xxJing wrote:

Also while this is old, it's pretty similar to what I've seen in multiple geography books.

[image removed to conserve space]

What this essentially means is that there is no population growth problem for first world countries. In fact there is actually a bit of a population decline in first world countries. Educated well off people generally do not have that many children. Rarely more than 2, and it's been stated that 2.3 I think the number was, was the number of children per fertile woman required to keep a country's population stable.

The massive population growth almost exclusively happens in countries stricken by poverty.

So in essence, there is no reason to be sterilized. If you have internet and can speak English, more likely than not you aren't going to have a crap load of children anyway.

Not quite. The difficultly is inherent to the word "growth rate." Because America (and presumably the rest of the world) is so terrible at explain percentages, it's never clear whether or not the growth rate is r or 1+r, where r is the nominal value. To put this in perspective, if I say you need to pay 20% more for a shirt, it means you need to pay 120% of it's base price (hence you add one)--it's not actually clear what I mean. Since the source is the CIA Factbook, we can actually confirm what they mean: https://www.cia.gov/library/publications/the-world-factbook/rankorder/2002rank.html

"Population growth rate compares the average

**annual percent change** in populations, resulting from a surplus (or deficit) of births over deaths and the balance of migrants entering and leaving a country. The rate may be positive or

**negative**."

First of all, if they were just giving the nominal growth rate, it'd be always positive. The other bolded statement ("annual percent change") confirms this. This actually means that all countries are increasingly steady, with an additionaly "x percentage" of the population in question.

In this context, 1% is a scary big number. In particular, let P be the population in some year t. Then P(t+1)=(1+r)*P(t), which for r=1%, we obtain that a graph that looks like this (letting P(0)=300 million, which is America's population right now). For reasons that involve calculus, this is approximately decently by P(t)=300exp(r*t), where 300 comes from the fact that America's population is 300 million.

Note: to get the exponential equation, first consider the the time anytime later such that P(t+1)=(1+r)*P(t) is instead P(t+Δt)=(1+r)*P(t) (it's the same equation, except Δt is restricted to years). Rearrange as necessary, and take limit as Δt->0, get a differential equation, and then let P(0)=300 million, that is, t=0 corresponds to about 2--6=2007.

Anyway, plot P(t)=300*exp(1%*t), keeping in mind the y-axis is millions of people and t is years, and you'll see that it doesn't take long to double: http://www.wolframalpha.com/input/?i=plot+P%28t%29%3Dexp%28t%2F100%29*300 . In fact, the doubling time is about 70 years. So in about 2080, if the trend continues, we could be looking at twice the amount of people.

Maybe that's scary and maybe it isn't, but because of how terrible percentages are reported, that graph doesn't make it clear how big some of those numbers are.