It’s after midnight, on Interstate I-80 just outside of Chicago. A convoy of semis is headed west. The truckers like to travel at night, when there is less traffic. The lead driver wants to make sure they make it past Quad Cities by dawn. So he puts the pedal to the metal and the whole convoy accelerates.
Meanwhile, not far away, along the banks of the Illinois River, a night watchman makes his rounds at an electricity generation plant. He checks that there aren’t any unlocked doors or alarms going off. Then he gets in his car and makes a tour of the parking lot and the surrounding area, looking for anything suspicious. Once that’s done, he parks a short distance away from the plant, pulls out a candy bar, and looks at the eerie lights of the plant and the fumes billowing out of the smokestack.
Here’s an interesting thing. When the old Greeks were naming things, they probably started by creating words for some of the most common stuff around them. They gave names to things like fire and water and trees and soil. And then they started doing science, giving names to concepts like distance and weight. Eventually they got around to really hard-to-figure-out things like chemistry. And they realized that one of the most important things in nature was in the air all around them. It made fire burn. It made things bright. It helped people breathe. It was so good at making other things work, that they used the little word ‘GEN’ to describe it. We still use that little word a lot today, in bigger words like ‘GENERATE’ and ‘GENETICS,’ words that describe things that form or properties of things that have been made.
But the Greeks also wanted to describe exactly what kinds of things this little element was good at helping form. And they noticed it made things that they thought were ‘sharp’ or ‘intense,’ like the heat of a flame, or the twinkle of a light, or the keen thought of a wise person. And the little word in Greek that describes this is ‘OXY.’ You can see that in one of our words today, ‘OXYMORON’, which is more than just one ‘moron’ that makes no sense, it is a ‘double moron’ of two words that each make sense but put together are sharply stupid, like ‘JUMBO SHRIMP.’
The Greeks could have put the two words together as ‘GEN-OXY’ to mean ‘MAKER OF SHARP THINGS.’ That is, something in the air all around us that makes other things sharper, brighter, smarter, more better. But there was another way to do it; they put them in the opposite order, to mean more succinctly, ‘SHARP MAKER.’ And so it came out as ‘OXY GEN.’
Oxygen is one of the most common elements on earth. And it’s the most dynamic, the busiest little maker of other amazing stuff. It just loves to combine. It will hang out with just about anything. For example, when it mixes with Hydrogen, it makes Water, the most necessary thing for life. Which literally does get into everything, floating around in the clouds, falling to the surface, running along the ground, leaking through a hole in the floor of a tent and soaking into some poor camper’s sleeping bag at 2 AM.
And when the Greeks thought about the things that Oxygen creates, they thought about something we all think about a lot, which is food. They noticed that things that were juicy, like pomegranates or olives, were often tart or tangy. And when those kinds of things sat around in the open air for a while, amazing things would happen. Something very crisp and refreshing, like grape juice, would miraculously transform into wine, which was even more tangy and delicious – though admittedly it made people’s brains a little less keen than before they drank it.
That’s not all! If people left wine sitting around, mixing with the air, it would spoil. Or at least, it would seem to spoil. But if they left it around even longer, just let it do its thing, it would turn into something even more miraculous. It would become vinegar. Which was super-duper tangy. And the amazing thing about vinegar is that no matter how long you leave it out, it hardly ever goes bad, it lasts forever. And – here’s the really wild part – if you put anything else into that tart, tangy, liquid vinegar, it too is preserved, almost indefinitely. Imagine that. By letting grape juice sit and completely spoil, by letting it get ruined, it transforms, with the help of oxygen, into something that never goes bad and helps other things also never go bad. Praise the Gods.
The magic of vinegar is one of the things that the Greeks were thinking about when they included the little word ‘OXY’ in describing ‘OXYGEN.’ Oxygen makes all the things that taste acidic. Or, put another way, when the Greeks made a word for the most important element in the whole wide world, when they named it ‘OXYGEN,’ the Greeks weren’t just calling it ‘SHARP MAKER,’ they were very specifically calling it ‘ACID MAKER.’
Don’t believe it? Well, let’s go back to those trucks on I-80. Let’s see what happens when Oxygen starts messing with them. And let’s see if the Greeks got this right. Ready?
Trucks burn a lot of diesel fuel. And in that fuel is a lot of Sulfur, a very common nasty element that smells like rotten eggs, and which some folks call ‘Brimstone.’ When Sulfur combines with Oxygen, it creates Sulfur Dioxide. Which comes pumping out of the tailpipes of the trucks. And when it does it runs into even more Oxygen in the air. And when those things combine, it sucks, because it makes a nasty thing called Sulfur Trioxide. In fact, every one of those combinations makes 2 molecules of it. Scientists notate it as 2SO2 + O2 > 2SO3.
Now, Sulfur Trioxide is a gas. So it flows out into the air along the highway, over the shoulder of the road into the trees, through the neighborhood next door, and eventually up into the sky. Once it gets up there, it might run into some water vapor hanging around in the clouds. That water vapor has Hydrogen and more Oxygen in it. And when all those things mix together long enough, the Acid Maker does what it does, and turns Sulfur Trioxide into a very terrible thing called Sulfuric Acid, like this: SO3 + H2O > H2SO4.
Meanwhile, over at the power plant, something very similar is happening. Instead of diesel fuel, most electric plants are powered by coal. And the burning of coal involves a lot of Nitrogen, which makes up most of the atmosphere. Well, sometimes when Oxygen messes around with Nitrogen, it makes Nitrogen Monoxide. And when that stuff pours out of the smokestack at the power plant, Oxygen takes a second run at it, and turns it into Nitrogen Dioxide. Here’s how: 2NO + O2 > 2NO2.
And guess what happens next? That floats along the banks of the Illinois River, and then up into the skies, and mixes with water vapor just like the Sulfur Dioxide did. Only this time, the result is twice as bad. When the Acid Maker in the cloud water does its little tango with Nitrogen Dioxide, it makes not one but two crappy acids, Nitric Acid and Nitrous Acid, like this: 2NO2 + H2O > HNO3 + HNO2.
See? It’s true.
Oxygen is the Acid Maker.
Now, here’s the next thing you need to know. The old Greeks knew that water was an essential thing for life. There was something about it, it tasted like, well, it tasted like nothing. Water tasted like nothing at all. It was neutral. Compared to water, many other things tasted tart, tangy, sharp, acidic. The Greeks didn’t have any way to say exactly how acidic things were, other than using words like ‘more’ or ‘less.’ They would have just said that water seemed normal, and it was less acidic than grape juice. Grape juice was less acidic than wine. And wine was definitely less acidic than vinegar.
It took a very long time until someone was able to measure acidity. And that someone was a scientist who was working for a beer company in Denmark in the early 1900’s. (How come the best science happens when alcohol is around?) He figured out that the acidity is related to how many Hydrogen ions – which scientists label H+ – are bouncing around free in something. The more free H+ ions, the tarter the taste. And so he developed a scale, based on what he called ‘the power of Hydrogen,’ which we now call the pH scale. It has at its middle point the number 7 to mean ‘neutral,’ which is the pH of pure water. Things that measure from 7 down to 0 are acidic, with the lower numbers meaning more acidic. Things that measure from 7 up to 14 are basic, with the higher numbers meaning more basic. But it’s not a linear scale like a ruler. It’s what math teachers call ‘logarithmic.’ Which means each step of one whole number on the scale in either direction is a difference of ten times. So an acid that measures pH 5 has 10X more H+ in it than an acid that measures pH 6, while something that measures pH 4 has 100X more H+ than something that measures pH 6. As for pH 0? That would be an acid ten million times more acidic than water. Pucker up.
So what did that pH scientist discover that the Greeks might have thought interesting? Well, he measured grape juice and found the pH to be between 3 and 4. Wine measured slightly lower. And vinegar tipped the scale at around 2.5, about twenty thousand times more acidic than water.
Now, if we go back to the skies above the highway and the power plant, and measure the pH of the Sulfuric Acid and Nitric Acid and Nitrous Acid, we find that they measure in pH from about 3 down to almost 1. And they are all dissolved into the water vapor in the clouds. In other words, the sky is now pretty much full of super-toxic nasty vinegar.
The next bit of our chemistry lesson involves pressure. Scientists realized long ago that the more pressure you put on something, the hotter it gets. When you squeeze a bunch of air, it has less space to move around, and all the molecules start bashing into each other, getting pissed, and causing a lot of heat. It’s not unlike a classroom full of students. If you were to push the walls of the classroom in from all sides, there’s gonna be less room for everybody, and eventually those kids are gonna get pretty grumpy. But if you pull the walls back out and give everyone a little more room to breathe, they will all calm down. It’s the same thing with air. When you relieve the pressure on it, it cools off too.
The next part is about temperature. Scientists have noticed the cooler the air is, the less water it can hold. For example, when it’s warm up in the sky, all the molecules have lots of energy, and they are able to bounce around without anything falling. But when things start to cool down, the molecules can’t dance around so fast, and some of them get tired. That’s why, on a hot day with lots of clouds, if a cold front comes in, everything gets sluggish, and the sky can’t carry around so many H2O’s without dropping a few. It starts pouring.
So what happens when you put all this together? Well, let’s say you’re a cloud. And as you passed over Illinois you got juiced up with a lot of super-toxic nasty acid made of Oxygen and Sulfur and Nitrogen. The wind is blowing, and so you are pushed to the east, passing over Indiana, Ohio and Pennsylvania, and eventually New York. All the time the ground below you has been flat, there’s nothing much to see, and you just keep going, minding your own business. But then suddenly, up ahead, maybe fifty miles in the distance, you see something on the horizon. It looks like a dome of mountains rising up out of the earth. It’s too wide to go around! So you are going to have to go up and over it!! As the ground rises below you, you get shoved up a thousand feet, then two thousand feet. And as you ascend, there is less atmosphere remaining above you. Which means you are under less pressure. The higher you go, the cooler you get. And the cooler you get, the harder it is to hold onto all your moisture. Uh-oh.
About the time that you’re passing over the westernmost Adirondack peaks, the Sewards, you realize you can’t hold on to all your super-potent Oxygen Sulfur Nitrogen vinegar much longer.
By the time you’ve got to get up and over all 5114 feet of Algonquin Mountain, you start pissing Acid Rain all over the place.
There’s not a lot of soil in the Adirondacks. When the mountains rose up out of the earth five million years ago, they pushed a lot of the dirt out of the way. Then, when the glaciers rumbled through about ten thousand years ago, they scraped a lot more off the surface. And since this is a high-altitude environment, the mountains continually cool the clouds and create more than their share of precipitation, and the rain and snow are constantly eroding what little remains. All of which means that the Adirondacks may be ancient and majestic and magical, but they are also very fragile.
So what happens when you pour toxic acid onto one of nature’s most vulnerable environments? Acid that falls on trees leeches out lots of critical things that the trees need to be healthy and grow. And it’s not just rain that does it. Trees that live high up in the mountains are often sitting in fog and clouds, which may be even more acidic than what comes down in falling water. The trees get sicker and sicker. Once the trees are unhealthy, they can’t fight off insects and diseases. Many of them die. And even those that survive still suffer. Studies of tree rings show that the annual growth rate of mountain trees in acidic environments gets slower, and slower, and slower. The forests are getting pickled.
When rain falls on open rock, it flows downhill until it finds some soil it can soak into. The dirt will do its heroic best to absorb it, and keep it from going any further. A lot of soil’s ability to do that is based on how much clay is in it. Unfortunately, the soil in these mountains doesn’t have a lot of clay, so it can’t hold onto water very well.
All the excess water flows downhill and ends up in little streams, which pour into small rivers, which fill little ponds and larger lakes. And here’s where the acid does the most evil things. When the pH of a body of water drops to about 6, small things like baby insects and slow-moving animals like snails and worms are the first to die. When the pH drops to 5.5, a smallmouth bass is in a lot of trouble. At pH 5, lake trout in the water are feeling the hurt, and salamanders hiding under old logs are suffering. At 4.5, small perch are flailing. Once you get down to 4, where there are 1000X more H+ ions than in pure neutral water, the frogs may still be wet, but they are toast. Once a lake or pond gets much lower than a pH of 4, it is essentially dead.
And there you have it, how to create environmental devastation through the wonders of chemistry. And how industrial activity in the Midwest severely damaged a pristine preserve more than 500 miles downwind.
Oxygen is the Acid Maker. Oxygen makes acid. Acid gets up in the clouds. The clouds move east. The clouds rise over the mountains. The mountains cool the clouds. The clouds leak Acid Rain. And when enough acid gets into something, it kills it.
Especially vulnerable little things like alpine ponds high in the center of the Adirondacks … like the one that Ebenezer Emmons found long ago … that’s just a few feet deep and completely still … that he determined was the source of the Hudson River … and that was so pretty that when Verplanck Colvin first saw it, he named it, ‘Lake Tear of the Clouds.’
Tragically, ironically, horribly, considering what industrial America did to it, it was very well named.
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