More and more activists in the sustainability movement are coming to the conclusion that carbon emissions can't be reduced to a safe range without curbing population growth. However at present, it's considered politically incorrect to even mention population control. The right accuses you of infringing on God-given personal rights to have babies and own guns. And what passes for the left accuses you of being naive and impractical for trying to address something that inflames the right.
Thus I feel compelled to begin with a disclaimer: I am not about mandatory sterilization, abortion or eugenics (mandatory sterilization and/or abortion for those considered "unfit" to reproduce). Nevertheless I believe those of us in the developed world face a stark choice: either we figure out how to substantially limit population growth or we face massive and I mean massive downsizing of our high tech lifestyles.
Resource Depletion: A Bigger Threat Than Climate Change
Unfortunately extreme weather events and other complications of increasing carbon dioxide concentrations aren't the only major crisis human kind faces at present. Fossil fuel depletion also poses a major threat because of its implications for food production. Our industrialized system of agriculture is totally dependent on cheap oil and natural gas not only to run farm machinery and transport produce to market, but in the manufacture of fertilizers, pesticides and herbicides. Even the oil companies acknowledge that production of oil and natural gas isn't keeping up with the exploding demand from a new, very large middle class in India and China . Although it will be decades before we totally run out of either, we have definitely reached a point where relative scarcity has significantly increased the cost of driving and heating our homes and, in many parts of the world, the cost of food.
The current wars in the Middle East and Africa (which the US government manages to keep out of the news) are primarily resource wars. In case people haven't noticed, the US and China are engaged in a colossal struggle over resources (energy mainly, but the Chinese are also massively investing in mineral resources in Africa , Pakistan and Central Asia ). China is using its economic might to monopolize oil and gas resources (mainly in Iran , Afghanistan and oil-rich African countries). While the US , which has no economy left to speak of, is using sophisticated guerrilla-style proxy warfare to try to stop them.
Has the Earth Already Exceeded Its Carrying Capacity?
In the 18th century political, economist Thomas Malthus made the observation that human beings have always outstripped their food supply. He also observed that when populations reach the limit of their ability to provide for themselves some external force usually famine, epidemics, or war intervenes to drastically reduce the number of hungry mouths to be fed.
It's a pattern as old as civilization. Human cultures on every continent except Antarctica adapted very early by using wars of conquest to increase their ability to produce food driving out the tribes in adjacent land and using it to grow crops and cattle for their own people. The Old Testament provides one of the clearest descriptions of resource driven conquest from ancient history as 4,000 years ago the Israelites, under the leadership of Moses and Joshua, crossed the Red Sea into the Sinai and drove the indigenous tribes from valley after valley to take over their farmlands for the use of the Jewish people.
The Industrial Revolution and Colonization
The industrial revolution, occurring between 1750 and 1850, supposedly changed all this. Scientists invented fantastic new machines that replaced human, horse and oxen power with the trapped energy of fossil fuels (oil, gas, and coal). And expanded exponentially the amount of food that could be produced from a given plot of land. It also vastly improved the ability of people who controlled fossil fuel resources to conquer and seize the resources not just of neighboring populations but of those that lived at a distance. A process known as colonization.
Do Fossil Fuels Invalidate Malthus' Law?
Over the last fifty years or so, political leaders have claimed that the industrial revolution invalidates Malthus' Law that thanks to fossil fuels and modern technology, humankind can now reproduce indefinitely without ever running out of food. At the same time it's impossible to escape the basic reality that we live a finite planet with finite resources which means we cannot provide food, water and other resources for an infinite number of human beings. Some in the sustainability movement pointing to the 1.2 billion people who are essentially starving to death from an epidemic of famines (due to increasing desertification, combined with the increasing frequency of tropical storms, floods, droughts and wild fires) - believe that at 6.8 billion we have already exceeded the number the earth can support.
Personally, I'm not convinced that the industrial revolution has been that effective in feeding the world. What it has done, I believe, is make the first world extremely effective at colonization. It's created a situation in which 20-25% of the world live extremely comfortably in the first world, 50% live with the misery of extreme oppression and exploitation and 20-25% live with chronic starvation and disease.
Moreover fossil fuels are predicted to become so expensive that the vast majority of the world will drop to the bottom tier and return to subsistence level agriculture (replacing farm machinery with horse, oxen and human labor) which in their view can only support a maximum global population of two billion.
Ignoring the Elephant Won't Make Him Go Away