I found this lecture by Dr. Albert Bartlett to be especially informative.
So informative for me, anyway, that I thought I would post each section of the video and comment on it. I look forward to your comments as well.
I wish I had had him for a teacher. But now he is a teacher for all of us.
The lecture was simply chopped to fit a YouTube video into eight nine-minute segments. You can follow along with a transcript thanks to Minnesotans for Sustainability.
In this first section, he introduces us to the exponential function. He says:
"The greatest shortcoming of the human race is our inability to understand the exponential function."He defines it:
The exponential function is used to describe the size of anything that is growing steadily, for example five % per year....If it takes a fixed length of time to grow five percent it takes a longer period of time to grow 100%. That longer period of time is the doubling time."You calculate the doubling time by taking the number 70 and divide by the percent growth.
70 divided by 5% is 14. Something that is growing at 5% per year will double in quantity after 14 years. 1% would double in 70 years. 10% per year would double in 7 years.
Dr. Bartlett says he wishes he could get everyone to make this mental calculation every time we see a percent growth figure in a news story. For example what sounds more ominous:
- "Crime has increased seven percent per year over the last decade" or
- "Crime has doubled over the last decade?"
Exponential growth is characterized by doubling, and a few doublings can lead quickly to enormous numbers.To illustrate, he uses the example of the chessboard:
A legend has it that the guy who invented chess brought the game to the king. The king was impressed and wanted to give him a present. The guy said just put one grain of rice on the first square, two on the second, four on the third, and so on. That will be enough.
1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096....
By the time he got to the 21st square--boom--a million grains. By the time he reached the 41st square a trillion grains. There wasn't enough rice in the world for the remaining squares.
Turning to energy:
When we read that the demand for electrical power in the U.S. is expected to double in the next 10-12 yr we should recognize that this means that the quantity of electrical energy that will be used in these 10-12 yr will be approximately equal to the total of all of the electrical energy that has been used in the entire history of the electrical industry in this country!The point of this first section is that any steady growth at any percentage level will eventually lead to astronomical numbers. Steady growth in finite systems is unsustainable.
Many people find it hard to believe that when the rate of consumption is growing a mere 7% / yr, the consumption in one decade exceeds the total of all of the previous consumption.
This is what has been interesting to me. We are told that a healthy economy is one that grows. But for the economy to grow, we need electricity or energy. We need more each year. When does it stop growing?
Eventually it will. It has to stop. The decision we are making today is whether we will allow natural forces to stop the growth for us or if we will make that decision consciously. Here is the video.
Next time he turns to human population.