What would happen if every human in the world suddenly vanished? When they were driving to work or eating breakfast their food falls on top of their plate with no one to eat. If they never came back what would happen. The cars would start to crash, the planes would start to fall, the Electricity would fail and unstoppable chaos would break lose. I think most species would die but some would grow, with no humans around they are free to come into the cities and farms and eat the plants and animal and the domestic animals would either have to escape from the house to save themselves from starvation or get stuck inside and die. That is why we should never disappear or else the planet will be doomed for ever.