What about a sky full of ashes and the temperatures go down??

The eruption of the volcano Krakatoa on August 26-27, 1883, was well recorded and studied eruption of a volcano over several years than. But what do we know of the climatic impact today? A plan B has not been prepared.

Few hours ago an Icelandic volcanic eruption has begun.

More at: https://oceansgovernclimate.medium.com/an-eruption-on-iceland-looms-is-a-plan-b-prepared-b06f052884f

That can serve as reminder that the lessons from Krakatoa have not been learned yet.