When examining the sources, it has become clear that Skaftáreldar, or the eruption that abroad is often attributed to Laki volcano, directly and indirectly killed about six million people. Millions of people died in Europe and the Americas, including indigenous people across North America. Almost two million Japanese died and a large number of people in China. It all started on a Sunday in the east in Skaftafellsýsla. Reverend Jón Steingrímsson describes this in his remarkable diary:
In this time a lot of diaries and chronicles were written about most countries. Newspapers were published in many cities of the world and reported on the weather and changes in nature. From all this data you can see what consequences the eruption in Iceland had on people’s lives in the most unlikely places, how it brought its dark paws over one country after another. Everywhere it got dark for a long time and everywhere the sun became red as blood at sunset. The pyroclastic cloud reached Norway, Scotland and the Faroe Islands on June 10, or two days after the eruption began. The gray fog of ashes had arrived in England on June 22, and on the 24th, the fog covered all of Europe, as far east as the Adriatic Sea. In the month of July, the lack of sun and the volcanic ash began to have consequences in Russia, Siberia and China. Reports of an unusual droughts came from India and the Yangtze region in China, where extreme cold also raged throughout the country in the summer of 1783. The Gray Fog (Gráaþokan), as it was often called, had a great effect on the nature of Syria and Egypt that summer and the annual Monsoon rains were nullified. The result was a severe water shortage and famine. In January 1785, a sixth of the then population of Egypt had either fled the country or died.
On the east coast of the United States, the winter of 1784 was five degrees Celsius colder than usual. In the harbor of Charleston, Virginia, you could skate around on ice. Ice floes moved down the Mississippi and there was an ice floes in the Gulf of Mexico. At its worst, the volcanic ash, or igneous rock in the upper atmosphere, covered a quarter of the entire earth, or the entire northern hemisphere down to 30° latitude. The impact on the environment and weather conditions was great and decisive for the next two years. Since the gray fog became persistent in Europe and elsewhere, it is estimated that up to a thousand kilograms of sulfuric acid (H2SO4) fell on every square kilometer of land in the first five months of the Skaftár fires.
The scenario affected crops in Europe for many years. The ensuing famine caused great social unrest and riots. About one million French people starved to death during this time. It is also widely accepted that the French Revolution had its roots in the aftermath of the Shafter fires. It is not considered unlikely that an eruption of this magnitude in Iceland today would have a huge impact around the world by possibly stopping all flights in the northern hemisphere for a whole year and better! Human ages have passed since the Skaftáreld and time, although long, heals all wounds. Conditions at Laka were at one time as hostile to all life as can be imagined. Poisonous fumes floated over the land that was then in the making, but now, more than two centuries later, soft beds of moss cover the rough lava, and crater walls and lava flows shelter all life. The craters at Laka and the surrounding lava are one of nature’s artistic gardens. There are moss-covered craters of all shapes and sizes, and some of them have either clear or blue-green ponds. In some places, beautiful low vegetation thrives in the shelter of the crater walls.