To the Editor: Walters recently suggested that Australia should implement population control strategies as part of an approach to reduce global warming.1 As a father of four, I found his assertion that my decision to father more than two children is “arrogant” to be offensive.

Walters’ arguments are, at best, poorly reasoned. As a “citizen of this world”, he clearly rejects the rights of other citizens to live on an equal footing and follow their religious, cultural or social beliefs if those beliefs oppose contraception. I would argue this is contrary to law.2,3 His mathematical calculations ignore all costs required to achieve his objective, such as those associated with “contraceptives, intrauterine devices, diaphragms, condoms and sterilisation procedures”. Further, he fails to consider costs associated with the supporting bureaucracies required to effect his policy, including material amendments to the Australian taxation system. Rather, and in my opinion strangely, he advocates issuing carbon credits for the additional consumption of contraceptive products.

According to Walters, people should be judged by their anticipated rather than actual emissions. A logical extension would be to punish those who exceed a predetermined mean acceptable level of emissions. No doubt, meeting the medical and ancillary needs of many sick, older and disabled people often generates excess emissions. Perhaps we should adopt some of the practices used in China and India, including abandonment and neglect of disabled children and older people.4,5 How would we deter and punish those who cannot pay?

Walters addresses the issue of overpopulation by comparing Australia to India and China. This is notwithstanding that Australia has one of the lowest population growth rates in the world6 and, with its ageing population and labour shortages,7,8 has significantly different population and social concerns to these countries. There are no grounds to support the comparison made.

Environmental issues are among the greatest challenges facing society. As a father, I am deeply concerned for the world my children will inherit. We must deploy our limited resources efficiently and effectively to maximise their impact. To demand social controls in the manner Walters suggests, within a society heavily burdened with laws and struggling to meet labour and health system demands, would defeat this objective.

Reading Walters’ views, which I consider fundamentally flawed, in a publication such as the Journal imparts to them a validity I believe is unjustified. I do not consider that Walters’ social engineering policies could benefit anyone in Australia, while his “moral” concerns are ill conceived.

In reply: I thank Smith for the opportunity to clarify some scientific points. The science behind climate change is undeniable and was reviewed in February this year. Moreover, “there is a greater than 90 per cent probability that the warming observed since the 1950s is due to human activities”. Therefore, attempts to prevent environmental calamity will not succeed with boundless population growth. In this sense, the more people there are, the worse it is for our earth. In particular, no nation should encourage population growth. I do not argue for compulsory sterilisation. I do argue that we recognise the cost of every extra human being to our overburdened earth.

Smith labelled my note of caution about limitless procreation as “offensive”. I believe such disparagement is founded on personal and cultural beliefs, not on science, which informs and guides medicine.

There is only one atmosphere. Australians occupy this planet with no more rights than others do. Racism is anathema to us. If others must observe population restraint, then so must we.

Contrary to Smith’s assertion, I plead that all should be able to “live on an equal footing”. Is this not the laudable basis of law? I share his concern for the world that his “children will inherit”; my concern embraces the children of others as well.