A child born in the west will consume vast amounts more resources than multiple children born in poverty.
Empowering women, with education, economic freedom, and reproductive choice, is the Correct Answer.
Fortunately, much progress has been made and will continue.
36 billion by the end of the century. You would have to convert all the land on Earth to farms and you still wouldn't be able to feed this many people.
216 billion by 2200 Which is almost four times as many as we could support if every planet in the solar system supported the same amount of people Earth does now.
1296 by 2300 An absurdly large number of people. You need to start expanding to other solar systems if you haven't already because this one is running out of resources. Transporting billions of people interstellar distances would take a ton of energy also.
362,797,056 billion (363 quadrillion) by the year 3000 We are running out of planets in the milky way to house them all.
2.19×10^25 by the year 4000
1.33×10^33 by 5000 We are out of planets in the universe to house them all.
8.02^40 by 6000 Now we are running out of atoms to make more humans.
And this is only 4,000 years, not even the amount of time civilization has been around. Not even a tiny fraction of the length of time humans have been around. Barely a blink of the eye for the age of the Earth, let alone the universe.
Exponential growth is a serious force.
It is naive and stupid to state that overpopulation increases the chances of a species' survival.
Please show your work.
Attempt #2: Gravitational potential energy = kinetic energy = .5massescape velocity^2. = .5human bodyweight kg 11,200 m/s. Convert the units and you've got a few years worth of calories (which I think I mixed up with kilocalories the first time).
As countries grow richer birthrates tend to trend downwards, for a variety of reasons. The one country that actually took population growth seriously and tried doing something about it (China) continues to get shit over its policies today (sometimes for good reason). Just providing people in developing countries with access to contraception ignores many of the reasons that people in those countries choose to have large families.
Finally, I've read that UCSD guy's blog, and while I respect his expertise, I can't get over the fact that his analysis often seems to rest upon rather shaky assumptions. For example, one of the blog posts he links to ("Galactic-Scale Energy") argues that exponential growth means that even a modest ~2% growth rate, sustained into the far future, would result in humanity needing to consume ludicrous amounts of energy. The math is sound, but the assumption is that the human population will also continue increasing exponentially (e.g. 1%), meaning that economic output continues to be divided among the current populace at a rate that is not necessarily exponential. However, if population growth really is slowing down (as statistics show [0]), then 2% growth into the far future with a constant or slowly increasing population results in a ludicrous amount of economic output available on a per-capita basis. The author's point is that unchecked growth is a bad thing; I don't think unchecked economic growth is even meaningful in the context of a population that is no longer increasing. Many of his other posts contain similar 'spherical cow' assumptions meant to make his mathematical models more appealing in terms of presenting his overall message.
[0] http://en.wikipedia.org/wiki/File:World_population_growth_ra..., data from US Census Bureau.