end of the world???

Depends on how you define "end". Do you mean an end to the existence of life on the planet? or the end of the planet itself? There is a pretty much certain end to the existence of the planet itself in a few billion years, when the sun enters it's end of life phase, expands out and swallows the entire inner half of the solar system, though earth will become uninhabitable long before that, probably a billion years or a little less, as it heats up from the sun's slow expansion. There is also constitutional drift that will eventually alter weather pasterns and alter the climate drastically that may or may not be a life ending event. Of course we could be smacked by a meteor tomorrow we never saw coming. Just a bundle of cheer aren't I? lol.

Well, since our sun is a G2 type star it will eventually (in about 5 billion years) grow into a red giant and swallow earth. So if by world you mean the planet we live on, yes it will end. I personally believe it will end long before that, probably as a result of a man made error, most bad things usuallly are.

You did not know how the world looks before your arrival on this beautiful world. It is very very difficult to say how the world ends. This is not our botheration - let us not waste time thinking. There is some other Supreme power which looks after that. Just enjoy life until it is live -this is my suggestion.