A single volcanic eruption could potentially destroy all life on Earth. The most likely way this could happen is if the eruption released enough ash and sulfur dioxide into the atmosphere to block out the sun. This would cause global temperatures to drop dramatically, leading to a phenomenon known as a "volcanic winter." The cold temperatures would kill plants, which would in turn kill animals that rely on plants for food. The extinction of plants and animals would disrupt the entire food chain, eventually leading to the extinction of all life on Earth.