There's no evidence or suggestion carbon dioxide was responsible for these well known shifts in climate in the recent past. Clearly, earth cooled & warmed rapidly in a random way & has done so throughout the 11,700y Holocene interglacial. If CO2 had caused these changes, wouldn't someone say so? But CO2 is not the reason as dust/ soot is the main factor Soot particles, chemical substances from, among other things, the explosions of the volcanoes, blocked sunlight and partly because of this a greenhouse effect was created in the world for long periods of time, many hundreds of years :grinning-face: