A thread on EpicSki reminded me that our current growth path is not sustainable as much as I wished it were. A 2% world-wide GDP growth rate is considered anemic, but that still results in an economic doubling in under 40 years. Economic growth has traditionally been highly correlated with increased energy use. Humans are becoming more and more technologically advanced, but we still haven’t figured out how to “improve” our lifestyle without using up more and more of the limited resources on this planet.
I have a bit of a brain teaser that I think is applicable to our current situation- Suppose a parent throws a piece of algae that doubles in size each year into a lake the day their first child is born. Assume that the Lake becomes completely full of algae the day the child dies at age 75. What portion of the Lake was filled with algae on the child’s 68th birthday?
According to http://en.wikipedia.org/wiki/World_energy_consumption the twentieth century saw a rapid twentyfold increase in the use of fossil fuels. Between 1980 and 2006, the worldwide annual growth rate was 2%.
Assuming that we continue with a 2% increase per year, that means roughly a quadrupling during the average lifetime. In terms of the total time humans have spent on this planet, 75 or 100 years is like a blink of the eye. I am not sure exactly when the “Lake” will become full, but future generations are in big trouble if we don’t find a way to stop the constantly increasing consumption of the worlds resources and the side effects this causes.
The point is, whatever your doubling time period is, you go from less than 1% of capacity to max capacity in 7 generations (assuming a constant growth rate)…something that seems like it is a trivial problem could become a huge problem after 7 doubling generations.
I am not sure how long you believe humans have been on Earth (Archeologists estimate that modern humans have been on the Earth for about 200,000 years), but according to http://en.wikipedia.org/wiki/World_population it took us until 1804 to reach a billion people. We doubled that the next 123 years and doubled that again (to 4 B) over then next 47 years. We now have almost 7 B with our doubling from 4 to 8 B estimated to take 53 years.
World population estimates milestones (USCB) Population
(in billions) 1 2 3 4 5 6 7 8 9
Year 1804 1927 1960 1974 1987 1999 2012 2027 2046
Years elapsed – 123 33 14 13 12 13 15 19
In the last couple of hundred years, our fossil fuel use has grown at even a faster rate than the world population (with a 20 fold increase in the 20th Century). I don’t pretend to know what the max capacity is for either population or fossil fuel use, but I know that we can’t continue to grow these exponentially forever. Even “slow” growth becomes a problem after a while with a 1% growth rate resulting in a doubling over the average lifetime.
Going back to my Lake example, a 1% yearly growth rate results in a 100x increase over 7 average lifetimes. Between 1990 & 2008, world energy use increased by 39%- that’s faster than a 1% annual growth rate.
I am not saying that I believe in climate change theories 100%, but I do believe that humans have an affect on the planet and that this affect has increased dramatically over the last 200 years. Basically, I think it is one big out of control experiment that we are living in with the inputs increase dramatically in recent years. From a mathematically standpoint, unless you think it is going to be possible to increase our use of fossil fuels 100x over the next 200 to 300 years, something has to change eventually. Much easier to make that change when the “Lake” is 1 or 2 or 4% full rather than waiting until is is half full (or more).
Most people think it is good to continually grow the economy, but is this really sustainable? The answer may be yes if we can find a way to do it WITHOUT the increased use of fossil fuels and other inputs that have a negative impact on our planet. Humans have been great innovators in recent years- it is time to turn this innovation in a direction that eliminates growth of fossil fuel use and other things that may eventually make this planet unlivable.