Today we add an additional one billion people to our population every twelve to fifteen years.  This graph shows that between 1975 and 1987, for example, we grew from four billion to five billion, and between 1987 and late 1999, we grew from five billion to six billion.  And today we are on track to add a seventh, eighth, and ninth billion between now and 2050.  

Examining our graph, first notice that virtually all of humanity's population growth has occurred since 1800.   Secondly, compare our graph with the disastrous climb and collapse pattern that took place in the reindeer study depicted below. 

Also notice that, if anything, our growth is not just exponential, but, as some scientists have observed, appears to be hyperexponential, generating an ascent that is far more severe than that seen in either reindeer population.

It took all of human history until 1830 for our species to reach, for the first time, a population of one billion people.  It took only one hundred years, between1830 and 1930, for us to add our second billion.  And today we add approximately one billion additional people to our population every twelve to fifteen years.

While nature and natural systems had all of human history until the early 1800s to adjust to the impacts of an unindustrialized humanity, today we are making the same demands and more every twelve to fifteen years. 

And Wecksaop’s chapter fourteen suggests that current assumptions underlying recent U.N. population projections may underestimate the numbers that are about to wash over our civilizations, society, and our planet.

pg 141  -  Thresholds and tipping points...

Thresholds are points that denote a limit or boundary, whether known or unknown, that result in serious or dramatic changes when transgressed. 

Kluger (2006) cites the boiling point of water as an example of such a boundary.  If we imagine a pan of hot water at 211 degrees Fahrenheit under conditions of standard pressure, the system persists in its liquid state.  If, however, we increase the temperature by just one added degree, the system is carried past a critical and unmarked tipping point and transforms abruptly to a gaseous system of billowing steam.

pg 140 

While an engineering firm may build a bridge to support a particular tonnage, if that threshold is breached, the integrity of the structure is compromised, leading to a potential collapse of failure.

In a similar way, elevators and aircraft have characteristic weight thresholds which, for safe operation, should not be transgressed.

MeMethane hydrates and warming...

                   The Age of Overpopulation...

                                  Demographic forces of our time...

                                                The Paleolithic, the Neolithic, and now...

pg 143

Some economic apologists ask us to assume that concepts of  "business as usual" apply to natural systems, no matter what pressures to which they may be subjected.  Yet, multiple systems may be more vulnerable to disruption than expected....

pg 119

Numbers making up an exponential progression are like a fire-alarm going off in a burning building - but this particular alarm can only be heard if our schools, our curricula, our teachers, and out textbooks, everywhere, teach us the deceptive, misleading, and extraordinarily powerful nature of exponential mathematics.

     Biodiversity hotspots...

                 Conserving ecosystems and services...

                                The rise and fall of a reindeer herd...

                                              Libraries, symphonies, and literature...