If you’re interested in anthropogenic global warming (AGW), and have frequented the intertubes where AGW is discussed, as I have, then you may have seen someone justifying their denial of AGW by saying something along these lines:
Humans are too tiny and insignificant to have an effect on something so vast as the climate. How arrogant you are to think that we are really changing the course of the planet’s geologic history.
I looked around for examples of this, but the only results I found were people writing about how to respond to this type of argument. So, trust me, I’m not making this up. People really do think that humans are too small and puny to be able to change the climate.
Clearly, they’re wrong. But it makes a sort of intuitive sense, given the nature of our individual experiences with nature. Who hasn’t stood at the edge of the ocean or looked up at the stars and ruminated on how vast the universe is, and how ant-like and minuscule we humans are in comparison?
But… hold up one second. We feel puny next to the vastness of the ocean. And we also feel puny next to the vastness of the stars. And yet the ocean itself is quite puny when compared to the volumes of space between the stars. And therein lies the difficulty. Our brains are not equipped to differentiate between something that’s just a little bit vast, like the ocean, and something that’s hugely, enormously vast, like our galaxy.
The total volume of the water in Earth’s oceans is approximately1.3 billion cubic kilometers. Let’s put that in scientific notation. Probably a lot of you already know what scientific notation means, but since I hope to eventually reach out to audiences that aren’t as familiar with basic scientific concepts, I’m going to go over it here.
To put a number in scientific notation means to take the number and show how it would look if it were multiplied by ten, but this ten is raised to the power of however many zeroes come after the main number. So,
10 x 10 = 100.
102 = 100.
Therefore, in scientific notation, 100 looks like this:
1 x 102
The number 130 in scientific notation looks like this:
1.3 x 102
And the number 1,300 looks like this:
1.3 x 103
With me so far? I know this is kind of annoying and dry, but I’m talking about it for a reason. Scientists use scientific notation because it allows them to quickly and easily compare numbers that are mind-bogglingly big to numbers that are mind-bogglingly bigger. Or, if you’re talking about chemistry or physics, where you’re talking about comparing the sizes of molecules, atoms, or sub-atomic particles, it allows you to differentiate between things that are so small you can’t comprehend it and things that are even smaller than that.
It’s hard to immediately perceive that 9,000,000,000,000,000,000 is a much smaller number than 10,000,000,000,000,000,000,000,000. But if you put it in scientific notation, then you can immediately see the difference between 9 x 1018 and 1 x 1025. The numbers in superscript after the ten are the most important thing here, much more important than the 1 or the 9 that come before the “x 10” part. Since the difference between 25 and 18 is 7, that means that the second number is approximately seven times larger than the first number. Or, as they say in Science Land, seven orders of magnitude greater. One “x 10” is the same thing as an order of magnitude. Sounds super impressive, doesn’t it? That’s why science it cool.
The concept of scientific notation is not, in and of itself, a truly difficult one to learn. What is difficult is learning to keep straight the various scales of measurement that are important in learning how to think about the reality in which we all live: there are the truly vast scales of interstellar space, the merely gargantuan scales of our solar system and our planet, the teeny-tiny ones we use to talk about single-celled organisms, the truly minuscule measurements we use to talk about molecules and atoms, and then there are those that we are more familiar with, the ones that work on a scale comprehensible to our monkey brains.
So, returning to our awe-inspiring oceans and galaxy: the volume of the Earth’s oceans is about 1,300,000,000 cubic kilometers, or 1.3 x 109 cubic kilometers. Okay, that’s a big volume, especially considering that a cubic kilometer is a space large enough to contain a smallish town as well as the air above it for a significant distance. Well, significant to humans. And we naturally feel a bit overwhelmed by the sheer bigness of the oceans. However, let’s consider the volume of space inhabited by the stars that also inspire feelings of awe in us tiny humans. The approximate volume of our galaxy, the Milky Way, is about 3.3×1053 cubic kilometers. And that’s just this galaxy. Lots of the stars we see at night aren’t even in the Milky way.
What I’m getting at is that it’s really easy to forget that even though our planet seems quite large to us, the Earth is tiny compared to the rest of the universe. It’s easy to forget the huge difference between the size of the earth and the size of, say, the solar system or the galaxy, because our brains aren’t equipped or predisposed towards dealing with numbers and scales like those. I’m a strong advocate of recognizing the limitations our evolutionary heritage sets upon us, and this is definitely one of them. The fact that many people have the misperception that humans are too insignificant to affect something so vast as the atmosphere or the climate is an artifact of that inherent limitation of our ape brains. It takes training and practice to get used to thinking about really big or really small numbers and understanding what they mean. Anytime we humans have to think outside the mental parameters set for us by millions of years of evolution–that is, anything not primarily revolving around social relationships, human-sized spaces or objects, or food–it takes a bit of extra mental effort. This refusal to recognize the power humans can have when they are numerous and equipped with technology dates back a long way. In another post, I’ll explore humanity’s long history of altering our environment, including climate and geology, dating all the way back to the beginning of civilization, but for now I’ll just leave you with this thought: in his book The Culture of Make Believe, Derrick Jensen talks about the Europeans’ first impression of the New World: they talked incessantly about the sheer, mind-boggling abundance: salmon so thick you could walk across a stream on their backs. Berries so numerous their juices dyed their horses’ bellies pink as they walked through them. Flocks of birds so numerous they blacked out the sun. All this abundance, they reasoned–puny humans could never put a dent in these enormous populations. Centuries later, flocks of birds no longer darken the sky, carrier pigeons are extinct, berries grow in isolated patches in gaps between human settlements, and fisheries worldwide are experiencing population crashes even as environmentalists struggle to restore salmon habitat. How long will we continue to make the same mistakes? About as long as we continue to fail to train our children to think beyond their human limitations. The true arrogance is thinking that our immediate intuitive reaction to a given problem is the correct one, and that we can comprehend the difficulties of existing in a world with advanced technology and 7+ billion human beings without taking drastic measures to change the way the majority of people think about life, nature, and the environment.