The global impact of the largest volcanic eruption in recorded history: The Year without Summer.

In 1815, the year of the Battle of Waterloo, another event was occurring half way around the globe with a world-wide impact that would last for decades. In the Dutch East Indies (Indonesia), Mount Tambora erupted with such violence over a sequence of days in April on the island of Sambora that vast amounts of ash and dust circulated high in the atmosphere. It wasn't just the particulates, but sulphur dioxide emissions that had additional significance. It led to what became known, in 1816, as - the Year without Summer.

Snow and frosts in May, June and July of 1816 in much of the northern hemisphere killed crops and reduced the harvest. Dark, cold days when candles had to be lit at midday. Orange snow and red fog were just some of the visible consequences. Poor harvests in subsequent years increased the impact and tens of thousands died from starvation or were reduced to poverty in a number of continents. Economic problems in Europe, already severe due to the Napoleonic Wars, intensified - leading to social and political unrest. Riots, the Peterloo Massacre, the writing of Frankenstein, and even the American Civil War half a century later may have had their nurturing in the impact of the Mt Tambora eruption - the largest recorded volcanic eruption in world history.

This 'In Our Time' broadcast with Melvyn Bragg and guests is an intriguing listen, and would be ideal to set as preparatory research for a discussion with your students on whether a major volcanic eruption today would have similar - if not more severe - impacts on the environment, and the social, economic and political dimensions of a far more globalised world.

http://www.bbc.co.uk/programmes/b077j4yv