Wednesday, February 12, 2014

Ponzi Population

Exponential growth, often expressed in terms of "doubling time", is what we see the bacteria doing in the petri dish pictured here.

On a chessboard, if you put a grain of rice on the first square, doubling to two on the second, four on the third, and so on until you completed the 64 squares, you'd have piled up all the rice in the world and then some. Doubling.  Pretty impressive.

'Linear growth' is perhaps like a tree that grows at a semi-steady rate, year after year.

'Exponential growth' can describe things like population growth and the associated consumption trends.

Microorganisms increase in number exponentially. The first will split into two, then two into four, and so on until some essential survival element is exhausted. Maybe it's food or perhaps the size of the environment.

Ponzi schemes (and pyramid schemes) show this kind of growth, providing good returns for a few early on, and losses for the rest down the timeline.

Meroe, between the Nile and Atbara rivers, was the capital of the Kingdom of Kush, a major
power for a thousand years beginning in the 8th century B.C.  Meroe was the seat of rulers 
who occupied Egypt.  They built pyramids, temples and major installations for water 
management. Their empire extended from the Mediterranean to central Africa.  Meroe
was magnificent until the forests were gone, harvested for charcoal and the iron smelting
industry.  Erosion and agricultural failure followed.

Human population grows exponentially. With occasional variations caused by large-impact factors like famine and disease, we follow the accelerating curve.

Some informative failures do occur such as in the Kingdom of Kush and it's capital, MeroĆ«. The kingdom grew and thrived for 1000 years, then disappeared, having exhausted the local resources of land and wood. No forests, no charcoal, no smelting, no trade, no economy.  No arable land, no food, no cattle, no people.  No kidding.

Here's what human population growth looks like on a timeline.  When a bacterium does that, it increases in number until some tip over point; then it dies in its own waste and decay.

That's the one of the many difficulties we face but not necessarily the result we'll get, provided we do something other than just mindlessly consuming everything we can.  Like the bacteria.

Plenty of options still available, right?

Thanks and a hat tip (for being a thought-provoking fellow) to Dr. Bob Cahalan, Chief of NASA-Goddard’s Climate and Radiation Laboratory, Director of the Sun-Earth Research Center at NASA Goddard Space Flight Center, a Fellow of the American Meteorological Society, and President of the International Radiation Commission, and Co-Grandfather to Her Royal Highness Princess Ruby Marie, our precious granddaughter.