Ecological doctors, like environmentalists generally, are conflicted about population growth. On one hand, in a crowded world, creating genuinely sustainable societies can be supported by medical practices that support limitations on population growth, such as first-class sex education, adequate contraception and access to termination of unplanned and unwanted pregnancies. Conversely, clinicians with fundamental religious beliefs about the sanctity of individual lives challenge these activities.

Humans are not just like birds. We can’t just fly away for the global winter.

Somewhere in the heated arguments, one of the greatest threats to global survival, unsustainable population growth, gets lost;  especially when attention is focussed on the populations of largely overdeveloped and underpopulated continents such as Europe, North America and Australia.

In prior centuries, the growth and decline of the human population occurred in cycles. The growth can be related mostly to improved childbirth and sanitation practices. The declines are largely due to conflicts and epidemics. In the 20^th century they included the World Wars and the influenza and HIV epidemics. More localized conflicts and medical advances have limited these downward swings in the global population and enabled increased migration.

There is not much clinicians can do to alter carbon emissions or change global migration crises other than to provide humanitarian care. According to the UN, by 2100 the population of Africa is projected to reach 4500 million compared with the 50 million projected population of Europe. It is no wonder that there is mass migration.

Humans, however, are not just like birds. We can’t just fly away for the global winter. Even with increased immigration to redirect some populations, the unsustainable growth of people won’t be alleviated.

There is a lot that can be done to educate our patients in our own countries about avoiding overpopulation through thoughtful planned parenthood. We need to become ecological doctors and provide rational and locally relevant advice to our communities about the ill health effects of overpopulation.  This is not just a global public health problem, it is the legacy of the current and future generations everywhere to ensure sustainable populations.