Can Yellowstone Trigger an Ice Age?

There is no scientific evidence that a Yellowstone supereruption could directly initiate a new Ice Age. While a massive eruption would inject vast amounts of ash and sulfur aerosols into the stratosphere, causing global cooling for several years (a "volcanic winter"), this is a temporary climatic perturbation—not a sustained glacial period. Ice Ages are driven by long-term orbital cycles (Milankovitch cycles) and feedbacks in the climate system over tens of thousands of years.