A documented event
On 10 April 1815, Mount Tambora in what is now Indonesia produced one of the largest recorded eruptions. NASA links material in the atmosphere to reduced sunlight, global cooling and the 1816 “year without a summer”.
The distance between Sumbawa and farms elsewhere makes this a useful case: where a shock begins is not necessarily where its consequences appear.
What to compare
A sound comparison needs a timeline, physical mechanism, geographic reach and documented effects. The case does not provide a weather or crop forecast for today. It gives us a way to ask better questions about indirect effects.