmanRobert Henson's Rough Guide to Climate Change (Rough Guides) is the best pocketbook primer on the subject. On its publication in late 2006, it was sent to every MP with a short questionnaire, including the question "How important a concern is climate change?" Hundreds answered, the majority of whom said it was the most pressing issue of our age. Gordon Brown never responded.
Hide Tide by Mark Lynas (Picador) is a journey through the climate change "hot spots" of the world. It's the testimonies of the people Lynas meets who are already suffering from the onset of climate change that produce the most persuasive argument for us to urgently face up to the challenge ahead.
Laurie DavidEarth in the Balance (Longman), written by Al Gore 15 years ago, is doubly fascinating to read now. It makes you realise how much he was right. I devoted myself to the issue of climate change after reading Ross Gelbspan's Boiling Point (Basic Books). If you look at Keith Bradsher's High & Mighty (PublicAffairs US), you will never walk past an SUV again without shaking your head.
What Al Gore is to awareness of global warming, William McDonough is to the solution. His Cradle to Cradle: Remaking the Way We Make Things (Rodale Press) is the only book about the environment that is actually waterproof. Also read anything by Gus Speth or Bill McKibben.
