If a super volcano were to erupt it would cause worldwide effects socially, economically and environmentally, this is because when it does erupt many people will die, the surrounding area will be destroyed and finally the country that has the super volcano, due to the damage and destruction they cause, will lose a lot of its profits. Super volcanoes have primary and secondary effects. Primary effects are things that occur as a direct result of the volcanic eruption, if we look at the eruption of Mount Toba in Sumatra that happened about 74,000 years ago it had a huge primary impact on humans and the ecosystem at that time. Many human beings were killed (a social effect) and a lot of plants (environmental effects) were killed because of the lava or the poisonous gases that the volcano released. If a super volcano erupted today people, building, plants and other surroundings would be affected; responses to this would be the government would have to rebuild the lost damage which would use a lot of money- affecting the economic welfare of the country.
Secondary effects are effects that come after primary effects, so in the case of Mount Toba the eruption caused the global temperature to plummet because the eruption that gave out Tephra (rock fragment ejected by a volcanic eruption) blocked the sunlight for months. If this happened today then world agriculture would be devastated and due to this, crops and some livestock would be killed and without supplies many people would starve. Since many people would have died in and as a result of the eruption the population would decrease greatly. Settlements near to the volcano would