Mount Tambora
During the northern hemisphere summer of 1816, global temperatures cooled by . This very significant cooling directly or indirectly caused 90,000 deaths. The eruption of Mount Tambora was the most significant cause of this climate anomaly. While there were other eruptions in 1815, Tambora is classified as a VEI-7 eruption with a column tall, eclipsing all others by at least one order of magnitude.