You are asserting that the genocide that China is perpetuating on its own female children stems solely due to its favouring of boys over girls. How about you read a bit more of the article!

From page 407,
“China’s population controls aim to reduce the number of births while ensuring that children born are only of the highest quality. Centuries of inbreeding in rural communities, a high prevalence of congenital hypothyroidism resulting from lower than normal iodine content in the soil of many rural areas, and hereditary diseases have contributed to higher than normal rates of mental retardation in many rural provinces. In an effort to eliminate this problem, the Chinese government instituted a series of measures including restrictive marriage laws, compulsory (or coercive) sterilizations, and forced abortions”.

From page 408,
“Interest in eugenic principles to promote a mentally and physically fit society is not a new phenomenon in China”.

This is the very definition of eugenics, as originating from the US to Nazi Germany and then back to China, and the floodgate is opened wide when we take it upon ourselves to minimise outputs, but also to maximise the quality of human beings.

So what are the methods that are universally employed whenever population control is deemed necessary, regardless of the motivation?

From page 399,
“This has led to the use of local informants to discover unauthorized pregnancies, monitoring women’s menses at the work place, and the implementation of draconian measures which include violence against women, forcible late-term abortions, forced IUD insertion, forced sterilization, the detention of pregnant women or their family members, and the destruction of “over-birth” families’ homes”.

Sound like the wonderful utopian vision you desire for NZ society in the years to come?

If you would like to actually have a clue about the 'reasonably humane' One-child policy, have a read of this article,

The Cardozo Journal of International & Comparative Law, Volume 15, Fall 2007,
"The dysfunctional progeny of eugenics"
http://www.cjicl.com/issues/15-2-Martin.pdf

Skip ahead to page 403 to start reading the fun stuff if you like,

"Being born is simply the first hurdle Chinese females face. Infanticide and abandonment, on the rise since the mid-1980s, led to the murder of an estimated fifteen million children from the initia- tion of the One-Child Policy until 1995, and one million females are left in orphanages every year. Many of the young girls who are turned over to state-controlled orphanages are destined to die from neglect, starvation, and exposure. In 1991, at the Shanghai Children’s Welfare Institute, China’s most prestigious orphanage, the death-to-admissions ratio was 77.6%. Additionally, the likelihood that an orphan would survive more than one year was less than fifty percent in 1989, and in some provinces the mortality rate among institutionalized orphans ranged from 59.2% to 72.5%. Females comprise ninety-five percent of the children in orphan- ages, and unlike many of their male counterparts, these abandoned girls are completely healthy. Nor are these girls always infants. In rural China, girls as old as five have been abandoned after family-planning officials began a “mobilization campaign” to enforce the policy. According to the Human Rights Watch of Asia, once these girls are admitted to an orphanage they are subjected to deliberately cruel treatment, including starvation, torture, and sexual abuse. Moreover, in a fashion reminiscent of Nazi Germany, children are selected through a process known as “summary resolution” whereby unwanted children are subjected to intentional starvation and dehydration."

Re: population, people forget what things used to be like in places like London, where everyone burnt dirty coal and streets were crowded.

Nowadays there are far more people living in London, but it's a far, far better place to live.

Humans can change local climate, but whether we can make changes to the global climate is quite another question.

Whether we can (or should try to) reverse any changes (assuming they exist) is yet another question, and that's quickly becoming less of a scientific question and more of a political one.

[ as a bit of an aside - there is a body of opinion, impossible to test, that Europe's transition from a feudal subsistence economy to the renaissance was not unrelated to the population collapse caused by the plague]