How will the planet end?

[Aoi Magi]

I can't quite remember the name but I read a good sci-fi book recently which is about a ship full of humans trying to survive in space but to go anywhere they have to stay and breed in space for a few generations, however without the earth's diverse ecosystem, it doesn't go too well and each successive generation gets physically and mentally weaker.

Was it the novelization of Wall-E?

It's more like a cross between Wall-E and The Hundred. It's quite interesting to read though because it deals with what we could actually do with our current technologies.

[abaris]

What do you guys think is the most likely scenario?

Without looking at the presented reasons, the sun going having spent all it's energy is a pretty good guess.

[Jackalope]

I'm going with "eaten by an ancient tentacled horror".

[Thumpalumpacus]

I like this one!
Looking forward to it but fear  I will be decrepit and too mentally deteriorated to appreciate the disaster to its fullest!

Thursday 9/11/2040 has inspired a broad range of researchers and publicists to preach doom and destruction. And no wonder. In the early morning hours of this particular Thursday, a rare cosmological event will take place. All visible planets -- Mars, Saturn, Jupiter, Mercury and Venus -- will align with both the Sun and the Moon. They will be in an exact row.

You won't be able to see much of it, since the brightness of the Sun will make the view on everything else impossible. But according to the doomsayers, we will definitely notice something. Just picture this: there's SEVEN huge objects in the sky, tugging at our tiny planet with their combined gravities. This will cause the Earth's axis to tilt, moving Middle Africa to the North Pole and the icy Antarctic to the equator.  

It will be quite a disaster. Rapidly, the ice caps of the poles will melt, causing massive floods and huge tsunamis all over the world. Millions will drown, entire continents will be flooded. Not to mention the faith of those poor Africans and Latin Americans, who will suddenly find themselves living on one of the poles!

And that's just the beginning. The tidal forces of the seven heavenly bodies combined will trigger earthquakes bigger than we've ever had. Also, there will be volcanoes erupting everywhere. If you don't drown, chances are you're crushed by a collapsing building or covered in lava. Well, if that isn't what you call `the end of the world', what is?

They feared something like that back in 1979 or 1980, I think, and many of the same fears were unrealized. When a human is born, the gravity exerted by the obstetrician on the child is stronger than the gravity exerted by Jupiter. I don't think the planet will be any more discombobulated than the newborn.

[Minimalist]

We're definitely going to blow ourselves up.

This is about the planet, not about humanity. I'm not sure you're able to blow the planet up.

[The Valkyrie]

The only problem I'm encountering with my plan is the huge cost of building a death star.

Donations accepted.

Maybe I should start an online donation....

[T.J.]

We're definitely going to blow ourselves up.

This is about the planet, not about humanity. I'm not sure you're able to blow the planet up.

On the link that's in the OP one of the things listed on the site is 'Boom' which goes on to talk about Nuclear Winter, which is what I was referring to.

[ignoramus]

The only problem I'm encountering with my plan is the huge cost of building a death star.

Donations accepted.

Maybe I should start an online donation....

Happy to donate Beccs, but please don't wear your hair in "buns".

[The Valkyrie]

The only problem I'm encountering with my plan is the huge cost of building a death star.

Donations accepted.

Maybe I should start an online donation....

Happy to donate  Beccs, but please don't wear your hair in "buns".

A ponytail is generally the only form of "up" my hair does, normally.

[Iroscato]