A volcanic eruption in Iceland is continuing to ground flights in the UK and Europe, but 227 years ago a far more devastating eruption occurred wiping out a fifth of the island's population - as well as tens of thousands across Europe.
On 8 June, 1783, the young country of Iceland - inhabited for less than 1,000 years - had a population of 50,000. In the coming years, as a result of what began that Sunday morning at 9am, 10,000 of those people would die.
The Laki eruption is the worst catastrophe in the country's relatively short history. Laki is a volcanic system in the same south-eastern part of Iceland where this week's eruption took place. But that's where the similarities end.
Back in 1783 it was ripped open with such force that a huge fissure produced scores of boiling craters. Over the next eight months the Lakagigar - literally "craters of Laki" - spewed lava that spread to cover 600 square kilometres in the surrounding countryside and belched more toxic gases than any eruption in the last 150 years. The effects were felt all over the northern hemisphere.
It is the second greatest eruption of the last 1,000 years, behind only the 1815 eruption of Mount Tambora in Indonesia, says Stephen Self, visiting professor of volcanology at the Open University.
Laki's output of sulphur dioxide dwarfs the 1990 eruption of Pinatubo in the Philippines, which is famous for halting global warming for several years. While that eruption produced 17 mega tonnes of sulphur dioxide, Laki was pumping the same amount out every three days at its peak, says Self. He estimates Laki's power was over 100 times greater than the current eruption.
"The 1783 eruption pumped out so much sulphur gas, creating a huge cloud of sulphuric acid droplets which began to drift over Europe travelling eastwards over the whole world," he says.
The noxious fog travelled down through Norway, Germany, France and across to Britain, causing panic when farm labourers began dropping like flies. People at this time had no idea where the fog had come from or that sulphur dioxide was mixing with water vapour in the lungs to choke victims. Research into parish records has led to estimates of more than 20,000 deaths in Britain alone during the summer of 1783.
The extreme heat - not connected to the volcano - would have made the fog all the more unpleasant, says Philip Eden, former BBC weatherman.
"July 1783 is the equal warmest month in 300 years of records for the UK. Because of the ash the sun shone from a white sky - it must have felt like the apocalypse."
It was only in the autumn that the fog finally lifted. But soon an even worse problem was on the way - the most severe winter for 250 years, caused by the build-up of heat absorbing sulphur dioxide in the stratosphere.
But nowhere suffered more than Iceland. It was not the eruption itself that proved deadly but the environmental consequences, says Gunnar Gudmundsson, a geophysicist at the Icelandic Meteorological Office.
"People died not because of the eruption, but because of starvation," he says. "The farm animals died, the crops died - it affected the whole country."
Toxic gases poisoned the plants and vegetation, which in turn killed the livestock. Eight of every ten sheep are thought to have died, while half of all the cattle and horses perished. The extreme winters that followed - caused by the sulphuric gases - ensured that a fifth of the country's population died, historians estimate.
'Sins of man'
It is a period of tragedy etched onto the Icelandic psyche, says Magnus Gudmundsson, professor of geophysics at the University of Iceland. It has become the yardstick by which all painful periods in the country's history are measured, he adds.
"We have a word for it - Moduhardindin - meaning "the hardship of the fog". When politicians compare it to the recent economic crisis it causes outrage - of course there's no comparison. Today 20 to 25% of the population are deeply in debt."
But in 1783 the same proportion of the population succumbed to a more terminal fate, he points out.
Today children learn about the Laki in school and because of the frequent volcanic eruptions, geology and the study of lava is a compulsory part of the education curriculum.
Gunnar Karlsson, one of Iceland's leading historians, argues that without the country's fish stocks the suffering would have been even more terrible.
"At the time of the eruption two thirds of people were farmers while the other third were fishermen," he says. "The animals died from lack of hay and the people died the following year."
In coastal areas where cod was plentiful the suffering was less, but the way the country was governed prevented any proper strategy. At the time Iceland was a part of the Danish Kingdom and governed from Copenhagen, 1300 miles away.
"The Danes tried to help," says Professor Karlsson. "There was a collection of money but communication was so sparse that it helped little. It takes weeks to sail between Copenhagen and Iceland and there was no other contact at this time."
Reykjavik was just a village and local officials were spread around the country. But there was no co-ordination when it came to dealing with the famine and sharing out the fish, he says.
"The officials in Iceland were extremely late to react. It's been estimated that more food was being exported than imported at this time. The main export was fish, but no effort was made to distribute this food."
The Laki struck at a time when supernatural beliefs were beginning to give way to ideas of human progress brought by the Enlightenment.
"The eruption was a great shock because people were beginning to believe in progress and improving their lives," says Prof Karlsson. "It must have been a great blow to realise they did not control their lives and see how powerless they were if the natural conditions were so strong."
The clergy stuck to the view that Iceland was being punished for the sins of man, he adds.
Prof Karlsson also believes Laki had other surprising consequences for Icelandic society. "The Icelanders stopped dancing and unlike the Norwegians and Faroe Islanders we lost the old dances. My guess is they stopped because people were in such shock after the famine that they didn't want to dance anymore."
Despite being the country's darkest hour, the country bounced back and it is argued by some that the event was not the defining moment for Iceland. The population was back to 50,000 within 20 years and continued to grow over the coming decades, and today stands at 320,000.
"It was dramatic when it happened but the effect was only felt for 20 years," says Prof Karlsson. "For the historian it is the events that have the longest effects that are the most important. For me the mechanisation of the fishing fleet in the early 20th Century was the nation's turning point. It turned Iceland from one of the poorest countries in Europe to one of the richest."
Nowadays with the economy again in ruins, some Icelanders may take hope from the way the country bounced back from the Laki nearly 250 years ago.
Here is a selection of your comments.
Doug L you are mistaken. As the article points out, it is events with the longest-lasting effects which are most significant. Of course a major asteroid strike could eclipse all other catastrophes; but climate change has indeed been observed, and unless tackled decisively will certainly change history negatively and permanently. All but the very largest volcanos (eg Toba 80K years BP) have only short-term consequences - albeit sometimes still major, like Laki, and the Tambora eruption which cancelled summer in 1816. The big difference is: we aren't responsible for volcanoes and can't stop them; whereas current climate change is self-inflicted, absolutely down to us.
Brian Cuthbertson, London
Andy from Glasgow - there is a volcano spewing out large amounts of particulates into the atmosphere. How are the scientists going to measure clean air?
Richard Hawes, Herts
I'm interested that you quote Eden as saying "The extreme heat - not connected to the volcano - would have made the fog all the more unpleasant"
A quick review of Thordarson and Self (2003)Atmospheric and environmental effects of the 1783-1784 Laki eruption: A review and reassessment
I quote from page 18: "It has been suggested that the unusual July heat wave in western and northern Europe resulted from a short-term greenhouse warming induced by the emissions from Laki and caused by high SO2 concentrations in the lower troposphere ... The July anomaly is strongest in western Europe and declines gradually with increasing distance from Laki, which can be taken as support for the above hypothesis."
One wonders what regional effects any continuation of the current eruption may hold in store for us this summer if activity continues?
I travelled around south Iceland not long ago, including around the current volcanic site, and the Laki region. The landscape is quite remarkable. Or should I say was... the changes that can be wreaked by such powerful forces are not to be underestimated. This is illustrated so well by the Laki region.
Matt, Paris, France
I must say, the eruption has really thrown Iceland into the spotlight. I've learned more about Iceland in the last few days than I had in the last 22 years of my life. I also had no idea a volcanic eruption could have such widespread effects. It is truly awe-inspiring, and a little bit frightening.
I find it incredibly touching to think that the nation ceased to dance out of collective grief. They do, however, sing very beautifully. What does this tell us about these primeval forces of expression? It is worthy of serious study. Is singing more suitable a vehicle for expressing grief? In grief one ceases to sing too, but maybe one continues to vocalise in some form, even if it is only a whimper. Dancing may just require too much energy. Pause for thought.
Deborah Y, Berlin
Isn't it great? Clear skies day and night untainted by contrails. The scientists will be loving this, the first occasion since 9/11 that they have had to measure the effect of air travel on the atmosphere.
With our focus on the minutiae of climate details that have so far not even really been observed and which some are calling civilisation's greatest threat, we should instead be applying that kind of effort towards making ourselves ready to address historically relevant threats such as the Iceland volcanoes, or the the eruptions in Indonesia, or for that matter the threat from periodic and game changing impacts from asteroids.