The Crash Course - Chris Martenson [20]
Here’s where we might use that knowledge in real life. You might have read about the fact that China’s energy consumption grew at a rate of slightly more than 8 percent between 2000 and 2009, which perhaps sounds somewhat tame. Using the Rule of 70, however, we discover that China is doubling the amount of energy it uses roughly every 9 years, as was confirmed by the International Energy Agency (IEA) in 2010.7 After 9 years of 8 percent growth, you’re not using just a little bit more energy, but 100 percent more. If a country has 500 coal-fired electricity plants today, after 9 years of 8 percent growth it will need 1000 such plants.
If this seems rather dramatic and nontrivial to you, you’re right. Time for another trick question about doublings: Which is larger in size, the amount of energy China used over just the past 9 years (its most recent doubling time), or the amount of energy China has used throughout all of history? The intuitive answer is that the total amount of energy consumed throughout China’s thousands of years of history is far larger than the amount consumed over the past 9 years, but the correct answer is that the most recent doubling is larger than all the prior doublings put together.8
This is a general truth about doublings, not China in particular, and applies to anything and everything that has gone through a doubling cycle. To make sense of this preposterous claim, let’s use the legend of the mathematician who invented the game of chess for a king. So pleased was the king with this invention that he asked the mathematician to name his reward. The mathematician made a request that seemed modest: to be given a single grain of rice for the first square on the board, two grains for the second square, four grains for the third square, and so on. The king agreed, and foolishly committed to a sum of rice that was approximately 750 times larger than the entire annual worldwide harvest of rice in 2009. That’s what 64 doublings will get you.
Note that the first square had one grain of rice placed upon it, while the next square, the first doubling, got two grains. Here on the very first doubling, we can observe that more rice was placed upon the board than was already on the board; two compared to one. That is, the doubling was larger in size than all of the grains that had come before it. And on the next doubling, when we place four grains upon the board, we see that these four grains of rice are more numerous than the three grains (1 + 2) already upon the board from all the prior doublings. And at the next doubling we place eight grains on the board, which is a larger total than the seven that are already upon it (1 + 2 + 4). And so on. In every doubling, we’ll find that the most recent doubling is larger in size than all of the prior doublings put together. That’s one of the less intuitive but more important features of doublings. Each doubling is larger than all the ones that came before put together.
So if your town administrators are targeting, say, 5 percent growth, what they’re really saying is that in 14 years time they want to have more than twice as much of everything in the town than it currently has. More than twice as many people, sewage treatment plants, schools, congestion, electrical and water demand, and everything else that a town needs. Not a few more, but more than twice as many.
Your Exponential World
The reason we took this departure into discussing exponential growth and doubling times is that you happen to be completely surrounded by examples of exponential growth. And your future, like it or not, will be heavily shaped by their presence.
As you read the rest of this book, it will be helpful to continue to recall these three concepts related to exponential