The Good, The Bad & the Ugly of Iceland’s Volcano
The Good, The Bad & the Ugly of Iceland’s Volcano
As scientists said that there was no sign that the current eruption from below the Eyjafjallajokull glacier was linked to global warming, they pointed to a thaw of Iceland’s ice caps in coming decades caused by climate change which may trigger more volcanic eruptions by removing a vast weight and freeing magma from deep below ground. As the airline industry is counting the cost of the volcanic cloud keeping its jets grounded, at least aviation emissions are being saved until they fly again. But the volcano is doing enough damage on its own, emitting between 150,000 and 300,000 tonnes of carbon dioxide (CO2) per day.
Reported by AFP (20 April 2010):
Iceland’s Eyjafjoell volcano is emitting between 150,000 and 300,000 tonnes of carbon dioxide (CO2) per day, a figure placing it in the same emissions league as a small-to-medium European economy, experts said on Monday.
Assuming the composition of gas to be the same as in an earlier eruption on an adjacent volcano, “the CO2 flux of Eyjafjoell would be 150,000 tonnes per day,” Colin Macpherson, an Earth scientist at Britain’s University of Durham, said in an email.
Patrick Allard of the Paris Institute for Global Physics (IPGP) gave what he described as a “top range” estimate of 300,000 tonnes per day. Both insisted that these were only approximate estimates.
Extrapolated over a year, the emissions would place the volcano 47th to 75th in the world table of emitters on a country-by-country basis, according to a database at the World Resources Institute (WRI), which tracks environment and sustainable development.
A 47th ranking would place it above Austria, Belarus, Portugal, Ireland, Finland, Bulgaria, Sweden, Denmark and Switzerland, according to this list, which relates to 2005.
Experts stressed that the volcano contributed just a tiny amount – less than a third of one percentage point – of global emissions of greenhouse gases.
Total emissions by six heat-trapping gases in 2005 were more than 36 thousand million tonnes (36 gigatonnes) as measured in CO2, according to the WRI index.
“It’s not of any significance compared to the anthropogenic [manmade] budget,” said Kjetil Toerseth, director of regional and global pollution at the Norwegian Institute for Air Research.
Specialists cautioned those who believe the eruption is good for climate change as carbon-emitting jetliners are unable to take to the skies.
According to the European Environment Agency (EAA), daily emissions from the aviation sector in the 27 nations of the European Union are around 440,000 tonnes per day.
Not all of this is saved because of the volcanic eruption, said the sources. Firstly, some airports in southern Europe have remained open for traffic.
In addition, carbon is emitted when passengers stranded by air travel use the train, bus, car or ferry as an alternative.
And many flights in, to and from Europe are merely being deferred until the crisis is over.
“Whether the emissions occur now or three weeks from now does not change things fundamentally,” said Herve Le Treut, a French climatologist.
“Another point is that these emissions are of long duration. CO2 is dangerous because it stays in the atmosphere for about a hundred years. Its short-term effect is not the big problem.”
Source: www.news.smh.com.au
Times, London ( 20 April 2010:
LONDON: The grounding of 63,000 flights over the past four days has saved 1.3 million tonnes of carbon dioxide, more than the annual emissions of many developing countries.
Aviation is responsible for about 2 per cent of global emissions of CO2, but accounts for a much higher proportion of emissions in European nations, which have many frequent flyers. Aircraft are responsible for more than 6 per cent of Britain’s CO2 emissions.
On a normal day, the 28,000 flights in European airspace emit about 560,000 tonnes of CO2, or a third of the world’s aviation emissions.
The Aviation Environment Federation calculated that the CO2 saving over four days had been greater than the annual emissions of Malawi, Sierra Leone, Rwanda and about 50 other developing countries.
Jeff Gazzard, the federation’s spokesman, said: “The use of trains, ferries and video conferencing has skyrocketed as planes have been grounded. While volcanic eruptions are not an everyday occurrence, surely the take-away message from the past few days is that the world has not stopped revolving and people can find alternatives to air travel. We hope that this will prompt people to stop and think about whether their flight is really necessary.”
The total environmental benefits of the grounding of aircraft may be far greater because millions of business travellers have had to find alternative ways of communicating – and some are likely to change their working habits permanently.
Source: www.theaustralian.com.au
Alister Doyle for Reuters World Environment News (19 April 2010):
A thaw of Iceland’s ice caps in coming decades caused by climate change may trigger more volcanic eruptions by removing a vast weight and freeing magma from deep below ground, scientists said.
They said there was no sign that the current eruption from below the Eyjafjallajokull glacier that has paralysed flights over northern Europe was linked to global warming. The glacier is too small and light to affect local geology.
“Our work suggests that eventually there will be either somewhat larger eruptions or more frequent eruptions in Iceland in coming decades,” said Freysteinn Sigmundsson, a vulcanologist at the University of Iceland.
“Global warming melts ice and this can influence magmatic systems,” he told Reuters. The end of the Ice Age 10,000 years ago coincided with a surge in volcanic activity in Iceland, apparently because huge ice caps thinned and the land rose.
“We believe the reduction of ice has not been important in triggering this latest eruption,” he said of Eyjafjallajokull. “The eruption is happening under a relatively small ice cap.”
Carolina Pagli, a geophysicist at the University of Leeds in England, said there were risks that climate change could also trigger volcanic eruptions or earthquakes in places such as Mount Erebus in Antarctica, the Aleutian islands of Alaska or Patagonia in South America.
MAGMA
“The effects would be biggest with ice-capped volcanoes,” she said. “If you remove a load that is big enough you will also have an effect at depths on magma production.”
She and Sigmundsson wrote a 2008 paper in the scientific journal Geophysical Research Letters about possible links between global warming and Icelandic volcanoes.
That report said that about 10 percent of Iceland’s biggest ice cap, Vatnajokull, has melted since 1890 and the land nearby was rising about 25 millimetres (0.98 inch) a year, bringing shifts in geological stresses.
They estimated that the thaw had led to the formation of 1.4 cubic km (0.3 cubic mile) of magma deep below ground over the past century.
At high pressures such as under an ice cap, they reckon that rocks cannot expand to turn into liquid magma even if they are hot enough. “As the ice melts the rock can melt because the pressure decreases,” she said.
Sigmundsson said that monitoring of the Vatnajokull volcano since 2008 suggested that the 2008 estimate for magma generation was “probably a minimum estimate. It can be somewhat larger.”
He said that melting ice seemed the main way in which climate change, blamed mainly on use of fossil fuels, could have knock-on effects on geology. The U.N. climate panel says that global warming will cause more floods, droughts and rising seas.
Source: www.planetark.org
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