Did Tambora eruption help defeat Napoleon at Waterloo?

On April 5 1815, Mount Tambora erupted on the Indonesian island of Sumbawa, killing some 100,000 people. The next year, 1816, became widely known as 'the year without a summer', as gases, ashes and dust drifted over the entire globe, reaching the stratosphere, where they remained long enough to create 'an enormous sun filter'.

The summer-less summer of 1816 even inspired writers, such as Mary Shelley who wrote Frankenstein, a gothic novel set in often stormy environments and gloomy weather conditions ('Yet I did not heed the bleakness of the weather').

Now, research seems to indicate that the effects of the eruption of Mount Tamboro were having a detrimental effect on the weather much quicker[1]. The eruptions can hurl this electrified ash much higher than previously thought into the atmosphere – up to 100 kilometres above ground. Very small electrified volcanic particles from eruptions can 'short-circuit' the electrical current of the ionosphere – the upper level of the atmosphere that is responsible for cloud formation. This ultimately leads to sudden formation of clouds.

These clouds brought heavy rains across Europe that contributed to Napoleon Bonaparte’s defeat at the Battle of Waterloo from 16 to 18 June 1815.

Author of the research, Dr Matthew Genge, explained: “Vigo Hugo in the novel 'Les Miserables' said of the Battle of Waterloo: "Had it not rained on the night of 17th/18th June 1815, the future of Europe would have been different …an unseasonably clouded sky sufficed to bring about the collapse of a World.”[2].’

[1] Genge: Electrostatic levitation of volcanic ash into the ionosphere and its abrupt effect on climate in Geology - 2018. See here.
[2] Wheeler, Demarée: The weather of the Waterloo campaign 16 to 18 June 1815: Did it change the course of history? in Royal Meteorological Society – 2005. See here.