The global population size is expected to reach over 9 billion individuals by 2050, according the United Nations. Feeding all these people requires an enormous increase in global food production compared to current production levels. But there is a limit to the world's resources. To prevent a collapse by global starvation immediate action is necessary.
There is more to it than just a growing population size and an increasing food demand. It started more or less with the industrial revolution, and the associated growth in knowledge, welfare, health and population size. This led inter alia to an enormous food and energy demand. The increased education and knowledge eventually led to a lower increase rate of a wealthy population in industrialised, developed, countries, but an increase, still. Which is exactly opposite to the situation in developing countries, where the poor population do not see better education as the way out of their miserable situation (long term). Unfortunately, they think that an increased workforce (more children) will alleviate their problems and provide sustainability (short term). This has been recognised already in 1972 by the Club of Rome in their publication Limits to Growth, and its update in 2004. Planet Earth cannot cope with human demand via its natural ecosystem services (e.g. food, clean water, energy,...), and overexploitation is expected. In other words the ecological footprint of human beings exceeds the carrying capacity of Earth. A well written synopsis can be found here.
What about the solution for achieving a sustainable ecological footprint? For me it is absolutely clear that first of all a decrease of the global population size is required or at least a stop to the growth, before the limited resources lead to global starvation. But how can this be achieved? Perhaps we should stop investing in medical care to prolong life, because how much fun is life when your body has reached its expiration date and depends on medication or surgery to sustain your mental abilities. Even worse when it is the other way around. It is also important that we distribute our accomplishmens over developed ánd developing countries evenly, with improved welfare in developing countries as a result. This will take away the pressure from developing countries to increase the growth rate of their population size.
An interesting concept has been suggested and developed by the Dutch artist Arne Hendriks. He suggest to decrease the size of man as such instead of decreasing the population size. Smaller individuals require less food to survive. In a way this enhances the efficiency of handling the available food. See the incredible shrinking man for how Hendriks want to solve future food shortages. Although I like the creative artist's mind, the evolutionary steps to shrink man to a 50 cm size will take too much time. A recent publication shows that a 100-fold evolutionary decrease in body size will take about 160.000 generations, and according Limits to Growth, The 30-Year Update the human ecological footprint already has grown beyond sustainable level. So, we should speed up the process of shrinking man. This requires genetic modification, altering the humane genome, and lots of ethical discussion. To me this seems like a no go area.
Another way of being more energy/nutrient efficient is eating less meat. Feeding animals to produce meat with maize, wheat or other grains is far less efficient than using these grains as human food. In other words it is better to eat plant proteins than animal proteins to achieve a sustainable ecological footprint.
When do we come to our senses, and do the right thing?
(Sources: PNAS, 30.01.2012; Science Alert, 01.02.2012; United Nations – World Population Prospects, the 2010 revision; Limits to Growth, The 30-Year Update by Meadows, Randers and Meadows, 2004; The Incredible Shrinking Man by Arne Hendriks)