China's 1 child policy (now 2 child, I guess) is a difficult to fully form an opinion on.
On one hand, "population crisis" is something a lot of people are concerned about^ and the policy was a direct and practical way of tackling it. On the other, it is unmistakably totalitarian.
Going to 2 is a strange choice. It's just as totalitarian, but probably has a fairly negligible effect on average fertility rate. I guess they don't see
^On a tangent, I don't totally buy population crisis and judging from how rarely I hear it mentioned these days I think I'm not alone. There is obviously some natural limit on human population, but I don't think we're near it.
The fact that we hear less concern about it is says something interesting about the zeitgeist. I think people believe in technological progress more in 2015 than they have since the space age and nuclear age of 50 years ago, maybe more than ever. At our current rate (ignoring the projected gradual reduction) we'll double every 65 years. I can certainly see us absorbing doubling population density in that time considering all the empty oceans, deserts, the potential for landless food productions, megacities and all that jazz. I mean, If the US & Australia went to the population densities of Germany and France (moderately dense with quite a lot of open spaces), we would be good for another 100 years.
Basically, I think we have the space.