Sunday, December 18, 2016

The population time bomb

I was a teenager in the 1970s and I had a poster from a lithograph (shown above) on my wall that was simply titled: "Overpopulation".  It was painted by John Pitre in 1973 and I remember spending hours looking at all the details of the thousands of nude or partly clothed humans in the ruins of this painting.  It is evocative of the third panel in Hieronymus Bosch's tryptych: "The Garden of Earthly Delights".  It presents a very dystopian view of the future of humanity and it affected my world view profoundly.

Population growth

In the 1970s the ecology movement was just getting started by the post-hippies and part of the dialogue centered around population growth and a concern for an unsustainable amount of people living on the planet.  What continues to surprise me is how rarely we talk about overpopulation in the context of Climate Change now.
The chart above dates from June 2010 and estimates that we will have more than 9 billion people on the planet by 2050.  There are various estimates as to how many people become unsustainable, and some say we have already passed that point.  What many of the estimates don't take into account is the potential crash of agriculture as a result of climate change.  This would make even our current population completely unsustainable.
Looking at the world population chart over the last two centuries, we see the classic hockey stick chart that evokes a similar chart representing CO2 in parts per million.  It's no accident that the two charts coincide.  Between 1999 and 2011, global population increased by a billion people.  Most of this population increase was in developing nations where individual carbon footprint is somewhat lower.  While population growth is likely to taper off eventually, we may already have crossed the tipping point.

Extinction versus population
Every twenty minutes, the human population grows by over 3000. That’s the same amount of time that it takes for another plant or animal species to become entirely extinct.  Yes, the sixth extinction has already begun!  From pollinating our crops, to purifying our water, providing fish to eat or fiber to weave, we are dependent on biodiveristy. Ecosystems can only continue to provide things for us if they continue to function in a harmonious balance.

Carrying Capacity

A 2014 study by the World Wildlife Fund found that the global human population exceeds the planet's biocapacity, and that it would take the equivalent of 1.5 Earths of biocapacity to meet our current demands.  So it comes down to a balance of population versus consumption, or more aptly put, over-consumption.  Studies would seem to indicate that the maximum carrying capacity for humanity is around 7.7 billion people, and as of this writing we are at 7.4 billion people.  But it's not just the birth rate that contributes to the issue, it's increased life expectancy.  People are living an average of 35 more years than they were 100 years ago.  So in essence we have already crossed the tipping point - or we will very shortly.  Here is a web page that tracks population and a lot of other relevant statistics:

Finite resources

By continuing to use up finite resources, extract and burn fossil fuels, and destroy wildlife habitat, we are moving inexorably towards a potential extinction for humanity.  
English economist Thomas Malthus (1766-1834) proposed that the world rate of population growth was exceeding the development of food supplies.  Malthus proposed that human population was growing exponentially, while food production was growing linearly.  Children born now will be growing up in a vastly changed world in which food scarcity is likely to become a significant issue as they become adults.  It is inevitable that wars will be fought over resources such as freshwater, arid land, and even dry land as the ocean levels rise.

There is a Chinese curse: "May you live in interesting times".  There is no question in my mind that there are interesting times ahead.   The real question is what can we do about it now to create a survivable scenario for humanity.  I'm doing what I can, but it often feels like I'm swimming alongside the Titanic trying to push it away from the iceberg.

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