An 1815 volcanic eruption in Indonesia was followed by a three-year famine around the world. This was due to:
a.The eruption's ash and gas significantly dimmed the sun.
The volcanic ash and gases like the sulphur dioxde remained suspended in the atmosphere for years. This reduced the availability of sunlight and hindered the process of photosynthesis that the crops perform for their growth. This lead to the death of farm crops causing a global shortage of food production (famines).
e.The eruption contributed to global warming.
The volcanic gases like CO, CO2 and CH4 caused the warming up of earth in the later years. This changed the weather patterns in various parts of the planet leading to drought, floods and cyclones. Such drastic climatic changes harm the crops and lead to their shortage.