Yesterday I commented about if there were a global oubreak of volcanic activity there could possibly be an increase in atmospheric temperature. I was criticized because the common thought is that there would be global cooling due to smoke and sulphur dioxide gases. That’s possible, but there’s other types of eruptions such as fissure eruptions which put out less smoke than stratovolcanoes. Large and I mean LARGE lava ((igneous) outpourings in geologic history has increased global temperatures according to geologists.
The major Laki fissure eruption of 1783 in Iceland caused much cooling and crop failure in Europe and probably was a significant factor in the outbreak of the French Revolution.