Rapid thawing of the Arctic could trigger a catastrophic "economic timebomb" which would cost trillions of dollars and undermine the global financial system, say a group of economists and polar scientists.Governments and industry have expected the widespread warming of the Arctic region in the past 20 years to be an economic boon, allowing the exploitation of new gas and oilfields and enabling shipping to travel faster between Europe and Asia. But the release of a single giant "pulse" of methane from thawing Arctic permafrost beneath the East Siberian sea "could come with a $60tn [£39tn] global price tag", according to the researchers who have for the first time quantified the effects on the global economy.
Even the slow emission of a much smaller proportion of the vast quantities of methane locked up in the Arctic permafrost and offshore waters could trigger catastrophic climate change and "steep" economic losses, they say.
The Arctic sea ice, which largely melts and reforms each year, is declining at an unprecedented rate. In 2012, it collapsed to under 3.5m sqkm by mid September, just 40% of its usual extent in the 1970s. Because the ice is also losing its thickness, some scientists expect the Arctic ocean to be largely free of summer ice by 2020.
The growing fear is that as the ice retreats, the warming of the sea water will allow offshore permafrost to release ever greater quantities of methane. A giant reservoir of the greenhouse gas, in the form of gas hydrates on the East Siberian Arctic Shelf (ESAS), could be emitted, either slowly over 50 years or catastrophically fast over a shorter time frame, say the researchers.
Thursday, 25 July 2013
Tuesday, 23 July 2013
You may recall, late last summer the Arctic sea ice extent dropped to its lowest level on record, 49 percent below the 1979-2000 average. It’s not clear if 2013 levels will match 2012′s astonishing record low, but – with temperatures over the Arctic Ocean 1-3 degrees above average – the 2013 melt season has picked up in earnest during July.“During the first two weeks of July, ice extent declined at a rate of 132,000 square kilometers (51,000 square miles) per day. This was 61% faster than the average rate of decline over the period 1981 to 2010 of 82,000 square kilometers (32,000 square miles) per day,” the National Snow and Ice Data Center writes on its website.
Friday, 3 May 2013
The Arctic's sea ice melted at a record pace in 2012, the ninth-hottest year on record, compounding concerns about climate change underscored by extreme weather such as Hurricane Sandy, the UN weather agency says. In a report on the situation in 2012, the World Meteorological Organisation said on Thursday that during the August to September melting season, the Arctic's sea ice cover was just 3.4 million square kilometres. That was a full 18 per cent less than the previous record low set in 2007.WMO Secretary-General Michel Jarraud dubbed it a "disturbing sign of climate change." "The year 2012 saw many other extremes as well, such as droughts and tropical cyclones. Natural climate variability has always resulted in such extremes, but the physical characteristics of extreme weather and climate events are being increasingly shaped by climate change," he said. "For example, because global sea levels are now about 20 centimetres higher than they were in 1880, storms such as Hurricane Sandy are bringing more coastal flooding than they would have otherwise," he added.
Thursday, 6 September 2012
Sunday, 2 September 2012
Following up to yesterday's quick lunchtime ice volume post. This morning I processed the data a bit differently by computing the average for each month in each year and then plotting the monthly series separately. The results are above. For the months July-December I fit a quadratic - which gives a decent fit in all cases.The extrapolations show the Arctic ice free for six months out of the year by 2025.
A word about extrapolations, which are always dangerous. They get more dangerous when:
There is no particular theoretical basis for the curve used as a model.
The model has a lot of parameters (so that it has the opportunity to fit tightly in the sample period but go haywire outside of it).
The extrapolation goes for a long way relative to the interval over which there is data.
There is reason to suspect the underlying dynamics of the system might change during the extrapolated period.
The underlying data are suspect, particularly if there are systematic errors that the fit is sensitive too.In this case, we have no theoretical model - this is purely an empirical fit. (The theoretical models of the Arctic are climate models, which uniformly failed to predict the rapid and early collapse in sea-ice volume that has actually been observed - so they are presumably missing something important about the dynamics). On the plus side, we only have three parameters - a quadratic is the simplest possible model of an accelerating process, and this process is clearly accelerating. Furthermore, the quadratic gives a decent fit for all months, it's not just a fluke that it happened to fit in September. The resulting extrapolations tell a fairly consistent plausible story: ice will disappear first in September, with October and August very close behind, and then November and July, followed by December.
For the extrapolation interval, it appears to be quite short for August - October - around 15% of the data interval. We don't need the system to keep behaving the same way for very long at all in order for the extrapolated curve to go to zero. For the succeeding months the extrapolations obviously get more and more speculative.
We don't particularly have any reason to expect the dynamics to change soon. The Arctic has long been expected to warm dramatically under climate change, and all indications are that it has indeed been warming and will continue to warm. There is no historical evidence of climate fluctuations this large in Arctic ice. However, it's possible that part of the recent move is a fluctuation that could revert and delay the inevitable. In particular, look at the recovery in ice volume in the early 1980s - a similar recovery in the next few years could push things out by a decade.
This was a follow up to an earlier post - Arctic Sea Ice Volume.
Strange that explorers competed for years to travel by sled to a place that will no longer exist. Maybe I'm naive, but it seems this will change the debate about climate change - the complete absence of a polar ice cap seems much easier for an ordinary person to understand, versus complex arguments about data-analysis on global temperature statistics, requiring that you trust scientists and their computer models. Arguing that climate change isn't happening will become akin to arguing that the earth is flat.
Monday, 27 August 2012
In the past week the Arctic sea ice cover reached an all-time low, several weeks before previous records, several weeks before the end of the melting season. The long-term decline of Arctic sea ice has been incredibly fast, and at this point a sudden reversal of events doesn’t seem likely. The question no longer seems to be “will we see an ice-free Arctic?” but “how soon will we see it?”. By running the Arctic Sea Ice blog for the past three years I’ve learned much about the importance of Arctic sea ice. With the help of Kevin McKinney I’ve written the piece below, which is a summary of all the potential consequences of disappearing Arctic sea ice.Arctic sea ice became a recurrent feature on planet Earth around 47 million years ago. Since the start of the current ice age, about 2.5 million years ago, the Arctic Ocean has been completely covered with sea ice. Only during interglacials, like the one we are in now, does some of the sea ice melt during summer, when the top of the planet is oriented a bit more towards the Sun and receives large amounts of sunlight for several summer months. Even then, when winter starts, the ice-free portion of the Arctic Ocean freezes over again with a new layer of sea ice.
Since the dawn of human civilization, 5000 to 8000 years ago, this annual ebb and flow of melting and freezing Arctic sea ice has been more or less consistent. There were periods when more ice melted during summer, and periods when less melted. However, a radical shift has occurred in recent times. Ever since satellites allowed a detailed view of the Arctic and its ice, a pronounced decrease in summer sea ice cover has been observed (with this year setting a new record low). When the IPCC released its Fourth Assessment Report in 2007, it was generally thought that the Arctic could become ice-free somewhere near the end of this century. But changes in the Arctic have progressed at such speed that most experts now think 2030 might see an ice-free Arctic for the first time. Some say it could even happen this decade.
Wednesday, 14 December 2011
Dramatic and unprecedented plumes of methane – a greenhouse gas 20 times more potent than carbon dioxide – have been seen bubbling to the surface of the Arctic Ocean by scientists undertaking an extensive survey of the region.
The scale and volume of the methane release has astonished the head of the Russian research team who has been surveying the seabed of the East Siberian Arctic Shelf off northern Russia for nearly 20 years.
In an exclusive interview with The Independent, Igor Semiletov, of the Far Eastern branch of the Russian Academy of Sciences, said that he has never before witnessed the scale and force of the methane being released from beneath the Arctic seabed.
"Earlier we found torch-like structures like this but they were only tens of metres in diameter. This is the first time that we've found continuous, powerful and impressive seeping structures, more than 1,000 metres in diameter. It's amazing," Dr Semiletov said. "I was most impressed by the sheer scale and high density of the plumes. Over a relatively small area we found more than 100, but over a wider area there should be thousands of them."
Friday, 23 September 2011
New research on the dynamics of Greenland’s ice sheets complicates efforts to forecast sea level rise in this century, as the Green Blog reports. Expanding fields of crevasses appear to be limiting the flow of water to the base of the ice through tube-like moulins. That flow has been thought to ease the seaward movement of the ice over bedrock. But the crevasses also warm the ice as liquid water descends deep inside the frozen mass, with that process also potentially speeding its flow. This diagram shows the two types of plumbing.
In the meantime, the high recent rate of ice loss in Greenland, according to other new research, has largely continued.
Tuesday, 13 September 2011
Ice at the North Pole has melted to the lowest level since satellite observations began in 1972, meaning the Arctic is almost certainly the smallest it has been for 8000 years, polar scientists said. If the trend continues, the Arctic will be largely ice-free in the northern summer 40 years earlier than anticipated in the last Intergovernmental Panel on Climate Change assessment report.
Daily satellite sea ice maps released by Bremen University physicists show that with a week's further melt expected this year, the floating ice in the Arctic covered 4.24 million square kilometres on September 8. The previous one-day minimum was 4.27 million square kilometres on September 17, 2007. ...
The German researchers said the record melt was undoubtedly because of human-induced global warming. ''The sea ice retreat can no more be explained with the natural variability … caused by weather,'' the head of the Institute of Environmental Physics at Bremen, Georg Heygster, said. ''Climate models show that the reduction is related to the man-made global warming, which, due to the albedo effect, is particularly pronounced in the Arctic.'' ...
Separate research suggests Arctic ice is in a downward spiral, declining in area and also thinning. Scientists at the Polar Science Centre of the University of Washington, Seattle, said last week that Arctic sea ice volume hit its lowest level in 2010 and was on course to set more records this year. Their data suggests that the volume of sea ice last month was half the average and 62 per cent lower than the maximum covering the Arctic in 1979. The research will be published in the Journal of Geophysical Research. …
The last time the Arctic was uncontestably free of summer-time ice was 125,000 years ago, at the height of the last major interglacial period. Arctic ice plays a critical role in regulating Earth's climate. Retreating summer sea ice is described by scientists as a measure and a driver of global warming. This year, the Northwest and Northeast passages were mostly ice free, as they have been twice since 2008.
Last month, the 74,000-tonne STI Heritage tanker passed through the Northeast Passage in just eight days on its way from Houston, Texas, to Thailand. The north-east sea route, which links the Atlantic to the Pacific, is likely to become a ship operator's favourite.
