The notion of overpopulation is one that is very much woven into ideological views. Those who wrote on the topic invariably refer to Malthus, and neo-Malthusian perspectives, to lay their argument. The best known of the neo-Malthusian writers is, arguably, Paul Ehrlich. These authors have been seriously criticized for the shortcomings of the neo-Malthusian approach, and such criticism is actually based on facts.
Anyone who knows about demographics is aware that Western countries (including Japan) are facing a serious demographic decline due to lower birthrates, and that immigration is the only way to avoid a population reduction in absolute numbers. This issue is discussed extensively and very publically in business, government and education milieus. Then, there are the cases of China and India which have experienced a slower population growth, in part directed by their respective government and in part caused by cultural practices of favouring male infants over female ones. Malthusian mathematical projections were always defeated by facts, and this conclusion still stand. So, really, where is the over-population problem?
Economists have studied this “C influence” on population and have provided powerful evidence that as a society becomes wealthier the lower its birthrate is. As well, from a sociological perspective, it is now well established that the higher the social status of women is the lower the birth rate is. This combination of influences explains in great part the demographic decline in the West, and provides additional clues to understand the slower growth in China and India.
Then, the issue is really why people still see a problem with over-population? One problem is, of course, confusing images from mass media and understanding processes. The Earth can sustain a much larger population, so the real issue is about how well resources are distributed, and not the lack of resources. So far, distribution is not very good, to say the least. If there are aliens visiting us, and I really do not think it is a possibility, I think that would be their first question: why are they not distributing their resources better?
Another problem is about how the unfair distribution is organized. Let’s be very clear here: overall, the browner your skin is the less you will have. The existing unfair distribution is very much an outcome of colonialism, which itself was based on racism and social Darwinism. So, these hypothetical aliens are likely to ask why these earthlings are dividing their resources unfairly on such a superficial and irrelevant issue as skin color (after all, aren’t we all Grey?...).
The last problem is the implicit fear that there will not be enough resources to sustain our Western life-style, so it is up to the (brown skin) others to curb their population growth and resource consumption. As an ethnocentric, and quite frankly racist, view, it is hard to beat. If there is a problem, it is in Western countries where industrialism and capitalism pushes the envelope of resources consumption to an ever-increasing level. Our hypothetical aliens would certainly ask themselves: they know this is unsustainable, so why they are persisting in that way of life?
In the end, I think our hypothetical aliens would say: “What a bunch of weirdoes! Let’s move on and see if there is something more interesting somewhere else”.