Friday, 7 March 2014
Tuesday, 25 September 2012
With Arctic sea ice reaching its in the satellite record after an , the question of whether disappearing sea ice might lead to more extreme winters in Europe and North America needs more scrutiny.
In an , I reported on a by Jennifer Francis of Rutgers University and Stephen Vavrus of the University of Wisconsin, which showed that the loss of Arctic summer sea ice cover is adding enough heat to the ocean and atmosphere that it is helping to redirect the jet stream — the fast-moving high-altitude river of air that steers storm systems across the northern hemisphere.
Since March, the amount of Arctic sea ice that has disappeared is about , combined. This continues recent trends, ever since the previous record melt year of 2007. The six lowest Arctic sea ice extents in the satellite era have occurred during the past six years. As a result of such extensive sea ice melt, says the study, the jet stream, which has always been rather capricious, is behaving differently now. It has become slightly more elongated during fall and winter, with bigger troughs and ridges. A more wavy jet stream may have contributed to recent extreme winters that have featured historic blizzards along the East Coast of the U.S. as well as in Europe, the study found.
But from an email conversation with Francis, Vavrus, and several other atmospheric scientists this week, it became clear that there may be more questions than answers at this point, given the large amount of natural variability that affects winter weather patterns, and the very short observational record of how the atmosphere responded to extreme losses of sea ice (only five winters of records since 2007).
The underlying logic is sound: as sea ice melts, it exposes darker ocean water, which absorbs more of the sun’s heat, causing the water temperatures to increase. During the fall, the heat that was added to the oceans gets released into the atmosphere as sea ice reforms, and this added heat is bound to change weather patterns somehow (this is a process known as ""). The “how” part is what’s open to debate.
The study by Francis and Vavrus proposed that the added heat is altering jet stream patterns, but other mechanisms are certainly possible, as both researchers said via email.
“It’s implausible that such a redistribution of heat in the Arctic system wouldn’t change weather patterns somehow, somewhere,” Vavrus said. But he cautioned that people should view their study as a “launching point” for more research, and not interpret it as having any predictive value for the upcoming winter, as some media outlets have portrayed it.
One way that Arctic sea ice decline could result in extreme winter weather is by changing either the effects of the or the workings of the oscillation itself. The Arctic Oscillation is a climate index that describes the state of atmospheric circulation over the Arctic, and it has a so-called “positive” and “negative” phase. When the Arctic Oscillation is negative, cold Arctic air masses tend to plunge southward and into the U.S., spawning snowstorms and leading to cooler than average conditions. A positive Arctic Oscillation, by contrast, tends to mean warmer than average weather with less snow for the eastern U.S.
The Arctic Oscillation can vary considerably on short timescales, such as within a single month or from one month to the next, and the causes of its variability aren’t entirely known. It was largely positive during the winter of 2007-8, which followed the previous sea ice record low, and then turned record negative during the winter of 2009-10, during which the infamous “” blizzard occurred along the East Coast. It was then largely negative during the winter of 2010-11, and positive to weakly negative last winter, which was the mildest winter on record for the U.S.
The continued swings in the Arctic Oscillation can make it difficult for climate scientists to determine how sea ice loss is altering winter weather, since there is so much natural variability in the system in the first place. Other sources of climate variability, like El Niño and La Niña, also help set up prevailing winter weather patterns. Francis, of Rutgers University, said the natural climate cycles will help determine where some of the extremes will occur
“Given this summer’s ice loss, and resulting enhanced absorption of solar heat into the Arctic Ocean, it’s hard to imagine that some interesting jet stream patterns won’t occur this fall and winter,” she said. “But where and when they appear are influenced by many factors...”
Judah Cohen, a climate forecaster at in Massachusetts, who issues seasonal snowfall forecasts several months in advance for his company’s clients, said the relationship between sea ice loss and the Arctic Oscillation is a key area for future research to focus on. One , published in in January, hinted at such a mechanism when it linked sea ice decline to apparent changes in the Arctic Oscillation during several winters preceded by large sea ice losses.
“I certainly believe that the loss in sea ice has a large impact on the energy budget, which can have a profound impact on the weather around the Northern Hemisphere,” Cohen said. “However, there are many moving parts to the climate system and Arctic sea ice is just one of many.”
Cohen has showing that above average fall snowfall in Siberia can lead to colder and snowier winters in the U.S. The sea ice loss-related increase in open water north of Siberia can contribute to increased fall snowfall in that region.
“It is not simple to explain how sea ice loss that peaks in August and September impacts the circulation at mid-latitudes [during] December through March. It is possible but it seems to me that it makes the most sense if sea ice first impacts another component of the climate system that then impacts the winter circulation,” Cohen said.
So, the bottom line when it comes to this research is — it’s an active area of interest, but no firm conclusions have been reached other than that you simply cannot lose so much sea ice without altering the weather somewhere. That may not be actionable intelligence, but it’s a disturbing truth, once it sinks in.
Posted by CarbonFixIt Foundation at 14:18
Sunday, 26 February 2012
As the Earth's crust buckles, volcanic activity will increase.
The idea that a changing climate can persuade the ground to shake, volcanoes to rumble and tsunamis to crash on to unsuspecting coastlines seems, at first, to be bordering on the insane. How can what happens in the thin envelope of gas that shrouds and protects our world possibly influence the potentially Earth-shattering processes that operate deep beneath the surface? The fact that it does reflects a failure of our imagination and a limited understanding of the manner in which the different physical components of our planet – the atmosphere, the oceans, and the solid Earth, or geosphere – intertwine and interact.
If we think about climate change at all, most of us do so in a very simplistic way: so, the weather might get a bit warmer; floods and droughts may become more of a problem and sea levels will slowly creep upwards. Evidence reveals, however, that our planet is an almost unimaginably complicated beast, which reacts to a dramatically changing climate in all manner of different ways; a few – like the aforementioned – straightforward and predictable; some surprising and others downright implausible. Into the latter category fall the manifold responses of the geosphere.
The world we inhabit has an outer rind that is extraordinarily sensitive to change. While the Earth's crust may seem safe and secure, the geological calamities that happen with alarming regularity confirm that this is not the case. Here in the UK, we only have to go back a couple years to April 2010, when the word on everyone's lips was Eyjafjallajökull – the ice-covered Icelandic volcano that brought UK and European air traffic to a grinding halt. Less than a year ago, our planet's ability to shock and awe headed the news once again as theeast coast of Japan was bludgeoned by a cataclysmic combination of megaquake and tsunami, resulting – at a quarter of a trillion dollars or so – in the biggest natural-catastrophe bill ever.
In the light of such events, it somehow seems appropriate to imagine the Earth beneath our feet as a slumbering giant that tosses and turns periodically in response to various pokes and prods. Mostly, these are supplied by the stresses and strains associated with the eternal dance of a dozen or so rocky tectonic plates across the face of our world; a sedate waltz that proceeds at about the speed that fingernails grow. Changes in the environment too, however, have a key role to play in waking the giant, as growing numbers of geological studies targeting our post-ice age world have disclosed.
Between about 20,000 and 5,000 years ago, our planet underwent an astonishing climatic transformation. Over the course of this period, it flipped from the frigid wasteland of deepest and darkest ice age to the – broadly speaking – balmy, temperate world upon which our civilisation has developed and thrived. During this extraordinarily dynamic episode, as the immense ice sheets melted and colossal volumes of water were decanted back into the oceans, the pressures acting on the solid Earth also underwent massive change. In response, the crust bounced and bent, rocking our planet with a resurgence in volcanic activity, a proliferation of seismic shocks and burgeoning giant landslides.
The most spectacular geological effects were reserved for high latitudes. Here, the crust across much of northern Europe and North America had been forced down by hundreds of metres and held at bay for tens of thousands of years beneath the weight of sheets of ice 20 times thicker than the height of the London Eye. As the ice dissipated in soaring temperatures, the crust popped back up like a coiled spring released, at the same time tearing open major faults and triggering great earthquakes in places where they are unheard of today. Even now, the crust underpinning those parts of Europe and North America formerly imprisoned beneath the great continental ice sheets continues to rise – albeit at a far more sedate rate.
As last year's events in Japan most ably demonstrated, when the ground shakes violently beneath the sea, a tsunami may not be far behind. These unstoppable walls of water are hardly a surprise when they happen within the so-called ring of fire that encompasses the Pacific basin but in the more tectonically benign North Atlantic their manifestation could reasonably be regarded as a bit of a shock. Nonetheless, there is plenty of good, hard evidence that this was the case during post-glacial times. Trapped within the thick layers of peat that pass for soil on Shetland – the UK's northernmost outpost – are intrusions of sand that testify to the inland penetration of three tsunamis during the last 10,000 years.
Volcanic blasts too can be added to the portfolio of postglacial geological pandemonium; the warming climate being greeted by an unprecedented fiery outburst that wracked Iceland as its frozen carapace dwindled, and against which the recent ashy ejaculation from the island's most unpronounceable volcano pales.
The huge environmental changes that accompanied the rapid post-glacial warming of our world were not confined to the top and bottom of the planet. All that meltwater had to go somewhere, and as the ice sheets dwindled, so the oceans grew. An astounding 52m cubic kilometres of water was sucked from the oceans to form the ice sheets, causing sea levels to plummet by about 130 metres – the height of the Wembley stadium arch. As the ice sheets melted so this gigantic volume of water was returned, bending the crust around the margins of the ocean basins under the enormous added weight, and provoking volcanoes in the vicinity to erupt and faults to rupture, bringing geological mayhem to regions remote from the ice's polar fastnesses.
The breathtaking response of the geosphere as the great ice sheets crumbled might be considered as providing little more than an intriguing insight into the prehistoric workings of our world, were it not for the fact that our planet is once again in the throes an extraordinary climatic transformation – this time brought about by human activities. Clearly, the Earth of the early 21st century bears little resemblance to the frozen world of 20,000 years ago. Today, there are no great continental ice sheets to dispose of, while the ocean basins are already pretty much topped up. On the other hand, climate change projections repeatedly support the thesis that global average temperatures could rise at least as rapidly in the course of the next century or so as during post-glacial times, reaching levels at high latitudes capable of driving catastrophic breakup of polar ice sheets as thick as those that once covered much of Europe and North America. Could it be then, that if we continue to allow greenhouse gas emissions to rise unchecked and fuel serious warming, our planet's crust will begin to toss and turn once again?
The signs are that this is already happening. In the detached US state of Alaska, where climate change has propelled temperatures upwards by more than 3C in the last half century, the glaciers are melting at a staggering rate, some losing up to 1km in thickness in the last 100 years. The reduction in weight on the crust beneath is allowing faults contained therein to slide more easily, promoting increased earthquake activity in recent decades. The permafrost that helps hold the state's mountain peaks together is also thawing rapidly, leading to a rise in the number of giant rock and ice avalanches. In fact, in mountainous areas around the world, landslide activity is on the up; a reaction both to a general ramping-up of global temperatures and to the increasingly frequent summer heatwaves.
Whether or not Alaska proves to be the "canary in the cage" – the geological shenanigans there heralding far worse to come – depends largely upon the degree to which we are successful in reducing the ballooning greenhouse gas burden arising from our civilisation's increasingly polluting activities, thereby keeping rising global temperatures to a couple of degrees centigrade at most. So far, it has to be said, there is little cause for optimism, emissions rocketing by almost 6% in 2010 when the world economy continued to bump along the bottom. Furthermore, the failure to make any real progress on emissions control at last December's Durban climate conference ensures that the outlook is bleak. Our response to accelerating climate change continues to be consistently asymmetric, in the sense that it is far below the level that the science says is needed if we are to have any chance of avoiding the all-pervasive devastating consequences.
So what – geologically speaking – can we look forward to if we continue to pump out greenhouse gases at the current hell-for-leather rate? With resulting global average temperatures likely to be several degrees higher by this century's end, we could almost certainly say an eventual goodbye to the Greenland ice sheet, and probably that covering West Antarctica too, committing us – ultimately – to a 10-metre or more hike in sea levels.
GPS measurements reveal that the crust beneath the Greenland ice sheet is already rebounding in response to rapid melting, providing the potential – according to researchers – for future earthquakes, as faults beneath the ice are relieved of their confining load. The possibility exists that these could trigger submarine landslides spawning tsunamis capable of threatening North Atlantic coastlines. Eastern Iceland is bouncing back too as its Vatnajökull ice cap fades away. When and if it vanishes entirely, new research predicts a lively response from the volcanoes currently residing beneath. A dramatic elevation in landslide activity would be inevitable in the Andes, Himalayas, European Alps and elsewhere, as the ice and permafrost that sustains many mountain faces melts and thaws.
Across the world, as sea levels climb remorselessly, the load-related bending of the crust around the margins of the ocean basins might – in time – act to sufficiently "unclamp" coastal faults such as California's San Andreas, allowing them to move more easily; at the same time acting to squeeze magma out of susceptible volcanoes that are primed and ready to blow.
The bottom line is that through our climate-changing activities we are loading the dice in favour of escalating geological havoc at a time when we can most do without it. Unless there is a dramatic and completely unexpected turnaround in the way in which the human race manages itself and the planet, then long-term prospects for our civilisation look increasingly grim. At a time when an additional 220,000 people are lining up at the global soup kitchen each and every night; when energy, water and food resources are coming under ever-growing pressure, and when the debilitating effects of anthropogenic climate change are insinuating themselves increasingly into every nook and cranny of our world and our lives, the last thing we need is for the dozing subterranean giant to awaken.
Bill McGuire is professor of geophysical and climate hazards at University College London. Waking the Giant: How a Changing Climate Triggers Earthquakes, Tsunamis and Volcanoes is published by Oxford University Press.
Posted by CarbonFixIt Foundation at 14:48
Thursday, 23 February 2012
There are many uncertainties around climate change-related human mobility, particularly when it comes to potential cross-border movements. In the first place, it is difficult to predict the number of people who will be displaced or who will decide to migrate for reasons related to climate change. And it is difficult to determine responsibility for caring for those who are displaced across borders. There are serious normative gaps which Nina Schrepfer and I explored in a recent paper published in UNHCR’s legal and protection policy research series.
Maldives has a population of some 400,000 islanders, whose livelihood from fishing and tourism is being hit by climate change.
Reinhard Krause / Reuters
In our paper we present the background, context and present discussions around climate change-related mobility and then identify normative gaps for each of five scenarios of population mobility likely to occur:
- In the case of sudden-onset disasters, most of those displaced will remain within their own countries as internally displaced persons (IDPs) where an existing normative framework would apply: the Guiding Principles on Internal Displacement. But some may cross international borders– for example if this is the only escape route or there are no protection and assistance capacities at home. While movement is forced, these people generally do not fall under the criteria of international refugee law.
- In the case of environmental degradation and slow-onset disasters, cross-border movements are traditionally seen as migrants moving voluntarily as a way of coping with the changing environment. But with worsening environmental degradation, the movement of persons will become increasingly involuntary. In both cases, they have no right to admission and little protection except to a limited extent under general human rights law.
- For small island states facing threats because of rising sea levels, people will have to move to other islands belonging to the same state or cross international borders. Initially they will probably be part of a migratory movement but eventually their movement will be forced. International law does not provide sufficient protection for them.
- The effects of climate change are likely to lead to zones prohibited for human habitation and it is likely that people will be relocated to other areas within the borders of their countries. But cross-border movements could occur if proposed relocation areas are unsuitable or if no durable alternatives in line with human rights standards are offered to the affected population. The character of this cross-border movement is unclear and will probably require individual determination as to whether such acts may amount to individual persecution under refugee law.
- Finally, if the effects of climate change lead to unrest, violence and armed conflict, those fleeing across a border may qualify as refugees under the 1951 Convention and related regional instruments.
In our paper, we explore the general obligations of states at the levels of mitigation, adaptation and protection. We identify critical legal issues which remain unaddressed, including the critical question of how to distinguish between voluntary and forced movements and suggest ways to address these gaps. Finally, we suggest that a strategy is needed to create an international regime for the protection of people crossing borders in the context of climate change which is based on the four pillars of prevention, migration management, temporary and permanent protection schemes and resettlement
Posted by CarbonFixIt Foundation at 14:32
Monday, 20 February 2012
Year after year, the world’s nations gather to find ways to reduce carbon dioxide, the main greenhouse gas, with little meaningful progress. Frustrated by this slow pace, the United States and five other countries announced this week a modest but potentially game-changing initiative to cut three other pollutants that also contribute significantly to climate change. The three pollutants — methane, soot (also known as black carbon) and hydrofluorocarbons — together account for about 30 percent to 40 percent of the rise in global temperatures. Unlike carbon dioxide, they do not remain in the atmosphere for a long time, but, while they are there, they drive temperatures upward.
Mainstream scientists believe that to avoid disastrous increases in the sea levels and widespread drought, the rise in global temperatures by 2050 should not exceed 2 degrees Celsius above preindustrial levels. Though cuts in carbon dioxide will also be necessary to reach that goal, curbing these three pollutants will help enormously.
Officials hope further that by tackling these pollutants they can achieve relatively quick and measurable reductions in emissions without waiting for politicians to act or the United Nations process to produce a global agreement on carbon dioxide.
The plan’s founding members are the United States, Canada, Sweden, Mexico, Ghana and Bangladesh. Washington and Ottawa will jointly underwrite a $15 million start-up fund. Clearly, the program must be scaled up over time, with many more countries participating. In the short term, officials say their purpose is to educate and test inexpensive and technologically accessible ways of capturing these gases.
Soot, a huge health hazard, can be reduced by installing filters on diesel engines, replacing traditional cook stoves with more efficient models and banning the open burning of agricultural waste. Methane can be captured from oil and gas wells, leaky pipelines, municipal landfills and wastewater treatment plants.
Significantly reducing hydrofluorocarbons, or HFCs, could be harder. These compounds, widely used in air-conditioners and originally developed to replace the refrigerants that were damaging the ozone layer, turned out to be a potent greenhouse gas. Efforts to find less-harmful substitutes have met resistance from countries like India and China, where most HFCs are manufactured.
Governments everywhere should obviously be pushing to reduce carbon dioxide, the most dangerous greenhouse gas. In the meantime, opening an important second front in the climate war will demonstrate that progress is possible.
Source : New York Times
Posted by CarbonFixIt Foundation at 04:59
Sunday, 19 February 2012
UK Environment Agency
New report by Environment Agency says river levels may fall by 80% as a result of climate change and the growing population. Britain's rivers are drying up. Unless emergency measures are adopted, some of our finest waterways could be reduced to trickles over the next few decades.
Nor will the worst effects be experienced in the south-east of England – even though UK temperatures will reach their highest in that part of the country as global warming reaches across the British isles.
Rivers in the north-west of England, such as the Derwent in Cumbria, are also at risk. The implications for wildlife, housing, business and tourism are extremely serious, adds the study.
"The problem is not just that average summer temperatures could rise by two or three degrees in Britain over the coming decades," said Trevor Bishop, the head of water resources at the Environment Agency. "It is also forecast that the population of England and Wales is likely to rise by more than 9 million. That will only add to the burden that we are placing on our water supplies."
The study – – is the second river report prepared by the agency. A previous version used less precise estimates of the likely impact of climate change. The new report uses more up-to-date figures and is more precise in its forecasts, says the agency.
In its analysis, the report identifies the twin dangers of climate change and increased population as threats to the water supply. The former is expected to bring warmer and drier summer weather, particularly to the south-east of England, leading to the drying up of rivers and reservoirs. The second factor, increased population, will produce a jump in demand for water from them. This twin assault on the nation's water system could have a devastating impact on its ecology. "Important habitats could be lost," states the report.
"Fish species such as Atlantic salmon and brown trout, which need cold water to thrive, may struggle to survive. While plants and animals decline in some parts of England and Wales, they are likely to become more prevalent in other areas out-competing species and habitats local to the area."
The impact on fish populations would also have an effect on other species. Otters and sea eagles, which have made successful returns to waterways in recent years, would suffer as fish stocks dropped, for example. Many plant species that rely on plentiful supplies of water would also be badly affected.
The agency's analysis suggests that urgent action is needed. "However, our understanding of the water needs of our ecosystem is still developing," adds the report. "Climate change will create a new level of complexity on top of our current understanding that we have only just begun to tackle."
The report studies a number of scenarios, some less severe. Yet all indicate that action will be needed and that measures will be required sooner rather than later.Significant changes will have to be introduced to halt the lavish amounts of water that are used, and often wasted, by people – although one encouraging sign was identified by Bishop.
"For the past hundred years or so, the average amount of water used by each person in England and Wales has steadily increased. However, that rise has now stopped and for the first time it has started to decline – slightly." A key factor in halting our increased use of water has been the introduction of domestic water meters. "When one is fitted, water usage drops by an average of 12.5% in a household," Bishop added. "People become aware they have left on taps or hose pipes and so they switch them off."
Around 37% of households are now fitted with water meters, and the figure is expected to rise to about 50% by 2015, cutting even further the average amount used by each person to reduce the strain on our rivers and reservoirs.
Currently, each person uses, on average, about 160 litres (35 gallons) a day – around a third for toilet flushing, a third for washing and bathing, a small amount for food and drink – and the rest for recreational activities, in particular gardening.
But this will not be enough to avert the crisis brought about by the double whammy of global warming and the projected rise in the population. "We have turned the corner but only just," said Bishop. "We need to adopt some really radical measures."
These could include the use of desalination plants that transform seawater into drinking water. These use considerable amounts of energy, however, and would only be worth using when water levels become dangerously low.
Similarly, the re-use of effluent water, after it had been treated may also be considered. In addition, the government may allow water companies to introduce higher charges in summer and at times of drought.
Posted by CarbonFixIt Foundation at 11:13