No, I don't believe the world will end, eventually it will because earth will be unable to sustain x amount of humans for x amount of time. Also, in 4 billion years the sun will run out of hydrogen to produce heat, therefore the sun will burn out and turn into a massive black hole, I may be wrong, but considering the Sun is a main sequence star that is usually the cycle of a star.
There are also possibilities of another ice age or automic war fare, but for now fingers cross that won't happen.
