[quote][b]Posted by:[/b] YakZSmelk [quote][b]Posted by:[/b] Spirit of Ember I'm guessing it's somewhere around 5 billion.[/quote] That cannot be right. If I had to guess without war and with no space travel the Earth would have about 50 billion in the time of Halo. Obviously there was alot of war and alot of space travel. so I would guess the population would be more around the 20-30 billion range in Halo 4. After Halo 4 I'd say around 13-24 billion. That's assuming the blast from the Didact was as insane as it looked.[/quote] But, according to the Bestarium, the population of Earth at the end of Halo 3 is estimated to be only around ~200 million. (Which is described as being a "sudden change".) So, if you take into account how much Earth's population would grow after 4 years plus the population of humans on the remaining UNSC colonies, it would probably add up to around 5-8 billion. But who knows? It's just my guess. [Edited on 12.08.2012 8:07 PM PST]

The Composer blast pretty much killed everyone in New Phoenix or something. So, we can pretty much assume that casualties were <5 million from the whole shabang. Populations tend to regenerate slowly, so I'd think that ~40-50 billion would be about correct. Much of Africa was glassed, but much of Africa is also uninhabited. The handful (maybe a dozen or so) of major colonies that weren't hit by the Covenant during the war would also probably have a few billion each. The remaining settlements are, I would assume, primarily small military/scientific/mining facilities with negligible population. Incidentally, the scene in the H4 Epilogue when the Marines search New Phoenix for survivors is my absolute favorite moment in all the Halo games I've played for some reason.

[quote][b]Posted by:[/b] Spirit of Ember I'm guessing it's somewhere around 5 billion.[/quote] That cannot be right. If I had to guess without war and with no space travel the Earth would have about 50 billion in the time of Halo. Obviously there was alot of war and alot of space travel. so I would guess the population would be more around the 20-30 billion range in Halo 4. After Halo 4 I'd say around 13-24 billion. That's assuming the blast from the Didact was as insane as it looked.

I'm guessing it's somewhere around 5 billion.

As far as I know, nobody has released any actual numbers via books or anything. If I had to guess, it's logical to assume it's higher than H3/post-H3.