In the summer of 1783, the largest volcanic eruption of the past1,000 years killed 9,000 Icelanders, dumped three cubic miles of lavainto the surrounding region, and spewed out more than 100 million tonsof gases.
As if that weren’t bad enough, Rutgers University climatologist Luke Oman says, the eruption of the Laki volcano created a climatic disasterthat rippled all across the Northern Hemisphere and caused a faminethat cut the population of the Nile River valley by a sixth.
Using a NASA computer model, Oman tracked the worldwide effects ofthe sulfate aerosol cloud that formed following the Laki eruption. Theresults show that the cloud blocked enough sunlight to cool largeportions of Asia and North America. Tree ring data support the model’sconclusion, showing that in some areas, the summer of 1783 was thecoldest in more than 500 years. That chilling, in turn, disrupted thedelivery of seasonal rains to Africa and India. Because monsoons resultfrom the temperature differences between land and sea, the yearlymonsoon was so weakened that northern Africa and India experienced adevastating drought.