Question: How can the world end, is there any acctual reason?

Drew Rae answered on 13 Jun 2011:

There are a number of ways the world could end. In most of them there would still be a planet, but it wouldn’t look at all like it does now. All of these are very unlikely, or a long time away.

1. We could have an environmental event that makes it hard for people to live. The earth regularly goes through periods when it gets hotter and colder over tens of thousands of years. The very cold times are called Ice Ages (or Glacial Ages), and the last one was 20,000 years ago. During an Ice Age Ice covers most of the places where people live, but near the equator things aren’t so bad.

A more immediate worry is the earth getting too hot. The amount of carbon dioxide (CO2) that humans produce from industry or power generation is making the earth heat up slowly. You only need a fairly small increase to change the weather, and to make the ocean rise higher from melting ice.

2. We could have a single big event like a nuclear war or a super-volcano erupting. All of the ash and dust from this could block out the sun, killing a lot of the plants and the algae that the fish eat.

3. We could get hit by an asteroid. Big asteroids regularly come fairly close to earth, and scientists try to keep track of all of the big ones. With enough warning we might be able to knock an asteroid off-course if it was going to hit us.

4. The sun could get too old. Eventually it will start to get colder and bigger – don’t worry, this isn’t going to happen any time soon.

5. The Vogons could decide to destroy earth to make room for an interstellar bypass. (This isn’t a serious science answer, but some people who believe the world will end soon do believe that it will happen because of aliens or supernatural forces).