Since Yellowstone Eruption, the climate of the world has been altered significantly. Not only have weather patterns been affected, the average world temperature has dropped and the ice has more claimed large tracts of land for itself. The world as we know it has been plunged into a sort of premature ice-age, with the temperatures not as cold as the last ice age and less ice covering up land in the north.
Climate Change post-Eruption Day
Predictions of numerous geologists pre-eruption day on the supervolcano Yellowstone erupting was proved right in part, with many theories being disproved.
Predictions of a Volcanic winter came true in a major fashion. What had occurred numerous times in history occurred again, but in a heavily intensified manner than before. Ash and sulphur dioxide were pumped into the air in a large manner by the supervolcano. The eruption was the largest in the world since the Toba explosion some 70,000 years ago and caused a small chain reaction in the explosion of volcanoes around the chain of fire. This would lead to the creation of new land at a largely rapid rate, but also cause numerous Tsunamis which would affect various nations on the Pacific Rim.
The Volcanic winter following Eruption day would not end so quickly. What would follow the eruption would be something which would come to be referred to as the Decade of No Summers in later years. For more than a decade, the world would be locked in a cold age as ice caps began to once more expand from the poles and the temperature grew cold, with no summer to speak of.
This would cause the largest human extintion event since the Toba explosion and would nominally half the world's population.
Summer would return to the planet following the Decade, but in a slightly milder fashion and would allow for the world to once more feed itself. In the Decade, the ice caps had begun to rapidly retreat southward, forcing millions of people southward from areas of the north where the ice had taken permanent hold. This continued, albiet at a much slower rate and allowed for the extent of the ice caps to be finally mapped. Another effect could also soon begun to be seen. Sunken land once more began to surface and allowed for the extending of farmland to newly uncovered lands.
The Effects of post Eruption Day climate change have been noted by scientists to be fairly similar to the last Ice age recorded on the planet from around 100000 BC to 8000-10000 BC - although a much milder version of it. This had lead to increased monsoon all over former deserts and the transformation of many of them into savannahs and wetlands.