EcoRadio

Category: Climate chaos

The atmosphere is to the earth as a layer of varnish is to a desktop globe. It is thin, fragile and essential for preserving the items on the surface.150 years of burning fossil fuel have overloaded the atmosphere to the point where the earth is ill. It now has a fever. Read the detailed article, Soothing Gaia’s Fever for an evocative account of that analogy. The items listed here detail progress on coordinating 6.5 billion people in the most critical project undertaken by humanity. 

  • ‘Flawed’ emissions trading scheme needs big changes: Andrew Robb.

    ‘Flawed’ emissions trading scheme needs big changes: Andrew Robb

     

    Christian Kerr | April 30, 2009

    Article from:  The Australian

    THE Coalition today ruled out supporting the emissions trading scheme in its current form, calling for the Government to analyse the “flawed” plan’s effect on jobs and to consider alternatives.

    But the Opposition’s emissions trading spokesman Andrew Robb left the door open to allowing the ETS to pass through the Senate.

    “No one is saying it’s all or nothing,” Mr Robb said, releasing a Coalition-commissioned analysis of the Government’s Carbon Pollution Reduction Scheme.

    “What we are saying go right back and do the work, fix up the flaws, do not put in jeopardy tens of thousands of Australian jobs, especially at a time when we’ve got the biggest financial crisis in 80 years,” he said.

    The analysis, prepared by David Pearce from the Centre for International Economics, warns that the Government has failed to adequately assess the level of environmental benefits the CPRS will achieve for its cost, its ability to deal with uncertainty and whether it explicitly accounts for international developments.

    Parliamentary Secretary for Climate Change Greg Combet effectively conceded yesterday that the Government will have to deal with the Coalition to pass the CPRS.

    He said the Greens had “made themselves irrelevant” with demands that amounted to “lunacy”.

    Mr Robb said the CIE report “clearly establishes that the design of the Government’s proposed emissions trading scheme needs to be reconsidered and compared empirically with alternatives.

    “For the Government to have ignored the impact of the global financial crisis beggars belief,” he said.

    “The costs over the next 20 years of lost competitiveness and lost jobs must be established, along with the likely impact, or not, on CO2 emissions.”

    Mr Robb accused the Government of “flying blind” on both the risk to jobs and emissions reductions.

    “The Rudd Government has no idea of how many jobs its scheme will destroy, how it affects different industries or regions, or even whether it is the most cost-effective option for Australia to reduce CO2 emissions.

    “Constructive alternatives to the Government’s flawed scheme are necessary. As well as reviewing the carbon pricing mechanism, energy efficiencies in the commercial building sector, carbon capture in soil and other means, and the efforts of individuals, must be part of an effective scheme.”

    Mr Robb said the Government’s CPRS will destroy jobs.

    “What the Pearce report confirms is that the Government has done no analysis, no analysis of what will be the transitional affects on businesses of their scheme,” he said.

    “The only work out there at the moment about what will happen to jobs is the work that has been commissioned by all of these companies who are very fearful about the circumstance and their future and about future investment and the viability of their businesses.”

    The report recommends that the Government ask the Productivity Commission to carry out this research.

    The Opposition seems no closer to a policy position on emissions trading despite the release of the report.

    “The Coalition will finalise its policy response once we’ve seen the results of the current Senate inquiries and following analysis of this report,” Mr Robb said.

    Opposition Leader Malcolm Turnbull’s office was unable to say if he would be commenting publicly on the Pearce report today.

    Coalition sources have suggested that Mr Turnbull will face major challenges in finding a policy path Liberals and Nationals will follow.

    Divisions over emissions trading and climate change policy dealt the final blow to the leadership of his predecessor, Brendan Nelson.

  • Malcolm Turnbull sets new ETS plan that gears for the recovery

    Malcolm Turnbull sets new ETS plan that gears for the recovery

    Lenore Taylor, National correspondent | April 30, 2009

    Article from:  The Australian

    MALCOLM Turnbull will use an independent economic report on the Rudd Government’s emissions trading scheme to demand major changes including a better deal for big polluters and tougher emissions-reduction targets as his price for considering support.

    The economic report’s release today comes as the Government concedes the Liberals are their only hope of getting the scheme through the Senate, and labels the Greens “irrelevant”.

    The squaring-off of the major parties before parliament to decide the fate of the Carbon Pollution Reduction Scheme next month comes as the Business Council of Australia appeals for bipartisanship in the interests of investment certainty, suggesting the financial impost of the new carbon cost should be deferred until the economy returns to growth.

    Opposition emissions trading spokesman Andrew Robb will today release a report from the Centre for International Economics that finds the scheme as proposed “threatens the balance sheets of key industries”.

    The report says the scheme does not quantify the economic cost in the short and medium term as the economy makes huge adjustments, and does not take advantage of potentially inexpensive ways to reduce emissions, for example through the use of more energy-efficient buildings.

    “Kevin Rudd said he would bring in a scheme that would deliver deep cuts and not disadvantage our export industries. Good. He should do it. And we’ll support it. But this report shows the scheme on the table fails on both counts,” Mr Robb said yesterday.

    Parliamentary Secretary for Climate Change Greg Combet effectively conceded yesterday that the Government would have to deal with the Coalition to get its scheme through the Senate, saying the Greens had “made themselves irrelevant” by arguing for an unconditional 40 per cent cut in emissions, which without an international agreement, would be economic “lunacy”, and opposing transitional assistance for emissions-intensive, trade-exposed industries.

    Mr Combet accused the Liberals of “extraordinary economic recklessness” by refusing to state a clear policy on reducing emissions pollution.

    “Failing to articulate what their policy is only encourages uncertainty as to their position and possible future carbon prices. I believe this is demonstrating extraordinary economic recklessness in the name of politics,” Mr Combet said. “The Liberal Party needs to tell Australia exactly how much they propose to reduce Australia’s emissions by, how they will deliver these reductions and how much it will cost. To keep putting off such announcements only encourages uncertainty for business and investors.”

    The CIE report supports some aspects of the growing list of Coalition demands, which it believes could protect export industries and deliver a tougher emissions-reduction target than that proposed by the Government by finding new emissions savings in better land and soil management and building efficiency.

    In a speech earlier this year, the Opposition Leader claimed he could find emissions reductions amounting to a 27 per cent cut on 2000 levels by 2020, compared with Labor’s proposal of cuts of between 5 and 15 per cent.

    Mr Robb is now saying the Coalition’s alternative ideas could generate cuts at least as deep as Labor’s.

    Demands being discussed within the Coalition include increasing the compensation for trade-exposed industries to 100 per cent free permits; allowing some flexibility in the nation’s proposed 2020 target, both up and down; delaying the Government’s proposed 2010 start date; and introducing building efficiency and land and soil management regulation to gain extra cuts in emissions that could be added to the Government’s carbon pollution reduction scheme target.

    It is also looking at mechanisms by which greater than expected emission reductions by individuals could be reflected in a more ambitious national target. And it will require a solution for the coal industry, which for technical reasons was left out of the Government’s main compensation scheme.

    Sources said the Coalition had yet to reach a final decision about whether to propose the sweeping amendments, which could prove attractive to business and possibly to some conservationists, or to declare the Government’s bill fatally flawed.

    Mr Turnbull could struggle to unite his party behind proposed amendments. The Liberal and Nationals members of a Senate committee looking at the scheme recently found the Government should “go back to the drawing board” and come back to the Senate next year with a different plan. But the Business Council of Australia, which has continued to support an amended carbon pollution reduction scheme despite public criticism of it from many of its members, appealed to the two major parties to reach a compromise in the interests of business and investment certainty.

    “Business needs a bipartisan approach,” a BCA spokeswoman said. “We need the Government and the Opposition to work together. We need the industry assistance measures to address the competitiveness concerns. We need the bill fixed and passed but we need the implementation to be calibrated to reflect the costs to the economy

  • A climate of doubt

    April 23, 2009, 11:22 pm

    A Climate of Doubt

    By Andrew C. Revkin

    climate documents

    [UPDATE, 2 p.m.: I’ve added a fresh post with comments from two members of the climate coalition’s advisory committee.]

    Documents have surfaced that offer a glimpse behind the public face of industries that, in the mid-1990s, were fighting hard to slow movement toward mandatory restrictions on greenhouse gases. You can read some of the material online. My article in The Times has more detail on how the documents illustrate the difference between the public stance of the Global Climate Coalition — the main industry voice on climate then — and what its own scientific advisers were saying.

    At the time, the target was the international climate agreement that, in December 1997, became known as the Kyoto Protocol. While the United States signed the agreement, it was clear from a forceful Senate vote months earlier — a 95-to-0 preemptive rejection of any treaty that would harm the economy or be unfair — that President Clinton or any successor would have a very tough time getting the approval from Congress necessary for ratification.

    There’s no way to gauge whether the industry-financed campaign of lobbying, public relations and advertising helped build that Senate blockade to ratification. But environmental campaigners say it’s clear that a little uncertainty goes a long way toward sustaining public inertia on an issue with the time scale and complexity of human-driven climate change.

    “Their objective was always to slow things down,” said Kert Davies, a climate campaigner at Greenpeace. “Their argument was essentially the inverse of the precautionary principle: We shouldn’t do anything until we know everything.”

    William O’Keefe, who was chairman of the Global Climate Coalition and a senior official at the American Petroleum Institute when the documents were produced, rejects such assertions. “The idea that there is some great industrial conspiracy to thwart progress is one of the greatest myths,” he told me. “Industry is rarely united on anything, and on this issue it’s totally not united.”

    The most important document is the final draft of a status report on climate science written by the science and technology advisory committee to the climate coalition late in 1995. It raised a host of questions about the scientific orthodoxy at the time, as reflected in the 1995 report from the United Nations Intergovernmental Panel on Climate Change. But it was similarly critical of what it called “contrarian” arguments against the idea that human-generated gases could substantially warm the world.

    That section was excised and the document itself never was publicly released. Have a look and see what catches your eye.

  • Climate countdown: Half a trillion tonnes of carbor left to burn

    Climate countdown: Half a trillion tonnes of carbon left to burn

    To avoid dangerous climate change of 2C, the world can only burn another half a trillion tonnes of carbon, climate change experts warn

    Didcot power plant

    Didcot coal-fired power station. Photo: Charles O’Rear/Corbis

    The world has already burned half the fossil fuels necessary to bring about a catastrophic 2C rise in average global temperature, scientists revealed today.

    The experts say about half a trillion tonnes of carbon have been consumed since the industrial revolution. To prevent a 2C rise, they say, the total burnt must be kept to below a trillion tonnes. On current rates, that figure will be reached in 40 years.

    Myles Allen, a climate expert at Oxford University who led the new study, said: “Mother Nature doesn’t care about dates. To avoid dangerous climate change we will have to limit the total amount of carbon we inject into the atmosphere, not just the emission rate in any given year.”

    The scientists say their research could simplify political attempts to tackle global warming, which encompass a range of targets and timetables. Such proposals usually set future limits on the amount of carbon dioxide allowed to build up in the atmosphere, such as 450 parts per million (ppm), or as future emission rates, such as the UK’s pledge to slash emissions 80% by 2050.

    The new study effectively re-frames such targets as an available budget – to avoid dangerous climate change of 2C the world can only burn another half a trillion tonnes of carbon.

    Writing in today’s Nature, Allen and colleagues say a trillion tonnes of carbon burnt would be likely to produce a warming of between 1.6C and 2.6C, with a “most likely” 2C rise.

    Chris Huntingford of the NERC Centre for Ecology and Hydrology said: “Research often reveals new complexities, but this analysis could actually simplify matters for policy makers. The relationship between total emissions and future warming can be inferred largely from quantities we can observe, and is remarkably insensitive to the timing of future emissions.”

    The key implication of the research, the scientists say, is that access to fossil fuels must somehow be rationed and eventually turned off, if the 2C target is to be met. “If country A burns it then country B can’t,” said Bill Hare, a climate expert with the Potsdam Institute in Germany. “It’s like a draining tank.”

    The research also highlights that continued high rates of fossil fuel use in the next decade will demand extraordinary cuts in emissions in future decades to hit the 2C target. Allen said: “If you use too much [carbon] this year, it doesn’t mean the planet will come to an end. It means you have to work even harder the next year.”

    A separate study, also published today in Nature, led by Malte Meinshausen at the Potsdam Institute, use a similar approach and sets a different carbon budget. They say the world can only emit 190bn tonnes of carbon between now and 2050 if it aims for a 2C rise. Emissions over 310bn tonnes in that time lead to a 50% chance of going over 2C.

    The new research does not say anything about the likelihood of reaching the 2C target. They simply change the way progress towards the target is measured.

    In an accompanying commentary article, the scientists behind both studies say: “These results are not incompatible with current proposals for near-term emission targets — the small size of the cumulative emission budgets to 2050 reinforces the need for global CO2 emissions to peak around or before 2020 so that emission pathways remain technologically and economically feasible.”

    They add: “Having taken 250 years to burn the first half trillion tonnes of carbon we look set, on current trends, to burn the next half trillion in less than 40. No one could credibly suggest that we should carry on with business as usual to the 2040s and then somehow suddenly stop using fossil fuels, switch to 100% carbon capture or just shut down the world economy overnight.”

  • Green energy a better bet

    Green energy a better bet

    Bjorn Lomborg | April 30, 2009

    Article from:  The Australian

    THE financial crisis has given many Australians reason to question the merits and timing of launching an emissions trading scheme to control carbon emissions. The debate is healthy, and hopefully will lead to a broader discussion about smarter ways to respond to this threat.

    The Australian Government is to be commended for recognising the threat of climate change. Natural science has undeniably shown us that global warming is man-made and real. But just as undeniable is the economic science, which makes

    it clear that a narrow focus on reducing carbon emissions could leave future generations lumbered with major costs, without major cuts in temperatures.

    At first glance, an ETS seems like a neat market solution to global warming. In fact, it is worse than a straightforward carbon tax, where the costs are obvious.

    With an ETS, the costs – to jobs, household consumption and economic growth – are hidden, and easily lead to lobbying, special favours and heavy rent-seeking.

    But there is a bigger problem with both a carbon tax and a cap-and-trade system: they are ineffective, expensive ways to cut temperatures.

    Countries that ratified the Kyoto Protocol – including, of course belatedly, Australia – promised to make significant reductions to their carbon emissions. A lot of nations are struggling to absorb the hit to economic growth that carbon cuts require, so many of these promises will not be fulfilled.

    But even if every country lived up to its Kyoto agreement vows for every year until 2099 – costing the world $250 billion in lost growth every year – temperature rises would only be cut by a tiny 0.2 degrees Celsius.

    It seems logical to think, then, that countries such as Australia should advocate even bigger carbon cuts. But this means even more financial pain, without an equivalent increase in benefits. Even if the European Union were successful in its radical plan to slash emissions by 20 per cent below 1990 levels within 12 years, global temperatures would only be one-sixtieth of one degree Celsius lower by 2100, at a cost of $10 trillion.

    When we calculate the environmental and human benefits from this minuscule reduction in temperature rises, we discover that all of Europe’s efforts would only achieve four cents worth of benefits for every dollar spent.

    The goal of carbon emission mitigation is to make burning carbon so expensive that everyone switches to green energy sources. But this will not happen any time soon.

    Low-carbon energy sources such as wind and solar power remain extremely expensive and uncompetitive. To produce the same amount of electricity, solar panels are four times more expensive than building a natural gas plant, and three times more expensive than a nuclear plant. Wind power is more than 50 per cent more expensive than electricity generated by coal.

    Rather than attempting the politically impossible by making fossil fuels so expensive that nobody will use them, we should try to make green energy so cheap everyone will use it.

    The typical cost of cutting a ton of CO2 is now about $29, but the damage that a ton of carbon causes in the atmosphere is about $10. Spending $29 to achieve $10 worth of “good’ makes no sense.

    It is clear that we need to reduce by roughly tenfold the cost of cutting emissions. That will not be achieved on the world’s present path: spending on research and development of alternative energy sources has declined since the Kyoto Protocol was signed.

    Instead of continuing with the politically challenging, financially expensive and economically flawed approach of an ETS, Australia should focus on boosting investment into research and development of green energy.

    Economists who have calculated the long-term benefits for humans and the planet from reducing global warming – such as fewer heat deaths and less flooding – show that every dollar invested in making low-carbon energy cheaper will do $16 worth of “good”. Spending a dollar to do $16 worth of good makes a lot of sense.

    The Australian Government plans to participate in discussions in Copenhagen this December to replace the Kyoto Protocol. Those discussions will be complicated and charged, with developing nations such as China and India – who were not responsible for the emissions that will hurt the planet – seeking to be paid off in return for the major blow to development that carbon cuts would necessitate.

    This could so easily be avoided and a more effective response to climate change embraced.

    Instead of promising even bigger carbon cuts than Kyoto, leaders could instead call for every country to spend 0.05 per cent of its gross domestic product on low-carbon energy research and development.

    That would increase the amount of such spending tenfold, yet the total cost would be only one-tenth of the cost of Kyoto.

    For Australia, it would mean an annual outlay of $540 million a year, considerably cheaper than many estimates of the industry damage that the ETS would cause.

    Kyoto-style emissions cuts can only ever be an expensive distraction from the real business of weaning ourselves off fossil fuels. Until green energy sources become genuinely competitive, carbon will continue its stranglehold on every economy on Earth.

    Carbon cuts have become the only answer to global warming that is discussed. There has been a convergence of interests between businesses that stand to make a fortune from an ETS and some environmental campaigners who see carbon cuts as virtuous, while both neglect the commonsense contribution from the field of economic science.

    Fears about climate change are understandable. But fear alone is a poor basis upon which to build sound decisions.

    We should take lessons from both natural science and economic science, and ensure that we choose the most effective and realistic response to this global threat.

    Bjorn Lomborg is the director of the Denmark-based think tank the Copenhagen Consensus Centre, author of The Skeptical Environmentalist and Cool It: The Skeptical Environmentalist’s Guide to Global Warming, and an adjunct professor at Copenhagen Business School.

  • Arctic meltdown is a threat to humanity

    Arctic meltdown is a threat to humanity

    I AM shocked, truly shocked,” says Katey Walter, an ecologist at the University of Alaska in Fairbanks. “I was in Siberia a few weeks ago, and I am now just back in from the field in Alaska. The permafrost is melting fast all over the Arctic, lakes are forming everywhere and methane is bubbling up out of them.”
    The permafrost is melting fast all over the Arctic, lakes are forming everywhere and methane is bubbling out of them
    Back in 2006, in a paper in Nature, Walter warned that as the permafrost in Siberia melted, growing methane emissions could accelerate climate change. But even she was not expecting such a rapid change. “Lakes in Siberia are five times bigger than when I measured them in 2006. It’s unprecedented. This is a global event now, and the inertia for more permafrost melt is increasing.”
    No summer ice
    The dramatic changes in the Arctic Ocean have often been in the news in the past two years. There has been a huge increase in the amount of sea ice melting each summer, and some are now predicting that as early as 2030 there will be no summer ice in the Arctic at all.
    Discussions about the consequences of the vanishing ice usually focus either on the opening up of new frontiers for shipping and mineral exploitation, or on the plight of polar bears, which rely on sea ice for hunting. The bigger picture has got much less attention: a warmer Arctic will change the entire planet, and some of the potential consequences are nothing short of catastrophic.
    Changes in ocean currents, for instance, could disrupt the Asian monsoon, and nearly two billion people rely on those rains to grow their food. As if that wasn’t bad enough, it is also possible that positive feedback from the release of methane from melting permafrost could lead to runaway warming.
    Runaway warming
    The danger is that if too much methane is released, the world will get hotter no matter how drastically we slash our greenhouse gas emissions. Recent studies suggest that emissions from melting permafrost could be far greater than once thought. And, although it is too early to be sure, some suspect this scenario is already starting to unfold: after remaining static for the past decade, methane levels have begun to rise again, and the source could be Arctic permafrost.
    What is certain is that the Arctic is warming faster than any other place on Earth. While the average global temperature has risen by less than 1 °C over the past three decades, there has been warming over much of the Arctic Ocean of around 3 °C. In some areas where the ice has been lost, temperatures have risen by 5 °C.
    This intense warming is not confined to the Arctic Ocean. It extends south, deep into the land masses of Siberia, Alaska, Canada, Greenland and Scandinavia, and to their snowfields, ice sheets and permafrost. In 2007, the North American Arctic was more than 2 °C warmer than the average for 1951 to 1980, and parts of Siberia over 3 °C warmer. In 2008, most of Siberia was 2 °C warmer than average (see map).
    Positive feedbacks
    Most of this is the result of positive feedbacks (see illustration) from lost ocean ice, says David Lawrence of the National Center for Atmospheric Research in Boulder, Colorado. His modelling studies show that during periods of rapid sea-ice loss, warming extends some 1500 kilometres inland from the ice itself. “If sea-ice continues to contract rapidly over the next several years, Arctic land warming and permafrost thaw are likely to accelerate,” he says.
    Changes in wind patterns may accelerate the warming even further. “Loss of summer sea ice means more heat is absorbed in the ocean, which is given back to the atmosphere in early winter, which changes the wind patterns, which favours additional sea ice loss,” says James Overland, an oceanographer at the Pacific Marine Environmental Laboratory in Seattle. “The potential big deal is that we now may be having a positive feedback between atmospheric wind patterns and continued loss of sea ice.”
    Incidentally, the changing winds might also be to blame for some of the cold and snowy weather in North America and China in recent winters, Overland says. Unusual poleward flows of warm air over Siberia have displaced cold air southwards on either side.
    Going global
    The rapid warming in the Arctic means that a global temperature rise of 3 °C, likely this century, could translate into a 10 °C warming in the far north. Permafrost hundreds of metres deep will be at risk of thawing out.
    This is where things go global. The Arctic is not just a reflective mirror that is cracking up. It is also a massive store of carbon and methane, locked into the frozen soils and buried in icy structures beneath the ocean bed.
    A quarter of the land surface of the northern hemisphere contains permafrost, permanently frozen soil, water and rock. In places, deep permafrost that formed during the last ice age, when the sea level was much lower, extends far out under the ocean, beneath the seabed. Large areas of permafrost are already starting to melt, resulting in rapid erosion, buckled highways and pipelines, collapsing buildings and “drunken” forests.
    Locked away
    The real worry, though, is that permafrost contains organic carbon in the form of long-dead plants and animals. Some of it, including the odd mammoth, has remained frozen for tens of thousands of years. When the permafrost melts, much of this carbon is likely to be released into the atmosphere.
    No one knows for sure how much carbon is locked away in permafrost, but it seems there is much more than we thought. An international study headed by Edward Schuur of the University of Florida last year doubled previous estimates of the carbon content of permafrost to about 1600 billion tonnes – roughly a third of all the carbon in the world’s soils and twice as much as is in the atmosphere.
    Time bomb
    Schuur estimates that 100 billion tonnes of this carbon could be released by thawing this century, based on standard scenarios. If that all emerged in the form of methane, it would have a warming effect equivalent to 270 years of carbon dioxide emissions at current levels. “It’s a kind of slow-motion time bomb,” he says.
    One hotspot is the 40,000-year-old east Siberian permafrost region. It alone contains 500 billion tonnes of carbon, says Philippe Ciais, co-chair of the Global Carbon Project, a research network analysing the carbon cycle. East Siberia was at times 7 °C warmer than normal during the summer of 2007, he says.
    Higher temperatures mean the seasonal melting of the upper layer of soil extends down deeper than normal, melting the permafrost below. Microbes can then break down any organic matter in the thawing layer, not only releasing carbon but also generating heat that leads to even deeper melting. The heat produced by decomposition is yet another positive feedback that will accelerate melting, Ciais says.
    Potent greenhouse gas
    What’s more, if summer melting depth exceeds the winter refreezing level then a layer of permanently unfrozen soil known as a talik forms, sandwiched between the permafrost below and the winter-freezing surface layer. “A talik allows heat to build more quickly in the soil, hastening the long-term thaw of permafrost,” says Lawrence.
    The carbon in melting permafrost can enter the atmosphere either as carbon dioxide or methane, which is a far more potent greenhouse gas, molecule-for-molecule. If organic matter decomposes in the low-oxygen conditions typical of the boggy soils and lakes in these regions, more methane forms.
    Researchers have been monitoring the Stordalen mire in northern Sweden for decades. The permafrost there is melting fast and, as conditions become wetter, it is releasing ever more methane into the air, says Torben Christensen of Lund University in Sweden. This is the future for most of the northern hemisphere’s permafrost, he says.
    Disturbing picture
    It’s not just existing boggy patches that are the problem. In low-lying areas, the loss of volume as ice-rich permafrost melts leads to the collapse of the ground and the formation of thermokarst lakes from the meltwater. Satellite surveys show the number and area of these lakes is increasing and, as the work by Walter and others shows, they could be a major source of methane.
    Put together, the latest research paints a disturbing picture. Since existing models do not include feedback effects such as the heat generated by decomposition, the permafrost could melt far faster than generally thought. “Instead of disappearing in 500 years, the deepest permafrost could disappear in 100 years,” Ciais says.
    The permafrost is not the only source of methane in the Arctic. Shallow ocean sediments can be rich in methane hydrates, a form of ice containing trapped methane. Particularly worrying are the huge amounts of methane hydrate thought to lie beneath the Arctic Ocean. Because the waters here are so cold, methane hydrates can be found closer to the surface than in most other parts of the world. These shallow deposits are far more vulnerable to the warming of surface waters.
    Blowouts
    Juergen Mienert at the University of Tromso in Norway, who has analysed past eruptions of methane hydrates from the Arctic, says current conditions are disturbingly similar to those in the past when warming waters penetrated sediments, triggering the release of hydrates. “Global warming will cause more blowouts, more releases,” he says.
    While shrinking sea ice in 2007 may have attracted all the headlines, some researchers say what is really scaring them is a simultaneous jump in methane levels. While the level of methane in the atmosphere has more than doubled since pre-industrial times, for the past decade or so there has been little change.
    Then, in 2007, several million tonnes of extra methane mysteriously entered the atmosphere. Detailed analysis from methane monitors around the world suggests that much of it came from the far north. Ciais says it looks like the biggest source was Siberian permafrost.
    Unstoppable
    This is still contentious. Matt Rigby of the Center for Global Change Science at the Massachusetts Institute of Technology, who has analysed the methane surge, says we cannot yet say whether emissions from melting permafrost contributed most to the rise. “But 2007 was unusually warm in Siberia, and we would expect emissions increases when temperature rises,” he adds.
    The rise could just be a blip – or the start of something big. “Once this process starts, it could soon become unstoppable,” Ciais says.
    Walter agrees. Right now, she estimates, only a few tens of millions of tonnes of methane are being emitted. “But there are tens of billions of tonnes potentially available for release.” And the faster the warming, the faster the emissions will rise.
    Out of control
    Most worrying of all is the risk of a runaway greenhouse effect. The carbon stored in the far north has the potential to raise global temperatures by 10 °C or more. If global warming leads to the release of more greenhouse gases, these releases will cause yet more warming and still more carbon will escape to the atmosphere. Eventually the feedback process would continue even if we cut our greenhouse emissions to zero. At that point climate change would be out of control.
    There is another concern about Arctic melting: the growing amount of fresh water flowing into the Arctic Ocean. The shrinking thickness and extent of sea ice has added a huge amount of fresh water already. Meanwhile, rivers are pouring up to 10 per cent more water into the ocean than they did half a century ago. This is partly the result of rising precipitation as the air warms – warmer air can hold more moisture – and partly the result of melting permafrost, ice and snow. Yet more fresh water is coming from the melting of the Greenland ice sheet. As the Arctic warms further, these flows of fresh water will increase.
    All this extra fresh water could weaken the pump that drives the thermohaline circulation, or ocean conveyor current. Its most famous element is the Gulf Stream in the North Atlantic, but the conveyor travels all the oceans. It has its beginnings in the far north of the Atlantic, off Greenland, where unusually dense water plunges to the ocean floor. The water becomes dense here partly because it cools and partly because the formation of sea ice increases salinity. As the water gets a bit warmer and a bit less salty, thanks to all the extra fresh water, the worry is that the pump could slow down.
    Fears that the conveyor will soon shut down altogether, causing a fall in temperatures in northern Europe, have receded. Models of the climate system do not predict a shutdown any time within the next century, says oceanographer Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany.
    Monsoon warning
    Even a slowdown in the conveyor could produce dramatic changes, though. Climate models suggest that changes in the ocean conveyor will alter rainfall patterns around the world. The models are backed by studies of how the climate has changed during past shutdowns of the ocean conveyor.
    The biggest consequence, says Buwen Dong of the Walker Institute for Climate System Research at the University of Reading, UK, is likely to be a disruption, and quite probably a complete collapse, of the Asian monsoon, causing severe droughts in south Asia. “It could have enormous social and economic impacts on these nations,” he says.
    The disruption of the monsoon would have enormous social and economic impacts in south Asia
    You can say that again. The Asian monsoon is the main source of water for large areas of the most heavily populated continent. An estimated 2 billion – getting on for 1 in 3 citizens on the planet – rely on it to grow their food. Take away the monsoon and they would starve. All because of warming in the Arctic.
    Unquantifiable
    Nobody can be sure how likely all this is. Indeed, the scientists at the Intergovermental Panel on Climate Change (IPCC) who compile its reports cannot even reach agreement on how to quantify the probabilities of such events. As a result, the “scary scenarios” were barely mentioned in the last report.
    Nonetheless, the latest findings suggest we cannot afford to ignore these possibilities, especially given that everything to do with global climate is linked. The loss of Arctic sea ice could lead to the release of ever more methane from permafrost and methane hydrates. That in turn would make a dramatic reduction in the strength of the ocean conveyor sometime this century increasingly likely, which could lead to abrupt changes in the Asian monsoon.
    With the summer sea ice in the Arctic Ocean already shrinking much faster than the IPCC models predicted, one thing is for sure. It is not just the polar bears who should be worrying about the warming Arctic

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