[user104658]

Originally Posted by Twosugars

Read somewhere that around 1 billion is sustainable for the planet.
The current forecasts say well reach 11 billion before it starts falling.

1 billion is sustainable at subsistence levels, if we're talking about every person being able to live in the land of milk 'n' honey it would have to be a lot less.

Here's a scary list:

1 Squirrel Unknown
2 Bat Unknown
3 Mice Unknown
4 Rat Unknown
5 Human 7.6 Billion
6 Cow 1.5 Billion
7 Sheep 1.1 Billion
8 Pig 1 Billion
9 Dog 900 Million
10 Goat 860 Million
11 Rabbit 709 Million
12 Cat 600 Million
13 Water Buffalo 175 Million
14 Horse 60 Million


Take out the rodents:


1 Human 7.6 Billion
2 Cow 1.5 Billion
3 Sheep 1.1 Billion
4 Pig 1 Billion
5 Dog 900 Million
6 Goat 860 Million
7 Cat 600 Million
8 Water Buffalo 175 Million
9 Horse 60 Million


Take out the large mammals that are only there because humans breed them for food etc:

1 Human 7.6 Billion
2 Dog 900 Million
3 Cat 600 Million
4 Horse 60 Million

It's just us and our pets - none of which even number a billion - and no other species of mammal in the world even gets close to 50 million. Wups.