Funny, I don't see people tripping up all over each other with over 6x more than your number there
Once again, it's not about space, it's about resources. It's funny that only a few of you seem to get that. Sure we could cram more and more into a tiny space and let the rest of the Earth be farmland, but the Earth does have its limits.
Unless humanity starts changing the way it consumes energy and other resources there will be a huge problem in the next 100 years.
Oil and food will be short and those will be sold at premium prices that most will not be able to afford.
We need different energy and food sources. And yes, even those genetically manipulated crops are showing signs of failure as many that were engineered to be resistant to certain bugs are already showing weak points and those bugs are the ones becoming resistant to those crops and eat/attack them once again.
And those that think we will level out...I think we wont, the number will rise exponentially untill some form of disaster happens or we limit population ourselves through diverse means.
Advances in medicine are one of those things that is changing the natural order of things. The survival of the fittest rule of evolution no longer applies because of it in this day and age (and this is coming from an MD).
I'm not saying what I'm doing as an MD is bad (I love helping people) but we are the ones that have changed the human population drastically from what it was 100 years ago and many people that would have died of natural causes, simply haven't and have been given a chance to procreate and increase our numbers.
If that immoratlity gene becomes reality and its use becomes widespread and we still procreate the way we do know, then the sh*t will really hit the fan, so to speak.